bluuebunny/crossref_metadata_2025 huggingface dataset:
Size-Controlled Synthesis of Colloidal Gold Nanoparticles at Room Temperature Under the Influence of Glow Discharge
Authors: Liang Xi , Wang Zhou-jun , Liu Chang-jun
Published: October 2009

Highly dispersed colloidal gold (Au) nanoparticles were synthesized at room temperature using glow discharge plasma within only 5 min. The prepared Au colloids were characterized with UV–visible absorption spectra (UV–vis), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) equipped with an energy dispersion X-ray spectrometer (EDX). UV–vis, XPS and EDX results confirmed that Au3+ ions in HAuCl4 solution could be effectively reduced into the metallic state at room temperature with the glow discharge plasma. TEM images showed that Au nanoparticles were highly dispersed. The size of colloidal Au nanoparticles could be easily tuned in the nanometer range by adjusting the initial concentration of HAuCl4 solution. Moreover, the as-synthesized Au colloids (d
av = 3.64 nm) exhibited good catalytic activity for glucose oxidation. The nucleation and growth of colloidal Au particles under the influence of the plasma was closely related with the high-energy electrons generated by glow discharge plasma.
Is it the music? Peer substance use as a mediator of the link between music preferences and adolescent substance use
Authors: Mulder Juul , Ter Bogt Tom F.M. , Raaijmakers Quinten A.W. , Nic Gabhainn Saoirse , Monshouwer Karin , Vollebergh Wilma A.M.
Published: October 2009

Both music preferences and the substance use behavior of peers are important elements in explaining adolescent substance use. The extent to which music preference and peer use overlap in explaining adolescent substance use remains to be determined. A nationally representative sample of 7324 Dutch school‐going adolescents (aged 12–16) provided data on music preferences, substance use behaviors and perceived number of peers using substances. Factor analyses showed that preferences for eight music genres factored into four styles: Pop (chart music, Dutch pop), Adult (classical music, jazz), Urban (rap/hiphop, soul/R&B) and Hard (punk/hardcore, techno/hardhouse); substance use was indicated by smoking, drinking, and cannabis use. Structural equation modeling revealed that the relationship between music preference and substance use was either wholly or partially mediated by perceived peer use. Music can model substance use and fans of different types of music may select friends with use patterns that reinforce their own substance use inclinations.
Emergency Radical Cystoprostatectomy for a Perforated Bladder Tumour Presenting with Peritonitis
Authors: Nandwani Ghulam Mustafa , Ramsden Karen L. , Gokhale Jay A. , Chaplin Brian J.
Published: October 2009

Spontaneous bladder perforation is a rare presenting feature of bladder malignancy. We report a case that presented with peritonitis and underwent emergency radical surgery with good postoperative recovery.
The role of N‐methyl‐d‐aspartate receptor subunit NR2B in spinal cord in cancer pain
Authors: Gu XiaoPing , Zhang Juan , Ma ZhengLiang , Wang JunHua , Zhou XiaoFang , Jin YanQing , Xia XiaoPing , Gao Qin , Mei FengMei
Published: October 2009

Cancer pain is one kind of the most common and severe kinds of chronic pain. No breakthrough regarding the mechanisms and therapeutics of cancer pains has yet been achieved. Based on the well established involvement of the NMDA (N‐methyl‐d‐aspartate) receptor containing NR2B in inflammatory pain and neuropathic pain and the effective pain relief obtained with ketamine in cancer patients with intractable pain, we supposed that NR2B in the spinal cord was an important factor for cancer pain. In this study, we investigated the possible role of NR2B in the spinal cord using a murine model of bone cancer pain. C3H/HeJ mice were inoculated into the intramedullary space of the right femur with Osteosarcoma NCTC 2472 cells to induce ongoing bone cancer‐related pain behaviors. At day 14 after operation, the expression of NR2B mRNA and NR2B protein in the spinal cord were higher in tumor‐bearing mice compared to the sham mice. Intrathecal administration of 5 and 10 μg of NR2B subunit‐specific NMDA receptor antagonist ifenprodil attenuated cancer‐evoked spontaneous pain, thermal hyperalgesia and mechanical allodynia. These results suggest that NR2B in the spinal cord may participate in bone cancer pain in mice, and ifenprodil may be a useful alternative or adjunct therapy for bone cancer pain. The findings may lead to novel strategies for the treatment of bone cancer pain.
MicroRNA 125a and its regulation of the p53 tumor suppressor gene
Authors: Zhang Yingjie , Gao Jin-Song , Tang Xiaoli , Tucker Lynne D. , Quesenberry Peter , Rigoutsos Isidore , Ramratnam Bharat
Published: October 2009

MicroRNA (miRNA) are a class of non‐coding RNA that suppress gene expression by degradation or translational inhibition of target RNA. Several miRNA have been shown to target oncogenes and recently miRNA‐125b was shown to translationally and transcriptionally inhibit the p53 gene. Here, we show that an additional isomer of miRNA‐125 (miRNA‐125a) translationally arrests mRNA of the p53 tumor suppressor gene. The basis of this activity is the high degree of sequence homology between the seed sequence of miR‐125a and the 3′‐UTR of p53. Our findings add miRNA‐125a to the growing list of miRNA with oncogenic targets.
Regulatory volume decrease in cardiomyocytes is modulated by calcium influx and reactive oxygen species
Authors: Rojas-Rivera Diego , Díaz-Elizondo Jessica , Parra Valentina , Salas Daniela , Contreras Ariel , Toro Barbra , Chiong Mario , Olea-Azar Claudio , Lavandero Sergio
Published: October 2009

We investigated the role of Ca2+ in generating reactive oxygen species (ROS) induced by hyposmotic stress (Hypo) and its relationship to regulatory volume decrease (RVD) in cardiomyocytes. Hypo‐induced increases in cytoplasmic and mitochondrial Ca2+. Nifedipine (Nife) inhibited both Hypo‐induced Ca2+ and ROS increases. Overexpression of catalase (CAT) induced RVD and a decrease in Hypo‐induced blebs. Nife prevented CAT‐dependent RVD activation. These results show a dual role of Hypo‐induced Ca2+ influx in the control of cardiomyocyte viability. Hypo‐induced an intracellular Ca2+ increase which activated RVD and inhibited necrotic blebbing thus favoring cell survival, while simultaneously increasing ROS generation, which in turn inhibited RVD and induced necrosis.
Activation of antithrombin as a factor IXa and Xa inhibitor involves mitigation of repression rather than positive enhancement
Authors: Gettins Peter G.W. , Olson Steven T.
Published: October 2009

Allosteric activation of antithrombin as a rapid inhibitor of factors IXa and Xa requires binding of a high‐affinity heparin pentasaccharide. The currently‐accepted mechanism involves removal of a constraint on the antithrombin reactive center loop (RCL) so that the proteinase can simultaneously engage both the P1 arginine and an exosite at Y253. Recent results suggest that this mechanism is incorrect in that activation can be achieved without loop expulsion, while the exosite can be engaged in both low and high activity states. We propose a quite different mechanism in which heparin activates antithrombin by mitigating an unfavorable surface interaction, by altering its nature, and by moving the attached proteinase away from the site of the unfavorable interaction through RCL expulsion.
Interferon regulatory factor‐2 induces megakaryopoiesis in mouse bone marrow hematopoietic cells
Authors: Masumi Atsuko , Hamaguchi Isao , Kuramitsu Madoka , Mizukami Takuo , Takizawa Kazuya , Momose Haruka , Naito Seishiro , Yamaguchi Kazunari
Published: October 2009

Megakaryopoiesis is associated with inflammatory reactions. To investigate the role of interferon regulatory factors (IRFs) in inflammation‐associated megakaryopoiesis, mouse bone marrow hematopoietic stem cells (HSCs) were analyzed. IFN‐γ treatment induced IRF‐2 expression as well as the expression of CD41 and IRF‐1 in HSCs. An in vitro clonogenic assay showed that IRF‐2‐ but not IRF‐1‐overexpressing cells increased the number of megakaryocytic colonies. IRF‐2 transfection up‐regulated CD41 promoter activity in hematopoietic cell lines. The number of CD41‐positive bone marrow cells increased in mice injected with IRF‐2‐expressing bone marrow cells. These findings suggest that IRF‐2 plays an important role in megakaryopoiesis in inflammatory states.
Let‐7a elevates p21WAF1 levels by targeting of NIRF and suppresses the growth of A549 lung cancer cells
Authors: He Xiaoyan , Duan Changzhu , Chen Junxia , Ou-Yang Xi , Zhang Zheng , Li Chunlei , Peng Huimin
Published: October 2009

Down‐regulation of let‐7 microRNA (miRNA) is a key event in lung cancer. Despite recent advances in survival signaling, the roles of let‐7 in the context of lung cancer are not fully clear. In this study, we showed that let‐7a, a member of let‐7 family, negatively regulated the expression of NIRF through NIRF 3′ UTR. We also showed that NIRF was required for the let‐7a‐mediated elevation of p21WAF1. These findings suggest that growth‐inhibitory effect of let‐7a on the A549 cells in vitro and in vivo may be explained in part by le‐7a‐induced suppression of NIRF and elevation of p21WAF1. This work reveals a novel regulatory mechanism for let‐7a in the control of cellular proliferation and lung carcinogenesis.
Adiponectin downregulates galectin‐3 whose cellular form is elevated whereas its soluble form is reduced in type 2 diabetic monocytes
Authors: Weber Markus , Sporrer Daniela , Weigert Johanna , Wanninger Josef , Neumeier Markus , Wurm Sylvia , Stögbauer Fabian , Kopp Andrea , Bala Margarita , Schäffler Andreas , Buechler Christa
Published: October 2009

Galectin‐3 plays a role in atherosclerotic diseases, and the effect of adiponectin that protects from atherosclerotic diseases on monocytic galectin‐3 was analysed. Adiponectin reduced galectin‐3 mRNA, its cellular and soluble form, and this effect was impaired in T2D cells. Cellular galectin‐3 was higher in monocytes of overweight than normal‐weight donors and was highest in T2D cells. Cellular galectin‐3 positively correlated with the BMI of the donors and negatively with soluble monocyte galectin‐3. Circulating levels of total adiponectin did not correlate with cellular or soluble galectin‐3 indicating that additional factors contribute to higher cellular monocytic galectin‐3 in obesity and T2D.
Mammary adenocarcinomas in three male cats exposed to medroxyprogesterone acetate (1990–2006)
Authors: Jacobs Terry M , Hoppe Bruce R , Poehlmann Cathy E , Ferracone Jackie D , Sorenmo Karin U
Published: October 2009

In this case series, three unrelated male housemate cats were treated repeatedly with injections of medroxyprogesterone acetate (MPA) for intercat aggression and urinary house soiling. All three cats subsequently developed multiple recurrent mammary adenocarcinomas and underwent numerous surgical resections. This report describes the clinical, histopathological and immunohistochemical findings in these three cats and highlights the potential for mammary carcinomas to develop in male cats years after receiving MPA injections. Extended survival times and a long delay between the administration of the progestin injections and the onset of mammary neoplasia are noted. Estrogen and progesterone receptor staining was performed on some of the tumors and the complex role of hormones in the pathogenesis and the prognosis of feline mammary carcinoma is discussed. Clinicians using MPA should institute life-long surveillance of their feline patients for mammary tumors.
Changes of Water Level in the Eemian Palaeolake at Imbramowice (SW Poland) Based on Isotopic and Cladoceran Data
Authors: Mirosław-Grabowska Joanna , Gąsiorowski Michał
Published: October 2009

Isotopic and cladoceran investigations of Eemian (MIS 5e) lake sediments from Imbramowice, SW Poland, allow us to reconstruct the environmental conditions, especially changes of water level and trophic status, during the early and middle Eemian Interglaciation. We analyzed the sediments from 6.5 to 11.0 m depth in a core provided by Mamakowa (1989). The upper 6.5 m had insufficient carbonates and cladoceran contents for analyses. The analyzed section consists of sandy and organic silts at the bottom, followed by gyttja characterized by increasing CaCO3 content. Measured δ18O values oscillate from ca. -9 to -4‰ and δ13C from -3.5 to above + 6‰. Based on stable isotope analyses of carbonates, we define and characterize eight isotopic horizons (Is). We identify 26 taxa of subfossil Cladocera and seven zones (CLZ) of faunal development. Probably the greatest depth of the lake occurred with pollen zone E2; shallowing then took place. During pollen zones E2-E3, gradual warming is observed and expressed through a positive trend in both δ18O and δ13C values. Pollen zone E4 is characterized by frequent changes of water level. During the Eemian Interglaciation, excluding the initial phase of lake evolution, the lake was meso-eutrophic and eutrophic with high phytoplankton productivity.
A short note on the geo-archeological significance of the ancient Theodosius harbour (İstanbul, Turkey)
Authors: Algan Oya , Yalçın M. Namık , Özdoğan Mehmet , Yılmaz İsak , Sarı Erol , Kırcı-Elmas Elmas , Ongan Demet , Bulkan-Yeşiladalı Özlem , Yılmaz Yücel , Karamut İsmail
Published: October 2009

The sedimentary sequence discovered at archaeological excavations in ancient Theodosius Harbour at İstanbul contains the records of sea level, environmental changes and the cultural history of the region. The cobbles at the base of the sequence include archaeological remnants of Neolithic culture that settled in the area between 8.4 and 7.3 14C ka BP, and are located at 6 m below the present sea level. The sediments representing a coastal environment indicate that the area was used as a harbour from AD 4th to at least the 11th century and were filled by the sediments derived from Lykos Stream after 11th century.
Hepatocellular Carcinoma Associated With Liver Abscess
Authors: Huang Ching‐I , Wang Liang‐Yen , Yeh Ming‐Lun , Hsieh Ming‐Yen , Huang Jee‐Fu , Lin Zu‐Yau , Chuang Wan‐Long
Published: October 2009

Hepatitis B and hepatitis C are highly prevalent in Taiwan. Chronic hepatitis patients are at high risk of progression to liver cirrhosis and hepatocellular carcinoma (HCC). However, HCC in association with liver abscess is very rare. Accordingly, this study analyzed the characteristics of HCC patients with liver abscess to improve the differential diagnosis of this condition. From January 2005 to July 2007, the medical records of nine HCC patients (4 females, 5 males; mean age, 65.8 years) treated for abscess formation at Kaohsiung Medical University Hospital were retrospectively reviewed. Their clinical characteristics, images, management approaches and outcomes were analyzed. Fever and highly elevated alkaline phosphatase levels were noted in all patients. All aspirate cultures revealedKlebsiella pneumoniae. All of the cases of HCC were confirmed by cytology or pathology. The imaging studies, which included abdominal ultrasonography and computed tomography, revealed liver tumors in all patients. In some cases, lead‐enhanced hypervascular areas were noted. The patients were treated with antibiotic therapy, transhepatic arterial chemoembolization, or surgery. The findings of this study indicate that focal liver inflammatory changes may mimic solid neoplasms. Differential diagnosis of HCC with abscess is extremely difficult and may require aspiration cytology or pathology.
A Giant Scrotal Cavernous Hemangioma Extending to the Penis and Perineum: A Case Report
Authors: Ergün Osman , Ceylan Berit Gokce , Armagan Abdullah , Kapucuoglu Nilgun , Ceyhan A. Murat , Perk Hakki
Published: October 2009

Cavernous hemangioma is a congenital, benign vascular tumor that occurs in the deep dermis and subcutaneous tissue. Scrotal hemangiomas are rare entities and are usually diagnosed in childhood. Adult scrotal hemangiomas are also extremely rare. They are infrequently encountered in adults because they are usually removed in childhood. Urologists often face difficulties in deciding surgery to treat a genital cavernous hemangioma. Here, we report a case of scrotal cavernous hemangioma that involved the entire penis and scrotum, and extended to the perineum in a 44‐year‐old man, and we review the literature.
Use of a Holmium Laser to Treat a Forgotten Double‐J Stent With Whole Stent Encrustations: A Case Report
Authors: Tsai Chia‐Chun , Shen Jung‐Tsung , Huang Shu‐Pin , Chang Shu‐Fang , Tsai Li‐Jien , Wu Wen‐Jeng , Huang Chun‐Hsiung
Published: October 2009

Short‐term placement of double‐J (D‐J) ureteral stents after endourologic procedures and some open urological surgery is common. It is rare for a patient to forget about the indwelling D‐J ureteral stent, and the major complications associated with that include infection, stone encrustation and multifractured stent. We report a case of a forgotten D‐J ureteral stent, which had been placed 24 months previously during ureterorenoscopic lithotripsy, in a 62‐year‐old man who presented with flank soreness and recurrent urinary tract infection. Radiography of the kidney, ureter and bladder, and computed tomography demonstrated stone encrustation over the whole D‐J stent. Cystolithotripsy and ureterorenoscopic lithotripsy with a Holmium laser were performed to remove the D‐J. We believe that this is the first case of successful removal of an intact, encrusted stent in one procedure by endoscopic manipulation.
The probioticLactobacillus acidophilusreduces cholesterol absorption through the down-regulation of Niemann-Pick C1-like 1 in Caco-2 cells
Authors: Huang Ying , Zheng Yongchen
Published: October 2009

Elevated blood cholesterol is an important risk factor associated with atherosclerosis and CHD. The search for mediators that fine tune cholesterol homeostasis has recognised probiotics as being potentially beneficial. Here, we present data describing bacterial regulation of Niemann-Pick C1-like 1 (NPC1L1), which, when weakly expressed, results in a marked reduction in intestinal absorption of cholesterol. The probioticLactobacillus acidophilusATCC 4356 reduced NPC1L1 gene expression and inhibited the cellular uptake of micellar cholesterol in Caco-2 cells. Soluble effector molecules secreted by ATCC 4356 were shown to be responsible for the decrease in NPC1L1. Furthermore, ATCC 4356 mediated this effect partly through the liver X receptors (LXR). The role of NPC1L1 and the LXR in cholesterol metabolism underscores the basis for the use of probiotics, such as ATCC 4356, in managing hypercholesterolaemia.
EFFECTS OF COMBINING ORGANIC MATERIALS WITH INORGANIC PHOSPHORUS SOURCES ON MAIZE YIELD AND FINANCIAL BENEFITS IN WESTERN KENYA
Authors: OPALA P. A. , OTHIENO C. O. , OKALEBO J. R. , KISINYO P. O.
Published: October 2009

Due to escalating costs of imported fertilizers, there is renewed interest in the use of local nutrient resources in managing soil fertility in Kenya. We tested the effect of two organic materials, farmyard manure (FYM) andTithonia diversifolia(tithonia), and an inorganic N fertilizer, urea, when applied alone or in combination with three inorganic P sources, triple superphosphate (TSP), Minjingu phosphate rock (MPR) and Busumbu phosphate rock (BPR), on maize yields and financial benefits. The study was conducted for three consecutive seasons, from March 2007 to August 2008 in western Kenya. FYM and tithonia were applied to supply 20 kg P ha−1in treatments where they were used either alone or in combination with the inorganic P sources while 40 kg P ha−1was from the inorganic P sources in the combination. Where urea was used, the inorganic P sources were applied at 60 kg P ha−1. When applied in combination with urea, MPR was a better P source for maize than TSP or BPR. However, when applied in combination with FYM or tithonia, TSP was the best P source. Treatments including tithonia were more effective in increasing maize yields than those without it with a similar total P application rate. The agronomic effectiveness of tithonia did not, however, translate to economic attractiveness, mainly due to very high labour costs associated with its use. FYM when applied alone at 20 kg P ha−1was the only treatment that exceeded a benefit:cost ratio of 2 and, therefore, the most likely, of the tested technologies to be adopted by farmers.
A prospective study of diurnal cortisol and cognitive function in community-dwelling elderly people
Authors: Beluche I. , Carrière I. , Ritchie K. , Ancelin M. L.
Published: October 2009

Background

Elevated cortisol levels due to hypothalamic–pituitary–adrenal (HPA) axis stress response have been associated with cognitive impairment. However, the causal relationship between stress and subsequent cognitive impairment remains unclear, notably because of the small number of gender-stratified prospective studies.

Method

Salivary cortisol secretion was evaluated in 197 non-depressed community-dwelling elderly people at three time points on the day of hospital attendance for a clinical examination and again on the following day at home, in a distinct environmental context. Cognitive performance was evaluated at baseline and at 2- and 4-year follow-up.

Results

Cross-sectional logistic analyses adjusted for age and education indicated that men with high morning cortisol at the hospital had higher risk of low cognitive performance in verbal fluency [odds ratio (OR) 3.0, p=0.05] and visuospatial performance (OR 5.1, p=0.03). Impairment in verbal fluency was observed in women with moderate high morning cortisol (OR 3.6, p=0.05) or moderate slow diurnal rhythm (OR 3.7, p=0.04). In longitudinal analyses, slow diurnal rhythm (flatter slope) was associated with decline over 4 years in visuospatial performance (OR 7.7, p=0.03) and visual memory (OR 4.1, p=0.03) in men, and in verbal fluency (OR 6.0, p=0.01) in women. High morning cortisol was associated with decline in visual memory in women (OR 5.1, p=0.06).

Conclusions

HPA axis dysregulation seems to be associated with low cognitive performance in the elderly. Slower cortisol elimination rates could predict cognitive decline affecting principally non-verbal functioning in men and verbal functioning in women. The effects are independent of environmental context, apolipoprotein E (ApoE) genotype or psychopathology. Interventions blocking this pathway may provide new therapeutic options to prevent cognitive decline.
Rabies epidemiology and control in Turkey: past and present
Authors: JOHNSON N. , UN H. , FOOKS A. R. , FREULING C. , MÜLLER T. , AYLAN O. , VOS A.
Published: October 2009

Turkey is the only country in Europe where urban dog-mediated rabies persists. Control measures in recent decades have reduced the burden of rabies to relatively low levels but foci of disease still persist, particularly in urban areas. Occasional human cases result from this persistence although the source of these appears to be both dog and wildlife reservoirs. This review considers the current state of rabies in Turkey including current control measures, the varying epidemiology of the disease throughout this country and the prospects for rabies elimination.
BOUNDARY BEHAVIOR OF SUPERHARMONIC FUNCTIONS SATISFYING NONLINEAR INEQUALITIES IN A PLANAR SMOOTH DOMAIN
Authors: HIRATA KENTARO
Published: October 2009

This paper presents a sharp boundary growth estimate for all positive superharmonic functions u in a smooth domain Ω in ℝ2 satisfying the nonlinear inequality where c>0, α∈ℝ and p>0, and δΩ(x) stands for the distance from a point x to the boundary of Ω. A result is applied to show the existence of nontangential limits of such superharmonic functions.
FLAT SETS, ℓp-GENERATING AND FIXING c0 IN THE NONSEPARABLE SETTING
Authors: FABIAN M. , GONZÁLEZ A. , ZIZLER V.
Published: October 2009

We define asymptotically p-flat and innerly asymptotically p-flat sets in Banach spaces in terms of uniform weak* Kadec–Klee asymptotic smoothness, and use these concepts to characterize weakly compactly generated (Asplund) spaces that are c0(ω1)-generated or ℓp(ω1)-generated, where p∈(1,∞). In particular, we show that every subspace of c0(ω1) is c0(ω1)-generated and every subspace of ℓp(ω1) is ℓp(ω1)-generated for every p∈(1,∞). As a byproduct of the technology of projectional resolutions of the identity we get an alternative proof of Rosenthal’s theorem on fixing c0(ω1).
GRAPH PRODUCTS OF RIGHT CANCELLATIVE MONOIDS
Authors: FOUNTAIN JOHN , KAMBITES MARK
Published: October 2009

Our first main result shows that a graph product of right cancellative monoids is itself right cancellative. If each of the component monoids satisfies the condition that the intersection of two principal left ideals is either principal or empty, then so does the graph product. Our second main result gives a presentation for the inverse hull of such a graph product. We then specialize to the case of the inverse hulls of graph monoids, obtaining what we call ‘polygraph monoids’. Among other properties, we observe that polygraph monoids areF*-inverse. This follows from a general characterization of those right cancellative monoids with inverse hulls that areF*-inverse.
Primary production and eddy correlation measurements of CO2 exchange over an intertidal estuary
Authors: Zemmelink H. J. , Slagter H. A. , van Slooten C. , Snoek J. , Heusinkveld B. , Elbers J. , Bink N. J. , Klaassen W. , Philippart C. J. M. , de Baar H. J. W.
Published: October 2009

Field measurements by eddy correlation indicate an average CO2 uptake of 1.9 g C m−2 d−1 by the intertidal Wadden Sea estuary in spring 2008. The flux did not show a dependency on the tide and fluxes during high and low tide were comparable. We hypothesize that biological production in the water column and in microbial mats that cover sediments lead to an undersaturation of CO2 that is strong enough to support the observed fluxes. The total carbon uptake by this intertidal estuary from day of the year 101–168 is estimated to be −1.7 Tg C. Extrapolation of this flux over three months in spring suggests that the uptake of CO2 by this estuary over this period is comparable to 24% of the yearly carbon flux over the North Sea and the European estuaries.
Gravity wave–fine structure interactions: A reservoir of small‐scale and large‐scale turbulence energy
Authors: Fritts David C. , Wang Ling , Werne Joe
Published: October 2009

A direct numerical simulation of gravity wave – fine structure interactions is performed to evaluate the effects of such a superposition on instability and turbulence for fine structure shears and a gravity wave (GW) amplitude that are individually stable. The superposition leads to deformations of the fine structure and GW fields that exhibit Kelvin‐Helmholtz (KH) shear instabilities and turbulence extending over more than 20 buoyancy periods. KH instabilities occur on multiple scales, deplete the kinetic energy of the initial fine structure, and yield a layering of the potential temperature field resembling “sheet and layer” structures observed in the oceans and the atmosphere. The interactions have a much smaller effect on the GW amplitude. Such interactions among GWs and fine structure are likely ubiquitous throughout the atmosphere and oceans and may account for sporadic bursts of turbulence and its persistence in regions of apparent static and dynamic stability (Ri > 1/4).
What are the demands on an observational program to detect trends in upper tropospheric water vapor anticipated in the 21st century?
Authors: Boers R. , van Meijgaard E.
Published: October 2009

An ensemble of runs made by a regional climate model was used to estimate the expected change in humidity in the atmosphere between 1950 and 2100. Output from the model runs at a midlatitude European site is used as a proxy for a perfect climate record of specific humidity at the 300 hPa level from which trends were derived. The trend analysis demonstrates that it takes 30 years for a trend to show up in the perfect climate record. The model output was degraded to simulate observations made with the best radiosonde equipment for recording water vapor. Results indicate that it would be necessary to conduct observations for at least five decades until a trend expected by current models could be confirmed by observations to within 20%.
Tropical origins of North and South Pacific decadal variability
Authors: Shakun Jeremy D. , Shaman Jeffrey
Published: October 2009

The origin of the Pacific Decadal Oscillation (PDO), the leading mode of sea surface temperature variability for the North Pacific, is a matter of considerable debate. One paradigm views the PDO as an independent mode centered in the North Pacific, while another regards it as a largely reddened response to El Niño‐Southern Oscillation (ENSO) forcing from the tropics. We calculate the Southern Hemisphere equivalent of the PDO index based on the leading mode of sea surface temperature variability for the South Pacific and find that it adequately explains the spatial structure of the PDO in the North Pacific. A first‐order autoregressive model forced by ENSO is used to reproduce the observed PDO indices in the North and South Pacific. These results highlight the strong similarity in Pacific decadal variability on either side of the equator and suggest it may best be viewed as a reddened response to ENSO.
Performance of a local ensemble transform Kalman filter for the analysis of atmospheric circulation and distribution of long‐lived tracers under idealized conditions
Authors: Miyazaki Kazuyuki
Published: October 2009

A data assimilation system for the analysis of atmospheric circulation and long‐lived tracer distributions in the troposphere and stratosphere has been developed and tested by using a local ensemble transform Kalman filter (LETKF), which has been applied to assimilate both meteorological fields and tracer concentrations into a general circulation model and an atmospheric transport model. Assimilated meteorological fields are used for driving the transport model. The performance of the LETKF data assimilation system is assessed under idealized conditions by assuming that the forecast models provide a perfect representation of atmospheric conditions. The LETKF meteorological analysis facilitates the study of atmospheric transport characteristics and provides high‐quality tracer transport simulations, reflecting its flow‐dependent and physically well balanced analysis. In particular, eddy mixing features are better analyzed by LETKF than by an analysis that employs a conventional assimilation scheme (i.e., nudging technique). The conventional analysis causes excessive tracer eddy dispersions, which were commonly observed in previous studies using three‐dimensional variational analyses. Further improvement in tracer analysis can be achieved by assimilating the tracer concentration within the LETKF. The assimilation of tracer concentration effectively reduces the tracer background error caused by initial distribution and surface flux errors. Tracer analysis can also be improved by considering the covariance with wind fields in a background error matrix, in which wind observation directly impacts the tracer states, reducing 20% of the tracer analysis error in the free troposphere. The sensitivity of the tracer analysis to assimilation parameters and model errors is discussed to obtain an optimal data assimilation framework.
Understanding and modeling the physical processes that govern the melting of snow cover in a tropical mountain environment in Ecuador
Authors: Wagnon P. , Lafaysse M. , Lejeune Y. , Maisincho L. , Rojas M. , Chazarin J. P.
Published: October 2009

The ISBA/CROCUS coupled ground‐snow model developed for the Alps and subsequently adapted to the outer tropical conditions of Bolivia has been applied to a full set of meteorological data recorded at 4860 m above sea level on a moraine area in Ecuador (Antizana 15 glacier, 0°28′S; 78°09′W) between 16 June 2005 and 30 June 2006 to determine the physical processes involved in the melting and disappearance of transient snow cover in nonglaciated areas of the inner tropics. Although less accurate than in Bolivia, the model is still able to simulate snow behavior over nonglaciated natural surfaces, as long as the modeled turbulent fluxes over bare ground are reduced and a suitable function is included to represent the partitioning of the surface between bare soil and snow cover. The main difference between the two tropical sites is the wind velocity, which is more than 3 times higher at the Antizana site than at the Bolivian site, leading to a nonuniform spatial distribution of snow over nonglaciated areas that is hard to describe with a simple snow partitioning function. Net solar radiation dominates the surface energy balance and is responsible for the energy stored in snow‐free areas (albedo = 0.05) and transferred horizontally to adjacent snow patches by conduction within the upper soil layers and by turbulent advection. These processes can prevent the snow cover from lasting more than a few hours or a few days. Sporadically, and at any time of the year, this inner tropical site, much wetter than the outer tropics, experiences heavy snowfalls, covering all the moraine area, and thus limiting horizontal transfers and inducing a significant time lag between precipitation events and runoff.
Efficient expression and secretion of recombinant human growth hormone in the methylotrophic yeast Pichia pastoris: potential applications for other proteins
Authors: Apte‐Deshpande Anjali , Rewanwar Sachin , Kotwal Prakash , Raiker Veena A. , Padmanabhan Sriram
Published: October 2009

A simple high yielding process for the production of rhGH (recombinant human growth hormone) in the Pichia pastoris system is described. The approach adopted the addition of surfactants during fermentation along with methanol induction. A Pichia integrant harbouring multiple‐copy, non‐codon‐optimized hGH showed poor expression in complex and defined media. Inclusion of the surfactants Tween 20 or Tween 80 during induction enhanced the expression levels significantly in shake flask studies. The combination of 2 litres of basal salt medium and Tween 20 in a bioreactor culminated in 3×104‐fold elevated expression of the protein (∼500 mg/l) as estimated by ELISA. SDS/PAGE and Western‐blot analyses revealed that the Pichia‐derived rhGH migrated as a single band with a molecular mass of ∼22 kDa and had the same immunoreactivity as native commercial rhGH. Analysis of Pichia‐derived purified rhGH and commercial rhGH on an Agilent 2100 Bioanalyzer revealed overlapping peaks displaying authentic N‐terminal processing of Pichia‐derived rhGH, which was further confirmed by N‐terminal sequencing. In addition, matrix‐assisted laser‐desorption ionization–time of flight analysis of the protein confirmed its authenticity. These results indicate that the P. pastoris expression system can be effective in the production of rhGH at commercially relevant levels.
Role of the cysteine protease interpain A of Prevotella intermedia in breakdown and release of haem from haemoglobin
Authors: Byrne Dominic P. , Wawrzonek Katarzyna , Jaworska Anna , Birss Andrew J. , Potempa Jan , Smalley John W.
Published: October 2009

The Gram-negative oral anaerobe Prevotella intermedia forms an iron(III) protoporphyrin IX pigment from haemoglobin. The bacterium expresses a 90 kDa cysteine protease, InpA (interpain A), a homologue of Streptococcus pyogenes streptopain (SpeB). The role of InpA in haemoglobin breakdown and haem release was investigated. At pH 7.5, InpA mediated oxidation of oxyhaemoglobin to hydroxymethaemoglobin [in which the haem iron is oxidized to the Fe(III) state and which carries OH− as the sixth co-ordinate ligand] by limited proteolysis of globin chains as indicated by SDS/PAGE and MALDI (matrix-assisted laser-desorption ionization)–TOF (time-of-flight) analysis. Prolonged incubation at pH 7.5 did not result in further haemoglobin protein breakdown, but in the formation of a haemoglobin haemichrome (where the haem Fe atom is co-ordinated by another amino acid ligand in addition to the proximal histidine residue) resistant to degradation by InpA. InpA-mediated haem release from hydroxymethaemoglobin–agarose was minimal compared with trypsin at pH 7.5. At pH 6.0, InpA increased oxidation at a rate greater than auto-oxidation, producing aquomethaemoglobin (with water as sixth co-ordinate ligand), and resulted in its complete breakdown and haem loss. Aquomethaemoglobin proteolysis and haem release was prevented by blocking haem dissociation by ligation with azide, whereas InpA proteolysis of haem-free globin was rapid, even at pH 7.5. Both oxidation of oxyhaemoglobin and breakdown of methaemoglobin by InpA were inhibited by the cysteine protease inhibitor E-64 [trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane]. In summary, we conclude that InpA may play a central role in haem acquisition by mediating oxyhaemoglobin oxidation, and by degrading aquomethaemoglobin in which haem–globin affinity is weakened under acidic conditions.
Literacy Development in Individuals With Down Syndrome
Authors: Cleave Patricia
Published: October 2009

This article discusses reading and writing development in children with DS. In addition to review of areas of strength and challenges, the author reviews literacy intervention research, and their effectiveness in improving literacy skills with this population.
Early Intervention in Down Syndrome: Targeting the Emerging Behavioral Phenotype
Authors: Fidler Deborah
Published: October 2009

This article discusses behavioral phenotype, or profile of development, associated with Down syndrome, and the implication of this knowledge of intervention for children with Down syndrome. A discussion of development in children with DS, and implications of behavioral phenotype research on intervention decisions, is reviewed.
Educating a Syndrome?: Seeking a Balance Between Identifying a Learning Profile and Delivering Inclusive Education
Authors: Rix Jonathan
Published: October 2009

This article summarizes research related to pedagogical approaches to special education, and characteristics of teacher’s attitudes and beliefs that supports effective inclusion practices. Additionally, the author summarizes factors that may both enable and disable children with DS’s progress, and notes speech and language characteristics from research to date.
Dysphagia Management in the Schools: Concepts in Training and Competency
Authors: O'Donoghue Cynthia R. , Hegyi Sarah E.
Published: October 2009

As the demands to care for children with swallowing and feeding disorders continue to evolve for school-based speech-language pathologists (SLPs), avenues to establish, maintain, and monitor competency are imperative. Optimally, these approaches should delineate dysphagia protocols and practices at school, district, and state levels that are grounded in evidence. Key foundational components to improving services for children, while minimizing the liabilities for SLPs, include legislated scope of practice within school licensure regulations, published guidelines and standard of practice protocols, documented yearly competencies, and established monitoring for knowledge and skill levels. This article outlines the Commonwealth of Virginia's approaches to these goals as a preliminary model to address these logistical issues. Although a concept not reported previously in the school-based swallowing and feeding literature, a continuum of knowledge and skills is considered. This continuum emphasizes acquired skills do not mean “competency” for life. Competency is dynamic; SLPs will advance or regress in their performances based on personal interests, continuing education, and clinical experiences.
Avoiding Disputes in School-Based Management of Students With Dysphagia: Five Key Strategies
Authors: Bailey Rita L. , Lugg Elizabeth T.
Published: October 2009

It is important that speech-language pathologists, administrators, and other school personnel understand the adverse effect of dysphagia on students' ability to receive an appropriate education. This article addresses the educational relevance of dysphagia management and provides practical strategies for avoiding potential disputes related to management of students with dysphagia.
Water-mediated signal multiplication with Y-shaped carbon nanotubes
Authors: Tu Yusong , Xiu Peng , Wan Rongzheng , Hu Jun , Zhou Ruhong , Fang Haiping
Published: October 2009

Molecular scale signal conversion and multiplication is of particular importance in many physical and biological applications, such as molecular switches, nano-gates, biosensors, and various neural systems. Unfortunately, little is currently known regarding the signal processing at the molecular level, partly due to the significant noises arising from the thermal fluctuations and interferences between branch signals. Here, we use molecular dynamics simulations to show that a signal at the single-electron level can be converted and multiplied into 2 or more signals by water chains confined in a narrow Y-shaped nanochannel. This remarkable transduction capability of molecular signal by Y-shaped nanochannel is found to be attributable to the surprisingly strong dipole-induced ordering of such water chains, such that the concerted water orientations in the 2 branches of the Y-shaped nanotubes can be modulated by the water orientation in the main channel. The response to the switching of the charge signal is very rapid, from a few nanoseconds to a few hundred nanoseconds. Furthermore, simulations with various water models, including TIP3P, TIP4P, and SPC/E, show that the transduction capability of the Y-shaped carbon nanotubes is very robust at room temperature, with the interference between branch signals negligible.
α-Actinin2 cytoskeletal protein is required for the functional membrane localization of a Ca2+-activated K+channel (SK2 channel)
Authors: Lu Ling , Timofeyev Valeriy , Li Ning , Rafizadeh Sassan , Singapuri Anil , Harris Todd R. , Chiamvimonvat Nipavan
Published: October 2009

The importance of proper ion channel trafficking is underpinned by a number of channel-linked genetic diseases whose defect is associated with failure to reach the cell surface. Conceptually, it is reasonable to suggest that the function of ion channels depends critically on the precise subcellular localization and the number of channel proteins on the cell surface membrane, which is determined jointly by the secretory and endocytic pathways. Yet the precise mechanisms of the entire ion channel trafficking pathway remain unknown. Here, we directly demonstrate that proper membrane localization of a small-conductance Ca2+-activated K+channel (SK2 or KCa2.2) is dependent on its interacting protein, α-actinin2, a major F-actin crosslinking protein. SK2 channel localization on the cell-surface membrane is dynamically regulated, and one of the critical steps includes the process of cytoskeletal anchoring of SK2 channel by its interacting protein, α-actinin2, as well as endocytic recycling via early endosome back to the cell membrane. Consequently, alteration of these components of SK2 channel recycling results in profound changes in channel surface expression. The importance of our findings may transcend the area of K+channels, given that similar cytoskeletal interaction and anchoring may be critical for the membrane localization of other ion channels in neurons and other excitable cells.
Exact solutions of a class of fractional Hamiltonian equations involving Caputo derivatives
Authors: Baleanu Dumitru , Trujillo Juan J
Published: October 2009

The fractional Hamiltonian equations corresponding to the Lagrangians of constrained systems within Caputo derivatives are investigated. The fractional phase space is obtained and the exact solutions of some constrained systems are obtained.
Tenseur diélectrique du plasma chaud dans un champ electromagnétique en rotation
Authors: Kazadi Mukenga Bantu A , Liyoko M , Nyamu M
Published: October 2009

In our paper, we derive the expression of the dielectric tensor for fully ionized hot plasma immersed in a rotating electromagnetic field. This tensor differs from the one obtained for a fully ionized cold plasma by the presence of a new factor due to the fact we took in a count of the thermal component.
Mechanical action of infrared light on atoms and molecules through a rectification of the electric force
Authors: Tu Yaoquan , Felicíssimo Viviane Costa , Guimarães Freddy Fernandes , Ågren Hans , Gel'mukhanov Faris
Published: October 2009

We report the mechanical action of infrared light on atoms and molecules based on the rectification of the electric force. This mechanism is qualitatively different from the conventional ways of controlling photochemistry. The rectification of the electric force originates from the synchronous charge transfer induced by the laser field. This brings about an opportunity to produce a site selective light-induced action, controlled by the tailored intense laser field, on atoms in molecules and clusters. The concept is illustrated by ab initio molecular dynamics simulations of the water hexamer.
Race Dynamics, Diversity, and Virulence Evolution in Puccinia striiformis f. sp. tritici, the Causal Agent of Wheat Stripe Rust in China from 2003 to 2007
Authors: Chen W. Q. , Wu L. R. , Liu T. G. , Xu S. C. , Jin S. L. , Peng Y. L. , Wang B. T.
Published: October 2009

Stripe (or yellow) rust caused by Puccinia striiformis f. sp. tritici is the most destructive foliar disease of wheat in China. The pathogen populations were analyzed for virulence evolution, complexity, phenotypic dynamics, and diversity on temporal and spatial bases. A total of 41 races were identified and characterized from 4,714 stripe rust isolates collected during 2003 through 2007 from wheat growing areas in 15 provinces in China. The races were based on avirulence/virulence patterns to 19 differential host genotypes. Chinese stripe rust population exhibited high diversity with a complex virulence structure. Comparisons using the relative Shannon's index indicated that some differences in the richness and evenness of races were present in pathogen populations within years and between regions despite a national tendency to reduced diversity over time. A noticeably increased frequency of race CYR33 (Chinese yellow rust 33) with virulence for YrSu was the major virulence change recorded in this study compared to the results on an annual basis. Isolates of Puccinia striiformis f. sp. tritici from different regions showed differences in the composition of races, distribution frequency, and diversity. The uneven distribution of major races and comparatively greater diversity in the Northwest and Southwest regions than that in the Huang-Huai-Hai region suggest that long-distance migrations of the pathogen occur from one or more over-summering areas eastward into over-wintering areas. This supports the hypothesis that southern Gansu and northwestern Sichuan comprises a “center of origin for virulence”. Mutation of virulence or avirulence for host resistance in the stripe rust fungus may be the basic cause of the occurrence of new virulent types. The subsequent dominance of certain races will vary with parasitic fitness and the opportunities to be selected through large-scale cultivation of varieties with matching resistance genes. Implications of the center of origin for virulence variation and diversity in the pathogen population and an alternative strategy for limiting virulence evolution are discussed.