bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical structure of habitat network differently affects migration patterns of native and invasive fishes in Lake Biwa and its tributary lagoons: stable isotope approach
Authors: Shibata Jun‐ya , Karube Zin'ichi , Oishi Mamiko , Yamaguchi Mana , Goda Yukiko , Okuda Noboru
Published: May 2010

A good understanding of how migratory animals use their habitat network is expected to provide important insights for the prediction of population dynamics at both local and regional scales. We focused on how the physical structure of a habitat network could affect fish migration between Lake Biwa and its tributary lagoons. Although the lagoons provide suitable breeding and nursery grounds for native fishes, it is a matter of concern that they can also be a hotbed of invasive exotic fishes. Here, we assessed the migration patterns of native crucian carps (Carassiusspp.) and exotic largemouth bass (Micropterus salmoides) and bluegill sunfish (Lepomis macrochirus) using their carbon and nitrogen stable isotopes as migration tracers. As there were marked differences in the carbon isotope ratios of basal food webs between the main lake and its tributary lagoons, stable isotopic signatures of individual fishes collected from each lagoon enabled us to judge whether they were residents of the lagoon or recent immigrants from the main lake. The analysis revealed that native and invasive fishes showed different migration patterns across a variety of lagoons. Exotic fishes frequently immigrated from the main lake to the lagoon as the distance of the channel connecting these two habitats was short. For native crucian carps, in contrast, their migrations were unaffected by the channel distance but were promoted by narrow channels. Physical barriers of weirs and dense vegetation within the channel obstructed their migrations. Such ecological information on migration behavior will be vital to plan designs for habitat restoration to conserve native fishes.
Metabolic acetate therapy improves phenotype in the tremor rat model of Canavan disease
Authors: Arun Peethambaran , Madhavarao Chikkathur N. , Moffett John R. , Hamilton Kristen , Grunberg Neil E. , Ariyannur Prasanth S. , Gahl William A. , Anikster Yair , Mog Steven , Hallows William C. , Denu John M. , Namboodiri Aryan M. A.
Published: May 2010

Genetic mutations that severely diminish the activity of aspartoacylase (ASPA) result in the fatal brain dysmyelinating disorder, Canavan disease. There is no effective treatment. ASPA produces free acetate from the concentrated brain metabolite, N‐acetylaspartate (NAA). Because acetyl coenzyme A is a key building block for lipid synthesis, we postulated that the inability to catabolize NAA leads to a brain acetate deficiency during a critical period of CNS development, impairing myelination and possibly other aspects of brain development. We tested the hypothesis that acetate supplementation during postnatal myelination would ameliorate the severe phenotype associated with ASPA deficiency using the tremor rat model of Canavan disease. Glyceryltriacetate (GTA) was administered orally to tremor rats starting 7 days after birth, and was continued in food and water after weaning. Motor function, myelin lipids, and brain vacuolation were analyzed in GTA‐treated and untreated tremor rats. Significant improvements were observed in motor performance and myelin galactocerebroside content in tremor rats treated with GTA. Further, brain vacuolation was modestly reduced, and these reductions were positively correlated with improved motor performance. We also examined the expression of the acetyl coenzyme A synthesizing enzyme acetyl coenzyme A synthase 1 and found upregulation of expression in tremor rats, with a return to near normal expression levels in GTA‐treated tremor rats. These results confirm the critical role played by NAA‐derived acetate in brain myelination and development, and demonstrate the potential usefulness of acetate therapy for the treatment of Canavan disease.
Pre‐Nucleation Structuring of TAG Melts Revealed by Fluorescence Polarization Spectroscopy and Molecular Mechanics Simulations
Authors: Dibildox‐Alvarado E. , Laredo T. , Toro‐Vazquez J. F. , Marangoni A. G.
Published: May 2010

We have studied the pre‐nucleation behavior of tripalmitin (TP) and tristearin (TS) in blends with triolein (TO), high oleic safflower oil (HOSfO) and soybean oil (SBO) by means of fluorescence polarization spectroscopy (FPS) and molecular mechanics simulations (MM). The FPS measurements at different temperatures showed that there is an increase in the anisotropy of the TP:HOSfO and TP:SBO blends as opposed to the TP:TO sample. This increase is directly related to an increase in the microviscosity of the blend which is interpreted as a structuring step prior to the nucleation and growth of the crystals. A similar but less pronounced effect was also observed in the TS:SBO blends. We performed MM simulations in an attempt to understand the molecular interactions responsible for this behavior. The simulation results have shown that short range van der Waals (vdW) interactions are the ones responsible for the increase in the microviscosity of the blends prior to crystallization. Our results also indicate that the presence of molecules that contain at least one chain of palmitic acid in their triglyceride (TAG) composition will induce a pre‐nucleation increase in the microviscosity of the blend in both TP and TS containing systems. Lastly, we studied the applicability of these conclusions to longer chain TAG analogues. Our MM results show that hypothetical blends of TS and TAGs containing stearic acid in their structure, will not have a low enough vdW energy to account for an increase in the microviscosity. Hence, there seems to be a specific interaction particularly favorable when the oil contains TAGs with at least one palmitic acid chain.
Impaired water reabsorption in mice deficient in the type VI adenylyl cyclase (AC6)
Authors: Chien Chen-Li , Wu Yu-Shuo , Lai Hsing-Lin , Chen Yen-Hui , Jiang Si-Tse , Shih Chia-Ming , Lin Sui-Shan , Chang Chen , Chern Yijuang
Published: May 2010

Adenylyl cyclase (AC) type VI (AC6) is a calcium‐inhibitable enzyme which produces cAMP upon stimulation. Herein, we characterized the specific role of AC6 in the kidneys using two AC6‐knockout mouse lines. Immunohistochemical staining revealed that AC6 exists in the tubular parts of the nephron and collecting duct. Activities of AC evoked by forskolin or a selective agonist of the V2 vasopressin receptor were lower in the kidneys of AC6‐null mice compared to those of wildtype mice. Results of a metabolic cage assay and dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) showed for the first time that AC6 plays a critical role in regulating water homeostasis.
Mammalian target of rapamycin complex 1 signaling opposes the effects of anchorage loss, leading to activation of Cdk4 and Cdc6 stabilization
Authors: Arakawa-Takeuchi Shiho , Kobayashi Kohei , Park Jung-ha , Uranbileg Baasanjav , Yamamoto Hanako , Jinno Shigeki , Okayama Hiroto
Published: May 2010

MINT‐7890626: cdc27 (uniprotkb:Q4V8A2) physically interacts (MI:0915) with Cyclin‐A (uniprotkb:Q6AY13) by anti bait coimmunoprecipitation (MI:0006)
Acute Carbon Monoxide Poisoning Resulting in ST Elevation Myocardial Infarction: A Rare Case Report
Authors: Hsu Po‐Chao , Lin Tsung‐Hsien , Su Ho‐Ming , Lee Hsiang‐Chun , Huang Chih‐Hsin , Lai Wen‐Ter , Sheu Sheng‐Hsiung
Published: May 2010

Acute carbon monoxide (CO) poisoning with cardiac complications is well documented in the literature. However, ST segment elevation is a rare presentation, and most of these cases with ST elevation have revealed non‐occlusive or normal coronary arteries. We report a case of CO poisoning complicated with ST elevation myocardial infarction. Emergency coronary angiography revealed total occlusion of the left anterior descending artery and primary percutaneous coronary intervention was performed. This report of a rare case should remind physicians that cardiovascular investigations, including electrocardiography, must be performed in cases with CO poisoning because mortality might increase if reperfusion therapy or appropriate medical treatments are not performed in patients with acute coronary artery occlusion.
The occurrence of Austrodiplostomum compactum (Lutz, 1928) (Digenea: Diplostomidae) metacercariae in the eyes of loricariid fish (Siluriformes: Osteichthyes: Loricariidae) from Brazil
Authors: Zica E.O.P. , Brandão H. , Zawadzki C.H. , Nobile A.B. , Carvalho E.D. , da Silva R.J.
Published: May 2010

The aim of this study was to report the occurrence of Austrodiplostomum compactum metacercariae in the eyes of 98 specimens of loricariid fish (Hypostomus ancistroides, H. hermanni, H. iheringii, H. margaritifer, H. regani, H. strigaticeps, Hypostomus sp. and Megalancistrus parananus) from the Chavantes reservoir (23°07′36″S and 49°37′35″W) located in the rio Paranapanema, upper Paraná river basin, municipality of Ipaussu, São Paulo State, Brazil. Fish were collected from October 2007 to February 2009 using nylon monofilament gill nets and transported to the field laboratory where they were euthanized and the eyes were taken and examined under a stereomicroscope. Hypostomus ancistroides and M. parananus were not infected by this diplostomid. Hypostomus hermanni and H. margaritifer were represented by only one specimen but both had a high intensity of A. compactum metacercarie (27 and 35, respectively). Hypostomus strigaticeps (n = 45) and H. iheringii (n = 28) were the most representative specimens and the prevalence, mean intensity of infection and mean abundance were 24.4%, 10.3 and 2.7, and 64.2%, 13.1 and 8.4, respectively. No correlation was observed between the intensity of infection and the standard length (r = − 0.223; P = 0.827) and weight (r = 0.03; P = 0.779) of studied fish. Similarly, linear regression among these variables showed a poor correlation and indicated that the infection by A. compactum metacercariae occurs similarly in small and large fish specimens. A seasonal pattern of infection was not observed. Hypostomus hermanni, H. iheringii, H. margaritifer and H. strigaticeps were new hosts recorded for A. compactum metacercariae. A review of morphometric data of A. compactum metacercariae is presented.
Resistance and resilience of traditionally managed West African Dwarf goats from the savanna zone of northern Nigeria to naturally acquired trypanosome and gastrointestinal nematode infections
Authors: Behnke J.M. , Chiejina S.N. , Musongong G.A. , Nnadi P.A. , Ngongeh L.A. , Abonyi F.O. , Fakae B.B.
Published: May 2010

A survey was conducted of gastrointestinal nematode infections and trypanosomosis in Nigerian West African Dwarf (WAD) goats from the savanna region of the country. Animals were screened at two markets, Gboko and Akpagher, from the beginning of April until the end of September, coinciding with the end of the dry season and the first 5 months of the wet season. Of 1054 goats that were examined, 80.5% carried gastrointestinal (GI) nematodes belonging to the genera Haemonchus (61.0%), Oesophagostomum (21.0%) and Trichostrongylus (17.9%). Faecal egg counts (FEC) increased very slowly but significantly from April to maximum levels in September, and varied marginally between the two market sources. The majority of goats (68.8 and 70.1% at the two markets) had low FEC not exceeding 50 eggs/g (epg). FEC did not differ significantly between the sexes or between age classes. Packed cell volume (PCV) also declined significantly with month of the study, but was affected by host sex (a significant month × sex interaction) being generally higher in male animals throughout the period. There was a highly significant negative correlation between log10(FEC+1) and PCV, when all other factors had been taken into account. Body condition scores (BCS) also declined with month of the study, but there was a marked difference between the two sexes, with male animals generally showing a greater stability of BCS across the months compared with females. Trypanosome infections were found in only 4% of the goats and only during the rainy season. Most infections (92.86%) were caused by Trypanosoma brucei alone although T. vivax and T. congolense were occasionally detected. Overall, the majority of goats sampled each month maintained generally good body condition (BCS 3.0–5.0), normal or slightly reduced PCV, even when concurrently infected with trypanosomes and GI nematodes. However, four concurrently infected goats showed signs of overt anaemia during periods of peak infection, during the late rainy season, with marked reductions in PCV ( < 15%). Two of the infected goats were also in poor body condition with BCS of < 2.0. There was no evidence of additive or synergistic pathogenic effects of the two parasites. These results are discussed in the context of the unexpectedly strong resistance and resilience of the savanna WAD ecotype to its native strains of GI nematode and trypanosome parasites.
Anxiety, emotional security and the interpersonal behavior of individuals with social anxiety disorder
Authors: Russell J. J. , Moskowitz D. S. , Zuroff D. C. , Bleau P. , Pinard G. , Young S. N.
Published: May 2010

Background

Interpersonal functioning is central to social anxiety disorder (SAD). Empirical examinations of interpersonal behaviors in individuals with SAD have frequently relied on analogue samples, global retrospective reports and laboratory observation. Moreover, research has focused on avoidance and safety behaviors, neglecting potential links between SAD and affiliative behaviors.

Method

The influence of situational anxiety and emotional security on interpersonal behaviors was examined for individuals with SAD (n=40) and matched normal controls (n=40). Participants monitored their behavior and affect in naturally occurring social interactions using an event-contingent recording procedure.

Results

Individuals with SAD reported higher levels of submissive behavior and lower levels of dominant behavior relative to controls. Consistent with cognitive–behavioral and evolutionary theories, elevated anxiety in specific events predicted increased submissiveness among individuals with SAD. Consistent with attachment theory, elevations in event-level emotional security were associated with increased affiliative behaviors (increased agreeable behavior and decreased quarrelsome behavior) among members of the SAD group. Results were not accounted for by concurrent elevations in sadness or between-group differences in the distribution of social partners.

Conclusions

These findings are consistent with predictions based on several theoretical perspectives. Further, the present research documents naturally occurring interpersonal patterns of individuals with SAD and identifies conditions under which these individuals may view social interactions as opportunities for interpersonal connectedness.
Genetic overlap between episodic memory deficits and schizophrenia: results from The Maudsley Twin Study
Authors: Owens S. F. , Picchioni M. M. , Rijsdijk F. V. , Stahl D. , Vassos E. , Rodger A. K. , Collier D. A. , Murray R. M. , Toulopoulou T.
Published: May 2010

Background

Visual and verbal episodic memory deficits are putative endophenotypes for schizophrenia; however, the extent of any genetic overlap of these with schizophrenia is unclear. In this study, we set out to quantify the genetic and environmental contributions to variance in visual and verbal memory performance, and to quantify their genetic relationship with schizophrenia.

Method

We applied bivariate genetic modelling to 280 twins in a classic twin study design, including monozygotic (MZ) and dizygotic (DZ) pairs concordant and discordant for schizophrenia, and healthy control twins. We assessed episodic memory using subtests of the Wechsler Memory Scale – Revised (WMS-R).

Results

Genetic influences (i.e. heritability) contributed significantly to variance in immediate recall of both verbal memory and visual learning, and the delayed recall of verbal and visual memory. Liability to schizophrenia was associated with memory impairment, with evidence of significant phenotypic correlations between all episodic memory measures and schizophrenia. Genetic factors were the main source of the phenotypic correlations for immediate recall of visual learning material; both immediate and delayed recall of verbal memory; and delayed recall of visual memory that, for example, shared genetic variance with schizophrenia, which accounted for 88% of the phenotypic correlation (rph=0.41) between the two.

Conclusions

Verbal memory and visual learning and memory are moderately heritable, share a genetic overlap with schizophrenia and are valid endophenotypes for the condition. The inclusion of these endophenotypes in genetic association studies may improve the power to detect susceptibility genes for schizophrenia.
Theoretical Perspectives on Listening
Authors: Lynch Tony
Published: May 2010

Research into listening over the past three decades has, above all, highlighted the fundamental intricacy of the processes involved. In order to make sense of spoken messages, listeners may need to integrate information from a range of sources: phonetic, phonological, prosodic, lexical, syntactic, semantic, and pragmatic. The fact that we achieve all this in real time as the message unfolds makes listening “complex, dynamic, and fragile” (Celce-Murcia 1995:366). In this review I consider research into four aspects of these complexities: processes (e.g., speech recognition, discourse comprehension, and memory); the role of context; factors influencing listening; and the relationship of listening with other language skills. Finally I suggest likely directions for future research into listening.
Theoretical Perspectives on Reading
Authors: Hudson Thom
Published: May 2010

Reading text is a relatively recent human activity, only having been around for about 5,000 years. Through text, writers are able to communicate with others at great distances. Readers are able to perceive arbitrarily determined shapes presented against some background and then form them into meaning. As the reader becomes more proficient at reading and uses reading in more and different ways, this process of interpreting letters and words becomes increasingly automatic.
Theoretical Perspectives on Writing
Authors: Cumming Alister
Published: May 2010

The word “writing” refers not only to text in written script but also to the acts of thinking, composing, and encoding language into such text; these acts also necessarily entail discourse interactions within a socio-cultural context. Writing is text, is composing, and is social construction. This threefold distinction—between text analytic, composing process, and social constructivist views of writing—has served usefully to distinguish the major orientations adopted in inquiry into second language writing and to circumscribe the implications they have for instruction (e.g., Grabe and Kaplan 1996, Raimes 1991, Silva 1990).
Teaching Listening
Authors: Mendelsohn David J.
Published: May 2010

The importance of listening is increasing in the world, and technological advances in global communication have made listening by non-native speakers even more crucial. The potential for misunderstanding has therefore also increased, making the teaching of listening comprehension (henceforth “listening”) even more important (Grant 1996).
Teaching Speaking
Authors: Burns Anne
Published: May 2010

Much recent work on optimal conditions for the teaching of speaking in second and foreign language classrooms has been grounded in educational psycholinguistics or in cognitive and social psychology. Theoretical constructs for language pedagogy have been drawn extensively from empirical studies, underpinned by the central notions of second language acquisition: communicative competence (Canale and Swain 1980); comprehensible input (Krashen 1985), negotiated interaction (Ellis 1990, Gass and Varonis 1994, Long 1983, Pica,et al.1989), input processing (VanPatten and Cadierno 1993), developmental sequences and routes of acquisition (Meisel, Clahsen and Pienemann 1981), and communication strategies (Faerch and Kasper 1983). Such constructs are widely taught in teacher preparation programs in second and foreign language teaching and clearly have relevance to oral language instructional practice.
Teaching Reading
Authors: Bamford Julian , Day Richard R.
Published: May 2010

Look through the window of any second or foreign language (L2) reading classroom and, invariably, you will see the teacher and students seated with books open in front of them. This superficial similarity masks vast differences in teaching methodology, however. As the 20th century draws to a close, there are, around the world, at least four distinctive approaches to the teaching of L2 reading: grammar-translation, comprehension questions, skills and strategies, and extensive reading. After brief descriptions of these four approaches to teaching reading and their status in the reading classroom, important issues in L2 reading instruction are addressed, leading to more general concerns involving the relationship among theory, research, and teaching practice.
Teaching Writing
Authors: Raimes Ann
Published: May 2010

With just the two words of the title “Teaching writing,” we are thrown into ambiguity characteristic of the enterprise the title names. Is that second word a participle, referring to the activity of generating, composing, and revising ideas on paper, or is it a more static gerund noun form—writing as an artifact, as text presented on a page, performing social functions? The position we take with regard to the multiple realities encompassed in this dichotomy and in others in our field gives shape to our teaching. And that shape is changing.
Assessing Speaking
Authors: Turner Jean
Published: May 2010

The publication of the ACTFL (American Council on the Teaching of Foreign Languages) Guidelines (1986) and the creation and popularization of the ACTFL Oral Proficiency Interview (ACTFL-OPI) have had a profound effect on foreign and second language instruction and assessment, drawing attention to language students' abilities to use language in performing particular functions and tasks rather than to what they have learned about language. The growing interest in communicative language teaching, with its emphasis on meaningful interaction in the language as opposed to knowledge of linguistic rules, has complemented interest in the ACTFL Guidelines' descriptions of functional language ability and the interview-format oral proficiency interview.
Assessing Reading
Authors: Perkins Kyle
Published: May 2010

The fields of reading comprehension per se and second language reading comprehension are vast indeed, and an attempt to survey them will, of necessity, be attenuated in a chapter of this size. As a consequence, I will limit my discussion to six areas: 1) general comments concerning areas of interest in reading research and assessment, 2) the adaptation of a suitable first-language reading comprehension model for second-language assessment, 3) the reliance on a top-down model of reading comprehension, 4) the validity of multiple-choice reading comprehension tests, 5) research on behavioral anchoring, and 6) the testing of reading comprehension in a CAT (Computer Adaptive Testing) context.
Task-Based Instruction
Authors: Skehan Peter
Published: May 2010

In the last twenty years or so, language teaching has changed to incorporate a higher proportion of meaning-based activities, in contrast to the era in which form was primary and a concern for meaning only followed the establishment of control over specific forms. Now, a wide range of classroom options are available for participant organization, content incorporation, and the units by which teaching is organized. In order to locate task-based work within such a range of options, it is necessary to address definitional issues at the outset, since many different contemporary options give task a central role. For the purposes of this chapter, a task is regarded as an activity which satisfies the following criteria:
Skills, Abilities, and Contexts of Reality
Authors: Widdowson H. G.
Published: May 2010

The contributions in this volume provide a comprehensive survey of recent research and pedagogic practice in what is described as ‘the four basic language skills.’ My brief, and my original intention, seemed straightforward enough: to provide a short overview which would comment on general trends in a relatively impartial manner. Impartiality is never easy to achieve, however, and since trends are typically a matter of implicit assumptions, discerning them is bound to be subjective in some degree. What I have done is to consider certain of these assumptions and relate them to general issues about the so-called language skills which have been subject to debate for some time. This commentary, then, is less a measured survey than a critical reflection, from an historical and personal perspective, on matters arising from these contributions.
Determinants of haemodialysis access survival
Authors: Diehm  , van den Berg  , Schnyder  , Bühler  , Willenberg  , Widmer  , Mohaupt  , Baumgartner
Published: May 2010

Background: Vascular access patency is of vital importance for patients requiring haemodialysis. This analysis validates potential risk factors and benefits in patients undergoing vascular access procedures. Patients and methods: Vascular access procedures performed over a two-year period were retrospectively analysed. Clinical data and concomitant medication were retrieved from files as were surgical data following a standardized data capture sheet. Outcome parameters were primary (PP) and secondary patency (SP) as well as freedom from repeated revascularization. Minimal follow-up with functioning access was 679 days. Results: During the observation period, 244 patients (mean age 62.2 ± 0.9 years, 60.7 % male patients, 36.1 % pre-emptive, 31.1 % late referral) underwent vascular accesses procedures. PP and SP were 35.6 % and 45.6 %, respectively, at 540 days. Presence of diabetes mellitus was associated with decreased PP (OR: 0.6, 95 %-CI: 0.3 - 1.0) and SP (OR: 0.4, 95 %-CI: 0.2 - 0.7), whereas female gender was associated with lower SP (OR: 0.6, 95 %-CI: 0.3 - 0.9) and freedom from repeated revascularization rates (OR: 0.6, 95 %-CI: 0.3 - 1.0). In contrast, presence of hyperparathyreoidism was associated with higher SP (OR: 1.7, 95 %-CI: 1.0 - 3.0) and freedom from repeated revascularization (OR: 1.7, 95 %-CI: 1.0 - 3.0) rates. Conclusions: Haemodialysis access performs worst in patients with diabetes mellitus and in women. The benefit of hyperparathyroidism should be interpreted as hypothesis generating.
Long-term follow-up of patients with popliteal artery entrapment syndrome treated by endoluminal revascularization
Authors: Meier  , Schneider  , Amann-Vesti
Published: May 2010

The popliteal artery entrapment syndrome (PAES), a rare cause for leg ischemia, is usually treated by surgical removal of the compressing structure and either venous bypass or interposition graft. However, endovascular revascularization followed by surgery to release the artery has been reported as a feasible alternative. So far long-term results of this approach are not known. We report the follow-up of three patients with PAES and thrombotic occlusion of the popliteal and calf arteries treated by local lysis, percutaneous thrombembolectomy and angioplasty followed by musculotendinous dissection. One patient had an uneventful follow-up of 11 years while the second patient developed a popliteal aneurysm four months after the index procedure. In the third patient, angioplasty of a stenosis of the popliteal artery was performed after two years. However, occlusion of the artery occurred two years later due to a small popliteal aneurysm. Endovascular revascularization followed by surgical release of the artery may be a viable alternative in the treatment of PAES especially in cases with distal embolization. However, careful follow-up by duplex ultrasound is mandatory because of the high risk of reocclusion or development of a popliteal aneurysm.
Proximal lower limb vein thrombosis following vipera berus hand bite
Authors: Gary  , Prüller  , Froehlich  , Werner  , Hafner  , Brodmann
Published: May 2010

Vipera berus has a wide geographical distribution throughout Central and Northern Europe. The symptoms after a bite usually are mild, life threatening symptoms are mainly described in children. We describe a case of popliteal vein thrombosis of the right leg after systemic envenoming with Vipera berus venom after a bite in the right hand by a female Vipera berus in the alpine region of Styria, Austria. Changes of the plasmatic coagulation system were obvious in our patient. These changes were due to an activation of the coagulation system and might be the reason for the thrombotic event in this usually healthy young male person.
Schilddrüsenknoten – Welche Abklärungsschritte sind sinnvoll?
Authors: Slahor  , Stettler  , Christ
Published: May 2010

Schilddrüsenknoten sind häufig, die Prävalenz ist altersabhängig und im Ultraschall deutlich höher als bei der klinischen Palpation. Bei der Abklärung eines Schilddrüsenknotens sollen zwei Aspekte berücksichtigt werden, einerseits die Dignität, andrerseits die Funktion. Die Schilddrüsensonographie ist der erste Abklärungsschritt bei Patienten mit palpablem Schilddrüsenknoten. Die weiteren Abklärungsschritte richten sich nach der Knotengrösse und dem TSH-Wert. Bei euthyreoter Stoffwechsellage wird eine Feinnadelpunktion (Zytologie) ab einer Knotengrösse von 1–1.5 cm empfohlen (bereits bei kleineren Knoten, wenn zusätzliche Risikofaktoren für ein Schilddrüsenkarzinom vorliegen). Ab einer Knotengrösse von 4 cm wird direkt die operative Entfernung mit Histologieuntersuchung des Knotens empfohlen. Bei Abwesenheit von zusätzlichen Risikofaktoren empfiehlt sich bei Schilddrüsenknoten eine klinische und sonographische Verlaufskontrolle nach 6–12 Monaten, bei Symptomen oder Knotenwachstum entsprechend früher.
Summer high‐latitude mesospheric observations of supersonic bursts and O(1S) emission rate with the UARS WINDII instrument and the association with sprites, meteors, and lightning
Authors: Lee Y.‐S. , Shepherd G. G.
Published: May 2010

Supersonic neutral velocities, called supersonic bursts, are observed in localized regions lasting for over 8 s of enhanced O(1S) emission rate for tangent altitudes of 73–80 km during summer daytime by the Wind Imaging Interferometer (WINDII) on board the UARS satellite; the occurrence rate is 40% (≥500 m s−1) for latitudes above 65°N. These bursts are proposed to be produced by accelerated electrons and ions in a strong electric field. Theory suggests that an electric field of 45 V m−1 is required to generate a typical supersonic velocity of 750 m s−1 forced by ion‐neutral collisions at 82 km, the altitude at which polar mesospheric clouds occur. Coincidences in space and time between supersonic velocity profiles and space‐based lightning detection observed at a wavelength of 777.4 nm were found in a limited number of cases in high‐latitude summer, a region for which the lightning detection has the highest occurrence frequency (2–3.5%) and optical energy (1 J m−2 sr−1μm−1) as a function of month and latitude. The electric field must have sufficient energy to generate atomic emission features, more than for sprites and comparable with tropospheric lightning. Support for the existence of supersonic bursts at high latitude is provided through the observation of “chirps” in infrasound emissions which frequently occur in the absence of tropospheric lightning.
Mechanisms governing sea surface temperature anomalies in the eastern tropical Pacific Ocean associated with the boreal winter Madden‐Julian Oscillation
Authors: Lucas Lisanne E. , Waliser Duane E. , Murtugudde Raghu
Published: May 2010

The study objective is to explore the relationship between the Madden‐Julian Oscillation (MJO) and intraseasonal sea surface temperature (SST) variability in the eastern tropical Pacific Ocean. Previous studies have illustrated the connection between MJO and the production of zonally large (>2000 km), persistent (∼weeks) SST anomalies. Those studies suggested that vertical processes, such as advection and entrainment, forced remotely by winds in the western Pacific (via Kelvin waves) may be the mechanism controlling SST changes. To overcome limitations in situ observations (e.g., sparse and missing data/quantities) and to develop a more comprehensive physical understanding, this study examines the relationship using an ocean general circulation model. A simulation was conducted in which the model was forced by idealized MJO conditions constructed from observed forcing fields. Analysis of the model simulation shows an equatorial Kelvin wave initiated in the western Pacific Ocean. However, analysis of the model's mixed layer temperature heat budget shows that in the eastern Pacific meridional advection plays the major role in the sea surface temperature change, 61.8% of the warming phase and 70.7% of the cooling phase percent heat budget. Zonal advection is the second most important term to the warming phase (20.5%) with the vertical advection and mixing term being second for the cooling phase (37.6%). In addition, the results indicate that the primary component of the meridional advection is the advection of the mean meridional temperature gradient by MJO‐forced meridional current anomalies. The implications and caveats of these results are discussed in relationship to results in prior studies.
Variations of δ18O in rainwater from southwestern Oregon
Authors: Ersek Vasile , Mix Alan C. , Clark Peter U.
Published: May 2010

We examine the relation between δ18O in rainwater collected in southwestern Oregon and climate variables including temperature, parcel trajectory, precipitation amount, and specific humidity. Local surface air temperature at the time of sample collection explains a large proportion of δ18O variability, suggesting that paleoclimatic archives that are related to rainfall δ18O should be useful for qualitative temperature reconstructions. Models of Rayleigh distillation of air masses originating in the North Pacific can broadly constrain the observed isotopic variability in southwestern Oregon. Results from a Hybrid Single‐Particle Lagrangian Integrated Trajectory Model suggest that recent parcel pathways have little influence on the isotopic composition of precipitation collected at our site. We also find no significant relation between rainfall δ18O and precipitation amount. Changes in specific humidity along the parcel tracks, however, indicate that the water vapor exchange of the air mass with the underlying ocean influenced the isotopic composition of the most enriched samples.
Mesoscale variations of sea surface temperature and ocean color patterns at the Mid‐Atlantic Bight shelfbreak
Authors: He Ruoying , Chen Ke , Moore Timothy , Li Mingkui
Published: May 2010

Concurrent sea surface temperature (SST) and color observations obtained by MODIS (Moderate Resolution Imaging Spectra‐radiometer) provide an excellent opportunity to investigate simultaneous mesoscale variations in SST and surface pigment at the Mid‐Atlantic Bight (MAB) shelf‐break. Cloud‐free MODIS images that clearly reveal mesoscale signals are used to estimate the dominant spatial scales of MAB shelfbreak water properties. Along‐shelfbreak decorrelation scales for SST and surface pigment are 45 and 40 km, respectively, whereas the across‐shelfbreak scales are much shorter, ranging from 19 km for SST to 25 km for pigment. The shelfbreak SST and surface pigment are generally inversely correlated. Cold (warm) SST corresponds to high (low) pigment concentration. Mesoscale variations account for 30% of the total variance in shelfbreak SST. For the shelfbreak surface pigment, the mesoscale variation is much larger, reaching 60–90% of its total variance.
Decadal variability of the Pacific subtropical cells and their influence on the southeast Indian Ocean
Authors: Feng Ming , McPhaden Michael J. , Lee Tong
Published: May 2010

Historical sea level records reveal that a strengthening of the Pacific subtropical cells (STCs) since the early‐1990's has reversed a multi‐decadal weakening tendency. Stronger STCs correspond to a stronger Leeuwin Current in the southeast Indian Ocean (SEIO) and a stronger Indonesian Throughflow, due to dynamic connections of the Pacific and SEIO through equatorial and coastal waveguides. Multi‐decadal trends of the STCs and their influence on the SEIO have confounded the detection of human induced global change signals in the short instrumental records of the two circulation systems.
Kinase-related protein/telokin inhibits Ca2+-independent contraction in Triton-skinned guinea pig taenia coli
Authors: Shcherbakova Olga V. , Serebryanaya Daria V. , Postnikov Alexander B. , Schroeter Mechthild M. , Zittrich Stefan , Noegel Angelika A. , Shirinsky Vladimir P. , Vorotnikov Alexander V. , Pfitzer Gabriele
Published: May 2010

KRP (kinase-related protein), also known as telokin, has been proposed to inhibit smooth muscle contractility by inhibiting the phosphorylation of the rMLC (regulatory myosin light chain) by the Ca2+-activated MLCK (myosin light chain kinase). Using the phosphatase inhibitor microcystin, we show in the present study that KRP also inhibits Ca2+-independent rMLC phosphorylation and smooth muscle contraction mediated by novel Ca2+-independent rMLC kinases. Incubating KRP-depleted Triton-skinned taenia coli with microcystin at pCa>8 induced a slow contraction reaching 90% of maximal force (Fmax) at pCa 4.5 after ~25 min. Loading the fibres with KRP significantly slowed down the force development, i.e. the time to reach 50% of Fmax was increased from 8 min to 35 min. KRP similarly inhibited rMLC phosphorylation of HMM (heavy meromyosin) in vitro by MLCK or by the constitutively active MLCK fragment (61K-MLCK) lacking the myosin-docking KRP domain. A C-terminally truncated KRP defective in myosin binding inhibited neither force nor HMM phosphorylation. Phosphorylated KRP inhibited the rMLC phosphorylation of HMM in vitro and Ca2+-insensitive contractions in fibres similar to unphosphorylated KRP, whereby the phosphorylation state of KRP was not altered in the fibres. We conclude that (i) KRP inhibits not only MLCK-induced contractions, but also those elicited by Ca2+-independent rMLC kinases; (ii) phosphorylation of KRP does not modulate this effect; (iii) binding of KRP to myosin is essential for this inhibition; and (iv) KRP inhibition of rMLC phosphorylation is most probably due to the shielding of the phosphorylation site on the rMLC.
Mutation of outer-shell residues modulates metal ion co-ordination strength in a metalloenzyme
Authors: Foo Jee-Loon , Jackson Colin J. , Carr Paul D. , Kim Hye-Kyung , Schenk Gerhard , Gahan Lawrence R. , Ollis David L.
Published: May 2010

The metal ion co-ordination sites of many metalloproteins have been characterized by a variety of spectroscopic techniques and small-molecule model systems, revealing many important insights into the structural determinants of metal ion co-ordination. However, our understanding of this fundamentally and practically important phenomenon remains frustratingly simplistic; in many proteins it is essentially impossible to predict metal ion specificity and the effects of remote ‘outer-shell’ residues on metal ion co-ordination strength are also poorly defined. This is exemplified by our inability to explain why metalloenzymes with identical metal ion co-ordination spheres, such as the closely related orthologues of bacterial PTE (phosphotriesterase) from Agrobacterium radiobacter and Pseudomonas diminuta, display different metal ion specificity and co-ordination strength. In the present study, we present a series of PTE variants that all possess identical metal ion co-ordination spheres, yet display large differences in their metal ion co-ordination strength. Using measurement of the rates of metal ion dissociation from the active site alongside analysis of structural data obtained through X-ray crystallography, we show that ‘outer-shell’ residues provide essential support for the metal ion ligands, in effect buttressing them in their optimal orientation. Remote mutations appear to modulate metal ion interactions by increasing or decreasing the stabilizing effects of these networks. The present study therefore provides a description of how the greater protein fold can be modified to ‘tune’ the strength of metal ion co-ordination and metal ion specificity, as well as reinforcing the concept of proteins as ensembles of conformational states with unique structures and biochemical properties.
Mössbauer spectroscopy and magnetic susceptibility studies of Cr–Al substituted strontium ferrite particles
Authors: Ghasemi Ali , Šepelák Vladimir , Liu Xiaoxi , Morisako Akimitsu
Published: May 2010

Substituted strontium ferrite SrFe12−xCrx/2Alx/2O19 (x=0–2.5) was prepared by sol-gel method. Ac susceptometer, and F57e Mössbauer spectroscopy were used to analyze the structure, static and dynamic magnetic properties of the prepared samples. Mössbauer spectra show that Al–Cr ions preferentially occupy the 12k sites. Magnetic dynamics of the samples was studied by the measurement of ac magnetic susceptibility versus temperature at different frequencies and dc magnetic fields. A frequency-dependent peak was observed in ac magnetic susceptibility versus temperature, which is well described by Vogel–Fulcher model. It was observed that with increasing substitutions, blocking temperature is decreased.
Heating characteristics of ferromagnetic iron oxide nanoparticles for magnetic hyperthermia
Authors: Kita Eiji , Hashimoto Shinji , Kayano Takeru , Minagawa Makoto , Yanagihara Hideto , Kishimoto Mikio , Yamada Keiichi , Oda Tatsuya , Ohkohchi Nobuhiro , Takagi Toshiyuki , Kanamori Toshiyuki , Ikehata Yoshio , Nagano Isamu
Published: May 2010

Heating characteristics of Fe oxide nanoparticles designed for hyperthermia were examined. Samples with coercive forces from 50 to 280 Oe(codoped magnetite) were produced with a coprecipitation technique following by hydrothermal reaction. The maximum specific loss powers (SLPs) of 420 W/g was obtained at 117 kHz (640 Oe) for a dispersant sample with coercive force of 280 Oe (ATH9D). SLPs measured on dry powder samples at 17 kHz and measured at 117 kHz on dispersant samples were compared. The measured SLP amplitudes are lower for 17 kHz and higher for 117 kHz than those expected from ferromagnetic dc minor loops. For the 117 kHz case, friction of particles in a carrier fluid (similar mechanism to Brown relaxation in superparamagnetic dispersant samples) is considered to contribute to the heating mechanism.
Influence of resistance area product on the noise in a tunneling magnetoresistive read head
Authors: Abe Tetsuya , Endo Yasushi , Yamaguchi Masahiro
Published: May 2010

This paper describes the noise spectra of tunneling magnetoresistive (TMR) heads as a function of both the dc bias current and the external magnetic field in order to understand the influence of resistance area (RA) product on the noise in the TMR head. The strong noise spectral peak appears in the frequency range between 4.0 and 7.0 GHz, which is ascribed to the thermally excited magnetization fluctuation noise (thermal mag-noise) originated from the free layer. This peak intensity, linewidth, and noise power strongly depend on both the dc bias current and the external magnetic field. These features mean that the peak is strongly influenced by the spin torque (ST) with increasing dc bias current in case that the magnetization of the free and reference layers is nearly antiparallel to each other. In addition, this noise power markedly strengthens with the RA and the size reductions in the TMR head. On the basis of this result, it is pointed out that the influence of the ST on the thermal mag-noise is markedly enhanced since the dc bias current density increases with both the RA and size reductions in the TMR head.
Transmittance spectra in one-dimensional superconductor-dielectric photonic crystal
Authors: Lee Huang-Ming , Wu Jong-Ching
Published: May 2010

Transmission characteristics at visible light range in a one-dimensional superconductor-dielectric photonic crystal have been numerically analyzed based on the finite element method using COMSOL RF module. The two-fluid model and wavelength-dependent dispersion formula were adopted to describe the optical response of the low temperature superconducting system. The simulation results clearly reveal a cutoff frequency or a photonic band gap that can be manipulated through the thicknesses of the superconductor and dielectric layers as well as the ambient temperature of the system. It is observed that the shift of cutoff frequency becomes more noticeable by adjusting the thickness of the superconductor layer than that of the dielectric one. Furthermore, the cutoff frequency becomes very sensitive when the system temperature is tuned to close vicinity of the critical temperature of the superconductor.
Magnetostriction and magnetic structure in annealed recrystallization of strain-forged ferromagnetic shape memory Fe–Pd–Rh alloys
Authors: Lin Yin-Chih , Lee Hwa-Teng
Published: May 2010

Bulk ferromagnetic shape memory Fe68–Pd30–Rh2 and Fe66–Pd30–Rh4 (at. %) alloys were strain-forged to produce a 35%–40% reduction in thickness. The reduced alloys were thermally annealed at 950–1050 °C for various times to induce recrystallization. The magnetostriction test demonstrated that the grain size reduction of recrystallization had a direct influence on the magnetic properties of the materials. The magnetostrictive strain measurements revealed that the strain-forged metal treated with thermal recrystallization to induce the fine-grained structure had a higher magnetostriction as well as a higher magnetostrictive susceptibility (Δλ∥s/ΔH). It was also found that at room temperature, the saturation magnetostriction (λs=77×10−6) of the fine-grained Fe–Pd–Rh alloys strain-forged with thermal recrystallization was higher than that of those without grain size reduction (λs=50–56×10−6), where λs is (2/3)[λ∥s−λ⊥s]. In addition, with the magnetic field applied perpendicular to the sample’s longitude, the fine-grained Fe–Pd–Rh material contracted by as much as λ⊥s=−36×10−6. This value is about three times higher than that of alloys without grain size reduction. Microstructure investigation indicated that a magnetic applied field normal to the sample’s longitude caused high contraction (λ⊥s) of the fine-grained Fe–Pd–Rh alloys, which could be ascribed mainly to the grain refinement as well as deformation twins or microtwins (transformation and transverse twins). The study demonstrates that the magnetostrictive strains of Fe–Pd–Rh alloys induced in the L10 martensite by the magnetic field can be attributed to the reorientation of the L10 martensite twin structures.
The third-order law for magnetohydrodynamic turbulence with shear: Numerical investigation
Authors: Wan M. , Servidio S. , Oughton S. , Matthaeus W. H.
Published: May 2010

The scaling laws of third-order structure functions for isotropic, homogeneous, and incompressible magnetohydrodynamic (MHD) turbulence relate the observable structure function with the energy dissipation rate. Recently [Wan et al. Phys. Plasmas 16, 090703 (2009)], the theory was extended to the case in which a constant velocity shear is present, motivated by the application of the third-order law to the solar wind. We use direct numerical simulations of two-dimensional MHD with shear to confirm this new generalization of the theory. The presence of the shear effect broadens the circumstances in which the law can be applied. Important implications for laboratory and space plasmas are discussed.