bluuebunny/crossref_metadata_2025 huggingface dataset:
Gallstone‐induced acute pancreatitis
Authors: Kimura Yasutoshi , Arata Shinju , Takada Tadahiro , Hirata Koichi , Yoshida Masahiro , Mayumi Toshihiko , Hirota Masahiko , Takeda Kazunori , Gabata Toshifumi , Amano Hodaka , Wada Keita , Sekimoto Miho , Hirota Morihisa , Yokoe Masamichi , Kiriyama Seiki , Ito Tetsuhide
Published: December 2009

In the care of acute pancreatitis, a prompt search for the etiologic condition of the disease should be conducted. A differentiation of gallstone‐induced acute pancreatitis should be given top priority in its etiologic diagnosis because it is related to the decision of treatment policy. Examinations necessary for diagnosing gallstone‐induced acute pancreatitis include blood tests and ultrasonography. Early ERCP/ES should be performed in patients with gallstone‐induced acute pancreatitis if a complication of cholangitis and a prolonged passage disorder of the biliary tract are suspected. The treatment for bile duct stones with the use of ERCP/ES alone is not recommended in cases of gallstone‐induced pancreatitis with gallbladder stones. Cholecystectomy for gallstone‐induced acute pancreatitis should be performed using a laparoscopic procedure as the first option as soon as the disease has subsided.
Treatment strategy for acute pancreatitis
Authors: Wada Keita , Takada Tadahiro , Hirata Koichi , Mayumi Toshihiko , Yoshida Masahiro , Yokoe Masamichi , Kiriyama Seiki , Hirota Masahiko , Kimura Yasutoshi , Takeda Kazunori , Arata Shinju , Hirota Morihisa , Sekimoto Miho , Isaji Shuji , Takeyama Yoshifumi , Gabata Toshifumi , Kitamura Nobuya , Amano Hodaka
Published: December 2009

When a diagnosis of acute pancreatitis (AP) is made, fundamental medical treatment consisting of fasting, intravenous (IV) fluid replacement, and analgesics with a close monitoring of vital signs should be immediately started. In parallel with fundamental medical treatment, assessment of severity based on clinical signs, blood test, urinalysis and imaging tests should be performed to determine the way of treatment for each patient. A repeat evaluation of severity is important since the condition is unstable especially in the early stage of AP. At the time of initial diagnosis, the etiology should be investigated by means of blood test, urinalysis and diagnostic imaging. If a biliary pancreatitis accompanied with acute cholangitis or biliary stasis is diagnosed or suspected, an early endoscopic retrograde cholangiopancreatography with or without endoscopic sphincterotomy (ERCP/ES) is recommended in addition to the fundamental medical treatment. In mild cases, the fundamental medical treatment should be continued until clinical symptom is subsided with normal laboratory data. In cases with severe acute pancreatitis (SAP) referral should be considered to medical centers experienced in the treatment of SAP, and intensive care is recommended for preventing both organ failures and infectious complications. Hemodynamic stabilization with vigorous fluid resuscitation, respiratory support and antibiotics are the major parts of intensive care in the early period of SAP. Continuous hemodiafiltration (CHDF) and continuous regional arterial infusion (CRAI) of protease inhibitor and/or antibiotics may be effective to improve pathophysiology of AP especially in the early stage of the disease. In the late stage of AP, infectious complications are critical. If an infectious complication is suspected based on clinical signs, blood test and imaging, a fine needle aspiration (FNA) is recommended to establish a diagnosis. The accuracy of FNA is reported to be 89 ~ 100%. For patients with sterile pancreatitis, non‐surgical treatment should be indicated. For patients with infected pancreatic necrosis, therapeutic intervention either by percutaneous, endoscopic, laparoscopic or surgical approach are indicated. The most preferred surgical intervention is necrosectomy, however, non‐surgical treatment with antibiotics is still the treatment of choice if the general condition is stable. Necrosectomy should be performed as late as possible. For patients with pancreatic abscess, drainage is recommended.
The effect of learning and search images on predator–prey interactions
Authors: Ishii Yumiko , Shimada Masakazu
Published: December 2009

In dealing with the spatial and temporal variability of prey species, predators may be able to forage optimally if they have flexible and rapid behavioral plasticity rather than predetermined responses. For predators that learn to focus attention on the cryptic prey type most frequently encountered during recent searching (termed a “search image”), rare prey types may be overlooked because of a focus on more common prey. Search imaging reflects biased searching for one of a number of available prey types, and has been studied widely in birds and mammals. Here we discuss the significant implications of this phenomenon for insect predator–prey systems, particularly with respect to parasitic wasps searching for host species using learned olfactory cues. We (1) review studies about perceptual development through individual ontogeny, (2) define the term “search image” and discuss the cognitive mechanisms involved in search‐image formation, (3) discuss the role of search images and frequency‐dependent predation as a proximate mechanism in the maintenance of prey diversity, (4) examine data on host–parasitoid olfactory search imaging, and (5) conclude by identifying important research areas for future studies in the field of olfactory search images.
Prey selection and prey preferences of spotted hyenas Crocuta crocuta in the Etosha National Park, Namibia
Authors: Trinkel Martina
Published: December 2009

The feeding ecology of the spotted hyena Crocuta crocuta was studied in the central and eastern part of the Etosha National Park, Namibia. Hyenas mainly hunted migratory ungulates such as springbok Antidorcas marsupialis, zebra Equus burchelli, and blue wildebeest Connochaetes taurinus, but also resident species such as the greater kudu Tragelaphus strepsiceros and gemsbok Oryx gazella. There were, however, major differences in the species most frequently killed by hyenas in central and eastern Etosha. The preferred prey species of spotted hyenas in central Etosha was springbok, whereas regarding the abundance of zebra and wildebeest, these two species were rather avoided. In contrast, the prey species preferred by hyenas in eastern Etosha was kudu. Zebra and gemsbok were taken in proportion to their abundance, whereas wildebeest and springbok seemed to be rather avoided. Differences in prey selection and preferences were also reflected in differences in hunting group sizes. In eastern Etosha, where spotted hyenas frequently hunted larger prey, hunting group sizes were significantly larger compared to those in the center of the park.
Challenges for Large Orthopaedic Hospitals Worldwide—An ISOC Position Statement
Authors: Sussmann Patrick S. , Simmen Beat R. , Goldhahn Joerg , Sculco Thomas P.
Published: December 2009

Since the foundation of the International Society of Orthopaedic Centers in 2006, the group has continued to grow, with currently 11 members worldwide. During the 2008 annual meeting, the bylaws and mission of the group were approved as well as the acceptance of two additional members. Strict inclusion criteria were established to keep the group both small and effective. The goal of the 2008 meeting and this position statement is to identify current challenges in both research and education for large-volume orthopedic hospitals and to discuss possible approaches and solutions.
Characterization of Soybean Proteins–Fatty Acid Systems
Authors: Quiroga A. , Añón María C. , Puppo María Cecilia
Published: December 2009

This study investigated, with the aim of obtaining more flexible and hydrophobic proteins, the attachment of a low chain fatty acid, decanoic acid, to alkaline and acid soybean proteins; and the effect on their conformational and functional properties. The extent of esterification was high at acid pH and also increased with heating. Protein solubility decreased, mainly at the highest temperature (60 °C). Increasing levels of fatty acid formed a complex with a slightly more soluble protein with less surface hydrophobicity. Esterified proteins exhibited aggregation/dissociation and were stabilized by different protein subunits belonging to 7S and 11S globulins. Denaturation of these soybean protein fractions (7S and 11S) were also detected in these complexes. The highest level of fatty acids favored formation of a more ordered protein structure.
Can vitamin C induce nucleotide excision repair? Support from in vitro evidence
Authors: Bevan Ruth J. , Mistry Nalini , Patel Parul R. , Halligan Eugene P. , Dove Rosamund , Lunec Joseph
Published: December 2009

Intracellular vitamin C acts to protect cells against oxidative stress by intercepting reactive oxygen species (ROS) and minimising DNA damage. However, rapid increases in intracellular vitamin C may induce ROS with subsequent DNA damage priming DNA repair processes. Herein, we examine the potential of vitamin C and the derivative ascorbate-2-phosphate (2-AP) to induce a nucleotide excision repair (NER) response to DNA damage in a model of peripheral blood mononuclear cells. Exposure of cells to elevated levels of vitamin C induced ROS activity, resulting in increased levels of deoxycytidine glyoxal (gdC) and 8-oxo-2′-deoxyguanosine (8-oxodG) adducts in DNA; a stress response was also induced by 2-AP, but was delayed in comparison to vitamin C. Evidence of gdC repair was also apparent. Measurement of cyclobutane thymine–thymine dimers (T < >T) in DNA and culture supernatant were included as a positive marker for NER activity; this was evidenced by a reduction in DNA and increases in culture supernatant levels of T < >T for vitamin C-treated cells. Genomics analysis fully supported these findings confirming that 2-AP, in particular, induced genes associated with stress response, cell cycle arrest, DNA repair and apoptosis, and additionally provided evidence for the involvement of vitamin C in the mobilisation of intracellular catalytic Fe.
Review of recent research (2002–2009) on applied linguistics and language teaching with specific reference to L2 German (part 2)
Authors: Eckerth Johannes , Tschirner Erwin
Published: December 2009

Angesichts gegenwärtiger Entwicklungen innerhalb des Lehr- und Forschungsgebietes Deutsch als Fremdsprache (DaF)/German as a Foreign Language (GFL) als auch im Lichte politischer Entwicklungen, die weiterhin einen deutlichen Einfluss darauf ausuüben, wie DaF verbreitet, gelehrt, gelernt und evaluiert wird, scheint eine kritische Bewertung von im Zeitraum 2002–2009 veröffentlichter DaF-Forschungsbeitraäge zeitgemäß und angebracht. Empirische Forschung zu Deutsch als Fremdsprache versteht sich nicht als isoliertes Forschungsfeld, das primär oder gar ausschließlich mit seinen kulturell, strukturell und politisch bedingten Besonderheiten beschäftigt ist, sondern vielmehr als ein substantieller Beitrag zur internationalen Zweitsprachenerwerbsforschung, Fremdsprachenunterrichtsforschung und Angewandten Linguistik. Im Mittelpunkt des zweiten Teils unseres Forschungsüberblicks stehen Beiträge die den Einfluss kontextueller Faktoren und methodisch-didaktischer Entscheidungen auf die Bedingungen, den Prozess und das Resultat fremdsprachlichen Lernens untersuchen. Űberlegungen zu alternativen epistomologischen Grundannahmen sowie einen Ausblick auf die gegenwärtige wie zukünftige Sprachenpolitik beschließt den zweiten Teil unseres Forschungsüberblicks.

This review of research on the learning, teaching, and assessment of L2 German may be particularly timely due to developments from within the profession as well as recent political changes which continue to have a strong bearing on the way L2 German is promoted, learned, taught and assessed. Far from representing an isolated field of research concerned only with the requirements and policies of its own subject matter, empirical research into L2 German now contributes greatly to the wider field of research on L2 acquisition, applied linguistics, and foreign language teaching. Part 2 of our review covers research concerned with the impact of contextual factors and pedagogical choices on learning conditions, learning processes, and learning outcomes. A consideration of competing epistemological frameworks as well as an outlook on current and future language policy concludes the review.
Skeletons in Motion, Ancestors in Action: Early Mesolithic Collective Tombs in Southern Belgium
Authors: Cauwe Nicolas
Published: December 2009

Collective tombs are a characteristic feature of Neolithic societies of Western Europe. Some recent studies have suggested that they originated from an earlier tradition of individual burials at the Mesolithic–Neolithic transition. The concept of collective burial involving movement and manipulation of bodies and body parts is, however, entirely different. The former tries to preserve the integrity of the bodies and does not acknowledge the stages of metamorphosis of the corpse. The latter by contrast involves observation and assistance in the dissolution of the body. Recent discoveries of Early Mesolithic collective tombs in southern Belgium have underlined the fact that collective burials are far from restricted to Neolithic contexts in Western Europe. They themselves, however, are not merely a potential point of origin for Middle and Late Neolithic collective tombs but form part of a long-standing tradition reaching back into the Upper Palaeolithic.
Suffering as a Consideration in Ethical Decision Making
Authors: Loewy Erich H.
Published: December 2009

Erhics committees and ethics consultants are becoming more involved in helping individuals make decisions and in advising institutions and legislatures about drafting policy. The role of these committees and consultants has been acknowledged in law, and their function is generally considered salutory and helpful. Ethics consultants and committees, furthermore, play a critical role in educating students and members of the hospital community and the public at large. More over, many ethicists engage in scholarky activities to expand the boundaries of our understanding and, in turn, facilitate our capacity for helping. The role of the ethicist and of the ethics committee is thus manifold. Ethics committees and ethics consultants somehow “in competition” is a mistaken notion: when ethics committees, ethics consultants, and the community work smoothly together, much good can be accomplished.
Ethics Committees and Their Framework: Commentary on “Suffering as a Consideration in Ethical Decision Making”
Authors: Heubel Friedrich
Published: December 2009

I find myself in a strange position writing a commentary to an article on ethics committees because in Germany, ethics committees in the American sense do not exist. What we call Ethikkommission are present in every German faculty of medicine and would be called institutional review boards (IRB) in the United States; committees that review research projects of faculty members with respect to ethical standards. So i most consult my imagination rather than my experience about what really happens in Americal ethics committees. There are only two things. I perhaps can fall back on to simultaneously inspire and bridle my imagination. I have been sitting for 5 years on the IRB of our faculty and have been giving ethics seminars and case discussions to students for more than 10 years. Ethics is an optional subject in Germany and attracts the more sensitive and thoughtful students. Perhaps the intellectual process generating itself in those groups in some ways similar to that occurring in ethics committees. As for the rest, I hope to profit from the so-called unprejudiced perspective of the foreigner. I agree with a great deal of Loewy's descriptions and even with suffering as a principle, but I have some doubt whether that occurring in ethics committees. As for the rest, I hope with a reat deal of Loewy's descriptions and even with suffering as a principle, but I have some doubt whether that principle has the highest possible generality.
New Voices ask to be Heard in Bioethics
Authors: Phillips Donald F.
Published: December 2009

The shape, function, and dynamic of the field of bioethics is in constant flux, and nowhere is this more apparent than at gatherings of those immersed in th discipline. This section presents coverage and commentary on conferences and settings where voices out-side the mainstream of biomedical ethics can be heard.
Surgical Care of the HIV-Infected Patient: A Moral Imperative
Authors: Schecter William P
Published: December 2009

An increasing number of HIV-infected patients require surgical care. Many surgeons, regardless of their venue of practice, would prefer not to treat HIV-infected patients.1 The reasons for this attitude differ from individual to individual but include the fear of contracting an incurable fatal illness, a desire to avoid interaction with homosexuals and intravenous drug users, and fears that occupationally acquired HIV infection would result in restriction of clinical privileges and loss of income.2,3 At the same time, many individuals, institutions, and professional organizations have affirmed the obligation of all healthcare workers, including surgeons, to care for patients without regard to their HIV status.4-6 This article explores the nature of this obligation from the perspective of a clinical surgeon working in an inner city hospital.
Decisions Near the End of Life: Resources Allocation Implications for Hospitals
Authors: Hofmann Paul B.
Published: December 2009

Heathcare spending, which was almost 13% of the gross national product last year, is estimated to jump to 14% in 1992. For the first time, hosital expenditures are projected to exceed $300 biilion, representing over 38% of the nation's total healthcare bill. In an effort to reduce federal and state budget deficits and to stimulate institutional cost containment, Medicare and Medicaid officials are becoming even more parsimonious in negotitation reimbursement levels.
Beneficence, Scientific Autonomy, and Self-Interest: Ethical Dilemmas in Clinical Research
Authors: Pellegrino Edmund D.
Published: December 2009

The ethics of clinical research may be viewed from three different perspectives: the process of acquiring new knowledge, the moral use of the knowledge acquired, and the ethics of the investigator seeking this knowledge.
Communication about Advance Directives: Are Patients Sharing Information with Physicians?
Authors: Yellen Suzanne B. , Burton Laurel A. , Elpern Ellen
Published: December 2009

Historically, patients have deferred to physicians′ judgments about appropriate medical care, thereby limiting patient participation in treatment decisions. In this model of medical decision making, physicians typically decided upon the treatment plan. Communication with patients focused on securing their cooperation in accepting a treatment decision that essentially had already been made.
In a Lonely Place? Social Networks, Job Seeking and the Experience of Long-Term Unemployment
Authors: Lindsay Colin
Published: December 2009

Combating long-term unemployment remains a central strand of policies to promote social and labour market inclusion. One area of increasing concern is that the long-term unemployed (and especially those residing in disadvantaged communities) can find themselves isolated from the diverse social networks that can contribute to effective job seeking. This article draws on interviews conducted with 220 job seekers in two areas of high unemployment within the city of Glasgow to investigate: whether long-term unemployed people in these areas struggle to access social networks for job search; and the extent to which long-term unemployment is in itself associated with a more general erosion of social/community relations and a withdrawal from what has been termed the ‘tertiary sphere of sociability’. The article concludes with a discussion of the potential role for social policy in seeking to help the long-term unemployed and other job seekers to develop and broaden social networks and activities.
Looking Again at Discipline and Gender: Theoretical Concerns and Possibilities In the Study of Anti-Social Behaviour Initiatives
Authors: Carr Helen
Published: December 2009

This paper suggests that current theoretical approaches to the contemporary governance of anti-social behaviour have certain limits which may be overcome by emphasis on its gendered dimensions. It argues that the paradoxical relationship that women have with the state may prove a fruitful starting point. Third way ideologies recognise and respond to the vulnerabilities of the ordinary citizen. The governance at a distance that they practice means that the responsibility for reassuring citizens falls disproportionately on women who have had a historical role in managing the anxieties provoked by proximity. Yet women's acknowledged vulnerability means that this is an incoherent strategy.
Terror Crime Prevention: Constructing Muslim Practices and Beliefs as ‘Anti-Social’ and ‘Extreme’ through CONTEST 2
Authors: Spalek Basia , McDonald Laura Zahra
Published: December 2009

This article discusses recent research into engagement and partnership work between Muslim communities and police for the purposes of counter-terrorism. It is argued that asserting a notion of ‘shared values’ as a foundational criterion for choosing which individuals/groups to engage in countering terrorism is strategically flawed. Not only is the notion of ‘values’ overly diffuse and conceptually ill-defined, it is dangerous in its potential to construct even the most normative Muslim practices and beliefs as ‘anti-social’ and ‘extreme’. This is likely to further alienate Muslim communities in general and to exclude those groups with whom the State has so far successfully engaged to counter terrorism. The article further reflects upon engagement and partnership work between police and Muslim minorities perceived as ‘radical’, highlighting how the goal of terror crime prevention can be – and is – shared between police and communities, despite negative and stigmatizing impacts of the ‘War on Terror’.
LOGICS FOR THE RELATIONAL SYLLOGISTIC
Authors: PRATT-HARTMANN IAN , MOSS LAWRENCE S.
Published: December 2009

The Aristotelian syllogistic cannot account for the validity of certain inferences involving relational facts. In this paper, we investigate the prospects for providing a relational syllogistic. We identify several fragments based on (a) whether negation is permitted on all nouns, including those in the subject of a sentence; and (b) whether the subject noun phrase may contain a relative clause. The logics we present are extensions of the classical syllogistic, and we pay special attention to the question of whetherreductio ad absurdumis needed. Thus our main goal is to derive results on the existence (or nonexistence) of syllogistic proof systems for relational fragments. We also determine the computational complexity of all our fragments.
MEASURING THE SIZE OF INFINITE COLLECTIONS OF NATURAL NUMBERS: WAS CANTOR’S THEORY OF INFINITE NUMBER INEVITABLE?
Authors: MANCOSU PAOLO
Published: December 2009

Cantor’s theory of cardinal numbers offers a way to generalize arithmetic from finite sets to infinite sets using the notion of one-to-one association between two sets. As is well known, all countable infinite sets have the same ‘size’ in this account, namely that of the cardinality of the natural numbers. However, throughout the history of reflections on infinity another powerful intuition has played a major role: if a collectionAis properly included in a collectionBthen the ‘size’ ofAshould be less than the ‘size’ ofB(part–whole principle). This second intuition was not developed mathematically in a satisfactory way until quite recently. In this article I begin by reviewing the contributions of some thinkers who argued in favor of the assignment of different sizes to infinite collections of natural numbers (Thabit ibn Qurra, Grosseteste, Maignan, Bolzano). Then, I review some recent mathematical developments that generalize the part–whole principle to infinite sets in a coherent fashion (Katz, Benci, Di Nasso, Forti). Finally, I show how these new developments are important for a proper evaluation of a number of positions in philosophy of mathematics which argue either for the inevitability of the Cantorian notion of infinite number (Gödel) or for the rational nature of the Cantorian generalization as opposed to that, based on the part–whole principle, envisaged by Bolzano (Kitcher).
BENACERRAF’S DILEMMA AND INFORMAL MATHEMATICS
Authors: LAVERS GREGORY
Published: December 2009

This paper puts forward and defends an account of mathematical truth, and in particular an account of the truth of mathematical axioms. The proposal attempts to be completely nonrevisionist. In this connection, it seeks to satisfy simultaneously both horns of Benacerraf’s dilemma. The account builds upon Georg Kreisel’s work on informal rigour. Kreisel defends the view that axioms are arrived at by a rigorous examination of our informal notions, as opposed to being stipulated or arrived at by trial and error. This view is then supplemented by a Fregean account of the objectivity and our knowledge of abstract objects. It is then argued that the resulting view faces no insurmountable metaphysical or epistemic obstacles.
Aerosol remote sensing over the ocean using MSG‐SEVIRI visible images
Authors: Bennouna Y. S. , de Leeuw G. , Piazzola J. , Kusmierczyk‐Michulec J.
Published: December 2009

With its observational frequency of 15 minutes, the Meteosat Second Generation (MSG) geostationary satellite offers a great potential to monitor aerosol transport using Spinning Enhanced Visible and Infra‐Red Imager (SEVIRI) data. To explore this potential, an algorithm for the retrieval of aerosol optical properties has been developed for use over the ocean. It is a multispectral algorithm based on the single‐view algorithm for the Along Track Scanning Radiometer (ATSR‐2) (Veefkind and de Leeuw, 1998) which has been adapted to the corresponding channels of SEVIRI (635 nm, 810 nm and 1640 nm). The SEVIRI Aerosol Retrieval Algorithm (SARA) provides the Aerosol Optical Depth (AOD) for these channels. To illustrate its capabilities, the application of this algorithm to two cases is presented: (1) a forest‐fire smoke plume advected from Spain and Portugal over the Atlantic Ocean in August 2006, and (2) an outbreak of Saharan dust over the Western Mediterranean Sea in February 2006. The results obtained are validated with AERONET ground‐based measurements for two coastal stations, and compared with the retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra and Aqua satellites. The diurnal variations of the aerosol optical depth observed at the AERONET sites are well reproduced, and the spatial patterns retrieved using the SARA algorithm are in reasonable agreement with those observed by MODIS.
Aerobic denitrification in permeable Wadden Sea sediments
Authors: Gao Hang , Schreiber Frank , Collins Gavin , Jensen Marlene M , Kostka Joel E , Lavik Gaute , de Beer Dirk , Zhou Huai-yang , Kuypers Marcel M M
Published: December 2009

Permeable or sandy sediments cover the majority of the seafloor on continental shelves worldwide, but little is known about their role in the coastal nitrogen cycle. We investigated the rates and controls of nitrogen loss at a sand flat (Janssand) in the central German Wadden Sea using multiple experimental approaches, including the nitrogen isotope pairing technique in intact core incubations, slurry incubations, a flow-through stirred retention reactor and microsensor measurements. Results indicate that permeable Janssand sediments are characterized by some of the highest potential denitrification rates (⩾0.19 mmol N m−2 h−1) in the marine environment. Moreover, several lines of evidence showed that denitrification occurred under oxic conditions. In intact cores, microsensor measurements showed that the zones of nitrate/nitrite and O2 consumption overlapped. In slurry incubations conducted with 15NO3− enrichment in gas-impermeable bags, denitrification assays revealed that N2 production occurred at initial O2 concentrations of up to ∼90 μm. Initial denitrification rates were not substantially affected by O2 in surficial (0–4 cm) sediments, whereas rates increased by twofold with O2 depletion in the at 4–6 cm depth interval. In a well mixed, flow-through stirred retention reactor (FTSRR), 29N2 and 30N2 were produced and O2 was consumed simultaneously, as measured online using membrane inlet mass spectrometry. We hypothesize that the observed high denitrification rates in the presence of O2 may result from the adaptation of denitrifying bacteria to recurrent tidally induced redox oscillations in permeable sediments at Janssand.
Hydrography shapes bacterial biogeography of the deep Arctic Ocean
Authors: Galand Pierre E , Potvin Marianne , Casamayor Emilio O , Lovejoy Connie
Published: December 2009

It has been long debated as to whether marine microorganisms have a ubiquitous distribution or patterns of biogeography, but recently a consensus for the existence of microbial biogeography is emerging. However, the factors controlling the distribution of marine bacteria remain poorly understood. In this study, we combine pyrosequencing and traditional Sanger sequencing of the 16S rRNA gene to describe in detail bacterial communities from the deep Arctic Ocean. We targeted three separate water masses, from three oceanic basins and show that bacteria in the Arctic Ocean have a biogeography. The biogeographical distribution of bacteria was explained by the hydrography of the Arctic Ocean and subsequent circulation of its water masses. Overall, this first taxonomic description of deep Arctic bacteria communities revealed an abundant presence of SAR11 (Alphaproteobacteria), SAR406, SAR202 (Chloroflexi) and SAR324 (Deltaproteobacteria) clusters. Within each cluster, the abundance of specific phylotypes significantly varied among water masses. Water masses probably act as physical barriers limiting the dispersal and controlling the diversity of bacteria in the ocean. Consequently, marine microbial biogeography involves more than geographical distances, as it is also dynamically associated with oceanic processes. Our ocean scale study suggests that it is essential to consider the coupling between microbial and physical oceanography to fully understand the diversity and function of marine microbes.
Significant roles of bacteriochlorophylla supplemental to chlorophylla in the ocean
Authors: Jiao Nianzhi , Zhang Fan , Hong Ning
Published: December 2009

Bacteriochlorophylla (BChla)-based phototrophy cannot be ignored in understanding of carbon cycle in the ocean. However, the role of BChla relative to chlorophylla (Chla) along environmental gradients remains unclear. On the basis of the investigations in the Pacific, Indian Oceans and the China Seas, we show that the average contribution of BChla relative to Chla is higher in open-ocean compared with shelf environments, the estimated BChla-based phototrophy could reduce respiratory organic carbon consumption of 2.4% and 5.4% of the primary productions in the shelf and oceanic waters, respectively. This suggests that BChla-based phototrophy has an important role supplemental to Chla-based photosynthesis in the ocean's carbon cycle and would be critical for a marine region to be a sink or a source of atmospheric CO2.
Lentivirus‐modified human umbilical cord mesenchymal stem cells maintain their pluripotency
Authors: Qian Hui , Zhang Xu , Xu Wenrong , Zhu Wei , Cao Huiling , Chen Yuan , Xu Xiaomeng , Wang Mei , Xie Ying , Sun Jing
Published: December 2009

Gene delivery into MSCs (mesenchymal stem cells) has great promise for gene therapy, and lentiviral transduction has recently been shown to be a highly efficient method for gene delivery. Our previous studies indicated that the umbilical cord is a new source of MSCs; however, it was unclear whether the UC‐MSCs (umbilical‐cord‐derived MSCs) would retain their characteristics after LV (lentivirus)‐mediated gene transduction. The aim of the present study is to investigate the feasibility of transducing UC‐MSCs with lentiviral vectors and to determine whether these transduced stem cells would retain their ability to differentiate into different lineages. Herein, we demonstrate that the percentage of EGFP (enhanced green fluorescent protein)‐positive cells increased with the MOI (multiplicity of infection) and the number of transduction cycles. In addition, we observed that the transduced MSCs were capable of differentiating into adipogenic and osteogenic lineages expressing lineage‐specific genes while maintaining high EGFP expression levels. In their undifferentiated state, the UC‐MSCs continued to express both the transgene [EGFP or TNF (tumour necrosis factor)‐Tumstatin] and stem cell markers such as Oct‐4, Nanog, BMI‐1 and nucleostemin. The presence of exogenous antitumour molecule‐coding gene integration was verified by PCR and RT–PCR (reverse transcription–PCR) and also by immunohistochemistry. It was also shown that TNF‐Tumstatin that can be secreted by MSCs has a cytotoxic effect on prostate cancer cells in vitro. These findings suggest that lentiviral transduction may be used to deliver therapeutic genes to human UC‐MSCs and this may have a wide range of applications in gene therapy.
Production of rhamnolipid biosurfactants by Pseudomonas aeruginosa DS10‐129 in a microfluidic bioreactor
Authors: Rahman Pattanathu K. S. M. , Pasirayi Godfrey , Auger Vincent , Ali Zulfiqur
Published: December 2009

A low‐cost μBR (microbioreactor) made from PTFE [poly(tetrafluoroethylene)] was used to cultivate a model organism, Pseudomonas aeruginosa DS10‐129. The progress of bioprocessing was monitored by comparing the growth of the organism in a μBR, a conventional bench scale bioreactor and a shake flask. Under the μBR conditions, the organism produced 23 mg/ml of pyocyanin that had antimicrobial effects against Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas teessidea and Pseudomonas clemancea. Furthermore, it produced a total of 106 μg/ml of effective biosurfactants consisting of dirhamnolipids (RL2) and monorhamnolipids (RL1). The biosurfactants reduced the surface tension of distilled water from 72 to 27.9 mN/m and emulsified kerosene by 71.30%. The pyocyanin and rhamnolipids were produced during the exponential and stationary phases of growth respectively. The results of the μBR were comparable to those obtained using conventional scale methods.
EYA1 mutations associated with the branchio‐oto‐renal syndrome result in defective otic development in Xenopus laevis
Authors: Li Youe , Manaligod Jose M. , Weeks Daniel L.
Published: December 2009

Background information. The BOR (branchio‐oto‐renal) syndrome is a dominant disorder most commonly caused by mutations in the EYA1 (Eyes Absent 1) gene. Symptoms commonly include deafness and renal anomalies.

Results. We have used the embryos of the frog Xenopus laevis as an animal model for early ear development to examine the effects of different EYA1 mutations. Four eya1 mRNAs encoding proteins correlated with congenital anomalies in human were injected into early stage embryos. We show that the expression of mutations associated with BOR, even in the presence of normal levels of endogenous eya1 mRNA, leads to morphologically abnormal ear development as measured by overall otic vesicle size, establishment of sensory tissue and otic innervation. The molecular consequences of mutant eya1 expression were assessed by QPCR (quantitative PCR) analysis and in situ hybridization. Embryos expressing mutant eya1 showed altered levels of multiple genes (six1, dach, neuroD, ngnr‐1 and nt3) important for normal ear development.

Conclusions. These studies lend support to the hypothesis that dominant‐negative effects of EYA1 mutations may have a role in the pathogenesis of BOR.
Rapid turnover of mitochondrial uncoupling protein 3
Authors: Azzu Vian , Mookerjee Shona A. , Brand Martin D.
Published: December 2009

UCP3 (uncoupling protein 3) and its homologues UCP2 and UCP1 are regulators of mitochondrial function. UCP2 is known to have a short half-life of approx. 1 h, owing to its rapid degradation by the cytosolic 26S proteasome, whereas UCP1 is turned over much more slowly by mitochondrial autophagy. In the present study we investigate whether UCP3 also has a short half-life, and whether the proteasome is involved in UCP3 degradation. UCP3 half-life was examined in the mouse C2C12 myoblast cell line by inhibiting protein synthesis with cycloheximide and monitoring UCP3 protein levels by immunoblot analysis. We show that UCP3 has a short half-life of 0.5–4 h. Rapid degradation was prevented by a cocktail of proteasome inhibitors, supporting a proteasomal mechanism for turnover. In addition, this phenotype is recapitulated in vitro: UCP3 was degraded in mitochondria isolated from rat skeletal muscle or brown adipose tissue with a half-life of 0.5–4 h, but only in the presence of a purified 26S proteasomal fraction. This in vitro proteolysis was also sensitive to proteasome inhibition. This phenotype is in direct contrast with the related proteins UCP1 and the adenine nucleotide translocase, which have long half-lives. Therefore UCP3 is turned over rapidly in multiple cell types in a proteasome-dependent manner.
X-ray absorption spectroscopy study of the local structures of crystalline Zn–In–Sn oxide thin films
Authors: Proffit D. E. , Buchholz D. B. , Chang R. P. H. , Bedzyk M. J. , Mason T. O. , Ma Q.
Published: December 2009

The local structure of a Zn, Sn codoped In2O3 thin film grown on ĉ-plane sapphire by pulsed-laser deposition was examined by polarization-dependent x-ray absorption spectroscopy. The bixbyite film structure is both out-of-plane and in-plane oriented, and the structural results show that both Zn and Sn dopants occupy In sites. The In–O bond length is comparable to that in powder In2O3. However, both Sn–O and Zn–O bonds have two distinct distances in the first shell. Some of the Zn dopants are undercoordinated and, accordingly, some isovalent Sn dopants are overcoordinated for charge balance. In addition, the results suggest that the aliovalent Sn dopants form Frank–Köstlin clusters, (2SnIn•Oi″)x, which provide enough charge carriers to explain the Hall measurements.
Combined dynamic and steady-state infrared camera based carrier lifetime imaging of silicon wafers
Authors: Ramspeck Klaus , Bothe Karsten , Schmidt Jan , Brendel Rolf
Published: December 2009

We report on a calibration-free dynamic carrier lifetime imaging technique yielding spatially resolved carrier lifetime maps of silicon wafers within data acquisition times of seconds. Our approach is based on infrared lifetime mapping (ILM), which exploits the proportionality between the measured infrared emission and the free carrier density. Dynamic ILM determines the lifetime analytically from the signal ratio of infrared camera images recorded directly after turning on an excitation source and after steady-state conditions are established within the sample. We investigate the applicability of dynamic infrared lifetime mapping on silicon wafers with rough surfaces, study the impact of injection dependencies, and examine the technical requirements for measuring low lifetime values in the range of microseconds. While the dynamic ILM approach is suitable for lifetimes exceeding 10μs, a combination with steady-state ILM is required to measure lifetime values in the range of 1μs. The injection dependence does not hamper a correct determination of the carrier lifetime by the dynamic evaluation procedure.
Development of a cryogenic duplexer for solid-state nuclear magnetic resonance
Authors: Mizuno Takashi , Takegoshi K.
Published: December 2009

To fully appreciate sensitivity enhancement achievable by reducing thermal noise at the detection coil for nuclear magnetic resonance (NMR), a duplexer operational at low temperature is required. In this work, we developed a cryogenic duplexer that can work below 50 K using GaAs diodes and rf-microelectrical mechanical systems switches. As the observed leakage of a rf pulse (100 W and 50 μs) through the duplexer is below 1 mW, it can be used not only for NMR in liquids but also for NMR in solids. We reported recently the cryocoil magic-angle spinning (MAS) probe [T. Mizuno et al., Rev. Sci. Instrum. 79, 044706 (2008)] into which was incorporated with this duplexer and a commercial rf preamplifier, we show that signal-to-noise ratio gain of 4.0 times can be achieved for H1 MAS-NMR by lowering the detection-coil temperature to 12 K and the temperatures for the rf preamplifier and the duplexer to 43 K.
High-field hole transport in silicon nanowires
Authors: Verma A. , Buin A. K. , Anantram M. P.
Published: December 2009

We report on ensemble Monte Carlo hole transport simulations for small diameter silicon nanowires. The basis for the simulations is provided by band structure calculations using sp3d5s∗ tight-binding scheme. Principal scattering mechanisms considered are hole-bulk acoustic and optical phonon interactions. Both steady-state and transient hole transport characteristics are explored. For the silicon nanowires considered, the steady-state average hole drift velocity saturates due to optical phonon scattering. Acoustic and intersubband scattering mechanisms strongly prevent an oscillation in the hole velocity in the transient regime. Room temperature hole mean free path for the different silicon nanowires considered is evaluated to be less than 10 nm at various electric fields.
Magnetization scissoring in aluminum/Permalloy microstructures
Authors: Yuan L. , Wisbey D. S. , Halloran S. T. , Pappas D. P. , da Silva F. C. S. , Fardi H. Z.
Published: December 2009

Induced scissoring of magnetization has been observed in aluminum/Permalloy (Ni81Fe19) thin films upon application of an alternating current. Harmonic analysis of the magnetoresistance indicates that the magnetization in the top and bottom portions of the film can rotate ±20° from the axis along which the current is applied. The opposite angles of rotation, or scissoring, can be explained by internal oersted fields from the current. These oersted fields will rotate the in-plane magnetization of the film in opposite directions through the thickness of the film. Simulation using OOMMF shows a high degree of correlation with the observed data.
Molecule-modulated photoconductivity and gain-amplified selective gas sensing in polar GaN nanowires
Authors: Chen R. S. , Lu C. Y. , Chen K. H. , Chen L. C.
Published: December 2009

We report the strong molecular effects on the surface-dominant photoconductivity with high-gain transport in the polar GaN nanowires. Both the transient and steady-state photocurrents are sensitive and selective to the adsorptions of oxygen and hydrogen. The surface band bending of GaN nanowires is proposed to be effectively reduced or enhanced by oxygen or hydrogen, respectively, as a donorlike or acceptorlike surface state. The molecular effect, corroborated with the high-gain photoresponse nature of GaN nanowires is found to amplify the molecule-selective photocurrent signal by near three orders of magnitude higher than its counterpart in dark current. The molecule-tunable photoconductivity, as demonstrated here, would benefit a variety of applications, ranging from the high-gain optoelectronic devices, photoelectric energy transducer, as well as gas and chemical sensors.
Conductance of individual channels in a carbon nanotube field-effect transistor studied by magnetic force microscopy
Authors: Ato Masayuki , Takahashi Takuji , Okigawa Yuki , Mizutani Takashi
Published: December 2009

We observed current-induced magnetic fields using magnetic force microscopy (MFM) to investigate the channel properties of carbon nanotube field-effect transistors (CNT-FETs). We first modified the shape of a MFM cantilever to enhance its response to magnetic force and then observed the MFM signals around individual CNT channels. We demonstrated that the MFM observations are quite appropriate for studying the CNT channel properties. We also found differences in the threshold gate bias and transconductance among different CNT channels and in the asymmetric conductance of a single CNT channel.
On nonautonomous Dirac equation
Authors: Hovhannisyan Gro , Liu Wen
Published: December 2009

We construct the fundamental solution of time dependent linear ordinary Dirac system in terms of unknown phase functions. This construction gives approximate representation of solutions which is useful for the study of asymptotic behavior. Introducing analog of Rayleigh quotient for differential equations we generalize Hartman–Wintner asymptotic integration theorems with the error estimates for applications to the Dirac system. We also introduce the adiabatic invariants for the Dirac system, which are similar to the adiabatic invariant of Lorentz’s pendulum. Using a small parameter method it is shown that the change in the adiabatic invariants approaches zero with the power speed as a small parameter approaches zero. As another application we calculate the transition probabilities for the Dirac system. We show that for the special choice of electromagnetic field, the only transition of an electron to the positron with the opposite spin orientation is possible.
In situ study of dynamic recrystallization and hot deformation behavior of a multiphase titanium aluminide alloy
Authors: Liss Klaus-Dieter , Schmoelzer Thomas , Yan Kun , Reid Mark , Peel Matthew , Dippenaar Rian , Clemens Helmut
Published: December 2009

Hot-compression tests were conducted in a high-energy synchrotron x-ray beam to study in situ and in real time microstructural changes in the bulk of a β-solidifying titanium aluminide alloy. The occupancy and spottiness of the diffraction rings have been evaluated in order to access grain growth and refinement, orientation relationships, subgrain formation, dynamic recovery, and dynamic recrystallization, as well as phase transformations. This method has been applied to an alloy consisting of two coexisting phases at high temperature and it was found that the bcc β-phase recrystallizes dynamically, much faster than the hcp α-phase, which deforms predominantly through crystallographic slip underpinned by a dynamic recovery process with only a small component of dynamic recrystallization. The two phases deform to a very large extent independently from each other. The rapid recrystallization dynamics of the β-phase combined with the easy and isotropic slip characteristics of the bcc structure explain the excellent deformation behavior of the material, while the presence of two phases effectively suppresses grain growth.
Integrability, analyticity, isochrony, equilibria, small oscillations, and Diophantine relations: Results from the stationary Korteweg-de Vries hierarchy
Authors: Bruschi M. , Calogero F. , Droghei R.
Published: December 2009

The isochronous variant is exhibited of the dynamical system corresponding to the Mth ordinary differential equation of the stationary Korteweg-de Vries (KdV) hierarchy. New Diophantine relations are thereby obtained, in the guise of matrices of arbitrary order having integer eigenvalues or equivalently of polynomials of arbitrary degree having integer zeros. Generalizations of these formulas to relations among rational functions are also obtained. The basic idea to arrive at such relations is not new, but the specific application reported in this paper is new, and it is likely to open the way to several analogous new findings.