bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in Interannual Variability and Decadal Potential Predictability under Global Warming
Authors: Boer G. J.
Published: December 2008

Global warming will result in changes in mean temperature and precipitation distributions and is also expected to affect interannual and longer time-scale internally generated variability as a consequence of changes in climate processes and feedbacks. Multimodel estimates of changes in the variability of annual mean temperature and precipitation and in the variability of decadal potential predictability are investigated based on the collection of coupled climate model simulations in the Coupled Model Intercomparison Project phase 3 (CMIP3) data archive. Pooled, multimodel standard deviations of annual mean temperature and precipitation for the unforced preindustrial control climates of the models show good resemblance to observation-based estimates. The internally generated variability of the unforced climate is compared with that of the warmer conditions for simulations with the B1 and A1B climate change scenarios with forcing stabilized at year 2100 values. The standard deviation of annual mean temperature generally decreases with global warming at extratropical latitudes, with the largest percentage decreases over the oceans and largest percentage increases in the tropics and subtropics, although the magnitudes of these increases are smaller. The standard deviation of annual mean precipitation increases almost everywhere, with larger increases in the tropics. Changes are generally larger for the more strongly forced, warmer A1B scenario than for the B1 scenario. The characterization of decadal variability changes in terms of potential predictability stems from the growing interest in producing forecasts for the next decade or several decades. The potential predictability identifies that fraction of the long time-scale variability that is, at least potentially and with enough information, predictable on decadal time scales. There is a general decrease in the internally generated decadal variability of temperature and its potential predictability in the warmer world. The decrease tends to be largest where the decadal potential predictability of the unforced control climate is largest over the high-latitude oceans. The potential predictability of precipitation is small to begin with and generally decreases further. Therefore, there is a potential decrease in the decadal potential predictability of the internally generated component in a warmer world.
Evaluation of Long-Term Cloud-Resolving Model Simulations Using Satellite Radiance Observations and Multifrequency Satellite Simulators
Authors: Matsui Toshihisa , Zeng Xiping , Tao Wei-Kuo , Masunaga Hirohiko , Olson William S. , Lang Stephen
Published: December 2008

This paper proposes a methodology known as the Tropical Rainfall Measuring Mission (TRMM) Triple-Sensor Three-Step Evaluation Framework (T3EF) for the systematic evaluation of precipitating cloud types and microphysics in a cloud-resolving model (CRM). T3EF utilizes multisensor satellite simulators and novel statistics of multisensor radiance and backscattering signals observed from the TRMM satellite. Specifically, T3EF compares CRM and satellite observations in the form of combined probability distributions of precipitation radar (PR) reflectivity, polarization-corrected microwave brightness temperature (Tb), and infrared Tb to evaluate the candidate CRM.

T3EF is used to evaluate the Goddard Cumulus Ensemble (GCE) model for cases involving the South China Sea Monsoon Experiment (SCSMEX) and the Kwajalein Experiment (KWAJEX). This evaluation reveals that the GCE properly captures the satellite-measured frequencies of different precipitating cloud types in the SCSMEX case but overestimates the frequencies of cumulus congestus in the KWAJEX case. Moreover, the GCE tends to simulate excessively large and abundant frozen condensates in deep precipitating clouds as inferred from the overestimated GCE-simulated radar reflectivities and microwave Tb depressions. Unveiling the detailed errors in the GCE’s performance provides the better direction for model improvements.
Vowel Production and Perception: Hyperarticulation without a Hyperspace Effect
Authors: Whalen D.H. , Magen Harriet S. , Pouplier Marianne , Min Kang A. , Iskarous Khalil
Published: December 2008

The ability of speakers to exaggerate speech sounds (“hyperarticulation”) has led to the theory that the targets themselves must be hyperarticulated. Johnson, Flemming, and Wright (1993) found that perceptual “best exemplar” choices for vowels were more extreme than listeners' own productions. Our first experiment, using their procedure, only partially replicated their results. Low vowels showed a higher F1, consistent with hyperspace. Front vowels also showed more frontness in F2, but back vowels were less extreme (“hypoarticulated”) on F2. Our second experiment used an identification and rating of each stimulus, yielding similar results of a smaller magnitude. Our results indicate that the perceptual space is calibrated to a particular (synthetic) vowel space, which is not related straightforwardly to the speakers' spaces. The original hyperspace hypothesis can be attributed to the methodology which led to extreme judgments and of the fronting of back vowels in California English. The present results indicate that no such hypothesis is needed. Vowel targets are measurable from an individual's productions, and the individual's perception of other speakers (even synthetic ones) is based on information about the vocal tract and dialect of the speaker.
Speech Rate in a Pluricentric Language: A Comparison Between Dutch in Belgium and the Netherlands
Authors: Verhoeven Jo , De Pauw Guy , Kloots Hanne
Published: December 2008

This paper investigates speech rate in two standard national varieties of Dutch on the basis of 160 15 mins conversations with native speakers who belong to four different regions in the Netherlands and four in the Dutch-speaking part of Belgium (Flanders). Speech rate was quantified as articulation rate and speaking rate, both expressed as the number of syllables per second (syll/s). The results show a significant effect of speakers' country of origin: subjects in the Netherlands speak 16% faster than subjects in Belgium (articulation: 5.05 vs. 4.23 syll/s, speaking: 4.23 vs. 4.00 syll/s). In addition, the independent variable sex was also found to be significant: on average, men speak 6% faster than women (articulation: 4.79 vs. 4.50 syll/s, speaking: 4.23 vs. 4.01 syll/s). The independent variable age was significant too: younger subjects speak 5% faster than older ones (articulation: 4.78 vs. 4.52 syll/s, speaking: 4.23 vs. 4.01 syll/s). The findings of this study confirm the traditional view that speech rate is determined by extralinguistic variables, but also suggest that there may be intrinsic tempo differences between language varieties.
The Dynamic Nature of Speech Perception
Authors: McQueen James M. , Norris Dennis , Cutler Anne
Published: December 2008

The speech perception system must be flexible in responding to the variability in speech sounds caused by differences among speakers and by language change over the lifespan of the listener. Indeed, listeners use lexical knowledge to retune perception of novel speech (Norris, McQueen, & Cutler, 2003). In that study, Dutch listeners made lexical decisions to spoken stimuli, including words with an ambiguous fricative (between [f] and [s]), in either [f]- or [s]-biased lexical contexts. In a subsequent categorization test, the former group of listeners identified more sounds on an [εf]—[εs] continuum as [f] than the latter group. In the present experiment, listeners received the same exposure and test stimuli, but did not make lexical decisions to the exposure items. Instead, they counted them. Categorization results were indistinguishable from those obtained earlier. These adjustments in fricative perception therefore do not depend on explicit judgments during exposure. This learning effect thus reflects automatic retuning of the interpretation of acoustic-phonetic information.
Input Frequency and Word Truncation in Child Japanese: Structural and Lexical Effects
Authors: Ota Mitsuhiko
Published: December 2008

Recent research indicates that the statistical properties of the input have an impact on the prosodic shape of young children's word production. However, it is still not clear whether the effects of input statistics emerge from the frequency of prosodic structures or the frequency of individual lexical items. This issue is investigated in this study by analyzing cases of word truncation spontaneously produced by three Japanese-speaking children (1;5—2;1) and the frequencies of relevant words and prosodic word structures produced by their mothers. A significant correlation was found between children's truncation rates for individual target words and the frequency of the same words in the maternal input, but not between the truncation rates for different prosodic word structures and the frequencies of the corresponding structures in maternal speech. The size and shape of truncated outputs were better explained in terms of their correspondence to the target structures than the frequencies of shorter forms in the input. The results indicate that variation in early word truncation is systematically related at least to the lexical frequency of the target words, and that input frequency has a clearer connection to what truncates than how it truncates.
Caught in the ACT: The Timing of Aspiration and Voicing in East Bengali
Authors: Mikuteit Simone , Reetz Henning
Published: December 2008

East Bengali is a language that displays a four-way contrast of voiced/voiceless and aspirated/unaspirated oral stops and affricates in all word positions. Additionally, in intervocalic position there is a quantity contrast between long and short obstruents.

In this production study we investigate medial palato-alveolar affricates and stops at the labial, dental, retroflex, and velar places of articulation and address the problems of VOT measurements. We introduce a different approach of measuring lag times, henceforth called after closure time (ACT). The results show that this approach can do away with the extra notion of breathy voice to distinguish between the voiced aspirates and unaspirates.

Moreover, as a result of analyzing the aspirated stops and affricates, an additional term (superimposed aspiration—SA) had to be introduced. The results of combining the notions of ACT and SA show that aspiration, measured from the point of release, is timed equally for voiced and voiceless stops. However, the difference in voice emerges in a trade-off relationship between ACT and SA.

The factors used for analysis were voice, aspiration, quantity, and place of articulation in correlation to closure duration, the length of the preceding vowel, ACT, and SA.
Structural Influences on Initial Accent Placement in French
Authors: Astésano Corine , Bard Ellen Gurman , Turk Alice
Published: December 2008

In addition to the phrase-final accent (FA), the French phonological system includes a phonetically distinct Initial Accent (IA). The present study tested two proposals: that IA marks the onset of phonological phrases, and that it has an independent rhythmic function. Eight adult native speakers of French were instructed to read syntactically ambiguous French sentences (e.g., Les gants et les bas lisses `the smooth gloves and stockings') in a way that disambiguated the scope of the adjective. When the final adjective ( lisses) applies to the conjoined NP, a prosodic boundary is warranted immediately before the adjective; when it applies to the second NP alone, a boundary before that NP is more appropriate. Length of the second noun and the adjective were varied from one to four syllables to investigate length-related tendencies toward phonological boundary marking and toward rhythmic placement of IA. For the materials from six speakers whose readings were correctly interpreted by native listeners, incidence of word-initial prosodic peaks was affected by both structure and length, with most reliable occurrence at onsets of Minor/Phonological Phrases. The only effect of rhythmicity independent of phrase structure was omission of FA in stress clash with IA.
An Event-Structural Account of Passive Acquisition in Korean
Authors: Lee Kwee-Ock , Lee Youngjoo
Published: December 2008

Some peculiar properties of children's passives have long been observed in various languages such as an asymmetry between actional passives and nonactional passives. These peculiarities have been accounted for under the hypothesis that children's early passives are adjectival, and as such exhibit properties of adjectival passives in adult grammar. Under this hypothesis, a new prediction follows, namely that children's comprehension of passive predicates will vary depending upon the event structures of predicates. If a predicate has a target/result state in its event structure, it makes a good adjectival passive, and children will comprehend the predicate more easily. By contrast, if a predicate lacks a target/result state, it does not make a good adjectival passive, and children will comprehend the predicate less easily. This paper tested and confirmed this prediction in Korean children's passives. In a picture-aided comprehension task with 67 Korean children ranging from 3;10—8;8, we have found a contrast due to the event structures of predicates. The result shows that children are sensitive to the event structures of passive predicates, and thus provides additional support for the adjectival passive hypothesis.
Transnationalizing entrepreneurship: a critical agenda for economic geography
Authors: Yeung Henry Wai-chung
Published: December 2008

This paper is concerned with entrepreneurship that takes place across borders, known as transnationalizing entrepreneurship, and its implication for economic-geographical research. It seeks to introduce geographers to a spatially informed synthesis and critique of two otherwise disparate strands of literature: entrepreneurship studies and international business studies. The silence about entrepreneurship studies in transnationalizing entrepreneurial activities and the relative lack of attention to entrepreneurship in international business studies are the key impetus for this paper. The `flat surface' assumption of spatial ontology in these studies also points to a very fertile ground for economic geographers to develop new theoretical insights into the spatialities of entrepreneurship. The paper proposes a relational conceptualization of spaces of entrepreneurship and applies this relational perspective to the emerging research topic of transnationalizing entrepreneurship. Theoretical insights for cutting-edge economic-geographical research are developed in order to arrive at a critical agenda for future research.
Functional complementarity between two languages in ICQ
Authors: Woon Yee Ho Judy
Published: December 2008

The concept of functional complementarity between speech and writing takes on a new dimension as a result of two phenomena in computer-mediated communication: hybridization of spoken and written forms of a single language and hybridization of different languages. This paper investigates how bilinguals realign to the requirements of communication within the context of modern technology by using a “mixed code”. It is based on a linguistic analysis of 40 ICQ histories (24490 lines, 197579 words) which have been collected from 21 tertiary students in Hong Kong. Most ICQ histories (95%) were written in an admixture of English and Chinese both at intersentential and intrasentential levels. Findings suggest a multileveled functional complementarity between Chinese and English in ICQ texts. There are the typical functional differences between written and spoken language, but at the same time the frequent Chinese-English switch suggests that this is bilinguals' most effective way of managing the pressure to achieve specific purposes in on-line, real time communication. Particular elements of one language are blended with those of the other to serve various functions, that is, the two languages complement each other functionally. The results pose a challenge to our understanding of emerging language forms and functions.
Is Social Support From Family Associated With PSA Testing? An Exploratory Analysis Using the Health Information National Trends Survey (HINTS) 2005
Authors: Thomas Kamilah B. , Simpson Sean L. , Tarver Will L. , Gwede Clement K.
Published: December 2008

African American and White men have the highest rates of prostate cancer in the United States. Families represent important social contexts within which illness occurs.The purpose of this study is to explore whether prostate-specific antigen (PSA) testing is associated with instrumental and informational social support from family members among a sample of Black and White men aged 45 and older. Data from the 2005 Health Information National Trends Survey were analyzed using logistic regression. The dependent variable was having a PSA test within the past year or less. The independent variables consisted of selected demographic and family informational and instrumental social support variables. The statistically significant variables included age and having a family member with cancer. Additional studies to elucidate the mechanisms of social support from family for prostate cancer are needed.
Specific activation of microRNA106b enables the p73 apoptotic response in chronic lymphocytic leukemia by targeting the ubiquitin ligase Itch for degradation
Authors: Sampath Deepa , Calin George A. , Puduvalli Vinay K. , Gopisetty Gopal , Taccioli Cristian , Liu Chang-Gong , Ewald Brett , Liu Chaomei , Keating Michael J. , Plunkett William
Published: December 2008

Chronic lymphocytic leukemia (CLL) is characterized by cells that exhibit dysfunctional apoptosis. Here, we show that deacetylase inhibition led to the E2F1- and myc-mediated transcriptional activation of the microRNA miR106b in primary CLL cells. Induction of miR106b was associated with a down-regulation in the levels of the E3-ubiquitin ligase Itch. Decreases in Itch protein levels were associated with a reciprocal accumulation of its proapoptotic substrate, TAp73 (p73), and induction of p53 up-regulated modulator of apoptosis (PUMA) mRNA and protein. This event was accompanied by mitochondrial dysfunction, processing of caspase-9, and apoptosis of CLL cells. Ectopic expression of miR106b in CLL cells demonstrated that Itch was a direct target of miR106b such that miR106b-induced decreases in Itch resulted in an accumulation of p73. Thus, our results identify a novel regulatory mechanism wherein microRNA regulate cell survival by mediating the posttranscriptional down-regulation of an ubiquitin ligase, leading to the induction of a proapoptotic regulator in malignant cells. Silencing of miRNA expression in CLL may selectively suppress proapoptotic pathways, providing such tumors with a survival advantage. Consequently, chemotherapeutic drugs that activate miR106b could initiate a p53-independent mechanism that targets CLL cells.
Prediction of regulatory elements in mammalian genomes using chromatin signatures
Authors: Won Kyoung-Jae , Chepelev Iouri , Ren Bing , Wang Wei
Published: December 2008

Background

Recent genomic scale survey of epigenetic states in the mammalian genomes has shown that promoters and enhancers are correlated with distinct chromatin signatures, providing a pragmatic way for systematic mapping of these regulatory elements in the genome. With rapid accumulation of chromatin modification profiles in the genome of various organisms and cell types, this chromatin based approach promises to uncover many new regulatory elements, but computational methods to effectively extract information from these datasets are still limited.

Results

We present here a supervised learning method to predict promoters and enhancers based on their unique chromatin modification signatures. We trained Hidden Markov models (HMMs) on the histone modification data for known promoters and enhancers, and then used the trained HMMs to identify promoter or enhancer like sequences in the human genome. Using a simulated annealing (SA) procedure, we searched for the most informative combination and the optimal window size of histone marks.

Conclusion

Compared with the previous methods, the HMM method can capture the complex patterns of histone modifications particularly from the weak signals. Cross validation and scanning the ENCODE regions showed that our method outperforms the previous profile-based method in mapping promoters and enhancers. We also showed that including more histone marks can further boost the performance of our method. This observation suggests that the HMM is robust and is capable of integrating information from multiple histone marks. To further demonstrate the usefulness of our method, we applied it to analyzing genome wide ChIP-Seq data in three mouse cell lines and correctly predicted active and inactive promoters with positive predictive values of more than 80%. The software is available at http://http:/nash.ucsd.edu/chromatin.tar.gz.
Genomic organization and phylogenetic utility of deer mouse (Peromyscus maniculatus) lymphotoxin-alpha and lymphotoxin-beta
Authors: Richens Tiffany , Palmer Aparna D~N , Prescott Joseph , Schountz Tony
Published: December 2008

Background

Deer mice (Peromyscus maniculatus) are among the most common mammals in North America and are important reservoirs of several human pathogens, including Sin Nombre hantavirus (SNV). SNV can establish a life-long apathogenic infection in deer mice, which can shed virus in excrement for transmission to humans. Patients that die from hantavirus cardiopulmonary syndrome (HCPS) have been found to express several proinflammatory cytokines, including lymphotoxin (LT), in the lungs. It is thought that these cytokines contribute to the pathogenesis of HCPS. LT is not expressed by virus-specific CD4+T cells from infected deer mice, suggesting a limited role for this pathway in reservoir responses to hantaviruses.

Results

We have cloned the genes encoding deer mouse LTα and LTβ and have found them to be highly similar to orthologous rodent sequences but with some differences in promoters elements. The phylogenetic analyses performed on the LTα, LTβ, and combined data sets yielded a strongly-supported sister-group relationship between the two murines (the house mouse and the rat). The deer mouse, a sigmodontine, appeared as the sister group to the murine clade in all of the analyses. High bootstrap values characterized the grouping of murids.

Conclusion

No conspicuous differences compared to other species are present in the predicted amino acid sequences of LTα or LTβ; however, some promoter differences were noted in LTβ. Although more extensive taxonomic sampling is required to confirm the results of our analyses, the preliminary findings indicate that both genes (analyzed both separately and in combination) hold potential for resolving relationships among rodents and other mammals at the subfamily level.
Gemcitabine-based versusfluoropyrimidine-based chemotherapy with or without platinum in unresectable biliary tract cancer: a retrospective study
Authors: Kim Mi-Jung , Oh Do-Youn , Lee Se-Hoon , Kim Dong-Wan , Im Seock-Ah , Kim Tae-You , Heo Dae Seog , Bang Yung-Jue
Published: December 2008

Background

There is no standard palliative chemotherapy regimen in biliary tract cancers (BTC). Fluoropyrimidine or gemcitabine, with or without platinum, are most frequently used. We conducted this study to clarify the efficacy of palliative chemotherapy in BTC.

Methods

Patients with unresectable BTC treated with palliative chemotherapy between Oct 2001 and Aug 2006 at Seoul National University Hospital were reviewed retrospectively. Histologically confirmed cases of intrahepatic cholangiocarcinoma, gallbladder cancer, extrahepatic bile duct cancer, and ampulla of Vater carcinoma were enrolled. We analyzed the efficacy of regimens: gemcitabine (G) versus fluoropyrimidine (F) and with or without platinum (P).

Results

A total of 243 patients were enrolled. 159 patients (65%) were male and the median age of the patients was 60 years (range 26–81). Intrahepatic cholangiocarcinoma, gallbladder cancer, extrahepatic bile duct cancer, and ampulla of Vater carcinoma were 92, 72, 58, and 21 cases, respectively. The median progression free survival (PFS) was 4.3 months (95% CI, 3.7–4.9) and median overall survival (OS) was 8.7 months (95% CI, 7.4–10.0). Ninety-nine patients received G-based chemotherapy (94 GP, 5 G alone), and 144 patients received F-based chemotherapy (83 FP, 61 F alone). The response rate (RR), disease control rate (DCR), PFS and OS of G-based chemotherapy versus F-based chemotherapy were 16.7% vs. 19.5% (P = 0.591), 52.8% vs. 58.9% (P = 0.372), 4.0 months vs. 4.3 months (P = 0.816), and 7.8 months vs. 9.1 months (P = 0.848), respectively. Sixty-six patients received F or G without P, and 177 patients received F or G with P. The RR, DCR, PFS and OS of chemotherapy without P versus chemotherapy including P were 12.7% vs. 20.6% (P = 0.169), 46.0% vs. 60.6% (P = 0.049), 3.3 months vs. 4.4 months (P = 0.887), and 10.6 months vs. 8.1 months (P = 0.257), respectively.

Conclusion

In unresectable BTC, F-based and G-based chemotherapy showed similar efficacy in terms of RR, DCR, PFS and OS. The benefit of adding P to F or G was not significant except for DCR. Further prospective studies which define the efficacy of various chemotherapeutic regimens in BTC are warranted.
Sublingual sugar for hypoglycaemia in children with severe malaria: A pilot clinical study
Authors: Graz Bertrand , Dicko Moussa , Willcox Merlin L , Lambert Bernard , Falquet Jacques , Forster Mathieu , Giani Sergio , Diakite Chiaka , Dembele Eugène M , Diallo Drissa , Barennes Hubert
Published: December 2008

Background

Hypoglycaemia is a poor prognostic indicator in severe malaria. Intravenous infusions are rarely feasible in rural areas. The efficacy of sublingual sugar (SLS) was assessed in a pilot randomized controlled trial among hypoglycaemic children with severe malaria in Mali.

Methods

Of 151 patients with presumed severe malaria, 23 children with blood glucose concentrations < 60 mg/dl (< 3.3 mmol/l) were assigned randomly to receive either intravenous 10% glucose (IVG; n = 9) or sublingual sugar (SLS; n = 14). In SLS, a teaspoon of sugar, moistened with a few drops of water, was gently placed under the tongue every 20 minutes. The child was put in the recovery position. Blood glucose concentration (BGC) was measured every 5–10 minutes for the first hour. All children were treated for malaria with intramuscular artemether. The primary outcome measure was treatment response, defined as reaching a BGC of >= 3.3 mmol/l (60 mg/dl) within 40 minutes after admission. Secondary outcome measures were early treatment response at 20 minutes, relapse (early and late), maximal BGC gain (CGmax), and treatment delay.

Results

There was no significant difference between the groups in the primary outcome measure. Treatment response occurred in 71% and 67% for SLS and IVG, respectively. Among the responders, relapses occurred in 30% on SLS at 40 minutes and in 17% on IVG at 20 minutes. There was one fatality in each group. Treatment failures in the SLS group were related to children with clenched teeth or swallowing the sugar, whereas in the IVG group, they were due to unavoidable delays in beginning an infusion (median time 17.5 min (range 3–40).

Among SLS, the BGC increase was rapid among the nine patients who really kept the sugar sublingually. All but one increased their BGC by 10 minutes with a mean gain of 44 mg/dl (95%CI: 20.5–63.4).

Conclusion

Sublingual sugar appears to be a child-friendly, well-tolerated and effective promising method of raising blood glucose in severely ill children. More frequent repeated doses are needed to prevent relapse. Children should be monitored for early swallowing which leads to delayed absorption, and in this case another dose of sugar should be given. Sublingual sugar could be proposed as an immediate "first aid" measure while awaiting intravenous glucose. In many cases it may avert the need for intravenous glucose.
Human Immunodeficiency Virus type-1 reverse transcriptase exists as post-translationally modified forms in virions and cells
Authors: Davis Adam J , Carr Jillian M , Bagley Christopher J , Powell Jason , Warrilow David , Harrich David , Burrell Christopher J , Li Peng
Published: December 2008

Background

HIV-1 reverse transcriptase (RT) is a heterodimer composed of p66 and p51 subunits and is responsible for reverse transcription of the viral RNA genome into DNA. RT can be post-translationally modified in vitro which may be an important mechanism for regulating RT activity. Here we report detection of different p66 and p51 RT isoforms by 2D gel electrophoresis in virions and infected cells.

Results

Major isoforms of the p66 and p51 RT subunits were observed, with pI's of 8.44 and 8.31 respectively (p668.44 and p518.31). The same major isoforms were present in virions, virus-infected cell lysates and intracellular reverse transcription complexes (RTCs), and their presence in RTCs suggested that these are likely to be the forms that function in reverse transcription. Several minor RT isoforms were also observed. The observed pIs of the RT isoforms differed from the pI of theoretical unmodified RT (p668.53 and p518.60), suggesting that most of the RT protein in virions and cells is post-translationally modified. The modifications of p668.44 and p518.31 differed from each other indicating selective modification of the different RT subunits. The susceptibility of RT isoforms to phosphatase treatment suggested that some of these modifications were due to phosphorylation. Dephosphorylation, however, had no effect on in vitro RT activity associated with virions, infected cells or RTCs suggesting that the phospho-isoforms do not make a major contribution to RT activity in an in vitro assay.

Conclusion

The same major isoform of p66 and p51 RT is found in virions, infected cells and RTC's and both of these subunits are post-translationally modified. This post-translational modification of RT may be important for the function of RT inside the cell.
KEGG spider: interpretation of genomics data in the context of the global gene metabolic network
Authors: Antonov Alexey V , Dietmann Sabine , Mewes Hans W
Published: December 2008

KEGG spider is a web-based tool for interpretation of experimentally derived gene lists in order to gain understanding of metabolism variations at a genomic level. KEGG spider implements a 'pathway-free' framework that overcomes a major bottleneck of enrichment analyses: it provides global models uniting genes from different metabolic pathways. Analyzing a number of experimentally derived gene lists, we demonstrate that KEGG spider provides deeper insights into metabolism variations in comparison to existing methods.
A role for the 30S subunit E site in maintenance of the translational reading frame
Authors: Devaraj Aishwarya , Shoji Shinichiro , Holbrook Eric D. , Fredrick Kurt
Published: December 2008

The exit (E) site has been implicated in several ribosomal activities, including translocation, decoding, and maintenance of the translational reading frame. Here, we target the 30S subunit E site by introducing a deletion in rpsG that truncates the β-hairpin of ribosomal protein S7. This mutation (S7ΔR77–Y84) increases both −1 and +1 frameshifting but does not increase miscoding, providing evidence that the 30S E site plays a specific role in frame maintenance. Mutation S7ΔR77–Y84 also stimulates +1 programmed frameshifting during prfB′-lacZ translation in many synthetic contexts. However, no effect is seen when the E codon of the frameshift site corresponds to those found in nature, suggesting that E-tRNA release does not normally limit the rate of prfB frameshifting. Ribosomes containing S7ΔR77–Y84 exhibit an elevated rate of spontaneous reverse translocation and an increased K1/2 for E-tRNA. These effects are of similar magnitude, suggesting that both result from destabilization of E-tRNA. Finally, this mutation of the 30S E site does not inhibit EF-G-dependent translocation, consistent with a primary role for the 50S E site in the mechanism.
Persistency Model and Its Applications in Choice Modeling
Authors: Natarajan Karthik , Song Miao , Teo Chung-Piaw
Published: December 2008

Given a discrete maximization problem with a linear objective function where the coefficients are chosen randomly from a distribution, we would like to evaluate the expected optimal value and the marginal distribution of the optimal solution. We call this the persistency problem for a discrete optimization problem under uncertain objective, and the marginal probability mass function of the optimal solution is named the persistence value. In general, this is a difficult problem to solve, even if the distribution of the objective coefficient is well specified. In this paper, we solve a subclass of this problem when the distribution is assumed to belong to the class of distributions defined by given marginal distributions, or given marginal moment conditions. Under this model, we show that the persistency problem maximizing the expected objective value over the set of distributions can be solved via a concave maximization model. The persistency model solved using this formulation can be used to obtain important qualitative insights to the behavior of stochastic discrete optimization problems. We demonstrate how the approach can be used to obtain insights to problems in discrete choice modeling. Using a set of survey data from a transport choice modeling study, we calibrate the random utility model with choice probabilities obtained from the persistency model. Numerical results suggest that our persistency model is capable of obtaining estimates that perform as well, if not better, than classical methods, such as logit and cross-nested logit models. We can also use the persistency model to obtain choice probability estimates for more complex choice problems. We illustrate this on a stochastic knapsack problem, which is essentially a discrete choice problem under budget constraint.
Searching for Google's Value: Using Prediction Markets to Forecast Market Capitalization Prior to an Initial Public Offering
Authors: Berg Joyce E. , Neumann George R. , Rietz Thomas A.
Published: December 2008

We conducted prediction markets designed to forecast post-initial public offering (IPO) valuations before a particularly unique IPO: Google. The prediction markets forecast Google's post-IPO market capitalization relatively accurately. While Google's auction-based IPO price was 15.3% below the first-day closing market capitalization, the final prediction market forecast was only 4.0% above it. The forecast also accorded with the level of over-subscription in the IPO auction. Evidence available to both outsiders (from the prediction market forecasts) and insiders (through the orders in Google's auction) predicted similar degrees of underpricing. We argue that, with repetition, such markets could provide useful information for understanding the IPO process.
Rifaximin for Treatment of Hepatic Encephalopathy
Authors: Maclayton Darego O , Eaton-Maxwell Angie
Published: December 2008

OBJECTIVE

To review the effectiveness and safety of rifaximin in the treatment of hepatic encephalopathy (HE).

DATA SOURCES

MEDLINE (1990–October 2008) was searched using the terms rifaximin, rifamycins, hepatic encephalopathy, liver cirrhosis, and acute liver failure. Other sources included the bibliographies of pertinent articles as well as programs and abstracts from infectious diseases and gastrointestinal diseases meetings.

STUDY SELECTION AND DATA EXTRACTION

All English-language articles identified from the search were evaluated. All primary literature that addressed the efficacy and safety of rifaximin in the treatment of HE was included in this review.

DATA SYNTHESIS

HE is a complex neuropsychiatric syndrome seen in patients with liver failure. It is characterized by disturbances in consciousness and behavior, personality changes, fluctuating neurologic signs, asterixis, and electroencephalographic changes. Although the etiology of HE is unknown, the accumulation of several gut-derived toxins such as mercaptans, ammonia, and benzodiazepine has been implicated. Current treatment options for HE include agents that reduce the concentration of these toxins, such as nonabsorbable disaccharides and antibiotics. Several studies have evaluated the use of rifaximin in the treatment of HE. They include a dose-finding study, 9 open-label studies, and 4 double-blind studies comparing rifaximin with either nonabsorbable disaccharides or antibiotics. Commonly used outcomes in most of these studies were changes in portal systemic encephalopathy index and the improvement in HE grade. Despite various limitations of the studies, rifaximin showed superior efficacy compared with lactulose for the treatment of HE, similar efficacy to paromomycin, and similar or greater efficacy than neomycin. Rifaximin was found to be associated with fewer hospitalizations, fewer days of hospitalization, and lower hospitalization charges than were seen with lactulose. Rifaximin also had a better tolerance profile than the comparative agents.

CONCLUSIONS

Rifaximin appears to be an effective and safe treatment option for HE. Better-designed studies are needed to characterize its efficacy in the treatment of HE. A For Our Patients summary of this article is available at www.ForOurPatients.info
A Novel Approach to Model Moving Heat Sources
Authors: Fischer F. D. , Krempaszky C. , Očenášek J. , Werner E.
Published: December 2008

The solution of quasistationary heat-conduction problems with moving heat sources on the surface of a body is a demanding task and still a topic of ongoing research. The authors have shown in several contributions that an exact analytical solution exists for a constant velocity of the heat source and constant thermal properties of the body. Since also convection at the surface can be treated properly, cooling and quenching problems can be solved, accordingly. The main characteristic of the governing equation is that the partial derivative of the temperature with respect to time must be replaced by the convective term being the velocity of the heat source times the gradient of the temperature. In this contribution it is shown that the quasistationary problem can be transformed into a stationary one, if a modified heat-conduction coefficient is introduced. The application of this concept and its limits are demonstrated in comparison with existing analytical solutions. For this purpose a model is set up which consists of two parts. In the first part the concept of transforming to a stationary problem is employed, whereas in the second part fictitious heat sources are defined. The methodology is shown to be very efficient as it avoids difficulties arising from the necessity to use very dense meshes and proper time integration routines necessary when applying standard fine element codes for a spatially fixed configuration of a body with moving heat sources on its surface.
Relationship between the coronal suture and the central lobe: how important is it and how can we use it in surgical planning?
Authors: Sarmento Stênio Abrantes , Jácome Danielle Cartaxo , Andrade Emerson Magno F. de , Melo Alessandra V. Albuquerque , Oliveira Osleuse Rocha de , Tedeschi Helder
Published: December 2008

The surgical treatment of the lesions located in the central lobe is a very difficult task for the neurosurgeon. The overall aim of this study is to verify the correlation of the coronal suture and the structures of the central lobe in 32 cadaver hemisphere brains and the importance of this information in surgical planning. The measurement of the nasion to the coronal suture ranged from 11.5 to 13.5 cm. The distance between the coronal suture in the midline to the central, precentral and paracentral sulcus ranged from 5.0 to 6.6, 2.5 to 4.5 and 1.3 to 4.0 cm respectively. Particularly in the normal cortex these measurements can be used to guide the surgical access. However, the identification of the central sulcus is not easy when the anatomical pattern is distorted or displaced by a lesion or edema. In cases such as these the use of other tools becomes crucial for good surgical planning and cortical mapping or awake craniotomy for a safer resection of the lesion as well.
Controle da dor no pós-operatório
Authors: Pimenta Cibele Andrucioli de Mattos , Santos Erika Maria Monteiro , Chaves Lucimara Duarte , Martins Luciana Mendes , Gutierrez Beatriz Aparecida Ozello
Published: December 2008

A dor é um fenômeno freqüente no pós-operatório e pode resultar em sofrimento e riscos desnecessários ao paciente. Estudos demonstram o inadequado alívio da dor após a cirurgia e sua relação com falhas na avaliação e falta de conhecimento sobre métodos analgésicos. O artigo discute o manejo da dor pós-operatória que inclui o uso de analgésicos antiinflamatórios não hormonais, opiáceos, intervenções cognitivo-comportamentais e alta tecnologia como cateter peridural e sistemas de analgesia controlada pelo paciente. Além disso, o adequado controle da dor inclui a discussão sobre aspectos éticos e econômicos.
Consequências da síndrome da tensão pré-menstrual na vida da mulher
Authors: Muramatsu Clarice H. , Vieira Olga Cristina Serafim , Simões Cirilo César , Katayama Daniela Aparecida , Nakagawa Flávia Hiroko
Published: December 2008

Este estudo tem como objetivo identificar as possíveis conseqüências da Síndrome da Tensão Pré-Menstrual na vida da mulher. Através do questionário, identificamos distúrbios relacionados a alterações físicas, emocionais e, como consequências às alterações nos relacionamentos envolvendo filho, marido/ namorado e familiar, assim como no ambiente de trabalho.
Possibilidades e limites do trabalho de vigilância epidemiológica no nível local em direção à vigilância à saúde
Authors: Rodrigues Verônica Maria , Fracolli Lislaine Aparecida , Oliveira Maria Amélia Campos de
Published: December 2008

O estudo tem como marco referencial o processo de trabalho em saúde e em enfermagem, e como objetivos descrever e analisar as ações de Vigilância Epidemiológica (VE) desenvolvidas em uma unidade de saúde, buscando identificar o quanto se aproximam da estratégia de Vigilância à Saúde (VS). Utilizou-secomo referência um check-list elaborado com base nas ações de VE preconizadas pelo Ministério da Saúde. Os dados obtidos demonstraram que na unidade de saúde estudada, as ações de VE restringiam-se à notificação e ao controle das doenças transmissíveis e que o trabalho da enfermeira na VE caracteriza-sepor atividades burocráticas. Conclui-sepela necessidade de se ampliarem as discussões sobre as formas de operacionalização da VS nos serviços de saúde.
Síndrome de Fournier: a percepçao do seu portador
Authors: Cavalini Fernanda , Moriya Tokico Murakawa , Pelá Nilza Teresa Rotter
Published: December 2008

O propósito da presente investigação foi identificar a percepção dos pacientes que tiveram Síndrome de Fournier (SF) sobre esta afecção, bem como sobre seus cuidadores. Os dados foram coletados através de entrevista com roteiro estruturado e a análise baseada na Análise de Prosa de André. Segundo os entrevistados, a SF causa dor intensa, edema, febre e ferida, necessitando tratamento cirúrgico, curativos e que traz problemas físicos, econômicos e familiares. Sobre seus cuidadores descreveram demonstração de atitudes e comportamentos mais negativos que positivos. A necessidade de melhor treinamento de seus cuidadores tanto nos aspectos cognitivos e psicomotor quanto afetivo, ficou evidente.
Eficiência no uso da água na cana-de-açúcar sob diferentes lâminas de irrigação e níveis de zinco no litoral paraibano
Authors: Farias Carlos H. A. , Fernandes Pedro D. , Dantas Neto José , Gheyi Hans R.
Published: December 2008

Esta pesquisa foi conduzida em área experimental da Fazenda Capim II, localizada no Município de Capim - PB, com o intuito de determinar a eficiência no uso da água (EUA) pela cana-de-açúcar (Saccharum officinarum L.), cultivar SP 79-1011. O delineamento experimental consistiu em blocos casualizados, com três repetições, em esquema fatorial 5 x 5. Os tratamentos referentes à lâmina de irrigação foram: sequeiro; 25; 50; 75 e 100% da ETc (1.026,57 mm) com as respectivas precipitações efetivas de 780,06; 713,31; 487,54; 243,71 e 194,51 mm; os níveis de zinco estudados foram 0; 1; 2; 3 e 4 kg ha-1. O equipamento de irrigação utilizado foi do tipo pivô central, com turno de rega de nove dias. A eficiência no uso da água (EUA) na produção de colmos e de açúcar aumenta à medida que se eleva a lâmina total de água aplicada à cultura. Para a região norte-paraibana dos tabuleiros costeiros, a EUA na produção de colmo e de açúcar, de forma maximizada, é 7,12 e 0,67 kg m-3, respectivamente.
Anatomia arterial hepática: estudo em 150 transplantes hepáticos
Authors: Freitas Alexandre Coutinho Teixeira de , Coelho Júlio Cezar Uili , Matias Jorge Eduardo Fouto , Zeni Neto Clementino , Martins Eduardo Lopes , Druszcz Crhistiano Coleto
Published: December 2008

OBJETIVO: O presente estudo tem por objetivo avaliar a anatomia arterial hepática em doadores e receptores de 150 transplantes hepáticos. MÉTODOS: 246 pacientes foram analisados, 129 doadores e 117 receptores de fígado. RESULTADOS: A anatomia arterial hepática era normal em 189 (76,82%) pacientes. Alterações anatômicas foram encontradas nos demais 57 (23,18%), sendo as principais: artéria hepática direita ramo da artéria mesentérica superior, artéria hepática esquerda ramo da artéria gástrica esquerda, artéria hepática direita ramo da artéria mesentérica superior associada à artéria hepática esquerda ramo da artéria gástrica esquerda e artéria hepática comum ramo da artéria mesentérica superior. Algumas anomalias raras foram visualizadas. CONCLUSÕES: Os achados deste estudo demonstram a variabilidade da anatomia do sistema arterial hepático e alertam para a necessidade de cautela nas dissecções cirúrgicas, principalmente nas captações de enxerto dos transplantes de fígado, para se evitar comprometimento do suprimento sangüíneo hepático.
Tratamento do carcinoma do canal anal com radioterapia e quimioterapia concomitantes: resultados preliminares do Hospital do Câncer A. C. Camargo
Authors: Lima Júnior Carlos Genésio Bezerra , Ferrigno Robson , Salvajoli João Victor , David Filho Waldec Jorge , Rossi Benedito Mauro , Lopes Ademar
Published: December 2008

OBJETIVO: Reportar os resultados preliminares do tratamento do carcinoma do canal anal com radioterapia e quimioterapia concomitantes. MÉTODOS: De janeiro de 1992 a maio de 1998, foram tratados 24 pacientes com diagnóstico histológico de carcinoma do canal anal, sendo 18 pacientes do sexo feminino e seis do sexo masculino (3:1). A idade dos mesmos variou de 35 a 74 anos e a média foi de 59 anos. A distribuição do número de pacientes por estádio clínico foi: I - 1, II - 13, III - 9 e IV - 1. A radioterapia foi realizada com dose de 45 Gy na pelve no Acelerador Linear de 4 MV, seguida de complementação de dose no canal anal até 55 Gy através de campo direto no cobalto. A quimioterapia foi realizada com 5-FU (1.000mg/m²) em infusão contínua e mitomicina C (10mg/m²) em bólus durante os cinco primeiros e os cinco últimos dias da radioterapia. RESULTADOS: O seguimento médio foi de 34 meses. Resposta completa ao tratamento foi obtida em 23 (95,8%) pacientes. Quatorze (58,3%) estão vivos sem doença, três (12%) vivos com doença, cinco (20,8%) mortos pelo câncer e um (4,2%) morreu sem câncer. Recidivas locais ocorreram em cinco (20,8%) pacientes e metástase a distância em quatro (16,6%). A função esfincteriana foi preservada em 18 (75%) pacientes. Complicações agudas e crônicas foram observadas em 19 (79,2%) e em nove (37,5%) pacientes respectivamente. CONCLUSÕES: O tratamento foi efetivo em termos de controle local e preservação esfincteriana, porém com toxicidade aguda e tardia elevadas. Diminuição da dose de radioterapia em toda pelve representa uma estratégia razoável para diminuir os efeitos colaterais agudos e crônicos. Um maior número de pacientes e seguimento mais longo trarão mais informações sobre esta abordagem terapêutica.