bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new function of Trypanosoma brucei mitochondrial topoisomerase II is to maintain kinetoplast DNA network topology
Authors: Lindsay Megan E. , Gluenz Eva , Gull Keith , Englund Paul T. 
Published: October 2008

SummaryThe mitochondrial genome of Trypanosoma brucei, called kinetoplast DNA, is a network of topologically interlocked DNA rings including several thousand minicircles and a few dozen maxicircles. Kinetoplast DNA synthesis involves release of minicircles from the network, replication of the free minicircles and reattachment of the progeny. Here we report a new function of the mitochondrial topoisomerase II (TbTOP2mt). Although traditionally thought to reattach minicircle progeny to the network, here we show that it also mends holes in the network created by minicircle release. Network holes are not observed in wild‐type cells, implying that this mending reaction is normally efficient. However, RNAi of TbTOP2mt causes holes to persist and enlarge, leading to network fragmentation. Remarkably, these network fragments remain associated within the mitochondrion, and many appear to be appropriately packed at the local level, even as the overall kinetoplast organization is dramatically altered. The deficiency in mending holes is temporally the earliest observable defect in the complex TbTOP2mt RNAi phenotype.
The Vallo di Diano and Auletta extensional basins in the southern Apennines (Italy): a simple model for a complex setting
Authors: Amicucci Laura , Barchi Massimiliano R. , Montone Paola , Rubiliani Nicola 
Published: October 2008

AbstractThe aim of this paper was to provide a significant case‐history concerning the evolution of a segmented system of extensional faults and related basins, investigated by a set of seismic reflection profiles. We investigated two kinematically linked semi‐grabens, developed at the hangingwall of two opposite‐dipping normal faults: the Vallo di Diano and Auletta basins, located in the southern Apennines, one of the most seismically active regions of the Italian peninsula. Our interpretation suggests that the Pliocene–Quaternary tectonic history consists of a single extensional phase, where the major NW–SE trending normal faults, generating the basins, and the strike‐slip and transtensional faults connecting adjacent normal fault segments, simultaneously act, being part of the same extensional system. We also conclude that major normal faults, bordering the basins, should be considered as potential seismogenic sources in the seismic hazard evaluation.
Plate tectonics, flood basalts and the evolution of Earth’s oceans
Authors: Korenaga Jun 
Published: October 2008

AbstractThe chemical composition of the bulk silicate Earth (BSE) indicates that the present‐day thermal budget of Earth is likely to be characterized by a significant excess of surface heat loss over internal heat generation, indicating an important role of secular cooling in Earth’s history. When combined with petrological constraints on the degree of secular cooling, this thermal budget places a tight constraint on permissible heat‐flow scaling for mantle convection, along with implications for the operation of plate tectonics on Earth, the history of mantle plumes and flood basalt magmatism, and the origin and evolution of Earth’s oceans. In the presence of plate tectonics, hotter mantle may have convected more slowly because it generates thicker dehydrated lithosphere, which could slow down subduction. The intervals of globally synchronous orogenies are consistent with the predicted variation of plate velocity for the last 3.6 Gyr. Hotter mantle also produces thicker, buoyant basaltic crust, and the subductability of oceanic lithosphere is a critical factor regarding the emergence of plate tectonics before the Proterozoic. Moreover, sluggish convection in the past is equivalent to reduced secular cooling, thus suggesting a more minor role of mantle plumes in the early Earth. Finally, deeper ocean basins are possible with slower plate motion in the past, and Earth’s oceans in the Archean is suggested to have had about twice as much water as today, and the mantle may have started as dry and have been gradually hydrated by subduction. The global water cycle may thus be dominated by regassing, rather than degassing, pointing towards the impact origin of Earth’s oceans, which is shown to be supported by the revised composition of the BSE.
Association Between Leptin, LH and its Receptor and Luteinization and Progesterone Accumulation (P4) in Bovine Granulosa Cell In Vitro
Authors: Montaño E , Olivera M , Ruiz‐Cortés ZT 
Published: October 2008

ContentsA full understanding of the cellular events that occur during in vitro luteinization of bovine granulosa cells, stimulated by LH and by leptin, is a complex goal that has not been completely achieved. The aim of this work was to study the effects of leptin, LH and leptin + LH on progesterone accumulation (P4) and on the expression of LH receptors (LHR) in bovine granulosa cells in culture. The results confirm that this in vitro model is representative of functional and morphological luteinization/differentiation. The pattern of expression of LHR with time of incubation was an important marker of in vitro luteinization, with 50–90% of cells expressing LHR by 96 h in culture. Cytoplasmic lipidic droplets were highly abundant in granulosa cells, suggesting a sufficient source of precursors for steroid hormone synthesis: P4 accumulation ranged between 40 and 550 ng/ml. In addition, a positive correlation (r = 0.58, p < 0.05) between the expression of LHR and accumulation of P4 throughout the time of incubation was observed. The expression of LHR was inhibited by LH and leptin + LH treatment. In conclusion, we found an inverse modulation between the expression of LHR and the concentration of LH, and the expression of LHR could be regulated by P4 produced by the luteinized granulosa cells. These findings are contributing to elucidate further the panoply of interactions during the differentiation of granulosa cells into luteal cells in vitro.
Visual function and performance with blue‐light blocking filters in age‐related macular degeneration
Authors: Kiser Ava K , Deschler Emily K , Dagnelie Gislin 
Published: October 2008

AbstractPurpose:  Some dispute has occurred over the use of blue‐light‐attenuating intraocular lenses in age‐related macular degeneration (AMD), as they may reduce scotopic vision. This study aimed to determine if a blue blocking filter would affect performance during eye–hand coordination and mobility tasks in scotopic illumination, psychophysically measured scotopic sensitivity or colour discrimination in AMD patients.Methods:  Scotopic measures performed with and without a blue‐attenuating filter included a mobility obstacle course, manipulation of cylindrical blocks and a psychophysical dark‐adapted full‐field flash test. A navy and blue sock colour sorting task evaluated photopic colour discrimination. Subjects were 22 bilateral pseudophakes with early AMD and visual acuity >6/24.Results:  On average with the filter, there was a 13% increase in time during the block test. The differences in time and number of bumps with versus without the filter were not significant for the mobility course. Performance with and without the filter was well correlated for the blocks (r = 0.70), flash test (r = 0.83) and mobility (r = 0.66), and the regression slopes were not significantly different from unity. 77% of subjects misidentified at least one navy sock as black with the filter compared with 9% without, with a significant increase in such misidentifications with the filter.Conclusions:  The difference in scotopic visual function or performance with versus without a blue‐blocking filter most likely does not produce a clinically significant effect or risk; however, detection of navy colour may be impaired.
Retinal arterial abnormalities correlate with brain white matter lesions in cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy
Authors: Liu Yang , Wu Yuan , Xie Sheng , Luan Xing‐hua , Yuan Yun 
Published: October 2008

AbstractPurpose:  The aim of this study is to determine the relationship between retinal abnormalities and brain white matter hyper‐intensities (WMH) in symptomatic patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL).Methods:  Fifteen patients with CADASIL and fifteen age‐matched healthy control individuals were enrolled in this study. Ophthalmological examinations were performed on all subjects and all patients with CADASIL underwent cerebral MRI scanning. Retinal artery abnormalities were graded according to the Keith‐Wagener‐Barker hypertensive retinopathy classification. WMH were classified as punctuate (Grade 1), nodular or early confluent (Grade 2) and diffusly confluent (Grade 3). Partial correlation was used to assess the relationship between retinal abnormalities and WMH, controlling for age.Results:  Retinal arteriole narrowing existed in 15 cases and 2 controls, with Grade 2 and Grade 3 being the most common grading of retinal artery narrowing in patients with CADASIL. All patients had WMH on MRI, rated as Grade 1 in one patient, Grade 2 in five patients and Grade 3 in nine patients. The correlation coefficient of retinal arteriole narrowing and WMH was 0.546 (P < 0.05).Conclusion:  Retinal arteriole narrowing may be associated with the severity of the cerebral lesions in CADASIL.
The quality of reporting of diagnostic accuracy studies in diabetic retinopathy screening: a systematic review
Authors: Zafar Atif , Khan Ghulam Ishaq , Siddiqui MA Rehman 
Published: October 2008

AbstractPurpose:  Diabetic retinopathy (DR) is a common cause of blindness among the working age group in the developed world. To identify potentially treatable DR, systematic screening is recommended. The aim of this study was to evaluate the quality of reporting of diagnostic accuracy studies in DR screening.Methods:  We conducted a systematic literature survey in which a highly sensitive MEDLINE search was performed. The aim was to identify reports of diagnostic accuracy for DR screening published during 1995–2006. Two reviewers appraised all selected papers independently. The Standards for Reporting of Diagnostic Accuracy (STARD) checklist was used to evaluate the quality of reporting of each publication. For every manuscript, each item was scored as completely reported (score = 2), partly reported (score = 1) or not reported (score = 0). We calculated the total number of reported STARD items per article, summary scores for each STARD item and the average number of reported STARD items per year.Results:  A total of 5887 citations were identified from Medline search. Seventy‐six fulfilled the criteria for inclusion. The mean score ± SD of articles included in our study was 19.8 ± 6.5 out of a maximum of 50. The mean number ± SD of fully reported items among included studies was 8 ± 3.3. Only 9 (11.8%) manuscripts completely reported at least 50% of the STARD items. Descriptions of key aspects of the methodology were frequently missing. Only 8% (6/76) of the manuscripts had a flow chart describing flow of participants within a study.Conclusion:  The quality of reporting of diagnostic‐accuracy studies for DR screening is suboptimal. Adherence to STARD guidelines may improve the quality of reporting of DR screening studies.
Ocular response analyser to assess hysteresis and corneal resistance factor in low tension, open angle glaucoma and ocular hypertension
Authors: Shah Sunil , Laiquzzaman Mohammad , Mantry Sanjay , Cunliffe Ian 
Published: October 2008

AbstractPurpose: The aim of this study is to compare the hysteresis and corneal resistance factor (CRF) in normal tension glaucoma (NTG), primary open angle glaucoma (POAG) and ocular hypertension (OHT) eyes measured by the ocular response analyser (ORA).Methods: This is a prospective, cross‐sectional and comparative clinical trial. The setting was a teaching hospital in Birmingham, England. Patients: 216 eyes with POAG, 68 eyes with NTG and 199 eyes with OHT. Observational procedures: Goldmann applanation tonometry and intraocular pressure (IOP), hysteresis and CRF measured by ORA and central corneal thickness (CCT) by ultrasonic pachymetery. The main outcome measures were IOP, CCT, hysteresis and CRF.Results: The hysteresis in NTG, POAG and OHT eyes was 9.0 ± 1.9, 9.9 ± 2.1 and 10.2 ± 2.0 mmHg; CRF was 9.1 ± 2.2, 10.6 ± 2.0 and 12.0 ± 2.0 mmHg; IOP by Goldmann applanation tonometry and ORA was 14.7 ± 2.8 and 15.3 ± 4.2 mmHg, 16.7 ± 4.0 and 16.9 ± 4.6 mmHg and 20.5 ± 4.1 and 20.0 ± 4.5 mmHg; CCT was 526.5 ± 42.2, 537.0 ± 36.0 and 563.4 ± 35.9 µm, respectively. The difference for CRF, IOP and CCT for NTG, POAG and OHT eyes was statistically significant.Conclusion: Hysteresis and CRF were highest in OHT eyes. These factors may prove to be useful measurements of ocular rigidity and may help to understand role of the corneal rigidity in monitoring the progress of conditions such as NTG, POAG and OHT.
Distinct subsets of nucleus accumbens neurons encode operant responding for ethanol versus water
Authors: Robinson Donita L. , Carelli Regina M. 
Published: October 2008

AbstractSubsets of nucleus accumbens (NAc) neurons process information about operant responses for drugs as well as natural rewards (food and water) by excitations and inhibitions in firing rate time‐locked to the operant response. The degree to which ensembles of neurons exhibit similar firing patterns when encoding cues and operant responses across different reinforcer conditions will provide critical information regarding the functional organization of this nucleus. The present experiment evaluated the relative contribution of subsets of accumbens neurons that encode distinct features of lever press responding for ethanol vs. water. Electrophysiological recordings (n = 153 neurons) were made in the accumbens of rats trained on concurrent reinforcement schedules for ethanol and water throughout a self‐administration session. During operant responding, 52% of neurons exhibited patterned discharges characterized by significant increases or decreases in firing rate of ± 1 s relative to lever presses for ethanol and/or water. Of these phasic cells, 85% discriminated between presses for ethanol and water (i.e. exhibited firing patterns unique to one reinforcer type), while 15% exhibited identical firing patterns relative to lever presses for both reinforcers. Notably, the data revealed that both high ethanol preference and spatially distinct lever positions contributed to the reinforcer specificity. Together, these data demonstrate that subsets of NAc neurons encode conditioned and instrumental aspects of ethanol vs. water reinforcement in well‐trained rats, and that reinforcer preference and spatial cues are important components of this differential information processing.
Morphine modulation of temporomandibular joint‐responsive units in superficial laminae at the spinomedullary junction in female rats depends on estrogen status
Authors: Tashiro A. , Okamoto K. , Bereiter D. A. 
Published: October 2008

AbstractThe influence of analgesic agents on neurons activated by stimulation of the temporomandibular joint (TMJ) region is not well defined. The spinomedullary junction [trigeminal subnucleus caudalis (Vc)/C1–2] is a major site of termination for TMJ sensory afferents. To determine whether estrogen status influences opioid‐induced modulation of TMJ units, the classical opioid analgesic, morphine, was given to ovariectomized (OvX) rats and OvX rats treated for 2 days with low‐dose (LE2) or high‐dose (HE2) 17β‐estradiol‐3‐benzoate. Under thiopental anesthesia, TMJ units in superficial and deep laminae at the Vc/C1–2 junction were activated by injection of ATP (1 mm) directly into the joint space. In superficial laminae, morphine inhibited evoked activity in units from OvX and LE2 rats in a dose‐related and naloxone‐reversible manner, whereas units from HE2 rats were not inhibited. By contrast, in deep laminae, morphine reduced TMJ‐evoked unit activity similarly in all groups. Morphine reduced the background activity of units in superficial and deep laminae and resting arterial pressure similarly in all groups. Morphine applied to the dorsal surface of the Vc/C1–2 junction inhibited all units independently of E2 treatment. Quantitative polymerase chain reaction and immunoblots revealed a similar level of expression for μ‐opioid receptors at the Vc/C1–2 junction in LE2 and HE2 rats. These results indicated that estrogen status differentially affected morphine modulation of TMJ unit activity in superficial, but not deep, laminae at the Vc/C1–2 junction in female rats. The site(s) for estrogen influence on morphine‐induced modulation of TMJ unit activity was probably outside the medullary dorsal horn.
From affective value to decision‐making in the prefrontal cortex
Authors: Grabenhorst Fabian , Rolls Edmund T. , Parris Benjamin A. 
Published: October 2008

AbstractRepresenting the affective value of a reward on a continuous scale may occur separately from making a binary, for example yes vs no, decision about whether to choose the reward. To investigate whether these are separable processes, we used functional magnetic resonance imaging to measure activations produced by pleasant warm, unpleasant cold, and affectively complex combinations of these stimuli applied to the hand. On some trials the affective value was rated on a continuous scale, and on different trials a yes–no decision was made about whether the stimulus should be repeated in future. Decision‐making contrasted with just rating the affective stimuli revealed activations in the medial prefrontal cortex area 10, implicating this area in binary decision‐making. Activations related to the pleasantness ratings and which were not influenced when a binary decision was made were found in the pregenual cingulate and parts of the orbitofrontal cortex, implicating these regions in the continuous representation of affective value. When a decision was yes vs. no, effects were found in the dorsal cingulate cortex, agranular (anterior) insula and ventral tegmental area, implicating these areas in initiating actions to obtain goals.
Sensory analysis of calcium‐biofortified lettuce
Authors: Park Sunghun , Elless Mark P. , Park Jungeun , Jenkins Alicia , Lim Wansang , Chambers IV Edgar , Hirschi Kendal D. 
Published: October 2008

SummaryVegetables represent an attractive means of providing increased calcium nutrition to the public. In this study, it was demonstrated that lettuce expressing the deregulatedArabidopsisH+/Ca2+transporter sCAX1 (cation exchanger 1) contained 25%–32% more calcium than controls. These biofortified lettuce lines were fertile and demonstrated robust growth in glasshouse growth conditions. Using a panel of highly trained descriptive panellists, biofortified lettuce plants were evaluated and no significant differences were detected in flavour, bitterness or crispness when compared with controls. Sensory analysis studies are critical if claims are to be made regarding the efficacy of biofortified foods, and may be an important component in the public acceptance of genetically modified foods.
TAKING DUE CARE: MORAL OBLIGATIONS IN DUAL USE RESEARCH
Authors: KUHLAU FRIDA , ERIKSSON STEFAN , EVERS KATHINKA , HÖGLUND ANNA T. 
Published: October 2008

ABSTRACTIn the past decade, the perception of a bioterrorist threat has increased and created a demand on life scientists to consider the potential security implications of dual use research. This article examines a selection of proposed moral obligations for life scientists that have emerged to meet these concerns and the extent to which they can be considered reasonable. It also describes the underlying reasons for the concerns, how they are managed, and their implications for scientific values.Five criteria for what constitutes preventable harm are suggested and a number of proposed obligations for life scientists are considered against these criteria, namely, the obligations to prevent bioterrorism; to engage in response activities; to consider negative implications of research; not to publish or share sensitive information; to oversee and limit access to dangerous material; and to report activities of concern.Although bioterrorism might be perceived as an imminent threat, the analysis illustrates that this is beyond the responsibility of life scientists either to prevent or to respond to. Among the more reasonable obligations are duties to consider potential negative implications of one's research, protect access to sensitive material, technology and knowledge, and report activities of concern. Responsibility, therefore, includes obligations concerned with preventing foreseeable and highly probable harm. A central conclusion is that several of the proposed obligations are reasonable, although not unconditionally.
J. R. Firth: a new biography1
Authors: Plug Leendert 
Published: October 2008

AbstractThis article presents a sketch of the life and work of J. R. Firth, the first professor of general linguistics in Great Britain and President of the Philological Society from 1954 to 1957, based on a study of existing biographical literature and commentary, Firth’s publications, and various hitherto unpublished archive materials. The article sheds new light on matters such as Firth’s entry into the fledgling field of linguistics in Britain, his relationships with colleagues such as Daniel Jones and Arthur Lloyd James, and his alleged attempts to present a book‐length exposition of his views on linguistics and phonetics.
Bayesian Model Selection using Test Statistics
Authors: Hu Jianhua , Johnson Valen E. 
Published: October 2008

SummaryExisting Bayesian model selection procedures require the specification of prior distributions on the parameters appearing in every model in the selection set. In practice, this requirement limits the application of Bayesian model selection methodology. To overcome this limitation, we propose a new approach towards Bayesian model selection that uses classical test statistics to compute Bayes factors between possible models. In several test cases, our approach produces results that are similar to previously proposed Bayesian model selection and model averaging techniques in which prior distributions were carefully chosen. In addition to eliminating the requirement to specify complicated prior distributions, this method offers important computational and algorithmic advantages over existing simulation-based methods. Because it is easy to evaluate the operating characteristics of this procedure for a given sample size and specified number of covariates, our method facilitates the selection of hyperparameter values through prior-predictive simulation.
Pseudomartingale Estimating Equations for Modulated Renewal Process Models
Authors: Lin Fengchang , Fine Jason P. 
Published: October 2008

SummaryWe adapt martingale estimating equations based on gap time information to a general intensity model for a single realization of a modulated renewal process. The consistency and asymptotic normality of the estimators is proved under ergodicity conditions. Previous work has considered either parametric likelihood analysis or semiparametric multiplicative models using partial likelihood. The framework is generally applicable to semiparametric and parametric models, including additive and multiplicative specifications, and periodic models. It facilitates a semiparametric extension of a popular parametric earthquake model. Simulations and empirical analyses of Taiwanese earthquake sequences illustrate the methodology’s practical utility.