bluuebunny/crossref_metadata_2025 huggingface dataset:
Competition–colonization trade-off promotes coexistence of low-virulence viral strains
Authors: Ojosnegros Samuel , Delgado-Eckert Edgar , Beerenwinkel Niko
Published: April 2012

RNA viruses exist as genetically diverse populations displaying a range of virulence degrees. The evolution of virulence in viral populations is, however, poorly understood. On the basis of the experimental observation of an RNA virus clone in cell culture diversifying into two subpopulations of different virulence, we study the dynamics of mutating virus populations with varying virulence. We introduce a competition–colonization trade-off into standard mathematical models of intra-host viral infection. Colonizers are fast-spreading virulent strains, whereas the competitors are less-virulent variants but more successful within co-infected cells. We observe a two-step dynamics of the population. Early in the infection, the population is dominated by colonizers, which later are outcompeted by competitors. Our simulations suggest the existence of steady state in which all virulence classes coexist but are dominated by the most competitive ones. This equilibrium implies collective virulence attenuation in the population, in contrast to previous models predicting evolution of the population towards increased virulence.
The central role of the host cell in symbiotic nitrogen metabolism
Authors: Macdonald Sandy J. , Lin George G. , Russell Calum W. , Thomas Gavin H. , Douglas Angela E.
Published: April 2012

Symbiotic nitrogen recycling enables animals to thrive on nitrogen-poor diets and environments. It traditionally refers to the utilization of animal waste nitrogen by symbiotic micro-organisms to synthesize essential amino acids (EAAs), which are translocated back to the animal host. We applied metabolic modelling and complementary metabolite profiling to investigate nitrogen recycling in the symbiosis between the pea aphid and the intracellular bacteriumBuchnera, which synthesizes EAAs. The results differ from traditional notions of nitrogen recycling in two important respects. First, aphid waste ammonia is recycled predominantly by the host cell (bacteriocyte) and notBuchnera. Host cell recycling is mediated by shared biosynthetic pathways for four EAAs, in which aphid transaminases incorporate ammonia-derived nitrogen into carbon skeletons synthesized byBuchnerato generate EAAs. Second, the ammonia substrate for nitrogen recycling is derived from bacteriocyte metabolism, such that the symbiosis is not a sink for nitrogenous waste from other aphid organs. Host cell-mediated nitrogen recycling may be general among insect symbioses with shared EAA biosynthetic pathways generated by the loss of symbiont genes mediating terminal reactions in EAA synthesis.
Reproductive biology of the spotback skate Atlantoraja castelnaui in the south‐west Atlantic Ocean
Authors: Colonello J. C. , García M. L. , Lasta C. A. , Menni R. C.
Published: April 2012

This study provides information on the reproduction of spotback skate Atlantoraja castelnaui. A total of 232 individuals (119 females and 113 males) were obtained from surveys carried out between 2003 and 2006, from the south‐west Atlantic Ocean, between 34 and 42° S and <50 m deep; another 514 specimens (241 females and 273 males) were obtained between 2005 and 2007 from commercial fishery operations carried out in the same area and landings in the port of Mar del Plata, Argentina. Males ranged from 185 to 1250 mm total length (LT) and females from 243 to 1368 mm LT. Length at maturity was estimated to be 980 mm for males and 1089 mm LT for females. Lack of variation of testis mass together with the continuous production of mature spermatocyst and spermatozoa in deferent ducts suggested that males can reproduce throughout the year. Females reproduced year‐round with peaks of reproductive activity an integral part of a continuous cycle. This conclusion is corroborated by the seasonal variation of ovaries, oviducal gland and the occurrence of females with eggs in the uterus throughout the year. Results from this study indicate that A. castelnaui is very susceptible to fishery pressure.
e‐Learning initiatives to support prescribing
Authors: Maxwell Simon , Mucklow John
Published: April 2012

Preparing medical students to prescribe is a major challenge of undergraduate education. They must develop an understanding of clinical pharmacology and acquire knowledge about drugs and therapeutics, as well as the skills to prescribe for individual patients in the face of multiple variables. The task of delivering the learning required to achieve these attributes relies upon limited numbers of teachers, who have increasingly busy clinical commitments. There is evidence that training is currently insufficient to meet the demands of the workplace. e‐Learning provides an opportunity to improve the learning experience. The advantages for teachers are improved distribution of learning content, ease of update, standardization and tracking of learner activities. The advantages for learners are ease of access, greater interactivity and individual choice concerning the pace and mix of learning. Important disadvantages are the considerable resource required to develop e‐Learning projects and difficulties in simulating some aspects of the real world prescribing experience. Pre‐requisites for developing an e‐Learning programme to support prescribing include academic expertise, institutional support, learning technology services and an effective virtual learning environment. e‐Learning content might range from complex interactive learning sessions through to static web pages with links. It is now possible to simulate and provide feedback on prescribing decisions and this will improve with advances in virtual reality. Other content might include a student formulary, self‐assessment exercises (e.g. calculations), a glossary and an on‐line library. There is some evidence for the effectiveness of e‐Learning but better research is required into its potential impact on prescribing.
Dynamics of soil carbon following destruction of tropical rainforest and the subsequent establishment of Imperata grassland in Indonesian Borneo using stable carbon isotopes
Authors: Yonekura Yusuke , Ohta Seiichi , Kiyono Yoshiyuki , Aksa Darul , Morisada Kazuhito , Tanaka Nagaharu , Tayasu Ichiro
Published: April 2012

Southeast Asia has the highest rate of tropical rainforest deforestation worldwide, and large deforested areas have been replaced ultimately by the highly invasive grass Imperata cylindrica. However, information on the carbon (C) budget with such land transition is very scarce. This study presents the dynamics of soil C following rainforest destruction and the subsequent establishment of Imperata grassland in the lowland humid tropics of Indonesian Borneo using stable C isotopes. To evaluate the relative contribution of organic matter originating from primary forest (C3) and grasslands (C4), we compared soil C stock and natural 13C abundance from six sites to a depth of 100 cm using samples with a wide range of soil textures. Twelve years after the first soil sampling in the grasslands, we re‐sampled to examine temporal changes in soil organic matter. The grassland topsoil (0–5 cm) is an active layer with rapid decomposition and incorporation of fresh C (mean residence time: 7.5 year) and a substantial proportion of the stable C pool (37%). The decline in forest‐derived C was slight, even at 5–10 cm depths, and subsoil (20–100 cm depth) forest‐derived C did not change along the forest‐to‐grassland chronosequence. Grassland‐derived C stock increased significantly in the subsurface and subsoils (5–100 cm). Simulation indicated that total soil C stock (0–100 cm) increased by 18.6 Mg ha−1 from initial primary forest (58.0 Mg ha−1) to a new equilibrium state of the grassland (76.6 Mg ha−1) after 30–50 years of grassland establishment. This research indicates that the soil did not function as a CO2 source when the deforested area was replaced by Imperata grassland on the Ultisols of the Asian humid tropics. Instead, increased soil C stocks offset CO2 emissions, with the C offset accounting for 6.6–7.4% of the loss of biomass C stock.
Defining the needs of ICU patient families in a suburban/rural Greek population: a prospective cohort study
Authors: Chatzaki Maria , Klimathianaki Maria , Anastasaki Maria , Chatzakis Georgios , Apostolakou Eleni , Georgopoulos Dimitrios
Published: April 2012

Aim.  To define the needs of intensive care unit patients’ families in the specific suburban/rural population of Crete Island.

Background.  Families of intensive care unit patients have specific needs that should also be addressed by the intensive care unit‐care team. Current research has mostly concentrated on families from an urban setting, therefore may not be applicable to other populations.

Design.  Prospective cohort study.

Methods.  Family members of patients admitted in the intensive care unit for ≥48 hours over 18 months, in a mixed medical‐surgical, 11 bed closed intensive care unit. Questionnaire: The Greek translation of Critical Care Family Need Inventory, which consists of 45 need items covering the information, reassurance, proximity, support and comfort domains. Each item was scored on a four‐point scale (1 = very important to 4 = not important). Participants were also asked to single out the most important need from the Critical Care Family Need Inventory and complete a questionnaire on basic demographic characteristics.

Results.  Two hundred and thirty (65%) family members completed the questionnaire. Mean score for each of the 45 items ranged from 1·03–3 (scale from 1: very important–4: not important). Fourteen items were rated by responders as very important (mean score <1·25). Reassurance need items were consistently singled out as most important regardless of the participant’s background. Participants with a lower educational and socio‐economical status rated support need items as more important than those with a higher status.

Conclusion.  In this particular suburban/rural population, both ‘universal’ reassurance needs and specific support needs related to responders’ educational or socio‐economical background were identified.

Relevance to clinical practice.  Enhanced recognition of these needs may improve quality of care offered by intensive care unit‐care team to families of their patients.
Effects of Malassezia yeasts on serum Th1 and Th2 cytokines in patients with guttate psoriasis
Authors: Aydogan Kenan , Tore Okan , Akcaglar Sevim , Oral Barbaros , Ener Beyza , Tunalı Sukran , Saricaoglu Hayriye
Published: April 2012

Background  Systemic and focal infections caused by microorganisms have been known to induce or exacerbate psoriasis. Although the role of yeast species of the genus Malassezia in the pathogenesis of psoriasis is not fully understood, it is thought that these lipophilic yeasts may represent a triggering factor in the exacerbation of psoriatic lesions.

Objectives  This study investigated the effects of Malassezia yeasts on serum Th1 and Th2 cytokines in patients with guttate psoriasis (GP) in order to define their role in the pathogenesis of psoriasis.

Methods  Fifty patients with GP and 29 clinically healthy individuals were included in the study. All samples consisted of scales and scrapings taken from the scalps, trunks, and upper limbs of both psoriasis patients and healthy subjects. Psoriasis patients and healthy subjects were grouped according to their positivity or negativity for Malassezia yeasts as ascertained by direct microscopy and/or culture. An enzyme‐linked immunosorbent assay (ELISA) was used to measure serum levels of Th1 and Th2 cytokines in these groups.

Results  No significant differences in positivity for Malassezia yeasts were found between psoriatic skin and healthy skin in samples taken from different body sites. Serum interleukin‐13 (IL‐13) levels were significantly lower in the psoriasis group compared with the control group (P = 0.04). Levels of other cytokines did not differ significantly between the psoriasis and control groups. Mean levels of Th2 cytokines (IL‐4, IL‐10, IL‐13), but not of Th1 cytokines (IL‐2 and IFN‐γ), were significantly lower in psoriasis patients positive for Malassezia yeasts compared with those negative for Malassezia yeasts and control subjects (P = 0.04, P < 0.001 and P = 0.01, respectively).

Conclusions  The isolation of Malassezia yeasts from GP lesions does not necessarily mean that these species are pathogenic, but their downregulating effects on anti‐inflammatory Th2 cytokines may contribute to the occurrence of GP.
Cardiovascular risk factors in subjects with psoriasis: a cross‐sectional general population study
Authors: Jensen Peter , Thyssen Jacob P. , Zachariae Claus , Hansen Peter R. , Linneberg Allan , Skov Lone
Published: April 2012

Background  Epidemiological data have established an association between cardiovascular disease and psoriasis. Only one general population study has so far compared prevalences of cardiovascular risk factors among subjects with psoriasis and control subjects. We aimed to determine the prevalence of cardiovascular risk factors in subjects with and without psoriasis in the general population.

Methods  During 2006–2008, a cross‐sectional study was performed in the general population in Copenhagen, Denmark. A total of 3471 subjects participated in a general health examination that included assessment of current smoking status, weight, height, waist and hip circumferences, systolic and diastolic blood pressures, resting heart rate, and plasma lipids, hemoglobin A1c, fasting glucose, and insulin levels.

Results  Physician‐diagnosed psoriasis was reported by 238 (7.1%) of 3374 participants. There were no differences between subjects with and without psoriasis with regard to traditional cardiovascular risk factors.

Conclusions  Our results contrast with the hitherto‐reported increased prevalence of metabolic syndrome in subjects with psoriasis in the general US population. However, our results agree with those of other previous studies in which the association between mild psoriasis and cardiovascular risk factors is often non‐significant. Further controlled research is needed to describe the prevalence of cardiovascular risk factors in subjects with mainly mild to moderate psoriasis in the general population.
Hydrogen peroxide is involved in nitric oxide‐induced cell death in maize leaves
Authors: Kong X. , Zhang D. , Pan J. , Zhou Y. , Li D.
Published: April 2012

Recent evidence indicates that nitric oxide (NO) plays an important role in plant hypersensitive cell death. Here, we report that NO treatment led to rapid cell death and induced hydrogen peroxide (H2O2) accumulation in maize leaves. We also show that NO induced the expression of Zmrboh genes. Pharmacological study suggests that NO‐induced cell death is in part mediated via H2O2. In addition, semi‐quantitative RT‐PCR revealed that NO induced expression of the systemic acquired resistance (SAR) genes, ZmPR1 and ZmPR5.
Partial anomalous pulmonary venous connection and pulmonary arterial hypertension
Authors: SAHAY SANDEEP , KRASUSKI RICHARD A. , TONELLI ADRIANO R.
Published: April 2012

Background and objective:  Isolated partial anomalous pulmonary venous connection (PAPVC) has been implicated as a cause of pulmonary arterial hypertension (PAH); however this condition is often overlooked in the diagnostic work up of patients with PH. We studied the prevalence of PAH both in patients with isolated PAPVC or associated with other congenital heart diseases (CHD) such as atrial septal defect (ASD). We also aimed to identify factors related to the presence of PAH in these patients.

Methods:  We retrospectively analyzed data from the Adult CHD database at the Cleveland Clinic, USA between October 2005–2010. We included all patients diagnosed with PAPVC with or without other CHD. We excluded all patients with previous corrective surgeries.

Results:  We identified 14 (2.5%) patients with PAPVC. Group I included patients with PAPVC (with or without patent foramen ovale (PFO)). Group II included patients with PAPVC associated with other CHD. PAH was seen in six (6/14, 42.8%) patients, two (2/7, 28.5%) in group I and four (4/7, 57.1%) in group II (P = 0.3). The mean pulmonary artery pressure in all patients (n = 14) was 29.5 ± 13.8 mm Hg. Group I had a mean PAP of 23.6 ± 6.6 mm Hg as compared to 33.7 ± 16.5 mm Hg for group II (P = 0.34). The two patients in group I with PAH had either two anomalous pulmonary veins or a condition (sickle cell disease) that could potentially explain the haemodynamic findings.

Conclusions:  Patients with PAPVC (with or without PFO) in the absence of other CHD had normal pulmonary arterial pressure (PAP) unless they have two pulmonary veins with anomalous return or associated conditions known to cause PAH.
Foliar freezing resistance of Australian alpine plants over the growing season
Authors: VENN SUSANNA E. , MORGAN JOHN W. , LORD JANICE M.
Published: April 2012

We assessed the freezing resistance of leaves ex situ of 25 Australian alpine plant species. We compared the freezing resistance of forb, graminoid and shrub species from three alpine summits of different altitudes; from a low altitude site just above treeline, to a fully alpine tundra site. Foliar freezing resistance (LT50) in spring varied from −5.9°C to −18.7°C and standardized LT50 values within species were significantly related to site altitude. Additionally, when comparing all the species in the study, freezing resistance was significantly related to site; the LT50 of samples from a low‐altitude summit (1696 m) were significantly lower than those of samples from mid‐ (1805 m) and high‐altitude (1860 m) summits. The LT50 of juvenile foliage did not differ significantly from that of adult foliage. Shrubs were highly resistant to freezing. At the highest summit, we examined the course of seasonal freezing resistance from early summer to early autumn across three alpine plant communities that differed in the time of natural snowmelt; from sheltered (snowpatch) to exposed (open heath). No differences in freezing resistance over the growing season were detected for exposed or sheltered communities and there were no consistent trends indicating frost hardening over the growing season. Overall, the common Australian alpine species we investigated appear well adapted to freezing conditions throughout the snow‐free growing season. We have no evidence to suggest that freezing temperatures soon after snowmelt in spring are especially damaging to the alpine plants at these summits.
Morphological patterns of the collateral sulcus in the human brain
Authors: Huntgeburth Sonja C. , Petrides Michael
Published: April 2012

The collateral sulcal complex is an important landmark on the medial surface of the temporal lobe. Anteriorly, it delineates the limbic regions of the parahippocampal gyrus from the visual‐processing areas of the fusiform gyrus. Posteriorly, it continues into the occipital lobe, bearing no relationship to the memory‐related limbic regions. Given the considerable extent of the sulcus and functional heterogeneity of the surrounding cortex, an investigation of the morphology of this sulcus was carried out to examine whether it is continuous or a series of sulcal parts, i.e. independent sulci classified together under the name collateral sulcus. We investigated the collateral sulcal complex using magnetic resonance images taking into account the three‐dimensional nature of the brain. Our examination demonstrated three separate sulcal segments: (i) an anterior segment, the rhinal sulcus, delineating the uncus from the adjacent temporal neocortex, (ii) a middle segment, the collateral sulcus proper, forming the lateral border of the posterior parahippocampal cortex, and (iii) a caudal segment, the occipital extent of the collateral sulcus, within the occipital lobe. Three relationships exist between the rhinal sulcus and collateral sulcus proper, only one being clearly identifiable from the surface. Posteriorly, the collateral sulcus proper and the occipital collateral sulcus, although appearing continuous on the brain surface, can be separated in the depth of the sulcus in all cases. These results provide quantification of the location and variability within standard stereotaxic space for the three collateral sulcus segments that could be used to aid accurate identification of functional activation peaks derived from neuroimaging studies.
Thinking of Co2+‐staining explant tissue or cultured cells? How to make it reliable and specific
Authors: Aurousseau Mark R. P. , Osswald Ingrid K. , Bowie Derek
Published: April 2012

Ca2+ and/or Zn2+ entry into neurons and glial cells is often a key step driving the processes of neurodevelopment and disease. As a result, a major pre‐occupation of many neuroscientists has been in tracking down when and where nervous tissues express ion channels with appreciable divalent ion permeability. The cobalt (Co2+)‐staining technique is one of the few techniques that allow a snapshot of the entire neuronal circuit, and selectively labels cells expressing divalent‐permeable ion channels with a brown–black precipitate. Despite this, its use has been remarkably limited in the past decade. Reluctance to employ this approach has largely been related to an earlier concern with obtaining a reliable and reproducible means of visualizing transported Co2+. Here we show that recent advances have resolved these issues, opening this straightforward and valuable technique to a much larger neuroscience audience.
Experience‐dependent regulation of functional maps and synaptic protein expression in the cat visual cortex
Authors: Jaffer Sajjida , Vorobyov Vasily , Kind Peter C. , Sengpiel Frank
Published: April 2012

Although the basis of our knowledge of experience‐dependent plasticity comes from studies on carnivores and primates, studies examining the physiological and molecular mechanisms that underlie development and plasticity have increasingly employed mice. We have used several common rearing paradigms, such as dark‐rearing and monocular deprivation (MD), to examine the timing of the physiological and molecular changes to altered experience in the cat primary visual cortex. Dark‐rearing from birth or for 1 week starting at 4 weeks of age produced a similar reduction in the amplitude of responses measured through intrinsic signal imaging and a reduction in orientation selectivity. One week of visual experience following dark‐rearing until 4 weeks of age yielded normal responses in both amplitude and orientation selectivity. The depression of deprived‐eye responses was similar in magnitude after 2 and 7 days of MD. In contrast, non‐deprived‐eye responses almost doubled in magnitude after 7 days compared with 2 days of MD. These changes in the functional properties of primary visual cortex neurons were mirrored by specific changes in synaptic protein expression. Changes in proteins such as the NR2A and NR2B subunits of the N‐methyl‐D‐aspartate receptor, postsynaptic density protein 95, alpha‐CA2+/calmodulin‐dependent protein kinase II (αCaMKII), and GABAAα1a indicated that the levels of sensory activity regulated mechanisms associated with both excitatory (NR2A and NR2B) and inhibitory (GABAAα1a) transmission so as to maintain response homeostasis. Additionally, we found that MD regulated the AMPA receptor glutamate (GluR1) subunit as well as signalling molecules (αCaMKII and synaptic Ras GTPase activating protein, SynGAP) downstream of N‐methyl‐D‐aspartate receptors. Proteins in a common signalling pathway appeared to have similar developmental expression profiles that were broadly similar between cats and rodents.
Heidegger and the Supposition of a Single, Objective World
Authors: McManus Denis
Published: April 2012

Christina Lafont has argued that the early Heidegger's reflections on truth and understanding are incompatible with ‘the supposition of a single objective world’. This paper presents her argument, reviews some responses that the existing Heidegger literature suggests (focusing, in particular, on work by John Haugeland), and offers what I argue is a superior response. Building on a deeper exploration of just what the above ‘supposition’ demands (an exploration informed by the work of Bernard Williams and Adrian Moore), I argue that a crucial assumption that Lafont and Haugeland both accept must be rejected, namely, that different ‘understandings of Being’ can be viewed as offering ‘rival perspectives’ on a common subject‐matter. I develop this case by drawing on an alternative account of what a Heideggerian ‘understanding of Being’ might be like.
Females first? Past, present and future variability in offspring sex ratio at a temperate sea turtle breeding area
Authors: Katselidis K. A. , Schofield G. , Stamou G. , Dimopoulos P. , Pantis J. D.
Published: April 2012

The long‐term survival of species with temperature‐dependant sex determination requires a sufficient range of incubation temperatures to ensure that both males and females are produced. The primary sex ratio of sea turtles is determined by the temperature experienced by eggs during the middle third of incubation. Here, we investigated the variability in the production of male and female offspring by loggerhead sea turtles Caretta caretta at six nesting beaches in the temperate breeding area of Zakynthos, Greece. Hatchling sex ratios were estimated using incubation durations and sand temperatures for 2007–2009, while the empirical relationship between air and sand temperature was used to infer historical (1875–2010) and future (2011–2100) hatchling sex ratios. First, all six beaches produced males; 55% of production was across five beaches, while 45% was focused on one beach (primarily in July). Second, male production varied across the season in different years; there was an initial peak in June, with production (rising, declining or plateauing) later in the season being regulated by August air temperatures. Interestingly, the annual male production rate estimated from the 3‐year dataset (23%) was half that estimated from the 135‐year reconstruction (50%), with the latter showing broad interannual variation. Finally, modelled predictions of future sex ratios ranged from a conservative 7.6% decline in male production by 2100 versus no production by 2038. This study provides a baseline from which predicted trends in hatchling sex ratio, in parallel to regular field assessments, could be used to provide guidelines for the selection of appropriate nest protection management protocols, to maintain required sex ratios that safeguard the future of this population.
Newspaper Representation of the Debates in the 2007 Jamaican General Election Campaign
Authors: CHARLES CHRISTOPHER A. D.
Published: April 2012

This article deconstructs the newspaper representations of three debates held in 2007 during the Jamaican General Election campaign. The theory of social representation is used in this article to explain political behaviour and outcomes. Representations are the images, words, symbols or phrases that are generated from people's dialogic interaction that signify meanings. Content analysis of relevant articles covering the electoral campaign in the main print media in Jamaica forms the empirical basis for study. The majority of representations of the three main debates were negative, revealing that political manifestos were largely ignored and policy funding was not addressed. Significant issues such as crime, education, health, garrison politics, corruption and unemployment were inadequately addressed, and the wider global context of these matters was ignored. The consensus was that the Jamaica Labour Party (JLP) won two of the three debates, notably the leadership debate in which the Leader of the Opposition, Bruce Golding MP, performed more effectively than the then current Prime Minister, Portia Simpson‐Miller of the People's National Party (PNP). Social representation theory is used to assess the types of political meanings generated by media coverage during the General Election. It is suggested that the perceived success of the JLP candidates in the main debates was an important contribution to the party's overall electoral victory.
An assessment of factors characterising the microbiology of Grana Trentino cheese, a Grana‐type cheese
Authors: ROSSI FRANCA , GATTO VERONICA , SABATTINI GIANCARLO , TORRIANI SANDRA
Published: April 2012

In this study, microbiological aspects of Grana Trentino, a variant of Grana Padano cheese, were defined by plate counts, random amplified polymorphic DNA (RAPD) PCR genotying, 16S rRNA gene sequencing of bacterial isolates and PCR–denaturing gradient gel electrophoresis (PCR–DGGE). Results showed variability in monthly fluctuations of whey culture counts, differences in the diffusion of bacterial genotypes among producers and dairy plant‐specific microbial associations. Moreover, the presence of bacteria not previously reported in this cheese type was highlighted, including coagulase‐negative staphylococci and Lactobacillus sanfranciscensis‐like micro‐organisms.
Accuracy of intraocular lens power calculation using partial coherence interferometry in patients with high myopia
Authors: Roessler Gernot F , Dietlein Thomas S , Plange Niklas , Roepke Anna‐Katharina , Dinslage Sven , Walter Peter , Mazinani Babac A
Published: April 2012

Citation information: Roessler GF, Dietlein TS, Plange N, Roepke A‐K, Dinslage S, Walter P, Mazinani BAE. Accuracy of intraocular lens power calculation using partial coherence interferometry in patients with high myopia. Ophthalmic Physiol Opt 2012, 32, 228–233. doi: 10.1111/j.1475‐1313.2012.00903.x

Purpose:  Ultrasound‐A‐scan‐biometry intraocular lens power calculation for cataract surgery sometimes shows lack of accuracy in patients with high myopia. The purpose of this retrospective study was to assess the accuracy of lens power calculation with optical biometry using the Zeiss IOLMaster across a large range of myopia levels.

Methods:  We included 37 consecutive, myopic eyes with an axial length >26.5 mm (31 patients, 62 ± 13 years old, average preoperative refraction of –14.46 ± 6.61 D, range −3.5 to −32.0 D), which underwent phacoemulsification and implantation of an intraocular lens following biometry using the IOLMaster. For lens power calculation, the Haigis formula was used in all cases. For comparison, refraction was back‐calculated using the SRK/T and Holladay I formulae.

Results:  The preoperative mean axial length was 29.37 ± 2.44 mm with a range of 26.50–35.52 mm. Thirty eyes (81.1%) showed a postoperative spherical equivalent which differed 1.00 D or less from the predicted value, in 20 cases (54.1%) the postoperative refractive error was within ± 0.50 D. The mean absolute error (MAE) was 0.70 ± 0.59 D (Holladay I, 0.85 ± 0.68; SRK/T, 1.01 ± 0.61 D).

Conclusions:  Optical biometry for intraocular lens power calculation seems to deliver reliable results for cataract surgery in patients with high myopia, although our data describe an increasing lack of accuracy beyond an axial length of 30 mm. The Haigis formula provided the best predictability of postoperative refractive outcome for myopic eyes in general.
Militant tropicality: war, revolution and the reconfiguration of ‘the tropics’c.1940–c.1975
Authors: Clayton Daniel
Published: April 2012

The critical literature on ‘tropicality’– the colonising discourse that constructs the tropical world as the West’s environmental Other – focuses chiefly on its historical links with colonialism and on the agency of Western colonisers. Scant attention has been paid to the trajectory of this discourse between the 1940s and 1970s, or to how it has been resisted by the ‘tropicalised’. This paper teases out how, in this post‐war era of decolonisation and Cold War, there arose in Western experience a potent image of the tropics as militant – as combative, belligerent and revolutionary. The term militant tropicality is deployed to recall this image and identify a suite of counter‐hegemonic knowledges, practices and experiences emanating from the tropical world that challenged the way the West judged the tropics against the presumed normality of the temperate north. The paper dwells on two sites in the promulgation of this militant tropicality – the Caribbean during the 1940s and 1950s, and Vietnam during the 1960s – and probes some of its salient imaginative and material geographies using a range of sources (literature, art, journalism, revolutionary thought, and government and military records). The paper underscores the (little studied) martial quality of tropicality and how, by the 1960s, militant tropicality had become closely associated with guerrilla wars in jungle settings that fractured the West’s ‘temperate’ model of war.
AMP‐activated protein kinase (AMPK)–dependent and –independent pathways regulate hypoxic inhibition of transepithelial Na+ transport across human airway epithelial cells
Authors: Tan CD , Smolenski RT , Harhun MI , Patel HK , Ahmed SG , Wanisch K , Yáñez‐Muñoz RJ , Baines DL
Published: April 2012

BACKGROUND AND PURPOSE Pulmonary transepithelial Na+ transport is reduced by hypoxia, but in the airway the regulatory mechanisms remain unclear. We investigated the role of AMPK and ROS in the hypoxic regulation of apical amiloride‐sensitive Na+ channels and basolateral Na+K+ ATPase activity.

EXPERIMENTAL APPROACH H441 human airway epithelial cells were used to examine the effects of hypoxia on Na+ transport, AMP : ATP ratio and AMPK activity. Lentiviral constructs were used to modify cellular AMPK abundance and activity; pharmacological agents were used to modify cellular ROS.

KEY RESULTS AMPK was activated by exposure to 3% or 0.2% O2 for 60 min in cells grown in submerged culture or when fluid (0.1 mL·cm−2) was added to the apical surface of cells grown at the air–liquid interface. Only 0.2% O2 activated AMPK in cells grown at the air–liquid interface. AMPK activation was associated with elevation of cellular AMP : ATP ratio and activity of the upstream kinase LKB1. Hypoxia inhibited basolateral ouabain‐sensitive Isc (Iouabain) and apical amiloride‐sensitive Na+ conductance (GNa+). Modification of AMPK activity prevented the effect of hypoxia on Iouabain (Na+K+ ATPase) but not apical GNa+. Scavenging of superoxide and inhibition of NADPH oxidase prevented the effect of hypoxia on apical GNa+ (epithelial Na+ channels).

CONCLUSIONS AND IMPLICATIONS Hypoxia activates AMPK‐dependent and ‐independent pathways in airway epithelial cells. Importantly, these pathways differentially regulate apical Na+ channels and basolateral Na+K+ ATPase activity to decrease transepithelial Na+ transport. Luminal fluid potentiated the effect of hypoxia and activated AMPK, which could have important consequences in lung disease conditions.
HIV‐HCV co‐infection facing HCV protease inhibitor licensing: implications for clinicians
Authors: Ingiliz Patrick , Rockstroh Jürgen K.
Published: April 2012

With the licensing of the first hepatitis C (HCV) protease inhibitors (PI), telaprevir (TVR) and boceprevir (BOC), cure rates for chronic HCV infection will substantially improve. Human immunodeficiency virus‐ chronic hepatitis C (HIV‐HCV) co‐infected patients are in urgent need for these new drugs, because they are facing both severe liver disease and lower response rates than HCV monoinfected patients. The currently available efficacy data are however, limited to two phase II trials. Fortunately, TVR and BOC appear to be able to improve cure rates in co‐infected patients. A major challenge for clinicians will be the management of drug–drug interactions of antiretroviral drugs and new PI. As HCV PI are also metabolized by the cytochrome P450 3A4 system interactions are probable as well with non‐nucleoside reverse transcriptase inhibitors as with HIV PI. To our knowledge, TVR can only be safely used with one protease inhibitor, boosted atazanavir, and also with efavirenz (EFV), although this combination requires TVR dose adjustments. Boceprevir should not be combined with HIV PI and should not be combined with EFV. The approval of TVR and BOC will create new chances of cure also for HIV‐HCV co‐infected patients. However, the decision who to treat or not has to be taken carefully on the basis of fibrosis stage and previous treatment outcomes. In addition, HIV therapy needs to be optimized according to the available drug–drug interaction data.
Implementing a diet and exercise program for limiting maternal weight gain in obese pregnant women: A pilot study
Authors: Lee Amelia , Karpavicius Jane , Gasparini Elisabeth , Forster Della
Published: April 2012

Background

Thirty‐four per cent of Australian women having a baby are overweight or obese. Excessive gestational weight gain leads to significant complications for mother and baby, not only during the pregnancy but in the long term. Limiting weight gain in pregnancy is thought to reduce complications, but there is limited evidence to guide practice.

Aim

To test the feasibility and acceptance of an intervention aimed at limiting gestational weight gain in obese pregnant women.

Methods

A low‐cost multidisciplinary program, comprised of four individual dietary education sessions and three exercise classes, was developed and implemented at a tertiary hospital in metropolitan Melbourne, Australia. The Maternal Weight Management program was offered to obese women at their pregnancy booking visit. Program uptake and women's views of the program were explored via telephone survey, and pregnancy and birth outcomes collected.

Results

Seventy‐four women participated in this pilot study; 95% attended at least one session of the program and the attrition rates were high. Fifty‐three per cent completed the postnatal survey. Women confirmed their preference for individual appointments and felt it was important for the hospital to offer a weight management program.

Conclusions

The program we designed had poor uptake and cannot be recommended in its current format. Future studies and considerations could look at more acceptable program design and recruitment strategies and should include formative work with women who would be eligible for such intervention.
Assessment of CSF Flow Dynamics Using PC‐MRI in Spontaneous Intracranial Hypotension
Authors: Hasiloglu Zehra Isik , Albayram Sait , Gorucu Yasin , Selcuk Hakan , Cagil Emin , Erdemli Halil Eren , Adaletli Ibrahim
Published: April 2012

(Headache 2012;52:808‐819)

Aim.— Spontaneous intracranial hypotension (SIH) is caused by spontaneous cerebrospinal fluid (CSF) leaks and is known to cause orthostatic headaches. Phase‐contrast magnetic resonance imaging (PC‐MRI) is a non‐invasive technique that can be used to quantify variation in CSF flow. The aim of this study was to assess CSF flow dynamics using PC‐MRI in SIH.

Materials and Methods.— Twenty‐five patients with a definitive diagnosis of SIH and 25 healthy subjects were evaluated with PC‐MRI. Magnetic resonance (MR) images were acquired using a 1.5‐T unit with an 8‐channel head coil. Differences between SIH patients and control subjects were assessed statistically using Wilcoxon's rank sum test, Spearman's rho test, or Pearson's chi‐square test, as appropriate.

Results.— CSF flow volumes toward the third ventricle, CSF flow volumes toward the fourth ventricle, the absolute stroke volume, the peak systolic velocity, and the peak diastolic velocity in SIH patients were significantly smaller than those in control subjects (P < .0001). On the other hand, the net CSF flow volume (P = .9227) and the net CSF flow direction (P = .2472) for SIH patients and control subjects were not significantly different.

Conclusions.— The results obtained by CSF flow analysis were directly related to values of CSF opening pressure, determined by lumbar puncture, and clinical findings, such as headache scores. Thus, CSF flow analysis with PC‐MRI, which has a short performance time and is non‐invasive, may contribute to assessment of SIH patients.
Sustained Safety and Efficacy of Once‐Daily Hydromorphone Extended‐Release (OROS® hydromorphone ER) Compared with Twice‐Daily Oxycodone Controlled‐Release Over 52 Weeks in Patients with Moderate to Severe Chronic Noncancer Pain
Authors: Richarz Ute , Waechter Sandra , Sabatowski Rainer , Szczepanski Leszek , Binsfeld Heinrich
Published: April 2012

Abstract  Once‐daily hydromorphone extended‐release (OROS® hydromorphone ER) and oxycodone controlled‐release (CR) are semisynthetic, ER opioid analgesics with established efficacy. An open‐label, randomized, 24‐week, parallel group, flexible‐dose study demonstrated noninferiority of OROS hydromorphone ER vs. twice‐daily oxycodone CR in patients with chronic noncancer pain. In total, 112 patients were enrolled in a 28‐week, open‐label extension study; 60 patients received OROS hydromorphone ER and 52 received oxycodone CR. The primary efficacy measure was the change from baseline to Weeks 38 and 52 in Brief Pain Inventory item “pain right now.” Global assessments of efficacy, dosing convenience, and tolerability were secondary endpoints. Mean change in “pain right now” from baseline to Week 38 was −3.0 (OROS hydromorphone ER) vs. −2.8 (oxycodone CR), and from baseline to Week 52 was −2.9 vs. −2.8; these changes were similar to the changes in the core phase (−2.1 vs. −2.1). Similar improvements were demonstrated for secondary assessments, including pain, pain interference, and quality of life. At Week 52, global assessment of efficacy was rated as “very good” or “good” by the majority of patients (OROS hydromorphone ER, 91.7%; oxycodone CR, 86.5%). More patients in the OROS hydromorphone ER group (35.0% vs. 21.2%) assessed mode of drug intake as “very convenient.” The majority of patients receiving OROS hydromorphone ER (88.3%) and oxycodone CR (88.5%) rated tolerability as “good” or “very good” at Week 52; few patients discontinued treatment because of an adverse event (1.6% vs. 0.4%, respectively). The effectiveness of OROS hydromorphone ER and oxycodone CR was maintained through 1 year.
Do Firms Knowingly Sell Overvalued Equity?
Authors: LEE INMOO
Published: April 2012

This article examines the relation between top executives' trading and the long‐run stock returns of seasoned equity issuing firms. Primary issuers, who sell mostly newly‐issued primary shares, significantly underperform their benchmarks, regardless of the top executives' prior trading pattern. However, top executives' trading is reliably associated with the stock returns of secondary issuers, who sell mostly secondary shares previously held by existing shareholders. On average, secondary issuers do not underperform their benchmarks. The results suggest that increased free cash flow problems after issue play an important role in explaining the underperformance of issuing firms.
Portfolio Disclosures and Year‐End Price Shifts
Authors: MUSTO DAVID K.
Published: April 2012

Commercial paper sells at an extra discount if it matures in the next calendar year but Treasury bills do not. The discount is apparent in downward price shifts before the year‐end, and upward price shifts at the turn of the year that are significantly correlated with the simultaneous returns to small stocks, and that cannot reflect tax‐loss selling. Cross‐sectional and time‐series tests on prices, as well as low of funds evidence on trades by institutional investors, indicate that both the debt and equity patterns reflect agency problems related to portfolio disclosures.
The Stochastic Behavior of Commodity Prices: Implications for Valuation and Hedging
Authors: SCHWARTZ EDUARDO S.
Published: April 2012

In this article we compare three models of the stochastic behavior of commodity prices that take into account mean reversion, in terms of their ability to price existing futures contracts, and their implication with respect to the valuation of other financial and real assets. The first model is a simple one‐factor model in which the logarithm of the spot price of the commodity is assumed to follow a mean reverting process. The second model takes into account a second stochastic factor, the convenience yield of the commodity, which is assumed to follow a mean reverting process. Finally, the third model also includes stochastic interest rates. The Kalman filter methodology is used to estimate the parameters of the three models for two commercial commodities, copper and oil, and one precious metal, gold. The analysis reveals strong mean reversion in the commercial commodity prices. Using the estimated parameters, we analyze the implications of the models for the term structure of futures prices and volatilities beyond the observed contracts, and for hedging contracts for future delivery. Finally, we analyze the implications of the models for capital budgeting decisions.
Journal Influence on the Design of Finance Doctoral Education
Authors: CORRADO CHARLES J. , FERRIS STEPHEN P.
Published: April 2012

This article surveys the influence of research journals on finance doctoral education. Influence is measured by citations from syllabi of finance seminars. A sample of 101 distinct syllabi submitted by 33 finance doctoral programs yields a list of 1,031 articles cited by at least two schools. These 1,031 articles generate 3,273 citations referencing 17 finance, economics, and accounting journals, where multiple citations from a single school are counted as a single citation. The most notable findings are the wide variety of seminar content across finance doctoral programs and the dominance of five finance journals in providing this diverse content.
Winner‐Loser Reversals in National Stock Market Indices: Can They be Explained?
Authors: RICHARDS ANTHONY J.
Published: April 2012

This article examines possible explanations for “winner‐loser reversals” in the national stock market indices of 16 countries. There is no evidence that loser countries are riskier than winner countries either in terms of standard deviations, covariance with the world market or other risk factors, or performance in adverse economic states of the world. While there is evidence that small markets are subject to larger reversals than large markets, perhaps due to some form of market imperfection, the reversals are not only a small‐market phenomenon. The apparent anomaly of winner‐loser reversals in national market indices therefore remains unresolved.
Good Timing: CEO Stock Option Awards and Company News Announcements
Authors: YERMACK DAVID
Published: April 2012

This article analyzes the timing of CEO stock option awards, as a method of investigating corporate managers' influence over the terms of their own compensation. In a sample of 620 stock option awards to CEOs of Fortune 500 companies between 1992 and 1994, I find that the timing of awards coincides with favorable movements in company stock prices. Patterns of companies' quarterly earnings announcements are consistent with an interpretation that CEOs receive stock option awards shortly before favorable corporate news. I evaluate and reject several alternative explanations of the results, including insider trading and the manipulation of news announcement dates.
The Implications of Equity Issuance Decisions within a Parent‐Subsidiary Governance Structure
Authors: SLOVIN MYRON B. , SUSHKA MARIE E.
Published: April 2012

We provide evidence about the motivation for a parent–subsidiary governance structure by analyzing valuation effects of seasoned equity offerings by publicly traded affiliated units. Our results support Nanda's (1991) theoretical model which predicts equity offerings convey differential information about subsidiary and parent value. Subsidiary equity issuance has negative valuation effects on issuing subsidiaries and positive effects on parents, while parent equity issuance reduces issuing parent wealth and increases subsidiary wealth. Our evidence suggests that a parent–subsidiary organizational structure enhances corporate financing flexibility and mitigates underinvestment problems identified by Myers and Majluf (1984). There is no evidence of subsidiary wealth expropriation.