bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitotic accumulations of PML protein contribute to the re-establishment of PML nuclear bodies in G1
Authors: Dellaire Graham , Eskiw Christopher H. , Dehghani Hesam , Ching Reagan W. , Bazett-Jones David P.
Published: February 2006

Although the mechanism of chromosomal segregation is well known, it is unclear how other nuclear compartments such as promyelocytic leukemia (PML) nuclear bodies partition during mitosis and re-form in G1. We demonstrate that PML nuclear bodies partition via mitotic accumulations of PML protein (MAPPs), which are distinct from PML nuclear bodies in their dynamics, biochemistry and structure. During mitosis PML nuclear bodies lose biochemical components such as SUMO-1 and Sp100. We demonstrate that MAPPs are also devoid of Daxx and these biochemical changes occur prior to chromatin condensation and coincide with the loss of nuclear membrane integrity. MAPPs are highly mobile, yet do not readily exchange PML protein as demonstrated by fluorescence recovery after photo-bleaching (FRAP). A subset of MAPPs remains associated with mitotic chromosomes, providing a possible nucleation site for PML nuclear body formation in G1. As the nuclear envelope reforms in late anaphase, these nascent PML nuclear bodies accumulate components sequentially, for example Sp100 and SUMO-1 before Daxx. After cytokinesis, MAPPs remain in the cytoplasm long after the reincorporation of splicing components and their disappearance coincides with new PML nuclear body formation even in the absence of new protein synthesis. The PML protein within MAPPs is not degraded during mitosis but is recycled to contribute to the formation of new PML nuclear bodies in daughter nuclei. The recycling of PML protein from one cell cycle to the next via mitotic accumulations may represent a common mechanism for the partitioning of other nuclear bodies during mitosis.
Preparation of Single-crystalline Selenium Nanowires in the Presence of Ethylenediaminetetramethylenephosphonic Acid
Authors: Lei Yun , Yao Lide , He Yuping , Wang Shiquan , Yu Richeng , Zou Bingsuo
Published: February 2006

Selenium nanowires have been synthesized by using 2-mercaptoethylamine-depleted CdSe nanoparticles as selenium source and ethylenediaminetetramethylenephosphonic acid as chelating agent. The products were characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and UV–vis spectrophotometry. The result shows that the selenium nanowires are single crystals grown along the [001] direction of hexagonal lattice. The optical measurement shows a blue shift relative to the bulk hexagonal selenium, and the optical bandedge might be attributed to the interchain interactions within a hexagonal selenium crystal.
A kinetic energy backscatter algorithm for use in ensemble prediction systems
Authors: Shutts Glenn
Published: February 2006

Physical justification is provided for the use of kinetic energy backscatter in forecast models, particularly in respect of ensemble prediction systems. The rate of energy backscatter to scales near the truncation limit is controlled by a total energy dissipation function involving contributions from numerical diffusion, mountain drag and deep convection. A cellular automaton is used to generate evolving patterns that, together with the dissipation function, define a stream‐function forcing field. Each member of the European Centre for Medium‐Range Weather Forecasts (ECMWF) ensemble forecast system is perturbed by a different realization of this backscatter forcing, and the resulting increase in ensemble spread, if not excessive, has a beneficial impact on probabilistic measures of forecast skill. The input of small‐scale kinetic energy by the backscatter algorithm also helps to correct a known problem with the energy spectrum in the ECMWF model—the absence of the observed −5/3 spectral slope in the mesoscales. Copyright © 2005 Royal Meteorological Society.
Climate change in tropical regions from high‐resolution time‐slice AGCM experiments
Authors: Coppola E. , Giorgi F.
Published: February 2006

In this study we discuss present‐day climate conditions (1961–90) and climate change projections (2071–2100) for four tropical regions as produced with a high‐resolution time‐slice AGCM experiment. We use the National Aeronautics and Space Agency/National Center for Atmospheric Research finite‐volume element global model FVGCM with a horizontal grid interval of 1° latitude and 1.25° longitude. The regions considered are South Asia, tropical South America, Sahel/equatorial Africa, and southern equatorial Africa, and the projections refer to the IPCC A2 emission scenario forcing. We focus on the rainy seasons of the four regions.

In all regions the FVGCM reproduces the rainy season climatologies reasonably well, in both their mean and their interannual variability characteristics. The greatest discrepancies with observations occur over South Asia, where the monsoon precipitation does not penetrate far enough inland. The climate change scenarios can be summarized as follows: (i) an intensification of monsoon precipitation over South Asia; (ii) a decrease in precipitation over the Amazon basin; (iii) a northward shift of the monsoon precipitation band over the Sahel and equatorial Africa; and (iv) a drying over southern equatorial Africa. In most cases these changes are statistically significant at the 95% confidence level. Statistically significant warming is found over all regions, varying from 2 to 5 K across regions.

A robust result of our analysis is a consistent increase in interannual variability for the scenario simulations over all the regions examined and for both precipitation and temperature. Because of the experiment design this increase is not due to an increase in variability of sea surface temperature, but is rather associated either with land–atmosphere feedbacks or with a general intensification of the global hydrological cycle under warmer conditions. We also compare our change projections with previous results from coupled global models. Copyright © 2005 Royal Meteorological Society.
The dynamics of heat lows in simple background flows
Authors: Spengler T. , Reeder M. J. , Smith R. K.
Published: February 2006

A three‐dimensional numerical model is used to study the evolution of an idealized heat low that develops over an isolated level land mass surrounded by sea. Calculations are carried out without a background flow and for simple background flows. In all cases, the flow shows a significant diurnal variation in which the sea‐breeze circulations are the prominent feature during the daytime and the nocturnal low‐level jet is the prominent feature at night. If the land area is large enough so that the sea breezes do not cover it entirely during the diurnal cycle, strong convergence associated with the low‐level jet leads to the formation of intense, but shallow, cold fronts along the inland boundaries of sea‐breeze air. These fronts decay rapidly after sunrise when surface heating leads to renewed vertical mixing, which destroys the low‐level stable layer.

The presence of a uniform easterly flow leads to the formation of a west‐coast trough, similar to the situation commonly observed over Western Australia. The trough broadens during the day due to the heating of the land, while at night it sharpens and again frontogenesis occurs at low levels near the leading edge of the sea breezes to form shallow cold fronts. In these calculations there is an east–west asymmetry in the sea‐breeze circulations: the cool air behind the west‐coast sea breeze is shallower than that behind the east‐coast sea breeze, but the vertical circulation associated with the west‐coast sea breeze is deeper. The east‐coast sea‐breeze front penetrates further inland, but is more diffuse and is recognizable more by its signature in the relative vorticity than by that in the horizontal temperature gradient.

The presence of a horizontal shear‐flow leads to the deformation of the heat trough, a process that appears to play an important role in the formation of cold fronts over central Australia. Again the calculations show the formation of shallow fronts over the land during the night, which frontolyse rapidly after sunrise. Despite the idealized nature of the calculations, the associated patterns of low‐level vorticity, divergence and horizontal temperature gradient that develop overnight show remarkable similarity to those observed over central Australia. Indeed, the calculations help to interpret the observations of nocturnal frontogenesis over this region. Copyright © 2005 Royal Meteorological Society.
Interaction between concentric eye‐walls in super typhoon Winnie (1997)
Authors: Zhang Qing‐hong , Kuo Ying‐hwa , Chen Shou‐jun
Published: February 2006

Super typhoon Winnie had one of the largest eye‐walls ever recorded in the western Pacific Ocean. The diameter of the outer eye‐wall reached 370 km when Winnie passed through Okinawa on 16 August 1997. Observations revealed a 24‐hour intensity cycle of concentric eye‐walls after the large eye‐wall formed. Using the Penn State University/National Center for Atmospheric Research mesoscale model MM5 with 3 km grid horizontal spacing on the finest nested mesh, Winnie was successfully simulated in terms of concentric eye‐walls, spiral rain bands in the moat and the cycle of concentric eye‐walls.

The life cycle of concentric eye‐walls is found to be associated with vortex Rossby wave propagation in the moat. The propagation properties of the PV (rainfall) spiral bands are found to be consistent with predictions using vortex Rossby theory. The initial inward vorticity gradient at the inner edge of the outer eye‐wall and outward vorticity gradient at the outer edge of the inner eye‐wall support inward and outward PV (rainfall) spiral bands, respectively, in the moat at the lower level. At the middle level, only an outward vorticity gradient exists at the outer edge of the inner eye‐wall, which permits the development of an outward PV band in the moat at initial time. The inward spiral PV (rain) band moves faster than the outward PV (rain) band and both of them propagate cyclonically. At 09 h, when the fast inward PV band catches up to the slow outward PV band, the slow outward rain band is replaced by the fast inward rain band, resulting in a well‐developed and independent inner eye‐wall at 14 h. After the vorticity gradient near the inner eye‐wall becomes stronger than that near the outer eye‐wall at lower level, the whole convective core is attracted to the outer eye‐wall. It finally merges with it at 37 h, leaving a weak vortex in the centre. The concentric eye‐walls of Winnie interact with each other through vortex Rossby waves. Copyright © 2005 Royal Meteorological Society.
Validation of precipitable water from ECMWF model analyses with GPS and radiosonde data during the MAP SOP
Authors: Bock Olivier , Keil Christian , Richard Evelyne , Flamant Cyrille , Bouin Marie‐noelle
Published: February 2006

Precipitable water vapour contents (PWCs) from European Centre for Medium‐Range Weather Forecasts (ECMWF) analyses have been compared with observations from 21 ground‐based Global Positioning System receiving stations (GPS) and 14 radiosonde stations (RS), covering central Europe, for the period of the Mesoscale Alpine Programme experiment special observing period (MAP SOP). Two model analyses are considered: one using only conventional data, serving as a control assimilation experiment, and one including additionally most of the non‐operational MAP data. Overall, a dry bias of about −1 kg m−2 (−5.5% of total PWC), with a standard deviation of ∼2.6 kg m−2 (13% of total PWC), is diagnosed in both model analyses with respect to GPS. The bias at individual sites is quite variable: from −4 to ∼0 kg m−2. The largest differences are observed at stations located in mountainous areas and/or near the sea, which reveal differences in representativeness. Differences between the two model analyses, and between these analyses and GPS, are investigated in terms of usage and quality of RS data. Biases in RS data are found from comparisons with both model and GPS PWCs. They are confirmed from analysis feedback statistics available at ECMWF. An overall dry bias in RS PWC of 4.5% is found, compared to GPS. The detection of RS biases from comparisons both with the model and GPS indicates that data screening during assimilation was generally effective. However, some RS bias went into the model analyses. Inspection of the time evolution of PWC from the model analyses and GPS occasionally showed differences of up to 5–10 kg m−2. These were associated with severe weather events, with variations in the amount of RS data being assimilated, and with time lags in the PWCs from the two model analyses. Such large differences contribute strongly to the overall observed standard deviations. Good confidence in GPS PWC estimates is gained through this work, even during periods of heavy rain. These results support the future assimilation of GPS data, both for operational weather prediction and for mesoscale simulation studies. Copyright © 2005 Royal Meteorological Society.
Embolization treatment of recurrent varices of pelvic origin
Authors: Monedero J Leal , Ezpeleta S Zubicoa , Castro J Castro , Ortiz M Calderón , Fernández G Sellers
Published: February 2006

Objective: To present our experience with embolization of pelvic reflux routes in patients with recurrent varices after surgery (REVAS).

Method: Single patient group study of patients with previous surgical treatment for varicose veins, with REVAS in Unidad de Angiología y Cirugía Vascular, Hospital Ruber Internacional, Madrid, España. Patients presenting with REVAS with pelvic venous insufficiency (PVI) documented per transvaginal colour duplex, undergoing selective pelvic venography, were treated with embolization of insufficient gonadal and hypogastric mainstem and collateral veins.

Results: In all, 215 patients (89.9%) reported relief of pelvic pain and symptoms of lower extremity venous stasis six months postembolization; total relief in 120 (50.2%) and partial relief in 95 (39.7%).

Conclusions: There is high incidence of PVI in patients with REVAS. Embolization of insufficient gonadal and hypogastric mainstem and collateral vessels is associated with significant relief of clinical signs and symptoms of pelvic and lower extremity venous stasis in patients with REVAS and PVI.
Is compression bandaging accurate? The routine use of interface pressure measurements in compression bandaging of venous leg ulcers
Authors: Satpathy A , Hayes S , Dodds S
Published: February 2006

Objective: To test the use of a low-cost, portable, battery-powered sub-bandage pressure monitor as a part of a quality control measure for graduated compression bandaging in the leg ulcer clinics.

Methods: A total of 25 healthy volunteers (mean age 40 years) providing 50 limbs were bandaged with a 4-layer compression bandaging system. Interface pressure was measured by placing pressure sensors on the skin at three points (2 cm above the medial malleolus, on the widest part of the calf and on a point midway between them) in supine and standing positions. A further 16 patients (mean age 62 years) providing 22 limb measurements also participated in this study. Bandages were reapplied in patients with the help of the pressure monitors when the target pressure was not achieved in the first attempt.

Results: The interface pressures varied with change of position and movement. With the operator blinded, the target pressure of 35–40 mmHg at the ankle was achieved in only 36% of healthy volunteers (mean±95% confidence interval, 32.3±1.6 mmHg [supine]; 38.4±2.4 mmHg [standing position]). With the help of the pressure monitors, the target pressure was achieved in 78% of the patients.

Conclusion: This result suggests that it is important to have a tool that is easy to operate, and available as a part of the quality assurance in connection with treatment and also training of care providers, nurses, etc in how to apply a compression bandage.
Ligation of the hairpin ribozyme in cis induced by freezing and dehydration
Authors: KAZAKOV SERGEI A. , BALATSKAYA SVETLANA V. , JOHNSTON BRIAN H.
Published: February 2006

Although reducing the temperature slows most chemical reactions, freezing can stimulate some reactions by mechanisms that are only partially understood. Here we show that freezing stimulates the self-ligation (circularization) of linear forms of the hairpin ribozyme (HPR) containing 2′,3′-cyclic phosphate and 5′-OH termini. Divalent metal ions (M2+) are not required, but monovalent cations and anions at millimolar concentrations can have various effects on this reaction depending on the specific ion. Under optimal conditions, the observed rate of M2+-independent self-ligation reaches a peak (0.04 min−1) at −10°C with a yield of −60% after 1 h. In contrast, no ligation occurs either at above 0°C or in solutions that remain unfrozen when supercooled to subzero temperatures. Under freezing conditions, the cleavage–ligation equilibrium strongly favors ligation. Besides freezing, evaporation of the aqueous solvent as well as the presence of ethanol at levels of 40% or above can also induce M2+-independent HPR ligation at 25°C. We argue that partial RNA dehydration, which is a common feature of freezing, evaporation, and the presence of ethanol, is a key factor supporting HPR ligation activity at both above- and below-freezing temperatures. In the context of the RNA world hypothesis, freezing-induced ligation is an attractive mechanism by which complex RNAs could have evolved under conditions in which RNA was relatively protected against degradation.
T. bruceiRNA editing: Action of the U-insertional TUTase within a U-deletion cycle
Authors: ZHELONKINA ALEVTINA G. , O’HEARN SEAN F. , LAW JULIE A. , CRUZ-REYES JORGE , HUANG CATHERINE E. , ALATORTSEV VADIM S. , SOLLNER-WEBB BARBARA
Published: February 2006

Trypanosome RNA editing is massive post-transcriptional U-insertion and U-deletion, which generates mature mRNA coding regions through cycles of endonuclease, terminal U transferase (TUTase) or 3′-U-exo, and ligase action. Both types of editing are thought to be catalyzed by distinct sets of proteins of a multiprotein complex, and no enzymatic activity of wild-type editing complex had been shown to function in both forms of editing. By examining the individual steps of the U-deletion cycle using purified editing complex, traditional mitochondrial extract, and rapidly prepared cell lysate, we here demonstrate that TbMP57 TUTase of U-insertion can act efficiently within a U-deletion cycle. When physiological UTP levels are provided, it adds U’s to the upstream cleavage fragment after U-deletional endonuclease and 3′-U-exo action, but before rejoining by the U-deletional ligase, generating partial U-deletion products. TUTase activity in U-deletion was not previously appreciated since its detection requires UTP, which is not normally added to in vitro U-deletion reactions. Fractionation and RNAi analyses show this U-addition in U-deletion requires TbMP57 TUTase be present and competent for U-insertion; such U-addition does not occur with another mitochondrial TUTase that is separate from the basic editing complex. Efficient TbMP57 action in both U-insertion and U-deletion suggests these two editing forms may be less separate than generally envisioned. Should such promiscuous TUTase action also occur in vivo, it could explain why editing utilizes substantially fewer U-deletional than U-insertional events and why partial editing appears preferential in U-deletion.
U7 snRNA mutations in Drosophila block histone pre-mRNA processing and disrupt oogenesis
Authors: GODFREY ASHLEY C. , KUPSCO JEREMY M. , BURCH BRANDON D. , ZIMMERMAN RYAN M. , DOMINSKI ZBIGNIEW , MARZLUFF WILLIAM F. , DURONIO ROBERT J.
Published: February 2006

Metazoan replication-dependent histone mRNAs are not polyadenylated, and instead terminate in a conserved stem–loop structure generated by an endonucleolytic cleavage involving the U7 snRNP, which interacts with histone pre-mRNAs through base-pairing between U7 snRNA and a purine-rich sequence in the pre-mRNA located downstream of the cleavage site. Here we generate null mutations of the single Drosophila U7 gene and demonstrate that U7 snRNA is required in vivo for processing all replication-associated histone pre-mRNAs. Mutation of U7 results in the production of poly A+ histone mRNA in both proliferating and endocycling cells because of read-through to cryptic polyadenylation sites found downstream of each Drosophila histone gene. A similar molecular phenotype also results from mutation of Slbp, which encodes the protein that binds the histone mRNA 3′ stem–loop. U7 null mutants develop into sterile males and females, and these females display defects during oogenesis similar to germ line clones of Slbp null cells. In contrast to U7 mutants, Slbp null mutations cause lethality. This may reflect a later onset of the histone pre-mRNA processing defect in U7 mutants compared to Slbp mutants, due to maternal stores of U7 snRNA. A double mutant combination of a viable, hypomorphic Slbp allele and a viable U7 null allele is lethal, and these double mutants express polyadenylated histone mRNAs earlier in development than either single mutant. These data suggest that SLBP and U7 snRNP cooperate in the production of histone mRNA in vivo, and that disruption of histone pre-mRNA processing is detrimental to development.
Biochemical and NMR analyses of an SF3b155–p14–U2AF-RNA interaction network involved in branch point definition during pre-mRNA splicing
Authors: SPADACCINI ROBERTA , REIDT ULRICH , DYBKOV OLEXANDR , WILL CINDY , FRANK RONALD , STIER GUNTER , CORSINI LORENZO , WAHL MARKUS C. , LÜHRMANN REINHARD , SATTLER MICHAEL
Published: February 2006

The p14 subunit of the essential splicing factor 3b (SF3b) can be cross-linked to the branch-point adenosine of pre-mRNA introns within the spliceosome. p14 stably interacts with the SF3b subunit SF3b155, which also binds the 65-kDa subunit of U2 auxiliary splicing factor (U2AF65). We combined biochemical and NMR techniques to study the conformation of p14 either alone or complexed with SF3b155 fragments, as well as an interaction network involving p14, SF3b155, U2AF65, and U2 snRNA/pre-mRNA. p14 comprises a canonical RNA recognition motif (RRM) with an additional C-terminal helix (αC) and a β hairpin insertion. SF3b155 binds to the β-sheet surface of p14, thereby occupying the canonical RNA-binding site of the p14 RRM. The minimal region of SF3b155 interacting with p14 (i.e., residues 381–424) consists of four α-helices, which are partially preformed in isolation. Helices α2 and α3 (residues 401–415) constitute the core p14-binding epitope. Regions of SF3b155 binding to p14 and U2AF65 are nonoverlapping. This allows for a simultaneous interaction of SF3b155 with both proteins, which may support the stable association of U2 snRNP with the pre-mRNA. p14–RNA interactions are modulated by SF3b155 and the RNA-binding site of the p14–SF3b155 complex involves the noncanonical β hairpin insertion of the p14 RRM, consistent with the β-sheet surface being occupied by the helical SF3b155 peptide and p14 helix αC. Our data suggest that p14 lacks inherent specificity for recognizing the branch point, but that some specificity may be achieved by scaffolding interactions involving other components of SF3b.
Acute Tubular Necrosis Associated with Chromium Picolinate–Containing Dietary Supplement
Authors: Wani Sachin , Weskamp Celia , Marple Jeffrey , Spry Leslie
Published: February 2006

Objective:

To report a case of acute tubular necrosis associated with the use of a chromium picolinate–containing dietary supplement.

Case Summary:

A 24-year-old white male who had been ingesting a dietary supplement (Arsenal X) for 2 weeks during his workout sessions developed acute renal failure. Radiologic investigation showed the presence of a solitary right kidney, and an open renal biopsy confirmed features of acute tubular necrosis. He developed significant renal impairment that required hemodialysis. He was also treated with plasmapheresis and steroids, as a diagnosis of pulmonary-renal syndrome was entertained early in the disease course, which was subsequently ruled out. The patient ultimately recovered and, on outpatient visits, was noted to have normal renal function.

Discussion:

The use of dietary supplements has become increasingly popular in the US, and these supplements are not subject to stringent premarketing testing or postmarketing surveillance. The main ingredients in the supplement discussed here were chromium picolinate, Sida cordifolia, synephrine, and guarana. An objective causality assessment using the Naranjo probability scale indicated a probable association between the use of this supplement and the development of acute renal failure in this patient.

Conclusions:

Current information regarding the beneficial effects of trivalent chromium is not very robust; therefore, use of this agent cannot be recommended at this time. This report serves as an important reminder to the public, as well as healthcare providers, of potential nephrotoxic reactions to dietary supplements.
Different Intracellular Pathomechanisms Produce DiverseMyelin Protein ZeroNeuropathies in Transgenic Mice
Authors: Wrabetz Lawrence , D’Antonio Maurizio , Pennuto Maria , Dati Gabriele , Tinelli Elisa , Fratta Pietro , Previtali Stefano , Imperiale Daniele , Zielasek Jurgen , Toyka Klaus , Avila Robin L. , Kirschner Daniel A. , Messing Albee , Feltri M. Laura , Quattrini Angelo
Published: February 2006

Missense mutations in 22 genes account for one-quarter of Charcot–Marie–Tooth (CMT) hereditary neuropathies.Myelin Protein Zero(MPZ,P0) mutations produce phenotypes ranging from adult demyelinating (CMT1B) to early onset [Déjérine-Sottas syndrome (DSS) or congenital hypomyelination] to predominantly axonal neuropathy, suggesting gain of function mechanisms. To test this directly, we produced mice in which either theMpzS63C (DSS) orMpzS63del (CMT1B) transgene was inserted randomly, so that the endogenousMpzalleles could compensate for any loss of mutant P0 function. We show that either mutant allele produces demyelinating neuropathy that mimics the corresponding human disease. However, P0S63C creates a packing defect in the myelin sheath, whereas P0S63del does not arrive to the myelin sheath and is instead retained in the endoplasmic reticulum, where it elicits an unfolded protein response (UPR). This is the first evidence for UPR in association with neuropathy and provides a model to determine whether and how mutant proteins can provoke demyelination from outside of myelin.
Synaptic Bombardment Modulates Muscarinic Effects in Forelimb Motor Cortex
Authors: Desai Niraj S. , Walcott Elisabeth C.
Published: February 2006

Neocortical neuronsin vivoexist in an environment of continuous synaptic bombardment, receiving a complex barrage of excitatory and inhibitory inputs. This background activity (by depolarizing neurons, increasing membrane conductance, and introducing fluctuations) strongly alters many aspects of neuronal responsiveness. In this study, we asked how it shapes neuromodulation of postsynaptic responses. Specifically, we examined muscarinic modulation of forelimb motor cortex, a brain area in which cholinergic stimulation is known to be necessary for modifications during motor skill learning. Using a dynamic clamp system to inject simulated conductances into pyramidal neurons in motor cortical slices, we mimickedin vivo-like activity by introducing a random background of excitatory and inhibitory inputs. When muscarinic receptors were stimulated with the agonist oxotremorine-M, several previously described currents were modified, and excitability was increased. However, the presence of the background conductances strongly attenuated most muscarinic agonist effects, with the notable exception that sustained firing responses to trains of inputs were well preserved. This may be important for promoting plasticityin vivo.
Workplace Vaccination against Influenza in Malaysia: Does the Employer Benefit?
Authors: Samad Abu H. , Usul Mohd H.B.H.J. , Zakaria Dalilah , Ismail Raman , Tasset‐Tisseau Anne , Baron‐Papillon Florence , Follet Alain
Published: February 2006

Workplace Vaccination against Influenza in Malaysia: Does the Employer Benefit?: Anne Tasset‐Tisseau et al. Sanofi Pasteur, France—This study was designed to evaluate the health and economic benefits of a workplace vaccination programme against influenza funded by the employer. Employees of a Malaysian petrochemical plant volunteered to take part in this prospective, nonrandomised, non‐placebo‐controlled study. Demographic and health information, including influenza‐like symptoms, sick leave and postvaccination adverse events were collected via questionnaires. Cost‐benefit analyses were performed from the employer's perspective. Results: A total of 1,022 employees took part in the study, with 504 choosing to be vaccinated against influenza, and 518 remaining unvaccinated. The rate of influenza‐like illness (ILI) was lower among vaccinated (8.13%) than non‐vaccinated subjects (30.31%). Fever and respiratory symptoms were associated with all ILI cases. ILI‐related sick leave was taken by 58.54% of vaccinated employees with ILI and 71.34% of nonvaccinated employees with ILI. Vaccination was financially beneficial, with the employer saving up to US$ 53.00 per vaccinated employee when labour costs only were considered. Savings rose to up to US$ 899.70 when the operating income of each employee was also considered. Workplace vaccination of healthy adults against influenza had a clear impact on ILI rates, absenteeism and reduced productivity in this Malaysian company. The health benefits translated into financial benefits for the employer, with cost savings significantly outweighing the costs of the vaccination programme.
Long-term Experience With Combination Antiretroviral Therapy That Contains Nelfinavir for up to 7 Years in a Pediatric Cohort
Authors: Scherpbier Henriëtte J. , Bekker Vincent , van Leth Frank , Jurriaans Suzanne , Lange Joep M.A. , Kuijpers Taco W.
Published: February 2006

OBJECTIVE. We sought to provide long-term data on the clinical, immunologic, and virologic response to highly active antiretroviral therapy in infants and children who are naive to protease inhibitors.

METHODS. HIV-1–infected children who were naive to protease inhibitors were treated with a combination of nelfinavir and 2 nucleoside reverse transcriptase inhibitors (stavudine and lamivudine) in an observational, prospective, single-center study. Virologic failure-free survival was assessed by Kaplan-Meier analyses. The increase in CD4+ T cells during follow-up was estimated with a generalized linear model incorporating repeated measurements.

RESULTS. Thirty-nine HIV-1–infected children were included and followed for a median period of 227 weeks (interquartile range: 108–275 weeks). The virologic failure-free survival rate was 74%, 66%, 58%, and 54% after 48, 96, 144, and 240 weeks, respectively. Children who experienced virologic failure in 48 weeks (or 96 weeks) were younger at baseline compared with the responders (0.8 vs 5.3 years). Eighteen children remained on the regimen for >5 years. All children, including the nonresponders, showed a sustained immunologic response. Grades 3 to 4 toxicity was observed in 2 patients only. Eleven developed clinically evident lipodystrophy.

CONCLUSION. Combination therapy can be used safely in infants and children over a long period. Young age is strongly associated with virologic failure. Although the virologic response declined, immunologic parameters and clinical improvement were sustained up to 7 years, at the expense of lipodystrophy.
Negativity towards Wilderness in the Biblical Record
Authors: Leal Robert Barry
Published: February 2006

In recent ecotheological writing little attention has been paid to the phenomenon of wilderness. This is surprising when one considers the centrality of wilderness to a theology of creation. Traditional Western attitudes to wilderness have emphasized conflict and domination rather than respect and collaboration. In some powerful political circles (such as the Bush Administration) such resistance to the natural order continues to be seen as grounded in the Bible and hence to be theologically justified. For these reasons it is important to address the various wilderness traditions that one encounters in the Bible and in particular to acknowledge the negativity that is present. Only when such negativity is taken into account and placed in context will a convincing, biblically-based, contemporary theology of creation be able to emerge. Negative attitudes towards wilderness are identified in the Pentateuch, in several of the prophets, in Job and in the New Testament, and their implications for theology suggested. While it is recognized that such a diverse collection of books as the Bible also contains other than negative attitudes towards wilderness, this article focuses on negativity as an attitude in need of highlighting and addressing in contemporary circumstances.
Wilderness, Religion and Ecological Restoration in the Scottish Highlands
Authors: Northcott Michael S.
Published: February 2006

The efforts of nature conservation bodies to return parts of the Highlands to a ‘pristine’ state involve attempts to reduce both signs of human dwelling and the destructive impacts of animals introduced by wealthy landlords for sport and cash such as deer and sheep. The irony is that such restoration projects will still not achieve the levels of biodiversity that obtained before the Clearances when Gaels dwelt in what are now regarded as ecologically rich but threatened regions. Wilderness restoration projects reflect in some ways the modern romantic fetishisation of wild nature which finds its modern equivalent in the growing practice of wilderness therapy. Discussions amongst philosophers of wilderness, and ecological restoration, frequently neglect the dimension of the environmental exclusion of indigenous people, and so also tend to fetishise wilderness. Biblical accounts of wilderness restoration are strongly at variance with modern approaches when they suggest that the divine intent to restore desert to fertile land involves also the redemption of the poor, and of other species, from the greed and corruption of the wealthy. In this sense the land reform project of the new Scottish Parliament comes closer to a Biblical vision of wilderness restoration than traditional nature conservation strategies.
Measurements of the UVR Protection Provided by Hats Used at School
Authors: Gies Peter , Javorniczky John , Roy Colin , Henderson Stuart
Published: February 2006

The importance of protection against solar ultraviolet radiation (UVR) in childhood has lead to SunSmart policies at Australian schools, in particular primary schools, where children are encouraged and in many cases required to wear hats at school. Hat styles change regularly and the UVR protection provided by some of the hat types currently used and recommended for sun protection by the various Australian state cancer councils had not been previously evaluated. The UVR protection of the hats was measured using UVR sensitive polysulphone film badges attached to different facial sites on rotating headforms. The sun protection type hats included in this study were broad‐brimmed hats, “bucket hats” and legionnaires hats. Baseball caps, which are very popular, were also included. The broad‐brimmed hats and bucket hats provided the most UVR protection for the six different sites about the face and head. Legionnaires hats also provided satisfactory UVR protection, but the caps did not provide UVR protection to many of the facial sites. The highest measured UVR protection factors for facial sites other than the forehead were 8 to 10, indicating that, while some hats can be effective, they need to be used in combination with other forms of UVR protection.
Safety Behaviors and Social Performance in Patients With Generalized Social Phobia
Authors: Stangier Ulrich , Heidenreich Thomas , Schermelleh-Engel Karin
Published: February 2006

The cognitive model of social phobia (Clark & Wells, 1995) suggests that safety behaviors, besides preventing disconfirmation of dysfunctional beliefs, cause significant impairment in social performance. To test this hypothesis, the current study investigated the relationship between observer-rated social performance, self-rated safety behaviors, and anxiety in 20 generalized social phobics, 14 controls with anxiety, and 17 controls without anxiety in two experimental tasks: a conversation with a stooge and a brief speech. Compared to the control groups, socially phobic patients displayed higher anxiety levels, reported more safety behaviors, and did not perform as well as the control groups in both tasks. There was a nonsignificant tendency of socially phobic patients to display more negative thoughts than both control groups. Differences in heart rate responses were not significant. A path analysis revealed that safety behaviors partially mediated the relation between diagnostic group and social performance deficit in both tasks. The results highlight the importance of safety behaviors for social performance deficit in social phobia.
Combining Cognitive-Behavioral Therapy and Pharmacotherapy for the Treatment of Panic Disorder
Authors: Smits Jasper A. J. , O’Cleirigh Conall M. , Otto Michael W.
Published: February 2006

This article focuses on the role of combination treatment strategies in the management of panic disorder (PD). Despite short-term benefits, there is not consistent evidence for a longer-term advantage of combined treatment over cognitive-behavior therapy alone. In discussing this result, we place emphasis on ways in which medication treatment may interfere with the learning of safety in relation to feared cues in PD. These considerations are placed in the context of animal and human studies of factors that interfere with the extinction of fears. Strategies to overcome this interference are also discussed as are novel approaches to combination treatment.
Measurement of Panic Interpretation Bias Using the Anxiety Interpretation Questionnaire for Children
Authors: Schneider Silvia , In-Albon Tina , Rose Uwe , Ehrenreich Jill T.
Published: February 2006

The purpose of the present study is to investigate the development of a reliable and valid measure for the assessment of panic-relevant interpretations in children. The resulting measure, the Anxiety Interpretation Questionnaire for Children (AIQ-C), presents descriptions of panic-relevant and panic-irrelevant ambiguous scenarios along with several possible interpretations of these scenarios. Child participants are also asked to rate their agreement with various strategies for coping. First, we investigated content validity of this measure by asking a group of experts to rate the relevance of the scenario interpretations. In a second step, reliability and validity of this measure was investigated utilizing a sample of 143 children. In this investigation, the AIQ-C demonstrated good construct, convergent, and discriminate validity as well as adequate internal consistency. The results of this study indicate that the AIQ-C appears to be a reliable and valid measure for the assessment of bodily sensation interpretations associated with panic in children.
Improving Goovaerts' and De Vylder's Stable Recursive Algorithm
Authors: Ramsay Colin M.
Published: February 2006

Goovaerts and de Vylder (1983) provided a stable recursive algorithm for calculating the probability of ultimate ruin. Their algorithm yielded bounds for this probability. It is shown that in practice their method may be inherently unstable because it is based on the subtraction of nearly equal numbers. An alternative to this type of subtraction is provided. It is proved that their algorithm converges only at a linear rate to the true value. It is suggested that this slow rate of convergence be improved via an application of the Richardson extrapolation technique.
Credit Risk and Prepayment Option
Authors: Artzner Philippe , Delbaen Freddy
Published: February 2006

The paper examines a type of insurance contract for which secondary markets do exist: default risk insurance is implicit in corporate bonds and other risky debts. It applies risk neutral martingale measure pricing to evaluate the option for a borrower with default risk, to prepay a fixed rate loan. A simple “matchbox” example is presented with a spreadsheet treatment.
Linear Estimation and Credibility in Continuous Time
Authors: Norberg Ragnar
Published: February 2006

The theory of linear filtering of stochastic processes provides continuous time analogues of finite-dimensional linear Bayes estimators known to actuaries as credibility methods. In the present paper a selfcontained theory is built for processes of bounded variation, which are of particular relevance to insurance. Two methods for constructing the optimal estimator and its mean squared error are deviced. Explicit solutions are obtained in a continuous time variation of Hachemeister's regression model and in a homogeneous doubly stochastic generalized Poisson process. The traditional discrete time set-up is compared to the one with continuous time, and some merits of the latter are pointed out.
On Allocation of Excess of Loss Premiums
Authors: Sundt Bjørn
Published: February 2006

In the present paper we study the question of how to allocate the reinsurance premium between the sub-portfolios when an excess of loss treaty is to be shared between several sub-portfolios. Several allocation schemes based on the expected value principle and the standard deviation principle are suggested. The calculations are relatively simple with unlimited free reinstatements. However, with limited and/or paid reinstatements the situation becomes rather tricky, and we therefore suggest a simulation scheme.
A Simulation Procedure for Comparing Different Claims Reserving Methods
Authors: Pentikäinen Teivo , Rantala Jukka
Published: February 2006

The estimation of outstanding claims is one of the important aspects in the management of the insurance business. Various methods have been widely dealt with in the actuarial literature. Exploration of the inaccuracies involved is traditionally based on a post-facto comparison of the estimates against the actual outcomes of the settled claims. However, until recent years it has not been usual to consider the inaccuracies inherent in claims reserving in the context of more comprehensive (risk theoretical) models, the purpose of which is to analyse the insurer as a whole. Important parts of the technique which will be outlined in this paper can be incorporated into over-all risk theory models to introduce the uncertainty involved with technical reserves as one of the components in solvency and other analyses (Pentikäinen et al. (1989)).

The idea in this paper is to describe a procedure by which one can explore how various reserving methods react to fictitious variations, fluctuations, trends, etc. which might influence the claims process, and, what is most important, how they reflect on the variables indicating the financial position of the insurer. For this purpose, a claims process is first postulated and claims are simulated and ordered to correspond to an actual handling of the observed claims of a fictitious insurer. Next, the simulation program will ‘mime’ an actuary who is calculating the claims reserve on the basis of these ‘observed’ claims data. Finally, the simulation is further continued thus generating the settlement of the reserved claims. The difference between reserved amounts and settled amounts gives the reserving (run-off) error in this particular simulated case. By repeating the simulation numerous times (Monte Carlo method) the distribution of the error can be estimated as well as its effect on the total outcome of the insurer.
On the Convergence Rate of Bonus-Malus Systems
Authors: Bonsdorff Heikki
Published: February 2006

Under certain conditions, a Bonus-Malus system can be interpreted as a Markov chain whose n-step transition probabilities converge to a limit probability distribution. In this paper, the rate of the convergence is studied by means of the eigenvalues of the transition probability matrix of the Markov chain.
Approximations of Ruin Probability by Di-Atomic or Di-Exponential Claims
Authors: Babier Joshua , Chan Beda
Published: February 2006

The sensitivity of the ruin probability depending on the claim size distribution has been the topic of several discussion papers in recent ASTIN Bulletins. This discussion was initiated by a question raised by Schmitter at the ASTIN Colloquium 1990 and attempts to make further contributions to this problem. We find the necessary and sufficient conditions for fitting three given moments by diatomic and diexponential distributions. We consider three examples drawn from fire (large spread), individual life (medium spread) and group life (small spread) insurance data, fit them with diatomics and diexponentials whenever the necessary and sufficient conditions are met, and compute the ruin probabilities using well known formulas for discrete and for combination of exponentials claim amounts. We then compare our approximations with the exact values that appeared in the literature. Finally we propose using diatomic and diexponential claim distributions as tools to study the Schmitter problem.
Premium Calculation Without Arbitrage Author's Reply on the Note by P. Albrecht
Authors: Venter G.
Published: February 2006

Albrecht's interesting discussion raises two major points: is an arbitrage free insurance market a reasonable assumption, and are adjusted distribution principles appropriate?

I had assumed an arbitrage free insurance market without really discussing reasons in support of it. Certainly there have been arbitrage profits made through reinsurance, possibly, for example, by selling excess on excess at rates based on regular excess policies, and perhaps in the London Market Excess arena. But even if arbitrage occurs frequently, I feel that an arbitrage free market is still a reasonable assumption for theoretical developments, if we take it to mean that systematic ongoing arbitrage is not possible. Although some arbitrage situations have probably lasted a few years, all I am aware of eventually have disappeared as they became better known. Either entrepreneurs try to outbid each other to take advantage of them, or the sellers lose their willingness to play. A list of insurers that are regularly making arbitrage profits would be an interesting refutation of this assumption.

Albrecht gives some examples of the well known and quite true proposition that larger portfolios are more stable. Large insurers can maintain the same security level at a lower price. Our risk theory training leads actuaries to believe that the smaller needed security premium for large insurers will induce them to charge lower prices. This is not necessarily true in the market, however. Larger insurers may in fact charge the market price and make more profits, for example. Also, it would be fairly surprising if small insurers actually do get away with charging more for the same risks. If they do, they should buy prorata reinsurance heavily from the large insurers at the large insurers' risk price and pocket the difference. There are of course transaction costs to buying prorata reinsurance; those may in fact be the limit of what the smaller insurers can demand as the supposed bonus price they get from the market for being small.