bluuebunny/crossref_metadata_2025 huggingface dataset:
Field‐Scale Relationships Among Soil Properties and Shallow Groundwater Quality
Authors: Derby Nathan E. , Korom Scott F. , Casey Francis X.M.
Published: August 2012

It is important to understand the link between land surface/soil properties and shallow groundwater quality. To that end, soil properties and near‐water‐table groundwater chemistry of a shallow, unconfined aquifer were measured on a 100‐m grid on a 64‐ha irrigated field in southeastern North Dakota. Soil properties and hydrochemistry were compared via multivariate analysis that included product‐moment correlations and factor analysis/principal component analysis. Topographic low areas where the water table was in close proximity to the soil surface generally had higher apparent electrical conductivity (ECa) and higher percent silt and clay than higher positions on the landscape. The majority of the groundwater was characterized by Ca‐ and Mg‐HCO3 type water and was associated with topographic high areas with lower ECa and net groundwater recharge. Small topographic depressions were areas of higher ECa (net groundwater discharge) where salts that precipitated via evapotranspiration and evaporative discharge dissolved and leached to the groundwater during short‐term depression‐focused recharge events. At this site, groundwater quality and soil ECa were related to surface topography. High‐resolution topography and ECa measurements are necessary to characterize the land surface/soil properties and surficial groundwater quality at the field‐scale and to delineate areas where the shallow groundwater is most susceptible to contamination.
Refinement of Bouwer‐Rice Baildown Test Analysis
Authors: Kirkman Andrew J.
Published: August 2012

The recoverability of light nonaqueous phase liquids (LNAPL) in the subsurface can be estimated using LNAPL transmissivity. LNAPL transmissivity is analogous to aquifer transmissivity in that it represents the volume of LNAPL that flows through a unit width of a porous medium for a unit gradient in a unit time. Methods for estimating LNAPL transmissivity from baildown test data have been modified from the Bouwer and Rice (1976) slug test method by Lundy and Zimmerman (1996) and Huntley (2000). The primary assumptions when estimating LNAPL transmissivity with the Bouwer‐Rice method include, a quasi‐steady‐state model for recharge to the well (the model assumes steady‐state radial flow to the well with rate dependent well drawdown and no storage effects) and that the ratio of change in LNAPL drawdown to change in LNAPL thickness at the well (ds/db) is constant. This ratio will be referred to as the j‐ratio. Rather than having to meet boundary conditions for a predetermined j‐ratio value, each baildown test provides the data to estimate the j‐ratio value that is unique to that data set. This calculation methodology in turn results in the Bouwer‐Rice method being applicable to a wider range of baildown tests where it is not required for the potentiometric surface or LNAPL/water interface to remain constant.
Causation: Empirical Trends and Future Directions
Authors: Rose David , Danks David
Published: August 2012

Empirical research has recently emerged as a key method for understanding the nature of causation, and our concept of causation. One thread of research aims to test intuitions about the nature of causation in a variety of classic cases. These experiments have principally been used to try to resolve certain debates within analytic philosophy, most notably that between proponents of transference and dependence views of causation. The other major thread of empirical research on our concept of causation has investigated the role that normative considerations play in causal judgments. These experimental results suggest that philosophical accounts of our concept of causation should take a broader view of what might be relevant. For both lines of research, we describe some of the significant experiments and outline key philosophical morals that have been drawn, all while pointing out various limitations. We conclude by considering other kinds of empirical research that should be philosophically interesting for those studying the nature of causation and our concept of causation. In particular, we point towards the need for philosophical research about causal perception, causal reasoning, and causal learning, as well as ways in which this research could play a role in prescriptive metaphysics.
A Descriptivist Refutation of Kripke's Modal Argument and of Soames's Defence
Authors: Bo Chen
Published: August 2012

This article systematically challenges Kripke's modal argument and Soames's defence of this argument by arguing that, just like descriptions, names can take narrow or wide scopes over modalities, and that there is a big difference between the wide scope reading and the narrow scope reading of a modal sentence with a name. Its final conclusions are that all of Kripke's and Soames's arguments are untenable due to some fallacies or mistakes; names are not “rigid designators”; if there were rigid designators, description(s) could be rigidified to refer fixedly to objects; so names cannot be distinguished in this way from the corresponding descriptions. A descriptivist account of names is still correct; and there is no justification for Kripke's theory of rigid designation and its consequences.
The Possibility of Modified Hedonism
Authors: Berkovski Sandy
Published: August 2012

A popular objection to hedonist accounts of personal welfare has been the experience machine argument. Several modifications of traditional hedonism have been proposed in response. In this article I examine two such responses, recently expounded byFeldman andSumner respectively. I argue that both modifications make hedonism indistinguishable from anti‐hedonism. Sumner's account, I claim, also fails to satisfy the demands of theoretical unity.
Cytological evidence supports the taxonomic status of the Sino‐Himalayan species Cimicifuga frigida (Ranunculaceae)
Authors: Ren Chen , Yuan Qiong , Yang Qin‐Er
Published: August 2012

Although Cimicifuga foetida L. (Ranunculaceae) has been shown to be a distinct species distributed only in northern Asia (Siberia, Mongolia), the Sino‐Himalayan species C. frigida Royle remains to be much confused with the Chinese endemic C. mairei H. Lév. The independent species status of C. frigida is recognized by some authors, but refuted by others. A cytogeographical study has shown that the ploidy level is well correlated with the geographical distribution of C. frigida and C. mairei. Cimicifuga frigida is a tetraploid (2n = 32) occurring in the Sino‐Himalayan region, whereas C. mairei is a diploid (2n = 16) occurring in central and southwestern China. There is only minor overlap in their geographical distributions in northwestern Yunnan, China. The ploidy level is also well correlated with the morphological characters, in particular the shape of the staminodes, which has previously been used as the only reliable morphological character to distinguish between C. frigida and C. mairei. The cytogeographical pattern, therefore, lends strong support for the recognition of the independent species status of C. frigida. This species is the only polyploid species currently known in the genus.
Bat Rabies, Public Health and European Bat Conservation
Authors: Racey P. A. , Hutson A. M. , Lina P. H. C.
Published: August 2012

Most records of European bat lyssaviruses (EBLVs) are confined to three species – the serotine bat for EBLV1 (900 records) and Daubenton’s bat and the pond bat for EBLV2 (25 records). High levels of seroprevalence, which may vary from year to year, are also recorded. All bat vectors of EBLVs are synanthropic, some exclusively so. Despite this, there have been only five cases of human rabies resulting from EBLV infection in the 590 million people of greater Europe during the last 35 years. These have triggered major programmes of surveillance in many European countries. The emphasis on active versus passive surveillance and the intensity with which they have been carried out has varied from country to country. Both involve cooperation between bat researchers, virologists and public health officials and the latter, in particular, engages amateur bat workers and members of the public. Bat NGOs throughout Europe have worked to persuade the public not to handle bats or to do so only with gloved hands and, in the case of bat workers, to receive pre‐exposure immunization. They have also countered negative media coverage of bat rabies. Householders with bat roosts in their dwellings have in general been persuaded to retain their bats. Attempts have been made to persuade all European countries to establish comparable EBLV surveillance programmes. In the last 25 years, virologists, public health officials, bat biologists and conservationists, both amateur and professional have worked closely and collaboratively for the protection of the public and the conservation of bats, with little polarization of views.
Autonomy, positive relationships, and IL‐6: Evidence for gender‐specific effects
Authors: Eisenlohr‐Moul Tory , Segerstrom Suzanne
Published: August 2012

Objectives. A body of evidence indicates that women value relationship‐centred aspects of well‐being more than men do, while men value autonomy‐centred aspects of well‐being more than women do. The current study examined whether gender moderates relations between autonomy and positive relationships and interleukin‐6 (IL‐6), a cytokine associated with inflammatory processes. Aspects of well‐being consistent with gender‐linked values were expected to be most health protective such that positive relationships would predict lower IL‐6 only or more strongly in women, and autonomy would predict lower IL‐6 only or more strongly in men.

Methods. In the first study, a sample of 119 older adults (55% female) living in Kentucky were visited in their homes for interviews and blood draws. In the second study, a sample of 1,028 adults (45% female) living across the United States underwent a telephone interview followed by a visit to a research centre for blood draws.

Results. In the Kentucky sample, autonomy was quadratically related to IL‐6 such that moderate autonomy predicted higher IL‐6; this effect was stronger in men. In the US national sample, more positive relationships were associated with lower IL‐6 in women only. When the national sample was restricted to match the Kentucky sample, moderate autonomy was again associated with higher IL‐6 in men only.

Conclusions. Results provide preliminary evidence for gender‐specific effects of positive relationships and autonomy on IL‐6. Further work is needed to establish the generalizability of these effects to different ages, cultures, and health statuses.

Statement of contribution

What is already known on this subject? A host of previous work indicates that women value relationship‐centred aspects of well‐being more than men, while men value autonomy‐centred aspects of well‐being more than women. Further, there is some evidence suggesting that well‐being consistent with gender‐linked values is more health protective, such that relationships are more protective for women than for men, while autonomy is more protective for men than for women.

What does this study add We provide preliminary support for the hypothesis that gender moderates the associations of autonomy and positive relationships with IL‐6. Specifically, higher levels of positive relationships may be associated with lower IL‐6 in women only, whereas moderate levels of autonomy may be associated with higher IL‐6 in males only, particularly among older adults.
A Parametric Study of Bipolar Plate Structural Parameters on the Performance of Proton Exchange Membrane Fuel Cell
Authors: Imanmehr Salar , Pourmahmod Nader
Published: August 2012

In this research, the impact of structural parameters of bipolar plates on the proton exchange membrane (PEM) fuel cell performance has been investigated using numerical method, and this model incorporates all the essential fundamental physical and electrochemical processes occurring in the membrane electrolyte, cathode catalyst layer, electrode backing, and flow channel, with some assumptions in each part. In formulation of this model, the cell is assumed to work under steady state conditions. Also, since the thickness of the cell is negligible compared to other dimensions, one-dimensional and isothermal approximations are used. The structural parameters considered in this paper are: the width of channels (Wc), the width of support (Ws), the number of gas channels (ng), the height of channels (hc), and the height of supports (hp). The results show that structural parameters of bipolar plates have a great impact on outlet voltage in high current densities. Also, the number of gas channels, their surface area, the contacting area of bipolar plates, and electrodes have a great effect on the rate of reaction and consequently on outlet voltage. The model predictions have been compared with the existing experimental results available in the literature, and excellent agreement has been demonstrated between the model results and the experimental data for the cell polarization curve.
Influence of Rounded Corners on Flow Interference Due to Square
Cylinders Using Immersed Boundary Method
Authors: Shyam Kumar M. B. , Vengadesan S.
Published: August 2012

The influence of rounded corners on the aerodynamic forces and flow interference has been studied in detail for a uniform flow past two side-by-side arranged square cylinders. The Reynolds number (Re) based on the cylinder diameter (D) and free stream velocity (U∞) is 100. Numerical simulations are carried out for seven different transverse gap ratios (T/D), each with a minimum and maximum corner radius. An inbuilt finite difference code with staggered arrangement of flow variables is used to discretize the governing equations. The concept of immersed boundary method (IBM) is employed to simulate flow around rounded corners using the regular Cartesian grids. The computational code was validated for flow past an isolated circular cylinder, square cylinder, and two equal sized circular cylinders and the results were found to be in very good agreement with available literatures. In the present study, results in terms of the mean and rms values of lift and drag coefficients, Strouhal number, phase diagrams, and contours of streamlines and vorticity are presented. As the corner radius is increased, a reduction in the drag force is observed. There exists a significant effect of gap ratio and corner radius on the phase angle of lift and drag coefficients. Three different flow patterns, namely the single bluff body flow, biased gapside flow, and two independent bluff body flows, were observed from this study.
Coupled Fluid-Structure Transient Thermal Analysis of a Gas Turbine Internal Air System With Multiple Cavities
Authors: Ganine Vlad , Javiya Umesh , Hills Nick , Chew John
Published: August 2012

This paper presents the transient aerothermal analysis of a gas turbine internal air system through an engine flight cycle featuring multiple fluid cavities that surround a HP turbine disk and the adjacent structures. Strongly coupled fluid-structure thermal interaction problems require significant computational effort to resolve nonlinearities on the interface for each time step. Simulation times may grow impractical if multiple fluid domains are included in the analysis. A new strategy is employed to decrease the cost of coupled aerothermal analysis. Significantly lower fluid domain solver invocation counts are demonstrated as opposed to the traditional coupling approach formulated on the estimates of heat transfer coefficient. Numerical results are presented using 2D finite element conduction model combined with 2D flow calculation in five separate cavities interconnected through the inlet and outlet boundaries. The coupled solutions are discussed and validated against a nominal stand-alone model. Relative performance of both coupling techniques is evaluated.
Investigations on the Rotordynamic Coefficients of Pocket Damper Seals Using the Multifrequency, One-Dimensional, Whirling Orbit Model and RANS Solutions
Authors: Li Jun , Li Zhigang , Feng Zhenping
Published: August 2012

The numerical approach using the multifrequency one-dimensional whirling orbit model and Reynolds-averaged Navier-Stokes (RANS) solution was proposed for prediction of rotordynamic coefficients of pocket damper seal (PDS). By conducting the multiple frequencies one-dimensional whirling orbit for rotor center as the excitation signal, the unsteady RANS solutions combined with mesh deformation method were utilized to calculate the transient response forces on the PDS rotor surface. Unlike the single frequency whirling orbit models which require a separate computation for each frequency, the multifrequency whirling orbit model yields results for multiple frequencies and therefore requires only one computation for different frequencies. The rotor motion signal and response force signal were transformed to the frequency domain using the fast fourier transform, then the eight rotordynamic coefficients of the PDS were determined at fourteen different vibration frequencies 20–300 Hz. The numerical results of rotordynamic coefficients of the PDS were in good agreement with experimental data. The accuracy and availability of the proposed method was demonstrated. The effects of vibration frequencies and pressure ratios on the rotordynamic coefficients of PDS were also investigated using the presented numerical method. The multifrequency one-dimensional whirling orbit model is a promising method for prediction of the rotordynamic coefficients of the PDS.
Effect of Cooling Flow on the Operation of a HotRotor-Gas Foil Bearing System
Authors: Ryu Keun , Andrés Luis San
Published: August 2012

Gas foil bearings (GFBs) operating at high temperature rely on thermal management procedures that supply needed cooling flow streams to keep the bearing and rotor from overheating. Poor thermal management not only makes systems inefficient and costly to operate but could also cause bearing seizure and premature system destruction. This paper presents comprehensive measurements of bearing temperatures and shaft dynamics conducted on a hollow rotor supported on two first generation GFBs. The hollow rotor (1.36 kg, 36.51 mm OD and 17.9 mm ID) is heated from inside to reach an outer surface temperature of 120 °C. Experiments are conducted with rotor speeds to 30 krpm and with forced streams of air cooling the bearings and rotor. Air pressurization in an enclosure at the rotor mid span forces cooling air through the test GFBs. The cooling effect of the forced external flows is most distinct when the rotor is hottest and operating at the highest speed. The temperature drop per unit cooling flow rate significantly decreases as the cooling flow rate increases. Further measurements at thermal steady state conditions and at constant rotor speeds show that the cooling flows do not affect the amplitude and frequency contents of the rotor motions. Other tests while the rotor decelerates from 30 krpm to rest show that the test system (rigid-mode) critical speeds and modal damping ratio remain nearly invariant for operation with increasing rotor temperatures and with increasing cooling flow rates. Computational model predictions reproduce the test data with accuracy. The work adds to the body of knowledge on GFB performance and operation and provides empirically derived guidance for successful rotor-GFB system integration.
Analytical Correction of Nonlinear Thermal Stresses Under Thermomechanical Cyclic Loadings
Authors: Gehlot Sarendra , Mahadevan Pradeep , Kannusamy Ragupathy
Published: August 2012

Automotive turbocharger components frequently experience complex thermomechanical fatigue (TMF) loadings which require estimation of nonlinear plastic stresses for fatigue life calculations. These field duty cycles often contain rapid fluctuations in temperatures and consequently transient effects become important. Although current finite element (FE) software are capable of performing these nonlinear finite element analyses, the turnaround time to compute nonlinear stresses for complex field duty cycles is still quite significant and detailed design optimizations for different duty cycles become very cumbersome. In recent years, a large number of studies have been made to develop analytical methods for estimating nonlinear stress from linear stresses. However, a majority of these consider isothermal cases which cannot be directly applied for thermomechanical loading. In this paper a detailed study is conducted with two different existing analytical approaches (Neuber’s rule and Hoffman-Seeger) to estimate the multiaxial nonlinear stresses from linear elastic stresses. For the Neuber’s approach, the multiaxial version proposed by Chu was used to correct elastic stresses from linear FE analyses. In the second approach, Hoffman and Seeger’s method is used to estimate the multiaxial stress state from plastic equivalent stress estimated using Neuber’s method for uniaxial stress. The novelty in the present work is the estimation of nonlinear stress for bilinear kinematic hardening material model under varying temperature conditions. The material properties including the modulus of elasticity, tangent modulus and the yield stress are assumed to vary with temperature. The application of two analytical approaches were examined for proportional and nonproportional TMF loadings and suggestions have been proposed to incorporate temperature dependent material behavior while correcting the plasticity effect into linear stress. This approach can be effectively used for complex geometries to calculate nonlinear stresses without carrying out a detailed nonlinear finite element analysis.
Component Failure Analysis From a Stationary Proton Exchange Membrane Fuel Cell Demonstration
Authors: Lux Scott , Johnson Kelsey , Josefik Nicholas
Published: August 2012

A fleet of 91 residential-scale proton exchange membrane (PEM) fuel cells, ranging in size from 1 to 5 kW, was demonstrated at various U.S. federal facilities worldwide. This detailed analysis looks into the most prevalent means of failure in the PEM fuel cell systems as categorized from the stack, reformer, and power conditioning systems as well as the subsequent subsystems. Also evaluated are the lifespan and failure modes of selected fuel cell components, based on component type, age, and usage. The balance of plant, with the numerous pumps and filters, accounted for 60.6% of the total component outages, followed by the fuel cell stack system (20.4%), fuel processing system (10.7%), and the power conditioning system (8.2%). Hydrogen cartridges were the most prevalent component replaced (79), but various filters (RO, DI, air-intake, carbon) account for almost 25% (175) of the total component outages. The natural gas fuel cell stacks had the highest average operational lifetime; one stack reached a total of 10,250 h.
Electrical Properties of Sr0.86Y0.08TiO3 Under Redox and Full Cell Fabrication Conditions
Authors: Zhao Li , Brouwer Jacob
Published: August 2012

The effects of manufacturing and preparation conditions on the structural and electrical properties of Sr0.86Y0.08TiO3 (SYT) reduced in 5% NH3 (95% N2) are discussed. The realization of an SYT-based SOFC anode is challenging because the conductivity of SYT is highly dependent upon the thermal history combined with heat treatment atmosphere used in manufacturing. To obtain highly conductive SYT as a candidate for an SOFC anode material, all samples in this study were prereduced to 1400 °C under reducing conditions (ammonia) for 8 h. After prereduction, three samples were oxidized in air at 850 °C, 950 °C, and 1050 °C, respectively, for 4 h to evaluate the impact of oxidizing conditions in practical cell fabrication processes on the SYT conductivity. XRD analyses showed that the lattice parameter of SYT sintered in ammonia was slightly different than the sample sintered in air. Measured at 800 °C in reducing atmosphere (dry N2/4% H2), the maximum electrical conductivity of 36.3 S/cm was observed in SYT reduced in ammonia at 1400 °C. However, the observed conductivities were not preserved after oxidation-reduction cycles. Various SYT samples prereduced in ammonia at 1400 °C and then oxidized in air at 850 °C, 950 °C, and 1050 °C showed an irreversible drop on conductivity measured in a reducing atmosphere, and the higher the oxidation temperature, the lower the conductivity became. The conductivity results indicate a strong dependence upon the SYT manufacturing and processing conditions. Despite the irreversible drop due to the oxidation cycle, the conductivity of SYT sintered in ammonia at 1400 °C is still reasonable as a candidate for SOFC anodes, with careful management of cell fabrication conditions to avoid any oxidation processes at temperatures above 1050 °C.
Pressure Losses and Limiting Reynolds Numbers for Non-Newtonian Fluids in Short Square-Edged Orifice Plates
Authors: Ntamba Ntamba Butteur , Fester Veruscha
Published: August 2012

Correlations predicting the pressure loss coefficient along with the laminar, transitional, and turbulent limiting Reynolds numbers with the β ratio are presented for short square-edged orifice plates. The knowledge of pressure losses across orifices is a very important industrial problem while predicting pressure losses in piping systems. Similarly, it is important to define stable operating regions for the application of a short orifice at lower Reynolds numbers. This work experimentally determined pressure loss coefficients for square-edged orifices for orifice-to-diameter ratios of β = 0.2, 0.3, 0.57, and 0.7 for Newtonian and non-Newtonian fluids in both laminar and turbulent flow regimes.
On a Numerical Model for Free Surface Flows of a Conductive Liquid Under an Electrostatic Field
Authors: Pooyan Sajad , Passandideh-Fard Mohammad
Published: August 2012

In this paper, a numerical model is developed that can simulate the unsteady axisymmetric free-surface flow of a perfectly conductive liquid under an electrostatic field. The effect of the electrostatic field is modeled by a force distributed on the liquid free surface. Assuming the liquid as a perfect conductor makes it possible to reduce the general electromagnetic equations to electrostatic equations. The Navier–Stokes equations are solved to find the velocity and pressure fields. The free surface advection and reconstruction are performed based on the volume-of-fluid method using Youngs’ algorithm. To evaluate the effect of the electric field on the free surface, the electrostatic potential is first solved for the entire computational domain. Next, the electric field intensity and the surface density of the electric charge are calculated on the free surface after which the electric force can be determined. The computational method for treating this force is similar to that of the surface tension using the continuum surface force method. The developed model is validated by a comparison between the calculated results with those of the analytics as well as experiments for an electrowetting scenario.
Tracking a Hospital Outbreak of Carbapenem-Resistant
Klebsiella pneumoniae
with Whole-Genome Sequencing
Authors: Snitkin Evan S. , Zelazny Adrian M. , Thomas Pamela J. , Stock Frida ,   NISC Comparative Sequencing Program, Henderson David K. , Palmore Tara N. , Segre Julia A.
Published: August 2012

Tracking a hospital outbreak of carbapenem-resistant
Klebsiella pneumoniae
with whole-genome sequencing revealed its origin and probable modes of transmission.
Group Acupuncture for Knee Pain: Evaluation of a Cost-Saving Initiative in the Health Service
Authors: White Adrian , Richardson Marion , Richmond Pamela , Freedman Jonathan , Bevis Mark
Published: August 2012

Background

Acupuncture has been provided in nurse-led group clinics in St Albans since 2008. It is funded by a commissioning group within the National Health Service, on a trial basis, for patients with knee osteoarthritis who would otherwise be referred to an orthopaedic surgeon.

Aim

To evaluate the patients seen in the service's first year of operation and their outcome up to the end of 2010.

Methods

Service evaluation was made of patient data from the referral centre and the acupuncture clinics, including baseline characteristics, attendance data and Measure Yourself Medical Outcome Profile (MYMOP) symptom, function and well-being scores over at least 2 years.

Results

114 patients were offered acupuncture, of whom 90 patients were assessed in the acupuncture clinics. 41 of these were still attending after 1 year and 31 (34%) after 2 years. MYMOP scores showed clinically significant improvements at 1 month for pain (4.2 (SD 1.2) to 2.9 (SD 1.4)), stiffness (4.1 (SD 1.3) to 2.9 (SD 1.3)) and function (4.5 (SD 1.1) to 3.3 (SD 1.2)) which continued up to 2 years. Well-being scores did not change.

Conclusions

This is the first evaluation of nurse-led group (multibed) acupuncture clinics for patients with knee osteoarthritis to include a 2 year follow-up. It shows the practicability of offering a low-cost acupuncture service as an alternative to knee surgery and the service's success in providing long-term symptom relief in about a third of patients. Using realistic assumptions, the cost consequences for the local commissioning group are an estimated saving of £100 000 a year. Sensitivity analyses are presented using different assumptions.
Successful public health action to reduce the incidence of symptomatic vitamin D deficiency
Authors: Moy Robert John , McGee Eleanor , Debelle Geoff D , Mather Ian , Shaw Nicholas J
Published: August 2012

Background

In response to a resurgence of symptomatic cases of vitamin D deficiency in a high-risk predominantly ethnic minority population, a programme of universal rather than targeted vitamin D supplementation was begun with a public awareness campaign about the importance of vitamin D.

Objective

To evaluate the effectiveness of this programme in reducing case numbers.

Methods

Cases of symptomatic vitamin D deficiency in children under 5 years resident in a primary care trust catchment area presenting at local hospitals were identified through laboratory records of low vitamin D levels which were cross-checked against medical records to confirm the diagnosis. Comparisons were made of the case incidence rate, level of public knowledge and vitamin supplement uptake rate at the onset of the programme in 2005 and 4 years later.

Results

The number of cases of symptomatic vitamin D deficiency in those under 5 years fell by 59% (case incidence rate falling from 120/100 000 to 49/100 000) despite the supplement uptake rate rising only to 17%. Public awareness of vitamin D deficiency rose to near universal levels.

Conclusions

A programme of universal rather than targeted Healthy Start vitamin D supplementation for pregnant and lactating women and young children has led to a substantial decrease in cases of symptomatic vitamin D deficiency in a high-risk population. Supplementation was also started at a younger age than in the national programme. This approach has implications for the delivery of vitamin D supplementation programmes in similar populations.
Adenoid cystic carcinoma of head and neck: apropos of a case
Authors: Graça Susana Alexandra Rodrigues , Sequeira Hugo , Coelho Gustavo , Costa Horácio
Published: August 2012

Adenoid cystic carcinoma (ACC) is a rare malignant neoplasm, arising from glandular tissues, found mainly in the head and neck. Generally, it presents insidiously but can behave aggressively making its course unpredictable. Surgery and adjuvant radiotherapy continue to be the cornerstone for its treatment. ACC remains extremely difficult to treat. The authors report a case of a 37-year-old woman with bloody rhinorrhea for 6 months. She was diagnosed with a left nasal cavity lesion that was biopsied, and the anatomopathological result showed ACC. The patient was submitted to a left extended maxillectomy, microsurgical reconstruction and radiotherapy.
Tacrolimus-induced unilateral ischaemic optic neuropathy in a non-transplant patient
Authors: Gupta Monika , Bansal Reema , Beke Nikhil , Gupta Amod
Published: August 2012

Tacrolimus is commonly used as an immunosuppressant in organ transplantation. Although it is well tolerated, visual loss has been known as a rare but serious complication of this drug. We report a woman developing visual complaints while on tacrolimus therapy for nephrotic syndrome. Omission of the drug led to partial visual field recovery. Visual complications in patients receiving tacrolimus should alert the treating physicians for timely discontinuation of the drug.
Post-traumatic headache: don't forget to test the supraorbital nerve!
Authors: Stewart Michael , Boyce Samantha , McGlone Ray
Published: August 2012

We present a series of four patients with neurological symptoms following head injury. In each case neuroimaging was normal, but careful examination demonstrated altered sensation over the distribution of the supraorbital nerve. We discuss traumatic supraorbital neuralgia and how it differs from the more commonly reported idiopathic form.
Effect of fabric on the behaviour of reservoir sandstones
Authors: Alvarado Giovanny , Lui Neville , Coop Matthew R.
Published: August 2012

A laboratory investigation was undertaken on the mechanical behaviour of two sandstones that are commonly used as analogous hydrocarbon reservoir sandstones, using triaxial apparatuses with a capacity of up to 70 MPa confining pressure. Both materials are lightly cemented, but show a mechanical behaviour at large strains that is similar to that seen in rocks with much stronger cementation. At small strains, however, these materials behave more like uncemented sands in that they show a strong stress dependency of the shear modulus and yield takes places at relatively small strains. It is believed that fabric plays a fundamental role in the observed behaviour and this is supported by the experimental evidence, so that the concept of strong fabric in sandstones is introduced.
Estimation of water retention curve of granular soils from particle-size distribution — a Bayesian probabilistic approach
Authors: Chiu C.F. , Yan W.M. , Yuen Ka-Veng
Published: August 2012

This study proposes two empirical relationships to estimate the parameters of van Genuchten’s formula for modeling the water retention curve from the particle-size distribution. The relationships are determined by the Bayesian probabilistic method for selecting the most plausible class of models based on a database of 90 soil samples. The highest plausibility model among the selected relationships shows that the parameter α can be expressed as a first-order function of the particle size at 50% passing (d50) and parameter n is expressed as a third-order polynomial of the reciprocal of the standard deviation of geometric mean particle size (σg). The predictability of proposed relationships for other soils outside the calibrated database is also presented. It is found that the model prediction is highly consistent with the measurements for sands. However it only matches well with the measurements in the low suction regime for soils with at least 20% of fines content.
GLOBAL DYNAMICS OF A MULTI-GROUP EPIDEMIC MODEL WITH GENERAL RELAPSE DISTRIBUTION AND NONLINEAR INCIDENCE RATE
Authors: WANG JINLIANG , ZU JIAN , LIU XIANNING , HUANG GANG , ZHANG JIMIN
Published: August 2012

In this paper, we investigate a class of multi-group epidemic models allowing heterogeneity of the host population and that has taken into consideration with general relapse distribution and nonlinear incidence rate. We establish that the global dynamics are completely determined by the basic reproduction number R0. The proofs of the main results utilize the persistence theory in dynamical systems, Lyapunov functionals and a subtle grouping technique in estimating the derivatives of Lyapunov functionals guided by graph-theoretical approach. Biologically, the disease (with any initial inoculation) will persist in all groups of the population and will eventually settle at a constant level in each group. Furthermore, our results demonstrate that heterogeneity and nonlinear incidence rate do not alter the dynamical behaviors of the basic SIR model. On the other hand, the global dynamics exclude the existence of Hopf bifurcation leading to sustained oscillatory solutions.
CAN CULLING TO PREVENT MONKEYPOX INFECTION BE COUNTER-PRODUCTIVE? SCENARIOS FROM A THEORETICAL MODEL
Authors: TCHUENCHE JEAN M. , BAUCH CHRIS T.
Published: August 2012

In the last two decades, monkeypox outbreaks in human populations in Africa and North America have reminded us that smallpox is not the only poxvirus with potential to cause harm in human populations. Monkeypox transmission is sustained in animal reservoirs, and animal–human contacts are responsible for sporadic outbreaks in humans. Here, we develop and analyze a deterministic epizootic (animal-based) transmission model capturing disease dynamics in an animal population, disease dynamics in an age-structured human population, and their coupling through animal–human contacts. We develop a single-patch model as well as a two-patch meta-population extension. We derive mathematical expressions for the basic reproduction number, which governs the likelihood of a large outbreak. We also investigate the effectiveness of culling strategies and the impact of changes in the animal–human contact rate. Numerical analysis of the model suggests that, for some parameter values, culling can actually have the counter-productive outcome of increasing monkeypox infection in children, if animal reproduction is a density-dependent process. The likelihood of this happening, as well as the prevalence of monkeypox in humans, depends sensitively on the animal–human contact rate. We also find that ignoring age structure in human populations can lead to overestimating the transmissibility of monkeypox in humans. The effectiveness of monkeypox control strategies such as culling can strongly depend on the details of demography and epidemiology in the animal reservoirs that sustain it. Therefore, to better understand how to prevent and control monkeypox outbreaks in humans, better empirical data from wild animal populations where monkeypox is endemic must be collected, and these data must be incorporated into highly structured theoretical models.
DYNAMICAL MODEL OF IN-HOST HIV INFECTION: WITH DRUG THERAPY AND MULTI VIRAL STRAINS
Authors: SRIVASTAVA PRASHANT K. , BANERJEE MALAY , CHANDRA PEEYUSH
Published: August 2012

In this paper, a mathematical model for the effect of drug therapy on the in-host dynamics of HIV is considered and analyzed. As the process of reverse transcription is highly error prone, it causes mutation of virus which results in the emergence of drug resistant virus. This is also accounted in the model and corresponding model with both drug resistant and drug sensitive viral strains is studied. We found that, if reproductive ratios for both the strains are less than one, the virus population goes to extinction. If the reproductive ratio of either strain is greater than one and the reproductive ratio of drug resistant virus is smaller than that of drug sensitive virus then both the virus strains persist and infection is not cleared. However if reproductive ratio of drug resistant virus is greater than that of drug sensitive virus then the drug resistant virus out-competes the drug sensitive virus and only drug resistant virus survives. Hence the ratio of two reproduction ratios works as invading capacity threshold value for drug resistant strain. We also noted that by increasing the effective efficacy of the drug, virus may be cleared. Numerical simulations are performed to support and elaborate the analytical findings.
Enhanced trabecular bone resorption and microstructural bone changes in rats after removal of the cecum
Authors: Charoenphandhu Narattaphol , Suntornsaratoon Panan , Jongwattanapisan Prapaporn , Wongdee Kannikar , Krishnamra Nateetip
Published: August 2012

The cecum, the proximal part of the large intestine, has the highest rate of calcium absorption compared with other intestinal segments. Previously, we showed that rats with the cecum surgically removed (cecectomized rats) had severe negative calcium balance, low bone mineral density (BMD), and a compensatory increase in colonic calcium absorption. Herein, we used the computer-assisted bone histomorphometric technique and microcomputed tomography (μCT) to analyze bone microstructural defects in cecectomized rats at 1 and 3 mo postsurgery compared with age-matched sham-operated control rats. Relatively low BMD as determined by dual energy X-ray absorptiometry was observed in the femora, tibiae, and lumbar vertebrae of the 3-mo cecectomized rats. μCT analysis revealed decreases in the tibial cortical thickness, periosteal and endosteal perimeters, and moment of inertia in cecectomized rats. The histomorphometric results further showed that trabecular bone volume and number were markedly decreased, whereas trabecular separation was increased in the proximal tibial metaphysis of cecectomized rats, thus leading to a decrease in trabecular volumetric BMD. Since osteoclast surface and eroded surface were increased after cecectomy, such bone loss in cecectomized rats appeared to result from an enhanced bone resorption. Moreover, decreases in bone formation rate and osteoblast surface indicated a suppression of osteoblast-mediated bone formation. In conclusion, cecectomy induced widespread osteopenia in rats presumably by enhancing the osteoclast-mediated bone resorption and suppressing bone formation. The present results underline the important role of cecum in the body calcium homeostasis.
Architecture of vasa recta in the renal inner medulla of the desert rodent Dipodomys merriami: potential impact on the urine concentrating mechanism
Authors: Issaian Tadeh , Urity Vinoo B. , Dantzler William H. , Pannabecker Thomas L.
Published: August 2012

We hypothesize that the inner medulla of the kangaroo rat Dipodomys merriami, a desert rodent that concentrates its urine to over 6,000 mosmol/kg H2O, provides unique examples of architectural features necessary for production of highly concentrated urine. To investigate this architecture, inner medullary vascular segments in the outer inner medulla were assessed with immunofluorescence and digital reconstructions from tissue sections. Descending vasa recta (DVR) expressing the urea transporter UT-B and the water channel aquaporin 1 lie at the periphery of groups of collecting ducts (CDs) that coalesce in their descent through the inner medulla. Ascending vasa recta (AVR) lie inside and outside groups of CDs. DVR peel away from vascular bundles at a uniform rate as they descend the inner medulla, and feed into networks of AVR that are associated with organized clusters of CDs. These AVR form interstitial nodal spaces, with each space composed of a single CD, two AVR, and one or more ascending thin limbs or prebend segments, an architecture that may lead to solute compartmentation and fluid fluxes essential to the urine concentrating mechanism. Although we have identified several apparent differences, the tubulovascular architecture of the kangaroo rat inner medulla is remarkably similar to that of the Munich Wistar rat at the level of our analyses. More detailed studies are required for identifying interspecies functional differences.
Identification of exercise capacity QTL using association mapping in inbred mice
Authors: Courtney Sean M. , Massett Michael P.
Published: August 2012

There are large interindividual differences in exercise capacity. It is well established that there is a genetic basis for these differences. However, the genetic factors underlying this variation are undefined. Therefore, the purpose of this study was to identify novel putative quantitative trait loci (QTL) for exercise capacity by measuring exercise capacity in inbred mice and performing genome-wide association mapping. Exercise capacity, defined as run time and work, was assessed in male mice ( n = 6) from 34 strains of classical and wild-derived inbred mice performing a graded treadmill test. Genome-wide association mapping was performed with an efficient mixed-model association (EMMA) algorithm to identify QTL. Exercise capacity was significantly different across strains. Run time varied by 2.7-fold between the highest running strain (C58/J) and the lowest running strain (A/J). These same strains showed a 16.5-fold difference in work. Significant associations were identified for exercise time on chromosomes 1, 2, 7, 11, and 13. The QTL interval on chromosome 2 (∼168 Mb) contains one gene, Nfatc2, and overlaps with a suggestive QTL for training responsiveness in humans. These results provide phenotype data on the widest range of inbred strains tested thus far and indicate that genetic background significantly influences exercise capacity. Furthermore, the novel QTLs identified in the current study provide new targets for investigating the underlying mechanisms for variation in exercise capacity.
Efficiency of Buzzing Bees in Fruit Set and Seed Set ofSolanum violaceumin Sri Lanka
Authors: Wanigasekara R. W. M. U. M. , Karunaratne W. A. I. P.
Published: August 2012

Plant-pollinator interactions are often considered as tightly coevolved, mutualistic relationships. The present study aimed at determining the flower visiting bees of the vegetable crop,Solanum violaceum, and the efficiency of buzz pollination by bees on fruit and seed production in Sri Lanka. Seven bee species:Hoplonomia westwoodi,Amegilla comberi,Patellapis kaluterae,Xylocopa tenuiscapa,Apis dorsata,Trigona iridipennis, andCeratina hieroglyphicavisited the flowers ofS. violaceum, and the first four species were buzzing bees. Buzzing bees were the first to visitSolanumflowers and were followed by nonbuzzing bees. Handling time ofH. westwoodiandP. kaluteraevaried with the availability of pollen in anthers that deplete with the age of flower and stayed longer at new flowers than at old flowers. Handling time of the larger buzzing bee,H. westwoodi, was higher than that of the smallerP. kaluterae. The fruit set, seed set, and seed germinability in flowers visited by buzzing bees were significantly higher than those of the flowers bagged to exclude pollinators.
Localized Subcutaneous Acute Febrile Neutrophilic Dermatosis in a Dog
Authors: Schoellhorn Karolin , Gurtner Corinne , Roosje Petra J. , Suter Maja M. , Schoellhorn Bernhard , Rytz Ulrich , Timm Katrin
Published: August 2012

A two-year-old spayed female mixed-breed dog was presented with a five-day history of hemorrhagic gastroenteritis and fever. On physical examination, the dog was lethargic and clinically dehydrated. The skin of the entire ventral abdomen extending to both flanks was erythematous, swollen and painful on palpation. Histopathological examination of skin biopsies revealed a severe diffuse neutrophilic dermatitis and panniculitis, resembling the subcutaneous form of Sweet’s syndrome in humans. A large part of the skin lesion developed full-thickness necrosis. After intensive care, three surgical wound debridements and wound adaptations, the wound healed by secondary intention within ten weeks. In the absence of infection of the skin or neoplasia, a diagnosis of neutrophilic dermatosis and panniculitis, resembling the subcutaneous form of acute febrile neutrophilic dermatosis, was made.