bluuebunny/crossref_metadata_2025 huggingface dataset:
THE SYSTEM Na2O‐B2O3, IV Vapor Pressures of Boric Oxide, Sodium Metaborate, and Sodium Diborate between 1150°C and 1400°C
Authors: Cole Sandford S. , Taylor Nelson W.
Published: October 2006

Vapor pressures of B203, Na2O, B2O3, and Na2O.2B3O were obtained at 50°C intervals between 1150°C and 1400°C, utilizing the dynamic method with dry N2 under normal atmospheric pressure. Assuming normal vapor densities, the vapor pressures in millimeters of mercury at O°C were as follows:

Temperature, °C
B2O3
Na2O·B2O3
Na2O·2B2O3

1150

2.55
2.1

1200
0.83
7.2
5.5

1250
2.0
28.0
13.0

1300
3.4
62.0
25.5

1350
6.9
160.0

1400
12.0

The calculated boiling point was found to be 1860°C for B2O3, 1434°C for Na2O‐B2O3, and 1575°C for Na2O.2B2O3. The molal entropy of vaporization of B2O3 was found to be 32.2 calories per degree. The molal heat of vaporization was calculated to be B2O3, 65,600 cal.; NaZO.B2O3, 96,910 cal.; and Na2O.2B2O3, 72,410 cal.

B2O3 and Na2O.B2O3 volatilized without change in composition, but Na2O.2B2O3 was found to dissociate at all temperatures studied. It yielded a vapor of calculated composition 51.6% Na2O, 48.4% B2O3. Vapor pressure data based on this composition are also reported.
THE EFFECT OF TEMPERATURE TREATMENT ON GLASS‐TO‐METAL SEALS*
Authors: Littleton J. T.
Published: October 2006

It has been known for some time that glass cooled from temperatures well above the annealing temperature contracts at a rate depending upon its cooling rate and the temperature from which its cooling begins. Expansion measurements taken on the glass during later heating do not follow the original contraction curve. A photoelastic method is described which gives information on how the contraction of the glass is affected by these temperature conditions. The observations are of particular interest when applied to glass‐metal seals.
OPACITY DEVELOPMENT IN COVER ENAMELS FOR SHEET STEEL*
Authors: Tetrick James D.
Published: October 2006

The results on a study of opacity development in cover enamels for sheet steel are given and the effects of firing time, firing temperature, gage of base metal, and of some opacifiers on enamel opacity are discussed.
CONE FUSION STUDY OF MIXTURES OF ZIRCONIUM SILICATE, SILICA, AND ALUMINA*
Authors: Rea Robert F.
Published: October 2006

Abstract

Alumina and alumina‐silica mixtures have a strong fluxing effect on zirconium silicate A eutectic between ZrSiO3 and Al2O3 occurs at approximately 20% Al2O3 and melts at cone 31. The ternary eutectic has an approximate composition of 70% SiO2, 15% ZrSiO3, 15% A12O3, and a P.C.E. of cone 27.
SHRINKAGE RATES IN FIRING FIRE‐CLAY REFRACTORIES*
Authors: Stevens Donald K. , Bikch Raymond E.
Published: October 2006

Abstract

Direct optical measurements of length changes of five commercial fire‐clay refractories were made during a 72‐hour firing on a uniform heating schedule of 35°F. (20°C.) per hour. Data obtained from room temperature to 2700°F. (1480°C.) revealed three periods of high shrinkage rate. The shrinkage within these periods, emphasized by plotting the rate of change in length against temperature, showed maximum values at 950° to 1000°F., 1630° to 1680°F., and 1940° to 2040°F. (510°to 540°C.,890° to 915°C., and 1060° to 1115°C.). The magnitude of these peak values increased in the sameorder. The highest linear‐shrinkage rate observed was 2.4% per 100°F. (55°C.) temperature rise in the interval between 2018° and 2060°F. (1105° and 1125°C.).
ULTRAVIOLET‐TRANSMITTING GLASSES FOR MERCURY‐VAPOR LAMPS*
Authors: Nordberg M. E.
Published: October 2006

Abstract

The ultraviolet transmission of Vycor brand glass No. 791 is compared with that of certain commercial glasses and fused silica. The loss in transmission after 230 hours of exposure to ultraviolet radiation (2537 a.u.) from a Hanovia arc was 2.5% for No. 791 glass and 32.5% for Pyrex brand glass No. 9741. The loss (approximately 12%), due to the darkened layer which forms on a glass surface in contact with a mercury arc, is smaller for No. 791 glass than for glasses in general. The decrease in 2537 a.u. output of experimental lamps was determined after operation times up to nearly 6000 hours; after 5000 hours, No. 791 glass showed 27% loss in hot cathode lamps and Pyrex brand No. 9741 showed 53%. Vycor brand glass No. 7911, developed for medium‐pressure arcs (such as sunlamps), is discussed. The electrical properties of Vycor brand No. 791 are resistivity at 350°C., 9.2 (log R, ohm‐cm.); loss factor at 1.0 mc., 0.00091; and dielectric constant, 3.8.
PROPERTIES OF ENAMEL SLIPS: II, SOLUBLE SALTS IN ENAMEL SLIPS*
Authors: King Burnham W. , Carter Herbert D. , Draker Harry C.
Published: October 2006

Abstract

This paper contains data on the soluble salts to be found in mill liquors obtained on milling a number of different commercial porcelain‐enamel frits. The change in soluble salts on aging the enamel slips and the variation in pickup was also investigated. The mill liquors were found to contain chiefly Na2O, B2O3, and NaF. The effect of various proportions of these salts was studied by adding NaOH, Na2B4O7. 10H2O, and NaF to a slip composed of clay, water, and fine‐ground quartz. The correlation of the various data is discussed
RAPID METHOD FOR DETERMINING NICKEL ON THE SURFACE OF ENAMELING IRON*
Authors: Ikenberry L. c. , Canfield† J. J.
Published: October 2006

Abstract

A photometric method for determining nickel on nickel‐coated steel is described. The method is very rapid, requiring less than 5 minutes. The standard deviation (σ) has been found to be 0.0028 gm. of nickel per sq. ft. when testing a sheet carrying 0.10 gm. of nickel per sq. ft. The sample is obtained by dissolving the nickel coating on a small area with dilute nitric acid. The nitric acid is confined by using a weighted rubber ring and is withdrawn by suction into a 200‐ml. Erlenmeyer flask marked at 200 ml. A large excess of ammonium hydroxide is added, followed by ammonium persulfate and dimethylglyoxime. The solution is diluted to 200 ml. with water. After filtering off the ferric hydroxide, the intensity of the red color, which is proportional to the amount of nickel present, is measured by means of a photoelectric photometer.
IMPROVED APPARATUS FOR MEASURING VISCOSITY OF GLASSES IN ANNEALING RANGE OF TEMPERATURE*
Authors: Poole James P.
Published: October 2006

Abstract

An instrument is described that has been found to be a valuable and precise tool for the measurement of viscosity in the annealing range of temperature. The outstanding feature of this apparatus is its high thermal inertia that makes it possible to maintain thermal equilibrium without auxiliary temperature‐control equipment.
Oxidation Behavior of Hot‐Pressed Si3N4
Authors: KIEHLE A. J. , HEUNG L. K. , GIELISSE P. J. , ROCKETT T. J.
Published: October 2006

The high‐temperature chemical stability of hot‐pressed Si3N4 was studied between 600° and 1450°C. Reactions were followed by X‐ray diffraction and scanning electron microscopy. In air, this material begins to oxidize at 700° to 750°C; a distinct amorphous siO2 surface layer results after 24 h at 750°C‐Concomitant formation of cristobalite occurs, depending on exposure time, and is enhanced as temperature is Increased. Magnesium and calcium magnesium silicates form above 1000°C. The data suggest that impurities, e.g. Mg, Ca, and Fe, greatly lower the oxidation resistance of Si3N4 in air.
Phase Transitions of Adsorbates: VI, Effect of Deicing Agents on the Freezing of Cement Paste*
Authors: LITVAN G. G.
Published: October 2006

Changes in the dimensions and heat content of hydrated cement specimens were determined as a function of temperature and concentration of deicing agent in cooling‐warming cycles between +15° and ‐ 70°C. The concentration of the polar deicer (NaCl) solution varied from 0 to 26% and that of the nonpolar (urea) solution from 0 to 40%. The W/C ratios were 0.4,0.6, and 0.8 plain and 0.5 air‐entrained. Experiments were also conducted to clarify the effect of cooling rate and sample size. The observations can be explained by the mechanism previously proposed for phase transitions of adsorbates. In the presence of salts, freezing and melting of liquid exuded from the pores on cooling proceed according to the bulk phase diagram, producing double peaks in the thermograms except at extreme concentrations. The detrimental effect of deicers is attributed mainly to the high degree of saturation, a consequence of the low vapor pressure of the solutions. A beneficial aspect is the widening of the temperature range in which transitions occur. These opposing effects result in the worst conditions at a low deicer concentration (5% NaCl) and optimum conditions at a moderately high concentration (13% NaCl). Since the effect of deicers is physical, it should be common to all chemicals. Air entrainment, although beneficial in most circumstances, can be detrimental. The best protection against “salt scaling” appears to be reduction of porosity.
Grain‐Boundary Sliding During Creep of MgO
Authors: LANGDON TERENCE G.
Published: October 2006

The magnitude of grain‐boundary sliding in 6 specimens of polycrystalline MgO of 2 grain sizes (33 and 52 μm) was measured by interferometry after compressive creep at 1200°C uner stresses from 34.4 to 103.3 MN m‐2. Grain‐boundary sliding increases in importance with decreasing stress and/or grain size, although the largest strain contributed by sliding under these experimental conditions was only 20% of the total strain.
Fracture Mechanics of Fracture Mirrors
Authors: KIRCHNER HENRY P. , KIRCHNER JAMES W.
Published: October 2006

Stress‐intensity‐factor calculations were used to account for variations in the shapes of fracture mirrors caused by surfaces and by nonuniform stress fields (flexure). The validity of the stress‐intensity criterion for crack branching was confirmed. The stress‐intensity factor at crack branching, KB, for flint glass was determined to be 2.55 MN m−3/2. Also, the stress‐intensity‐factor calculations account for the transition from mist to mir‐rorlike regions as a neutral axis is approached, in cases in which this is observed. The results are compared with earlier results.
Sintering Chromium Oxide with the Aid of TiO2
Authors: CALLISTER WILLIAM D. , JOHNSON MYRON L. , CUTLER IVAN B. , URE ROLAND W.
Published: October 2006

The influence of additives on the sintering behavior of Cr2O3 was studied. The oxygen pressure and temperature at which the sintering rate becomes significant are dramatically altered by adding ∼ 1 wt% TiO2; the sintering temperature decreases, whereas the oxygen pressure for appreciable densification increases. At temperatures as low as 1280°C, densities of 92% of theoretical were obtained. Densification was examined as a function of temperature, oxygen pressure, and TiO2 concentration. Several other transition metal oxides were tested for their ability to enhance sintering; none was successful.
Structure and Dielectric Properties of Materials in the Solid Solution System Pb(Mg1/3Nb2/33)O3:Pb(W1/2Mg1/2)O3
Authors: NOMURA S. , JANG S. J. , CROSS L. E. , NEWNHAM R. E.
Published: October 2006

Solid solutions between the relaxor ferroelectric Pb3MgNb2O9 (PMN) and the ordered antiferroelectric Pb2MgWO6 (PMW) were studied. X‐ray diffraction shows that the superstructure reflections characteristic of the doubling of the perovskite subcell evident in pure PMW begin to appear in compositions containing more than 20 mol% PMW. Dielectric measurements, however, show that the diffuse transition behavior characteristic of PMN persists up to compositions Containing 80 mol% PMW. Results are discussed on the basis of present models for ferroelectric relaxor behavior.
Effect of Crystallization on the Auger Electron Signal Decay in an Li2O·2SiO2 Glass and Glass‐Ceramic
Authors: OHUCHI F. , CLARK D. E. , HENCH L. L.
Published: October 2006

Problems associated with Auger analysis of glasses are well recognized. When an electron beam impinges on the surface of a glass specimen, the Auger signal produced by the alkali species decreases with exposure time. The rate at which the signal decays depends on the glass composition, beam current density, accelerating potential of the primary beam, and substrate temperature, all of which must be carefully controlled to obtain a reliable analysis. A similar decay of the alkali Auger signal is observed for glass‐ceramic systems. The rate of decay for the crystalline phase is different from that for the glass and depends on the extent of crystallization. This behavior may provide a basis for using Auger electron spectroscopy for microstructural as well as compositional analysis.
Quenched Metastable Glassy and Crystalline Phases in the System Lithium‐Sodium‐Potassium Metaniobate‐Tantalate
Authors: NASSAU KURT , WANG CHRISTINE A. , GRASSO MICHAEL
Published: October 2006

A previous study of the system (Li,Na,K)TaO3 was extended to include the metaniobates. Glasses were made by twin‐roller‐quenching 33 compositions in the three pseudobinary systems as well as in the pseudoternary system composed of LiNbO3, NaNbO3, and KNbO3 and in the pseudobinary M(Nb,Ta)O3 where M is Li, Na, or K. Glasses were obtained in all but the most Na‐rich regions. Study of these metastable compositions by X‐ray diffraction and differential thermal analysis showed the appearance of four metastable crystalline phases on crystallization, one centered at KNbO3, one with an extended occurrence in the ternary system (Li,Na,K)NbO3, one centered about Li0.6Na0.4NbO3, and one at KNb0.25Ta0.75O3. There is some evidence for a subsolidus two‐glass region in the system (K,Na)NbO3. The ionic conductivity of the LiNbO3 glass was ∼10−5Ω−1 cm−1 and the dielectric constant shows ferroelectricity‐like behavior. Some infrared absorption data gave almost identical curves for the glass and the metastable crystalline phase, which was the first to crystallize.
Making sure the residents get their tablets: medication administration in care homes for older people
Authors: Barnes Lynne , Cheek Julianne , Nation Roger L. , Gilbert Andrew , Paradiso Lisa , Ballantyne Alison
Published: October 2006

Aim.  This paper reports an exploratory study of issues concerning the nursing practice of altering medication dose forms prior to administration of medicines to residents in homes for older people.

Background.  Medication use and administration is a major issue in residential homes for older people. Research suggests that the alteration of medication dose forms in these homes is a widespread practice. Despite its prevalence, there is limited nursing or pharmaceutical literature exploring the decision‐making processes surrounding this practice, the methods by which medicines are altered, or the types of medicines which are modified.

Method.  Semi‐structured interviews were carried out with 11 Registered Nurses working in a purposive sample of 10 residential homes for older people drawn from each of the six regions of South Australia. The data were collected in 2000.

Findings.  Nurses felt constrained to ensure that prescribed medication was administered to residents, despite their concern that this was not without risk. Nurses were concerned that they were working in an information vacuum, due to limited information resources and informal communication with other healthcare professionals such as speech pathologists, pharmacists and general practitioners. There was also concern about the difficulty of coordinating information and policies about altering medications and of implementing appropriate procedures in individual facilities.

Conclusion.  Clinical guidelines for the processes surrounding the alteration of medication dose forms and relevant pharmaceutical information are needed in all residential homes for older people. Ongoing education for nurses in this area is also required.
Experience with the use of piperacillin–tazobactam in pediatric non‐renal solid organ transplantation
Authors: Wiesmayr Silke , Stelzmueller Ingrid , Mark Walter , Muehlmann Gilbert , Tabarelli Walther , Tabarelli Dominique , Laesser Rainer , Antretter Herwig , Ladurner Ruth , Zimmerhackl Lothar‐Bernd , Margreiter Raimund , Guggenbichler Josef‐Peter , Bonatti Hugo
Published: October 2006

Abstract: Bacterial infection remains a major problem after solid organ transplantation (SOT), especially in children. Piperacillin–tazobactam (Pip–Tazo) is a beta‐lactam‐antibiotic combination with a broad spectrum of activity including gram‐positive cocci as well as gram‐negative rods, non‐fermentative and anaerobic bacteria. The aim of this retrospective study was to critically review our experience with Pip–Tazo as perioperative prophylactic agent in pediatric non‐renal SOT. Between 1993 and 2003 Pip–Tazo was used as initial perioperative prophylaxis in 45 pediatric patients who underwent a total of 49 transplants (36 liver‐, seven cardiac‐, two lung‐, and four small bowel‐) at our department. Median age of the children was 7.9 (range 0.5–18.1) years. A total of 34 rejection episodes following 27 transplants were diagnosed. During first hospitalization 44 infectious episodes were observed. Bacteria were responsible for 22 episodes including sepsis (n = 10), pneumonia (n = 5), wound infection (n = 4), urinary tract infection (n = 1), and clostridial colitis (n = 2). The isolated organisms were gram‐positive cocci (n = 12), gram‐negative rods (n = 3), non‐fermentative bacilli (n = 4), and anaerobes (n = 3). Ten episodes were caused by Pip–Tazo resistant bacteria. Twenty‐one of these infections were observed following antirejection therapy with pulse steroids. At later time points nine infectious episodes were successfully treated with a second course of Pip–Tazo. During follow up, eight patients died. Six deceased perioperatively: five from infection including aspergillosis (n = 4) andPneumocystis jirovecipneumonia (n = 1) and cerebrovascular bleeding (n = 1) and two children later on. At present 37 children (82%) are alive with well functioning graft after a median follow up of 39.2 (range 0.6–123.5) months. No severe side effects caused by Pip–Tazo were observed in any of the children. Pip–Tazo may be a suitable single agent for perioperative prophylaxis in pediatric non‐renal solid organs recipients, however, a prospective comparative study is needed to make final conclusions.
Case–control study of risk factors for the development of post‐transplant lymphoproliferative disease in a pediatric heart transplant cohort*
Authors: Katz B. Z. , Pahl E. , Crawford S. E. , Kostyk M. C. , Rodgers S. , Seshadri R. , Proytcheva M. , Pophal S.
Published: October 2006

Abstract: PTLD is an important complication following heart transplantation. To better define the risk factors of PTLD in children, we performed a case–control study. All pediatric cardiac transplant recipients who developed their first episode of PTLD were matched by age (±1 yr) and time since transplant (±1 yr) with those who did not. PTLD occurred in nine of 95 cardiac transplant recipients (9%), 0.3–7.8 yr following cardiac transplantation (median = 2.5 yr). Patients were 0.1–16.4 yr (median = 3.7) at transplantation. Biopsies revealed polymorphic B cell hyperplasia (three), polymorphic B cell lymphoma (one), monomorphic diffuse large cell B cell lymphoma (three) and monomorphic Burkitt's‐like lymphoma (two). Patients who developed PTLD were at no greater risk of death (p = 0.31). Recipient EBV seronegativity at time of transplant (p = 0.08), EBV seroconversion (p = 0.013) and recipient CMV seronegativity (p = 0.015) were associated with the development of PTLD by conditional logistic regression; sex, race, donor age, recipient diagnosis, donor CMV seropositivity, recipient treatment for CMV infection, EBV seropositivity at the time of PTLD diagnosis, and number of rejection episodes, treated rejection episodes, and lympholytics used were not. There was no significant association between PTLD and death in our recipients. EBV seroconversion and recipient CMV seronegativity were associated with the development of PTLD.
Maintaining Activity Engagement: Individual Differences in the Process of Self‐Regulating Motivation
Authors: Sansone Carol , Thoman Dustin B.
Published: October 2006

ABSTRACT
Typically, models of self‐regulation include motivation in terms of goals. Motivation is proposed to differ among individuals as a consequence of the goals they hold as well as how much they value those goals and expect to attain them. We suggest that goal‐defined motivation is only one source of motivation critical for sustained engagement. A second source is the motivation that arises from the degree of interest experienced in the process of goal pursuit. Our model integrates both sources of motivation within the goal‐striving process and suggests that individuals may actively monitor and regulate them. Conceptualizing motivation in terms of a self‐regulatory process provides an organizing framework for understanding how individuals might differ in whether they experience interest while working toward goals, whether they persist without interest, and whether and how they try to create interest. We first present the self‐regulation of motivation model and then review research illustrating how the consideration of individual differences at different points in the process allows a better understanding of variability in people's choices, efforts, and persistence over time.
Cranial and peripheral neuropathy in rheumatoid arthritis with special emphasis to II, V, VII, VIII and XI cranial nerves
Authors: HAMED Sherifa A. , HAMED Eman A. , ELATTAR Amal M. , RAHMAN Mohamed S. AbdeL , AMINE Nabila F.
Published: October 2006

Background:  Cranial neuropathy in rheumatoid arthritis (RA) is relatively rare compared to the frequently reported peripheral neuropathy.

Methods:  We investigated the occurrence of subclinical cranial and peripheral nerve involvement in 55 patients with RA.

Results:  Patients had a mean age of 43.1 years and a mean duration of illness of 6.4 years. All patients presented with electrophysiological findings suggestive of peripheral neuropathy. In addition, 69.1% of them had entrapment neuropathies, in which carpal tunnel syndrome was the most common (54.6%). Sensorimotor neuropathy at sites other than usual entrapment sites was diagnosed in 70.9%, while bilateral distal sensory neuropathy in lower limbs was identified in 29.1%. Among cranial nerves examined, optic and vestibulocochlear neuropathies were common (29.1% of eyes and 40% of ears examined). Spinal accessory neuropathy was reported in 21.8% of records. Neither facial nor trigeminal nerves were affected. Electrophysiological characteristics of neuropathies were indicative of axon loss. Significant association was identified between neuropathy and patients’ ages (P < 0.01), duration of the illness (P < 0.001), presence of rheumatoid nodules (P < 0.001) and disease stages (P < 0.001).

Conclusions:  Our results indicate that cranial and non‐compressive neuropathies are not uncommon in RA. This extends the pathologic disease spectrum. We do not confirm, but suggest the contribution of chronic immune‐mediated vasculitis and/or neurotoxicity in RA neuropathies. Of clinical importance, subclinical neuropathy may never progress and/or be of clinical significance, which contradicts that of comparable diseases, such as systemic lupus erythematosus. Advances in genetics implicate a complex immune genetics which controls susceptibilities and adaptive molecular mechanisms as a culprit of phenotypical heterogenicity among related diseases.
Clinical manifestations of Behcet's disease in Chinese patients
Authors: ZHANG Zhuoli , PENG Jinmin , HOU Xiaomeng , DONG Yi
Published: October 2006

Aim and method:  The data of 1996 patients from 46 medical centres were meta‐analysed for the purpose of determining the type and frequency of clinical features of Behcet's disease in Chinese patients. The age at onset was 33.8 ± 12.2 years with 1144 male and 852 female patients. The duration of follow‐up at study entry was 8.9 ± 5.2 years.

Results:  The common manifestations observed throughout the disease course were oral aphthae (98.4%), genital aphthae (76.3%), various cutaneous lesions including erythema nodosum and pseudo‐folliculitis (69.0%), inflammatory ocular disease (34.8%) and arthralgia/arthritis (30.0%). Other systems, such as gastrointestines, vessels, nerves, heart, lungs, kidneys and blood, were also involved in Chinese Behcet's disease patients at the prevalence of 8.8%, 7.7%, 6.5%, 4.0%, 2.2%, 1.9% and 0.8%, respectively. Ophthalmologic presentation occurred earlier than the involvement of major vessels, gastrointestines, the nervous system and the haematological system. Vascular involvement as well as ocular, heart and nervous system involvement were more common in men than women (11.8%vs. 2.2%, P < 0.001, OR = 5.947; 39.9%vs. 27.9%, P < 0.001, OR = 1.715; 5.4%vs. 2.1%, P < 0.005, OR = 2.661; 8.0%vs. 4.5%, P < 0.05, OR = 1.845, respectively); while haematological involvement occurred more frequently in women than men (0.4%vs. 1.3%, P < 0.05, OR = 0.305) and gastrointestinal involvement was equally common in both sexes (8.3%vs. 9.4%, P > 0.05). Positive pathergy test was present in 57.9% of all patients and most of these were male (70%vs. 41.7%, P < 0.001).

Conclusions:  Behcet's disease starts frequently around the beginning of the third decade and has a male predominance. The disease is usually more severe in men than women in Chinese populations.
Uncertainty Analysis for Regional‐Scale Reserve Selection
Authors: MOILANEN ATTE , WINTLE BRENDAN A. , ELITH JANE , BURGMAN MARK
Published: October 2006

Abstract: Methods for reserve selection and conservation planning often ignore uncertainty. For example, presence‐absence observations and predictions of habitat models are used as inputs but commonly assumed to be without error. We applied information‐gap decision theory to develop uncertainty analysis methods for reserve selection. Our proposed method seeks a solution that is robust in achieving a given conservation target, despite uncertainty in the data. We maximized robustness in reserve selection through a novel method, “distribution discounting,” in which the site‐ and species‐specific measure of conservation value (related to species‐specific occupancy probabilities) was penalized by an error measure (in our study, related to accuracy of statistical prediction). Because distribution discounting can be implemented as a modification of input files, it is a computationally efficient solution for implementing uncertainty analysis into reserve selection. Thus, the method is particularly useful for high‐dimensional decision problems characteristic of regional conservation assessment. We implemented distribution discounting in the zonation reserve‐selection algorithm that produces a hierarchy of conservation priorities throughout the landscape. We applied it to reserve selection for seven priority fauna in a landscape in New South Wales, Australia. The distribution discounting method can be easily adapted for use with different kinds of data (e.g., probability of occurrence or abundance) and different landscape descriptions (grid or patch based) and incorporated into other reserve‐selection algorithms and software.
Deforestation and Plant Diversity of Madagascar's Littoral Forests
Authors: CONSIGLIO TRISHA , SCHATZ GEORGE E. , MCPHERSON GORDON , LOWRY PORTER P. , RABENANTOANDRO JOHNY , ROGERS ZACHARY S. , RABEVOHITRA RAYMOND , RABEHEVITRA DAVID
Published: October 2006

Abstract:  Few studies have attempted to quantify the reduction or document the floristic composition of forests in Madagascar. Thus, we focused specifically on deforestation and plant diversity in Madagascar's eastern littoral community. We used a data set of approximately 13,500 specimen records compiled from both historical and contemporary collections resulting from recent intensive inventory efforts to enumerate total plant species richness and to analyze the degree of endemism within littoral forests. Change in littoral forest cover from original to current extent was estimated using geographical information systems tools, remote sensing data (satellite imagery and low‐elevation digital photography), and environmental data layers. Of the original littoral forest only 10.3% remains in the form of small forest parcels, and only 1.5% of these remaining fragments are included within the existing protected‐areas network. Additionally, approximately 13% of Madagascar's total native flora has been recorded from these forests that originally occupied <1% of its total land surface, and over 25% of the 1535 plant species known from littoral forests are endemic to this community. Given the ongoing pressure from human settlement along Madagascar's eastern coast, protection of the remaining forest fragments is critical for their survival. Fifteen of the largest intact littoral forest fragments we identified, collectively representing 41.5% of remaining littoral forest, are among priority sites recommended to the government of Madagascar for plant conservation and incorporation into the protected‐areas network.
Genetic Structure and Early Effects of Inbreeding in Fragmented Temperate Forests of a Self‐Incompatible Tree, Embothrium Coccineum
Authors: MATHIASEN PAULA , ROVERE ADRIANA E. , PREMOLI ANDREA C.
Published: October 2006

Abstract:  Deforestation of temperate forests has created landscapes of forest remnants in matrices of intense human use. We studied the genetic effects of fragmentation in southern Chile on Embothrium coccineum J.R. et G. Forster, an early colonizing, bird‐pollinated tree. We tested the hypothesis that, because of its self‐incompatibility and life‐history strategy, E. coccineum is less strongly affected by fragmentation. We studied the effects of reduced population size and increased isolation on population genetic structure and early performance of progeny. Samples were collected from spatially isolated trees and six fragments of differing sizes (small, 1 ha; medium, 20 ha; large, >150 ha). Based on isozyme polymorphisms we estimated parameters of genetic diversity, divergence, and inbreeding for adults and greenhouse‐grown progeny. We also measured germination, seedling growth, and outcrossing rates on progeny arrays. Genetic variation of adults did not correlate significantly with population size, as expected, given that fragmentation occurred relatively recently. Weak effects of fragmentation were measured on progeny. Only adults yielded significant inbreeding. Similar total genetic diversity was found in adults and progeny. Low but significant genetic differentiation existed among adult and progeny populations. Seedling growth correlated positively with the effective number of alleles, showing deleterious effects of inbreeding on progeny. Seeds from small fragments had the highest outcrossing rates and germination success, indicating that higher pollinator activity in such fragments reduced selfing, thereby buffering genetic erosion and maintaining adaptive variation. The effects of forest fragmentation were detectable in E. coccineum, but these effects will probably not be detrimental to the viability of remnant populations because small, fragmented populations demonstrated higher levels of gene flow and lower inbreeding than larger stands. Pioneer species that are insensitive to forest clearing may be crucial in recovery plans to facilitate the establishment of species intolerant to such disturbance.
Beyond Substituted Judgment: How Surrogates Navigate End‐of‐Life Decision‐Making
Authors: Vig Elizabeth K. , Taylor Janelle S. , Starks Helene , Hopley Elizabeth K. , Fryer‐Edwards Kelly
Published: October 2006

OBJECTIVES: To characterize how surrogates plan to make medical decisions for others.

DESIGN: Descriptive study using semistructured qualitative interviews.

SETTING: Surrogates were interviewed by telephone from their homes.

PARTICIPANTS: Fifty experienced surrogate decision‐makers identified to make decisions for older, chronically ill veterans.

MEASUREMENTS: Surrogates were asked to describe advance care planning conversations with loved ones and how they planned to make future medical decisions. Thematic content analysis was used to identify bases for decision‐making.

RESULTS: Surrogates described the motivators and the content of advance care planning conversations with loved ones. Surrogates described five bases for decision‐making: (1) conversations (making decisions based on their knowledge of their loved ones' preferences), (2) relying on documents (referring to their loved ones' advance care directives), (3) shared experience (believing an “inner sense” would guide decisions because of shared lived experience with loved ones), (4) surrogates' own values and preferences about life, and (5) surrogates' network (enlisting the help of others).

CONCLUSION: Although ethicists and clinicians expect surrogates to use substituted judgment or patients' best interests when making decisions, these data indicate that many surrogates rely on other factors such as their own best interests or mutual interests of themselves and the patient or intend to base substituted judgments on documents with which they have little familiarity.
Cognitive Correlates of Financial Abilities in Mild Cognitive Impairment
Authors: Okonkwo Ozioma C. , Wadley Virginia G. , Griffith H. Randall , Ball Karlene , Marson Daniel C.
Published: October 2006

OBJECTIVES: To investigate the cognitive correlates of financial abilities in mild cognitive impairment (MCI).

DESIGN: Controlled, matched‐sample, cross‐sectional analysis regressing five cognitive composites on financial performance measures.

SETTING: University medical and research centers.

PARTICIPANTS: Forty‐three persons with MCI and 43 normal controls.

MEASUREMENTS: The Financial Capacity Instrument (FCI) and a comprehensive neurocognitive battery.

RESULTS: Patients with MCI performed significantly worse than controls on cognitive domains of executive function, memory, and language and on FCI domains of financial conceptual knowledge, bank statement management, and bill payment. Patients with MCI also needed significantly more time to complete a multistep financial task and were significantly more likely than controls to make errors on this task. Stepwise regression models revealed that, within the MCI group, attention and executive function were significant correlates of FCI performance.

CONCLUSION: Although impaired memory is the cardinal deficit in MCI, the neurocognitive basis of lower functional performance in MCI appears to be emergent declines in abilities to selectively attend, self‐monitor, and temporally integrate information. Compromised performance on cognitive measures of attention and executive function may constitute clinical markers of lower financial abilities and should be evaluated for its relationship to functional ability in general. These cognitive domains may be appropriate targets of future intervention studies aimed at preservation of functional independence in people with MCI.
Hypoalbuminemia is an important risk factor of hypotension during hemodialysis
Authors: NAKAMOTO Hidetomo , HONDA Nobuko , MIMURA Taku , SUZUKI Hiromichi
Published: October 2006

Hypotension during hemodialysis (HD) is an important problem in patients on HD. To investigate the risk factors that contribute to the hypotension during HD, we compared background factors of hypotensive (HP) patients during HD. Among 58 patients undergoing HD in Tamura Memorial Hospital, 12 patients could not continue full HD because of hypotension. We compared the data of ultrafiltration volume, cardiothoracic ratio (CTR), total protein (TP), serum albumin, blood urea nitrogen (BUN), serum creatinine, total cholesterol (TC), hemoglobin (Hb), blood glucose (BS), brain natriuretic peptide (BNP), and cardiac function between HP patients (HP group; n=12) and sex‐ and age‐matched control patients (NP group; n=12). There were no significant differences of age, sex, and duration of HD between the 2 groups. Cardiothoracic ratio is bigger and BNP is higher in the HP group compared with the NP group (CTR: HP 55.8±2.9% vs. NP 47.7±1.1%, p=0.0165; BNP: HP 602±171 vs. NP 147±38, p=0.0167). Serum albumin in the HP group is significantly lower compared with the NP group (HP 3.2±0.1 g/dL vs. NP 3.5±0.1 g/dL, p=0.0130). However, there were no significant differences of ultrafiltration rate (UFR), BS, TC, Hb, and cardiac function between the 2 groups. There is a significant negative correlation between changes of systolic blood pressure (delta systolic blood pressure) and serum albumin in these patients (r=−0.598, p=0.0016). From these data, we conclude that hypoalbuminemia is a major risk factor of hypotension during HD.
Comparison of survival between short‐daily hemodialysis and conventional hemodialysis using the standardized mortality ratio
Authors: BLAGG Christopher R. , KJELLSTRAND Carl M. , TING George O. , YOUNG Bessie A.
Published: October 2006

More frequent hemodialysis (5 or more times weekly, both short during the day and long overnight) has been shown to improve patient well‐being, reduce symptoms during and between treatments, and have beneficial effects on clinical outcomes. Because of the relatively small patient sample sizes, there are little or no data on mortality from any single study at this time. This study compares survival in 117 U.S. patients treated by short‐daily hemodialysis in 2003 and 2004, with patients reported in the 2003 data from the United States Renal Data System (USRDS). Expected mortality was calculated from the USRDS and compared with observed actual mortality. The standardized mortality ratio (SMR) was used to adjust for differences in patient age, sex, race, and cause of renal failure. The SMR for the short‐daily hemodialysis patients was 0.39, statistically significantly better (p<0.005) than data from the overall U.S. population of hemodialysis patients and indicating that daily hemodialysis patients had a 61% better survival. Patients treated by short‐daily hemodialysis have a better survival rate than comparable populations treated by conventional hemodialysis.
Flow distribution analysis by helical scanning in polysulfone hemodialyzers: Effects of fiber structure and design on flow patterns and solute clearances
Authors: RONCO Claudio , LEVIN Nathan , BRENDOLAN Alessandra , NALESSO Federico , CRUZ Dinna , OCAMPO Catalina , KUANG Dingway , BONELLO Monica , De CAL Massimo , CORRADI Valentina , RICCI Zaccaria
Published: October 2006

The efficiency of a hemodialyzer is largely dependent on its ability to facilitate diffusion, as this is the main mechanism by which small solutes are removed. The diffusion process can be impaired if there is a mismatch between blood and dialysate flow distribution in the dialyzer. The objective of the paper was to study the impact of different fiber bundle configurations on blood and dialysate flow distribution and urea clearances. The Optiflux 200 NR hemodialyzer was studied and the standard F 80 A hemodialyzer was used as a control for the study. Six dialyzers of each type were studied in vitro in the radiology department utilizing a new generation of helical computed tomography (CT) scan following contrast medium injection into the blood and dialysate compartment. Dynamic sequential imaging of longitudinal sections of the dialyzer was undertaken to detect flow distribution, average and peak velocities, and calculate wall shear rates. Six patients were dialyzed with 2 different dialyzers in random consecutive sequence. In these patients, 2 consecutive dialyses were carried out with identical operational parameters (Qb=300 mL/min, Qd=500 mL/min). In each session, blood and dialysate side urea clearances were measured at 30 and 150 min of treatment. Macroscopic and densitometrical analysis revealed that flow distribution was most homogeneous in the dialyzer with a new bundle configuration. Significantly increased urea clearances (p<0.001) were seen with the Optiflux dialyzer compared with the standard dialyzer. In conclusion, more homogeneous dialysate blood and dialysate flow distribution and improved small solute clearances can be achieved by modifying the configuration of the filter bundle. These effects are achieved probably as a result of reduced blood to dialysate mismatch with reduction of flow channeling. The used radiological technique allows detailed flow distribution analysis and has the potential for testing future modifications to dialyzer design.
Daily dialyses decrease plasma levels of brain natriuretic peptide (BNP), a biomarker of left ventricular dysfunction
Authors: ODAR‐CEDERLÖF Ingegerd , BJELLERUP Per , WILLIAMS Amy , BLAGG Christopher R. , TWARDOWSKI Zbylut , TING George , KJELLSTRAND Carl M.
Published: October 2006

Brain natriuretic peptide or B‐type natriuretic peptide (BNP) is a sensitive marker of heart disease. Plasma levels of BNP increase in left ventricular failure and determination of plasma BNP has become a useful tool in the diagnosis of heart failure. Hemodialysis (HD) patients may have elevated plasma levels of BNP, particularly predialysis, that correlate with echocardiographic signs of left ventricular dysfunction. High BNP levels are also a strong predictor of mortality in both nonrenal and HD patients. We studied plasma BNP levels in patients who changed from conventional thrice‐weekly dialysis to daily dialysis 6 times a week while maintaining a total weekly time on dialysis of 12 hr. Twelve HD patients, mean age 55 years, had 4 hr of conventional thrice‐weekly treatment for 4 weeks. Predialysis and postdialysis blood samples were obtained at the last dialysis. Patients were then dialyzed for 2 hr, 6 times weekly, for 4 weeks (daily dialysis). Again, predialysis and postdialysis blood samples were collected at the last HD. Brain natriuretic peptide plasma concentrations were determined by immunoradiometric assay. Predialysis BNP levels decreased from 194±51 ng/L (68±19 pmol/L; mean+SE) during thrice‐weekly HD to 113±45 ng/L (41±18 pmol/L; p=0.001) after 4 weeks on daily dialysis. With thrice‐weekly HD, predialysis BNP levels were higher than postdialysis levels: 120±26 ng/L (39±8 pmol/L; p=0.059). With daily dialysis, predialysis BNP levels did not differ significantly from postdialysis levels. Elevated predialysis plasma levels of BNP, considered sensitive and early markers of left ventricular dysfunction, decreased when patients were changed from conventional thrice‐weekly HD to daily dialysis maintaining total hours of dialysis per week constant. Given the accumulated evidence that BNP is a biomarker of left ventricular dysfunction and can be used for risk stratification and guidance in pharmacotherapy of heart failure, daily dialysis appears to lead to less cardiac distress.
Social and Emotional Impacts of Farmwork Injuries: An Exploratory Study
Authors: Robertson S. M. , Murphy Dennis J. , Davis Lisa A.
Published: October 2006

ABSTRACT: 
Context: The physical hazards of farming have been extensively studied and reported upon. Far less studied are the social and emotional impacts of farmwork injuries and deaths. Purpose: To investigate and document broad but targeted issues regarding the impact on individuals, families, and communities of farmwork injuries and fatalities of farmer leaders. Methods: Ten incidents of farmwork injuries with disabilities or fatalities in Pennsylvania were used for a collective case study. Data were collected through a total of 47 interview sessions with 66 individuals including next of kin, other family members, injured persons, and community members. Thematic analysis was used to identify themes and issues in this descriptive study. Findings: Community members missed the rich, broad, and comprehensive skills, abilities, and perspectives that farmers brought to community service. Participants expressed that the community assistance and support provided to injured persons and families benefited not only the injured persons and their families and farms but also the community members. Participants reported emotional anguish and loss as well as positive transformations and consequences. As expressed by participants, God and religion play an important role in their beliefs regarding the occurrence and outcome of farmwork injury incidents. Conclusions: Social and emotional impacts on individuals, families, and communities are varied and multileveled. The role that religion and storytelling play in the process of dealing with serious injury incidents raises questions regarding agricultural injury prevention.
Segmentation of bone CT images and assessment of bone structure using measures of complexity
Authors: Saparin Peter , Thomsen Jesper Skovhus , Kurths Jürgen , Beller Gisela , Gowin Wolfgang
Published: October 2006

A nondestructive and noninvasive method for numeric characterization (quantification) of the structural composition of human bone tissue has been developed and tested. In order to quantify and to compare the structural composition of bones from 2D computed tomography (CT) images acquired at different skeletal locations, a series of robust, versatile, and adjustable image segmentation and structure assessment algorithms were developed. The segmentation technique facilitates separation of trabecular from cortical bone and standardizes the region of interest. The segmented images were symbol‐encoded and different aspects of the bone structural composition were quantified using six different measures of complexity. These structural examinations were performed on CT images of bone specimens obtained at the distal radius, humeral mid‐diaphysis, vertebral body, femoral head, femoral neck, proximal tibia, and calcaneus. In addition, the ability of the noninvasive and nondestructive measures of complexity to quantify trabecular bone structure was verified by comparing them to conventional static histomorphometry performed on human fourth lumbar vertebral bodies. Strong correlations were established between the measures of complexity and the histomorphometric parameters except for measures expressing trabecular thickness. Furthermore, the ability of the measures of complexity to predict vertebral bone strength was investigated by comparing the outcome of the complexity analysis of the CT images with the results of a biomechanical compression test of the third lumbar vertebral bodies from the same population as used for histomorphometry. A multiple regression analysis using the proposed measures including structure complexity index, structure disorder index, trabecular network index, index of a global ensemble, maximal L‐block, and entropy of x‐ray attenuation distribution revealed an excellent relationship (, ) between the measures of complexity and compressive bone strength. In conclusion, the image segmentation techniques and the assessment of bone architecture by measures of complexity have been successfully applied to analyze high‐resolution peripheral quantitative computed tomography (pQCT) and CT images obtained from the distal radius, humeral mid‐diaphysis, third and fourth lumbar vertebral bodies, proximal femur, proximal tibia, and calcaneus. The proposed approach is of broad interest as it can be applied for the quantification of structures and textures originating from different imaging modalities in other fields of science.
Cone‐beam mammo‐computed tomography from data along two tilting arcs
Authors: Zeng Kai , Yu Hengyong , Fajardo Laurie L. , Wang Ge
Published: October 2006

Over the past several years there has been an increasing interest in cone‐beam computed tomography (CT) for breast imaging. In this article, we propose a new scheme for theoretically exact cone‐beam mammo‐CT and develop a corresponding Katsevich‐type reconstruction algorithm. In our scheme, cone‐beam scans are performed along two tilting arcs to collect a sufficient amount of information for exact reconstruction. In our algorithm, cone‐beam data are filtered in a shift‐invariant fashion and then weighted backprojected into the three‐dimensional space for the final reconstruction. Our approach has several desirable features, including tolerance of axial data truncation, efficiency in sequential/parallel implementation, and accuracy for quantitative analysis. We also demonstrate the system performance and clinical utility of the proposed technique in numerical simulations.