bluuebunny/crossref_metadata_2025 huggingface dataset:
Variations in late-age mortality by household structure and marital status in Parma, Italy
Authors: PIZZETTI PAOLA , MANFREDINI MATTEO , LUCCHETTI ENZO
Published: April 2005

The objective of this study was to investigate the relationship between household structure and mortality at older ages in Parma, Italy. The household is an important setting for older people's social roles and social relations and its composition has a strong association with their health. The study examines 57,830 people aged 65 or more years drawn from the population registers of Parma (Italy). Record linkage from 1989 to 2000 was carried out using their unique identification numbers. Through the linked records, it was possible to follow changes in each person's and family's history provided they remained resident in Parma. The descriptive analyses show that elderly women were more likely than men to live alone, probably on account of their higher longevity. Only 10 per cent of elderly men lived alone, as compared with 32 per cent of older women. Nonetheless, the survival curves demonstrate that up to the age of 80 years, women living alone experienced lower mortality than those living with partners. A logistic regression model based on ‘event history analysis’ was performed using the longitudinal data. The results suggest that being married provides a protective role against mortality in later life only for men. It is possible that elderly women who take care of a husband or relatives do not care for themselves (or their health), as do older women who live alone.
Wisdom in later life: ethnographic approaches
Authors: EDMONDSON RICCA
Published: April 2005

The concept of wisdom, popularly associated with the idea of old age, was neglected during the 20th century. It has recently revived as a matter of academic concern, but remains imperfectly understood. This article therefore begins to explore both the concept of wisdom and some forms we might expect wise behaviour to take. It emphasises the contemporary relevance of historical approaches through an examination of Hebrew and Greek writing on wisdom. Recent contributions from psychology develop aspects of these traditions; but studying wisdom ethnographically also substantially expands our understanding of what wisdom is. An ethnographic interview from Austria exemplifies social as well as psychological aspects of wisdom, showing that part of the meaning of wisdom resides in its effects on a social setting. Aspects of discourse in rural Ireland, when interpreted in the light of maxim-related wisdom traditions, extend this claim, showing more about how wise interventions activate wisdom in the society surrounding them. Other ethnographic cases also develop this notion of wisdom as based on social interaction, by exploring its effects. If we face the methodological challenges entailed in tracing wisdom ethnographically, we enhance our understanding of the concept itself and stress the fruitfulness of the idea of wisdom as an attainment of the lifecourse.
The prevalence of, and risk factors for, loneliness in later life: a survey of older people in Great Britain
Authors: VICTOR CHRISTINA R. , SCAMBLER SASHA J. , BOWLING ANN , BOND JOHN
Published: April 2005

This study examines the prevalence of loneliness amongst older people in Great Britain, and makes comparisons with the findings of studies undertaken during the last five decades. In addition, the risk factors for loneliness are examined using a conceptual model of vulnerability and protective factors derived from a model of depression. Loneliness was measured using a self-rating scale, and measures of socio-demographic status and health/social resources were included. Interviews were undertaken with 999 people aged 65 or more years living in their own homes, and the sample was broadly representative of the population in 2001. Among them the prevalence of ‘severe loneliness’ was seven per cent, indicating little change over five decades. Six independent vulnerability factors for loneliness were identified: marital status, increases in loneliness over the previous decade, increases in time alone over the previous decade; elevated mental morbidity; poor current health; and poorer health in old age than expected. Advanced age and possession of post-basic education were independently protective of loneliness. From this evidence we propose that there are three loneliness pathways in later life: continuation of a long-established attribute, late-onset loneliness, and decreasing loneliness. Confirmation of the different trajectories suggests that policies and interventions should reflect the variability of loneliness in later life, for undifferentiated responses may be neither appropriate nor effective.
Older workers and employment: managing age relations
Authors: BROOKE LIBBY , TAYLOR PHILIP
Published: April 2005

This article reports the findings of research into the functioning of companies' and organisations' internal labour markets. Four case studies of Australian and United Kingdom public and private sector organisations have been undertaken with two principal aims: to elucidate the challenges and barriers to the employment of older workers, and to demonstrate the benefits to business and to older workers of age-aware human resource management policies. In each of the case-study organisations, age-related assumptions affected the management of knowledge and skills and the ways in which older and younger workers were employed. Managing age relations in organisations requires an understanding of the ways in which workers of different ages are perceived and how these associate with sub-optimal deployment. The article concludes by suggesting that policies directed at older workers alone will ignore the age and age-group dynamics that pervade workplaces. To promote the better deployment of younger and older individuals in rapidly transforming organisations, there is a need for policy makers, employers and employees to be attentive to the age-group relationships that currently inform workplace practices. Organisations cannot ignore these age dynamics, but should adopt ‘age aware’ rather than ‘age free’ practices. The recommended human-resources approach would attend to individuals' capabilities and not stereotype them by age.
Associations between socio-economic status measures and functional change among older people in Taiwan
Authors: CHIU HERNG-CHIA , HSIEH YING-HUI , MAU LIH-WEN , LEE MEI-LIN
Published: April 2005

The major purpose of this study was to examine the effects of socio-economic status (SES) on changes in functional abilities, as measured by Activities of Daily Living (ADL) scales, among older people in Taiwan. A prospective longitudinal study design was used. A panel of 874 community-dwelling older people were followed over four years (1994 to 1998). Three SES indicators, education, having ‘extra’ money (more than required for basic necessities), and principal lifetime occupation were included in separate multiple logistic regression models of functional change in physical ADL (PADL) and in instrumental ADL (IADL). Over the four years, the study cohort experienced greater decreases in IADL functioning than in PADL functioning. Having ‘extra’ money was significantly and negatively associated with PADL decline, while level of education had a strong positive relationship with IADL functioning. In addition to SES, age was significantly associated with PADL and IADL functioning change. The paper also reports a comparison of similar findings from several eastern and western countries. This has established that among the available SES indicators, the level of education has most consistently been shown in both eastern and western population studies to be related to health and health change, and that self-perceived economic resource is also related to older people's health in Asian populations.
ATTENTION WHEN?: An Investigation of the Ordering Effect of Input
and Interaction
Authors: Gass Susan M. , Torres María José Alvarez
Published: April 2005

This paper investigates the effects of input and interaction as
separate entities and in combination. We further investigate these
effects as a function of different language areas. One hundred two
learners of L2 Spanish were provided with input on (a) Spanish gender
agreement (noun + adjective), (b) estar + location, and (c)
seven vocabulary items. There were four conditions: (a) material
focused solely on input, (b) material focused solely on interaction,
(c) input-focused material followed by interaction, and (d)
interaction-focused material followed by input. A control group
completed a pretest and posttest. In general, greatest improvement from
pretest to posttest for all conditions was noted for vocabulary.
Learners exposed to input and interaction in combination showed greater
improvement than those in conditions with only input or only
interaction. In the two grammatical areas (gender agreement and
estar + location), learners who received interaction followed
by input showed greatest improvement. We consider issues such as
complexity and abstractness to account for the findings of differential
effects on language areas.
RECEPTIVE AND PRODUCTIVE VOCABULARY LEARNING: The Effects of
Reading and Writing on Word Knowledge
Authors: Webb Stuart
Published: April 2005

This study investigates the effects of receptive and productive
vocabulary learning on word knowledge. Japanese students studying
English as a foreign language learned target words in three glossed
sentences and in a sentence production task in two experiments. Five
aspects of vocabulary knowledge—orthography, syntax, association,
grammatical functions, and meaning and form—were each measured by
receptive and productive tests. The study uses an innovative
methodology in that each target word was tested in 10 different ways.
The first experiment showed that, when the same amount of time was
spent on both tasks, the reading task was superior. The second
experiment showed that, when the allotted time on tasks depends on the
amount of time needed for completion, with the writing task requiring
more time, the writing task was more effective. If the second
experiment represents authentic learning, then a stronger argument can
be made to use productive vocabulary learning tasks over receptive
tasks.
PARAMETER SETTING IN LANGUAGE ACQUISITION
Authors: Montrul Silvina
Published: April 2005

PARAMETER SETTING IN LANGUAGE ACQUISITION. Dalila Ayoun. New
York: Continuum, 2003. Pp. x + 212. $110.00 cloth.

This book presents an overview of the parameter setting theory of
learnability in first (L1) and second (L2) language acquisition within
the generative linguistic framework. It also attempts to challenge and
refine common assumptions underlying the model. The book comprises five
central chapters as well as short introductory and concluding chapters.
The introductory chapter summarizes the general aim of the book and the
specific aims of the chapters to follow. In chapter 2, Ayoun presents
historical background on the concept of parameter throughout
different versions of generative linguistics and distinguishes the
standard notion of parameter from the notions of associated clusters of
structures, microparameters (referring to structures), and
macroparameters (which apply to a family of typologically different
languages). This chapter also reviews the concept of parameter setting
for language changes, creole formation, computational linguistics, and
neurolinguistics, ending with a brief discussion of Universal Grammar
and the Critical Period Hypothesis. In brief, this chapter argues that
the parameter setting approach is a model worthy of further development
and refinement, capable of explaining and predicting a wide range of
phenomena in linguistic theory and its applications despite
misunderstandings and lack of clarity in the field.
TEACHING ACADEMIC ESL WRITING: PRACTICAL TECHNIQUES IN VOCABULARY
AND GRAMMAR
Authors: Cohen Alissa
Published: April 2005

TEACHING ACADEMIC ESL WRITING: PRACTICAL TECHNIQUES IN VOCABULARY AND
GRAMMAR. Eli Hinkel. Mahwah, NJ: Erlbaum, 2004. Pp. xii + 360.
$79.95 cloth, $37.50 paper.

In this text, Hinkel argues that second language (L2) writing
instruction has long favored teaching the writing process and discourse
and rhetorical features of text while neglecting the essential language
skills that L2 writers need to succeed in mainstream university
classes. She attempts to redress this perceived shortcoming by
identifying and describing the formal syntactic and lexical
characteristics of academic text and advocating the explicit teaching
of these key structures and lexical chunks.
LITERACY AND THE SECOND LANGUAGE LEARNER
Authors: Haynes Margot
Published: April 2005

LITERACY AND THE SECOND LANGUAGE LEARNER. Joann Hammadou Sullivan
(Ed.). Greenwich, CT: Information Age, 2002. Pp. xii + 279. $29.95
paper.

In this age of Internet plenty, research collections need a
justification for presentation in book format. According to the
editor's introduction, the main justification for Literacy and
the second language learner is to provide a sampling of the range
of “possible voices and possible questions that make up the broad
and complex field of second language literacy study” (p. xi).
PRAGMATIC DEVELOPMENT IN A SECOND LANGUAGE
Authors: Burt Susan Meredith
Published: April 2005

PRAGMATIC DEVELOPMENT IN A SECOND LANGUAGE. Gabriele Kasper and
Kenneth R. Rose. Oxford: Blackwell, 2002. Pp. x + 352. $36.95
paper.

The goal for this useful volume is to survey and evaluate research on
pragmatic development of second language learners. In the first
chapter, Kasper and Rose note that numerous studies in crosscultural
pragmatics assess nonnatives' language use and contrast it with
the performance of natives but that relatively few studies have focused
on how language learners' pragmatic abilities change and develop
over time. For researchers in SLA, however, this question of
development is central.
INVISIBLE WORK: BILINGUALISM, LANGUAGE CHOICE, AND CHILDREARING IN
INTERMARRIED FAMILIES
Authors: Bayley Robert
Published: April 2005

INVISIBLE WORK: BILINGUALISM, LANGUAGE CHOICE, AND CHILDREARING IN
INTERMARRIED FAMILIES. Toshie Okita. Amsterdam: Benjamins,
2002. Pp. vi + 274. $102.00 cloth.

In recent years, studies of bilingualism and SLA have paid increasing
attention to the contexts in which languages are acquired and used.
This broadened perspective has led scholars to combine insights from a
number of different disciplines. In this highly original study, Okita
combines insights from studies of families, ethnicity, and bilingualism
to examine the factors that promote or inhibit Japanese maintenance by
the children of British fathers and Japanese mothers living in Britain.
The result is a finely nuanced study that illustrates the difficulties
of maintaining a minority language in a setting that provides few
sources of institutional support.
Wet and dry African dust episodes over eastern Spain
Authors: Escudero M. , Castillo S. , Querol X. , Avila A. , Alarcón M. , Viana M. M. , Alastuey A. , Cuevas E. , Rodríguez S.
Published: April 2005

The impact of the African dust on levels of atmospheric suspended particulate matter (SPM) and on wet deposition was evaluated in eastern Iberia for the period 1996–2002. An effort was made to compile both the SPM and wet episodes. To this end, the time series of levels of TSP and PM10 in Levantine air quality monitoring stations were evaluated and complemented with the computation of back trajectories, satellite images, and meteorological analysis. Wet deposition frequency was obtained from weekly collected precipitation data at a rural background station in which the African chemical signature was identified (mainly pH and Ca2+ concentrations). A number of African dust episodes (112) were identified (16 episodes per year). In 93 out of the 112 (13 episodes per year) the African dust influence caused high SPM levels. In 49 out of 112 (7 episodes per year), wet deposition was detected, and the chemistry was influenced by dust. There is a clear seasonal trend with higher frequency of dust outbreaks in May‐August, with second modes in March and October. Wet events followed a different pattern, with a marked maximum in May. Except for one event, December was devoid of African air mass intrusions. On the basis of seasonal meteorological patterns affecting the Iberian Peninsula, an interpretation of the meteorological scenarios causing African dust transport over Iberia was carried out. Four scenarios were identified with a clear seasonal trend. The impact of the different dust outbreak scenarios on the levels of PM10 recorded at a rural site (Monagrega, Teruel, Spain) in the period 1996–2002 was also evaluated.
Transport of Saharan dust over the Caribbean Islands: Study of an event
Authors: Petit R. H. , Legrand M. , Jankowiak I. , Molinié J. , Asselin de Beauville C. , Marion G. , Mansot J. L.
Published: April 2005

A dust plume transported across the Atlantic Ocean from West Africa to Guadeloupe in June 1994 is studied using several complementary and cross‐checking techniques. During this event the dust optical depth measured in Guadeloupe was high from 19 to 22 June, peaking at 1. Meteosat‐5 IR imagery is used to locate in SW Sahara the source of emitted dust, consistent with the simulated backward trajectories of the dusty air masses arriving over Guadeloupe. Meteosat‐3 visible light spectrometer (VIS) imagery over the north tropical Atlantic shows the dust plume leaving the African coast on 15 June and its subsequent spreading over ocean on the following days. The back trajectories indicate a strong uplift from the African source to an altitude of 5000 m on 14 and 15 June, followed by a subsiding motion of the dust plume from the African coast to Guadeloupe, in agreement with the meteorological soundings performed at east and west sides of the Atlantic Ocean. Such uplifts, observed during summer, are shown to be a condition for the long‐range transport of dust through the Atlantic. It is also observed that while dust transport is associated with the dynamics of the Saharan air layer, the latter can be dust free. The transported mass of dust was in the range 2.5–5 Mt for this event. Electronic microscopy applied to the mineral particles collected in rainwater just after the dust event shows the predominance of particles larger than 1 μm in the long‐range transport from Africa.
Simulation of potential impacts of land use/cover changes on surface water fluxes in the Chaophraya river basin, Thailand
Authors: Kim Wonsik , Kanae Shinjiro , Agata Yasushi , Oki Taikan
Published: April 2005

The Chaophraya river basin in Thailand is one of the most significant land use/cover change (LUCC) regions where clearing of natural vegetation to cropland or secondary forest has occurred over several decades. The LUCC affects surface water fluxes (SWF), including transpiration, interception loss, evaporation, and runoff, because the SWF components are controlled by aerodynamic characteristics, soil moisture content, and potential photosynthetic activities according to vegetation type. Therefore, to understand the potential impacts of LUCC on SWF in the Chaophraya river basin, the simple biosphere model 2 (SiB2) with paddy scheme was run in uncoupled mode with forcing in keeping with the International Satellite Land Surface Climatology Project Initiative I data set. The simulation results revealed the following: (1) The absorbed radiation energy of forest was larger than other vegetation types although the Bowen ratios are similar. (2) The characteristics of SWF for each vegetation type were significantly controlled by soil water content, photosynthetic activity, and leaf area index. (3) The SWF index (W) and the relative SWF index (RW) were suggested as scaling parameters to estimate the seasonality of SWF as follows (definitions are given in section 3.4): Wi = i) and RWi = . (4) The WS were divided into two groups: the low seasonality SWF type (WS ≤ 0.5) consisting of forest or paddy field and the high seasonality SWF type (WS > 0.5) consisting of grassland or crop. (5) Runoff of the Chaophraya river basin decreased because of expanding crop area and paddy fields, an increase in the evaporation during the rainy season caused by changes in various vegetation types to paddy fields, and an increase in transpiration during the dry season caused by an expanding crop area.
Diagnosis of Community Atmospheric Model 2 (CAM2) in numerical weather forecast configuration at Atmospheric Radiation Measurement sites
Authors: Boyle J. S. , Williamson D. , Cederwall R. , Fiorino M. , Hnilo J. , Olson J. , Phillips T. , Potter G. , Xie S.
Published: April 2005

The Community Atmospheric Model 2 (CAM2) is run as a short‐term (1–5 days) forecast model initialized with reanalysis data. The intent is to reveal model deficiencies before complex interactions obscure the root error sources. Integrations are carried out for three Atmospheric Radiation Measurement (ARM) Program intensive operational periods (IOPs): June/July 1997, April 1997, and March 2000. The ARM data are used to validate the model in detail for the Southern Great Plains (SGP) site for all the periods and in the tropical west Pacific for the March 2000 period. The model errors establish themselves quickly, and within 3 days the model has evolved into a state distinctly different from the ARM observations. The summer forecasts evince a systematic error in convective rainfall. This error manifests itself in the temperature and moisture profiles after a single diurnal cycle. The same error characteristics are seen in the March 2000 tropical west Pacific forecasts. The model performs well in the spring cases at the SGP. Most of the error is manifested during rainy periods. The ARM cloud radar comparison to the model reveals cloud errors which are consistent with the relative humidity profile errors. The cloud errors are similar to those seen in climatological integrations, but the state variable errors are different. Thus there is the possibility that the some basic parameterization errors are obscured in the climatological integrations. The approach described here will facilitate parameterization experimentation, diagnoses, and validation. One way of reducing cloud feedback uncertainty is to make the physical processes behave in the most realistic manner possible. Paradoxically, perhaps the best way to reduce uncertainty in cloud feedback mechanisms is to evaluate the model processes with realistic forcing before such feedbacks have any significant affect.
Diurnal cycle of summertime deep convection over North America: A satellite perspective
Authors: Tian Baijun , Held Isaac M. , Lau Ngar‐Cheung , Soden Brian J.
Published: April 2005

High‐resolution (0.1° × 0.1°) geostationary satellite infrared radiances at 11 μm in combination with gridded (2.5° × 2.0°) hourly surface precipitation observations are employed to document the spatial structure of the diurnal cycle of summertime deep convection and associated precipitation over North America. Comparison of the diurnal cycle pattern between the satellite retrieval and surface observations demonstrates the reliability of satellite radiances for inferring the diurnal cycle of precipitation, especially the diurnal phase. On the basis of the satellite radiances, we find that over most land regions, deep convection peaks in the late afternoon and early evening, a few hours later than the peak of land surface temperature. However, strong regional variations exist in both the diurnal phase and amplitude, implying that topography, land‐sea contrast, and coastline curvature play an important role in modulating the diurnal cycle. Examples of such effects are highlighted over Florida, the Great Plains, and the North American monsoon region.
Photoelectron resonance capture ionization‐aerosol mass spectrometry of the ozonolysis products of oleic acid particles: Direct measure of higher molecular weight oxygenates
Authors: Zahardis James , LaFranchi Brian W. , Petrucci Giuseppe A.
Published: April 2005

The heterogeneous reaction of particle‐phase 9‐octadecenoic acid (oleic acid) and gas‐phase ozone in a flow reactor was studied by photoelectron resonance capture ionization (PERCI) mass spectrometry. This soft ionization technique facilitated one of the first simultaneous, direct observations of all four of the major products predicted for this reaction: nonanal, nonanoic acid, 9‐oxononanoic acid, and azelaic acid. In addition, a series of higher molecular weight oxygenated compounds were observed directly for the first time. The proposed structures are all cyclic oxygenates and contain the oxygen‐oxygen moiety, including secondary ozonides and cyclic geminal diperoxides. Mechanisms for the formation of these products are proposed. The mechanisms are generally 1,3‐dipolar cycloadditions that lead to five‐ and six‐member oxygen‐containing rings. The mechanisms are shown to involve short‐lived Criegee intermediates reacting with aldehydes and other Criegee intermediates. Atmospheric implications of these higher molecular weight compounds are suggested and include enhancing the fatty acid medium's capacity to act as a source of radicals due to the prominence of the peroxide moiety. The low volatility coupled with the high polarity of these compounds may alter particle phase hygroscopicity that can enhance the cloud condensation nuclei properties of these particles.
A new metric for comparing precipitation patterns with an application to ensemble forecasts
Authors: Venugopal V. , Basu S. , Foufoula‐Georgiou E.
Published: April 2005

Ensemble forecasting can be seen as serving two purposes: (1) by comparison of the control and ensemble members to the observed precipitation field, one can assess the forecast performance probabilistically; and (2) by comparison of ensemble members to the control forecast, one can assess the “diversity” of an ensemble and quantify the uncertainty of the forecast. Both problems are grounded to the basic requirement of being able to compare spatially nonhomogeneous, intermittent fields and come up with low‐dimensional metrics that can summarize this comparison. Several standard metrics exist (e.g., root mean square error (RMSE), Brier score, and equitable threat score (EqTh)) and are adopted in many operational studies. We studied (1) a fine‐scale ensemble precipitation forecast produced from the Advanced Regional Prediction System (ARPS) and (2) forecasts from multiple models (e.g., the 1998 Storm and Mesoscale Ensemble Experiment (SAMEX '98)) for the purpose of exploring how the selection of the performance metric can affect inferences about the quality and uncertainty of a forecast. We propose a new measure called forecast quality index, which combines image analysis and nonlinear shape comparison features, and we show that it is a more robust and informative metric compared to traditional metrics such as RMSE and EqTh.
Streamflow simulations of the terrestrial Arctic domain
Authors: Su Fengge , Adam Jennifer C. , Bowling Laura C. , Lettenmaier Dennis P.
Published: April 2005

Predicting riverine discharge to the Arctic Ocean has become increasingly important because of the dominant role that river runoff plays in the freshwater balance of the Arctic Ocean, and the predicted high sensitivity of the region to global warming. The ability of land surface models to represent runoff and streamflow from northern river basins is critical to an understanding of the Arctic hydrologic cycle. A set of simulations with the land surface scheme VIC (Variable Infiltration Capacity) implemented at 100 km EASE‐Grid across the pan‐Arctic domain was conducted to evaluate the model's representation of various hydrologic processes in the Arctic land region, and to provide a consistent baseline hydroclimatology for the region. The pan‐Arctic drainage basin system was partitioned into 12 regions for purposes of model implementation and testing. Streamflow observations at various basin outlets, satellite‐based snow cover extent, observed dates of lake freeze‐up and break‐up, and sited monitored summer permafrost maximum active layer thickness were used to evaluate various simulated hydrologic variables. The results indicate that the VIC model was able to reproduce these hydrologic processes in the Arctic region. A 21‐year average river inflow (1979–1999) to the Arctic Ocean from the AORB (Arctic Ocean River Basin) illustrated in Prowse and Flegg (2000), was estimated with the simulated streamflow as 3354 km3/yr, and 3596 km3/yr with the inclusion of the Arctic Archepelago, which are comparable to the previous estimates derived from the observed data.
Tropospheric ozone evolution between 1890 and 1990
Authors: Lamarque J.‐F. , Hess P. , Emmons L. , Buja L. , Washington W. , Granier C.
Published: April 2005

In this study, we have performed a set of simulations to detail the evolution of tropospheric ozone from 1890 to 1990. The simulations are compared with available measurements for present‐day conditions and earlier. Using our best estimates of ozone precursors emissions (based on the work by van Aardenne et al. (2001)), we have found a tropospheric ozone burden increase of 71 Tg between 1890 and 1990, an increase of ∼30%. When no anthropogenic emissions in 1890 are considered, this burden increase reaches 88 Tg. The ozone lifetime is shown to have decreased by ∼30%, especially after 1930. It is also shown that the net chemical production in the lower troposphere exceeded that in the free troposphere for the first time in the 1950–1970 period. In addition, the ozone production in this study increased rapidly between 1890 and 1930 and from 1970 to 1990. However, the ozone production efficiency in the troposphere is shown to have decreased during the 20th century, making the troposphere less NOx limited. Finally, a decrease in the OH burden is estimated to be on the order of 8%, matched by a similar increase in the CO lifetime.
On the enigma of day‐to‐day variability in equatorial spread F
Authors: Tsunoda Roland T.
Published: April 2005

We show that large‐scale wave structure (LSWS), in plasma density in the bottomside F layer, is a hitherto unheralded contributor to the long‐standing enigma of day‐to‐day variability in equatorial spread F (ESF). Little is known about LSWS; it seems to appear in altitude near a vertical shear in zonal plasma drift, during the post‐sunset rise of the F layer, and its growth via an interchange instability appears to predispose quasi‐periodically spaced regions to development of plasma bubbles. First indications are that LSWS development is necessary and sufficient for ESF occurrence. We suggest that variability in LSWS development, perhaps together with the shear in zonal drift, may contribute to day‐to‐day ESF variability. A need revealed by this study is that a cluster of distributed sensors, not isolated ones, is necessary to pursue the problem of day‐to‐day variability.
Extending the record of photosynthetic activity in the eastern United States into the presatellite period using surface diurnal temperature range
Authors: Bonfils Céline , Angert Alon , Henning Cara C. , Biraud Sébastien , Doney Scott C. , Fung Inez
Published: April 2005

In this study, we demonstrate that mid‐latitude surface measurements of diurnal temperature range (DTR) can be used to reconstruct decadal variability of regional‐scale terrestrial photosynthetic activity 1) during and prior to the period with satellite retrievals of land greenness and 2) without the need for moisture data. While the two relative maxima present in the seasonal evolution of DTR can determine the beginning and the end of the growing season, the summertime average DTR can be used as a proxy of summertime terrestrial photosynthesis. In a case study in the eastern United States (1966–1997), the DTR reconstructions indicate significant natural decadal variability in photosynthetic activity, but no secular, long‐term trend. The summertime photosynthesis was found to be controlled primarily by moisture availability. Also, contrary to existing model parameterizations, the timing of spring onset was found to depend on both temperature and moisture.
Diabetes‐induced changes in the 5‐hydroxytryptamine inhibitory receptors involved in the pressor effect elicited by sympathetic stimulation in the pithed rat
Authors: García Mónica , Morán Asunción , Calama Elena , Martín Maria Luisa , Barthelmebs Mariette , Román Luis San
Published: April 2005

We investigated the effect of alloxan‐induced diabetes on the inhibitory mechanisms of 5‐hydroxytryptamine (5‐HT) in the pressor responses induced by stimulation of sympathetic vasopressor outflow in pithed rats, and analysed the type and/or subtype of 5‐HT receptors involved.

Diabetes was induced in male Wistar rats by a single s.c. injection of alloxan, then 4 weeks later, they were anaesthetized, pretreated with atropine and pithed. Electrical stimulation of the sympathetic outflow from the spinal cord (0.1, 0.5, 1 and 5 Hz) resulted in frequency‐dependent increases in blood pressure.

Intravenous infusions of 5‐HT (1–80 μg kg−1 min−1) reduced the pressor effects obtained by electrical stimulation. The 5‐HT1 receptor agonist 5‐carboxamidotryptamine, 5‐CT (5 μg kg−1 min−1), caused an inhibition of the pressor response, whereas the selective 5‐HT2 receptor agonist, α‐methyl‐5‐HT (5 μg kg−1 min−1) and the selective 5‐HT3 receptor agonist, 1‐phenylbiguanide (40 μg kg−1 min−1), did not modify the sympathetic pressor responses. 5‐HT had no effect on exogenous noradrenaline (NA)‐induced pressor responses.

The inhibition of electrically induced pressor responses by 5‐HT (10 μg kg−1 min−1) was unable to be elicited after i.v. treatment with methiothepin (100 μg kg−1) because of the marked inhibition produced by methiothepin alone. The 5‐HT‐induced inhibition was blocked after i.v. administration of WAY‐100,635 (100 μg kg−1) and not affected by ritanserin (1 mg kg−1), MDL 72222 (2 mg kg−1).

The selective 5‐HT1A receptor agonist, 8‐hydroxydipropylaminotretalin hydrobromide (8‐OH‐DPAT) (5–20 μg kg−1 min−1) but neither the rodent 5‐HT1B receptor agonist, CGS‐12066B (5 μg kg−1 min−1), nor the selective nonrodent 5‐HT1B and 5‐HT1D receptor agonist, L‐694,247 (5 and 40 μg kg−1 min−1), inhibited the electrically induced pressor response. The selective 5‐HT1A receptor antagonist, WAY‐100,635 (100 μg kg−1), blocked the inhibition induced by 8‐OH‐DPAT (10 μg kg−1 min−1). 8‐OH‐DPAT had no effect on exogenous NA‐induced pressor responses.

Experimental diabetes produces changes in the inhibitory effect induced by 5‐HT on electrically induced sympathetic pressor responses, such that the inhibitory action induced by 5‐HT in diabetic pithed rats is mediated by prejunctional 5‐HT1A receptors.

British Journal of Pharmacology (2005) 145, 593–601. doi:10.1038/sj.bjp.0706216
Phase 2 ventricular arrhythmias in acute myocardial infarction: a neglected target for therapeutic antiarrhythmic drug development and for safety pharmacology evaluation
Authors: Clements‐Jewery Hugh , Hearse David J , Curtis Michael J
Published: April 2005

Ventricular fibrillation (VF), a cause of sudden cardiac death (SCD) in the setting of acute myocardial infarction (MI), remains a major therapeutic challenge. In humans, VF may occur within minutes or hours after the onset of chest pain, so its precise timing in relation to the onset of ischaemia is variable. Moreover, because VF usually occurs unobserved, out of hospital, and is usually lethal in the absence of intervention, its precise timing of onset is actually unknown in most patients. In animal models, the timing of susceptibility to VF is much better characterised. It occurs in two distinct phases. Early VF (defined as phase 1 VF, with possible subphases 1a and 1b in some animal species) occurs during the first 30 min of ischaemia when most myocardial injury is still reversible. Late VF, defined as phase 2 VF, occurs when myocardial necrosis is becoming established (after more than 90 min of ischaemia). Although much is known about the mechanisms and pharmacology of phase 1 VF, little is known about phase 2 VF. By reviewing a range of different types of data we have outlined the likely mechanisms and clinical relevance of phase 2 VF, and have evaluated possible future directions to help evolve a strategy for its suppression by drugs. The possibility that a proarrhythmic effect on phase 2 VF contributes to the adverse cardiac effects of certain cardiac and noncardiac drugs is also discussed in relation to the emerging field of safety pharmacology. It is concluded that suppression of phase 2 as well as phase 1 VF will almost certainly be necessary if drugs of the future are to achieve what drugs of the past and present have failed to achieve: full protection against SCD. Likewise, safety will require avoidance of exacerbation of phase 2 as well as phase 1 VF.

British Journal of Pharmacology (2005) 145, 551–564. doi:10.1038/sj.bjp.0706231
Calculation of Efficiency of Thermoelectric Devices
Authors: Sherman B. , Heikes R. R. , Ure R. W.
Published: April 2005

A procedure has been developed for the exact calculation of the efficiency of thermoelectric generators and cooling devices in which the parameters of the materials have arbitrary temperature dependence. High speed computer techniques are found necessary. Approximate methods are reviewed and their discussion extended. A number of examples are worked out by both the exact and approximate methods. Comparison of these results show that the approximate methods agree with the exact method to about 5% in the case of power generation and to about 15% in the case of the refrigeration coefficient of performance. However, in the case of the maximum heat pumping rate deviations as large as a factor of 2 are found.
Shapes of Etch Hillocks and Pits and Their Correlation with Measured Etch Rates
Authors: Irving B. A.
Published: April 2005

The factors which govern the occurrence and stability of etch hillocks and pits have been examined. Batterman's original analysis has been reconsidered and extended to account for all the crystallographic facets of etch hillocks and pits produced by a dilute hydrogen peroxide-hydrofluoric acid etchant on germanium surfaces. The treatment should be valid for other etchants and materials but suitable data are not available.
Interferometric Determination of Twist and Polytype in Silicon Carbide Whiskers
Authors: Hamilton D. R.
Published: April 2005

Whiskers of hexagonal SiC have been prepared in a graphite tube furnace. They are grown by sublimation of SiC in hydrogen, depositing at temperatures about 2000°C as acicular crystals of hexagonal section, with [0001] along the whisker length. The {11̄00} faces have been examined using optical interference techniques, and are found to exhibit a twist. The Eshelby formula for twist caused by a screw dislocation has been used to estimate the strength of the associated Burgers vector. It is found that, within the experimental error, the estimated Burgers vector is equal to, or is an integral multiple of the unit cell of the SiC polytype 4H. It is thus concluded that these twisted whiskers grow by means of a screw dislocation of integral strength parallel to the axis, and that they are of polytype 4H.
Defects in Dislocations Produced by Focusing Collisions in f.c.c. Lattices
Authors: Leibfried G.
Published: April 2005

It is assumed that a focusing collision of sufficiently high energy encountering a stacking fault area of an extended dislocation produces a Frenkel pair. This effect is thought to be important in radiation damage where primary knock-ons produce long range focusing collisions. The number of Frenkel pairs which are produced this way is calculated. Two effects are discussed in detail for Cu: (1) The enhancement of damage by enhanced production of Frenkel pairs if dislocations are present. It is shown that one can expect an appreciable enhancement of damage for heavily cold-worked material. (2) The pinning of dislocation motion. If one assumes that each Frenkel pair produced in a dislocation acts as a primary point, the theoretical result is in qualitative agreement with the experimental data on dislocation pinning by irradiation.
Impurity Effects upon Mobility in Silicon
Authors: Logan R. A. , Peters A. J.
Published: April 2005

In sufficiently pure n-type silicon, the carrier mobility follows a T−1.5 law at low temperature and agrees well with Herring's theory of lattice scattering mobility. Similar results for p-type silicon give a T−2 law for the temperature dependence and is in disagreement with theory. In less pure samples, scattering is by ionized impurities and the magnitude of the mobility reduction agrees well with the theory of Herring and Brooks. Scattering by large concentrations (∼1018 cm−3) of dissolved neutral oxygen is negligible compared to that by other mechanisms.
Flow Rates Using Nuclear or Electron Paramagnetic Resonance Techniques with Applications to Biological and Chemical Processes
Authors: Singer J. R.
Published: April 2005

The equations for measuring flow rates are derived using NMR and EPR relaxation time determinations. Several experimental procedures are discussed. One method of measurement depends upon the difference between static relaxation times and the apparent relaxation time of materials flowing through the observation region. Another procedure utilizes saturated or inverted spins as a ``tracer'' to measure flow rates. These schemes may readily be applied to blood flow velocity measurements in humans or animals, or to mineral and chemical flow rate determinations. The advantage of this spin resonance flowmeter is that the flow channel is not disturbed. Thus blood flow velocities are readily measured without the necessity of breaking the skin.
Interaction of Atomic Hydrogen with Glass
Authors: Hickmott T. W.
Published: April 2005

An omegatron ion resonance mass spectrometer has been used to study residual gases in an ultra-high vacuum system. Atomic hydrogen, produced from molecular hydrogen by an incandescent tungsten filament, reacts with glass to produce contaminant molecules, CO, H2O, and CH4, whose presence seriously interferes with studies of surface phenomena. Such spurious effects are substantially reduced by substituting a lanthanum boride-coated tantalum filament for the tungsten electron source of an ionization gauge used to measure pressures of hydrogen. Quantitative measurements of the binding of atomic hydrogen by glass show the existence of two distinct binding sites of nearly equal population that are occupied simultaneously at low surface coverages and low temperatures. The rate of recombination of atomic hydrogen bound to glass is proportional to the number adsorbed and is much smaller than the rate of recombination of atomic hydrogen impinging on a glass surface from the vapor phase.
Ion Drag Pumps
Authors: Stuetzer Otmar M.
Published: April 2005

The behavior and the efficiency of a simplified model of an ion drag pump for insulating fluids is discussed theoretically. Supporting measurements on real pumps are reported. Cascading and paralleling of pumping stages is investigated.
Magnetization of the Compound TiFe
Authors: Nevitt M. V.
Published: April 2005

Magnetization curves were determined for the CsCl-type compound TiFe at six temperatures ranging from 9°K to 110°K. The curves show a saturation effect at high field strength but they are of a form that is not characteristic of ferromagnetism. A saturation magnetization of 3.30±0.07 cgs units per gram was derived from the high field data. This moment is tentatively interpreted as resulting from a small concentration of uncompensated spins produced by disorder in the CsCl-type lattice. The electrical resistance of samples of TiFe was measured over the temperature range from 10°K to room temperature. Magnetization measurements were attempted on the CsCl-type compounds TiCo and TiNi, but their magnetizations were too small to be detected.
Asymmetrical Triple Probe Method for Determining Energy Distribution of Electron in Plasma
Authors: Okuda Takayoshi , Yamamoto Kenzo
Published: April 2005

A new probe method is proposed. This method is an improvement of the floating triple probe method, which was proposed by us in a previous paper. In this method, the dimension of one operating probe is different from the other, so that the smaller probe behaves as the single probe. Thus, the measurable range of electron energy can be extended as much as that in the single probe method. The asymmetrical triple probe and double probe methods are verified experimentally. The asymmetrical triple probe method has a merit that a disturbance, which is inevitable in the single probe method, can be eliminated in this method. The electron energy distribution obtained by the new probe method is not always in accord with that obtained by the usual single probe method. The hump often observed at high energy range in the single probe method does not appear in the new method, illustrating that the latter is free from erroneous estimation due to the disturbance.
Figure of Merit for Thermionic Energy Conversion
Authors: Rasor N. S.
Published: April 2005

The optimum performance for emission-limited thermionic energy conversion is derived in convenient analytical form. The steps which are thereby indicated to reduce fundamental performance limitations are enumerated and briefly discussed. A figure of merit is defined with brief description of its usefulness and significance. A comparison of thermionic and thermoelectric conversion is thereby afforded by the analysis.
Specific Heat of High Purity Iron by a Pulse Heating Method
Authors: Wallace D. C. , Sidles P. H. , Danielson G. C.
Published: April 2005

A dynamic pulse-heating method has been developed for measuring with an error of less than 2% the specific heats of metal wires from room temperature to 1000°C. The method consists essentially of recording the resistance of the sample wire while it is being heated by a pulse of large current and short time duration; then obtaining the temperature of the wire throughout the pulse with the aid of the measured resistance as a function of temperature; and finally computing the specific heat of the sample from the temperature as a function of time during the pulse, the measured power input to the wire, and the theoretically computed heat loss corrections. Results are given for high-purity iron over the temperature range 25° to 1050°C. Variations of the specific heat near the phase transitions are shown in detail.
Waves on a Filamentary Electron Beam in a Transverse-Field Slow-Wave Circuit
Authors: Siegman A. E.
Published: April 2005

The waves on a filamentary electron beam in a longitudinal dc magnetic field, and their interaction with a transverse-field slow-wave circuit, are studied in detail. All quantities are expressed in terms of circular polarization, with the circuit fields having arbitrary polarization. The beam is found to carry four waves: a positively polarized negative-energy slow cyclotron wave, a negatively polarized positive-energy fast cyclotron wave, and two synchronous (β=βe) waves, one with positive polarization and positive energy, one with negative polarization and negative energy. The coupling of these waves to the circuit is described both in the manner of Pierce's longitudinal traveling wave tube (TWT) analysis and in a coupled-mode description. For the two special cases of positive or negative circularly polarized fields, only the appropriately polarized beam waves couple. A third special case of linear polarization is more complicated, but essentially only the two cyclotron waves couple. In each of the three cases one positive-energy and one negative-energy beam wave is involved. In each case the equations can be made identical with the longitudinal TWT equations. As one example, a positively polarized circuit can be used as a fast-wave coupler for an Adler-type parametric amplifier, and its design becomes formally identical with the longitudinal Kompfner dip problem. Published Kompfner dip data can be used. The beam-circuit interaction is found to be correctly described by considering only the apparent transverse motion of the beam's position, although the actual interaction mechanism involves both the true transverse interaction with the actual transverse electron velocities, and the longitudinal interaction of the dc beam velocity with the longitudinal ac fields off the dc beam axis. The latter leads to changes in longitudinal dc velocity of the electrons and thus accounts for the negative rf energies of two of the waves.