bluuebunny/crossref_metadata_2025 huggingface dataset:
AN INTERPRETATION AND DEFENSE OF THE SOCIALIST PRINCIPLE
OF DISTRIBUTION
Authors: Carens Joseph H.
Published: April 2003

For this collection entitled “After Socialism,”
we were asked to reflect upon such questions as what rectifications
(if any) to present market capitalist systems might be desirable
and whether there is any viable remnant in the socialist ideal
that ought to be preserved. My basic answer to the latter is
that the socialist principle of distribution “From each
according to abilities, to each according to needs” remains
a compelling moral ideal, superior to the resigned, complacent,
or enthusiastic acceptance of economic inequality that is offered
by defenders of conventional capitalism and by many versions
of liberalism. And so, my answer to the former is that the
rectifications to present market capitalist systems that would
be desirable would be to reduce the deep injustices and social
malformations of these systems as much as possible by moving
their distributive outcomes in the direction of the socialist
ideal.
BEYOND FEAR AND GREED?
Authors: Shearmur Jeremy
Published: April 2003

Let us assume, for the sake of argument, that socialism is
over. (It looks to me as if this is very much open for debate.
In some respects, the collapse of the Soviet Union has given
Marxist socialism a new lease on life. It is no longer stuck
with the heritage of “actually existing socialism,”
and can, instead, develop its more plausible, critical side
and tell stories of the revolution betrayed.) Be that as it
may, it is now widely accepted that socialism, understood as
involving the social ownership of the means of production and
the abolition of markets, faces real and perhaps insuperable
difficulties. For without both markets and individual ownership,
it is difficult to see how problems of individual motivation
and information transmission are to be tackled—to say
nothing of Ludwig von Mises's underlying concern with how
to make economic (as opposed to purely technical) decisions
about the utilization of resources within an economy.
Counting the poor: an elementary difficulty in the measurement of proverty
Authors: Subramanian S.
Published: April 2003

This note suggests that the exercise of measuring poverty in a society is greatly aided by clarity on precisely what one means by “the extent of poverty”. The latter concept may refer to the extent of poverty normalized for population size, or to the extent of poverty not so normalized. Absence of clarity on this distinction – which is both simple and non-trivial – could lead to rather straightforward problems of coherence and consistency in the measurement of poverty.
OPTIMAL CONTROL OF A SIMPLE IMMIGRATION PROCESS THROUGH THE
INTRODUCTION OF A PREDATOR
Authors: Kyriakidis E.G.
Published: April 2003

This article is concerned with the problem of controlling a
simple immigration process, which represents a pest population,
by the introduction of a predator. It is assumed that the cost
rate caused by the pests is an increasing function of their
population size and that the cost rate of the controlling action
is constant. The existence of a control-limit policy that minimizes
the expected long-run average cost per unit time is established.
The proof is based on the variation of a fictitious parameter
over the entire real line.
STOCHASTIC COMPARISONS ON RESIDUAL LIFE AND INACTIVITY TIME
OF SERIES AND PARALLEL SYSTEMS
Authors: Li Xiaohu , Lu Jingyi
Published: April 2003

Inactivity time is a reliability conception dual to the residual
life. In this article, we establish some stochastic comparisons
on inactivity time and the residual life of series and parallel
systems, respectively. Some applications are presented as well.
Conditioning light differentially desensitizes rod
phototransduction mediated by native and 9-demethyl analog visual
pigment
Authors: CORSON D. WESLEY , PEPPERBERG DAVID R.
Published: April 2003

Light adaptation in rod photoreceptors is thought to involve
down-regulation of the signaling activity of photoactivated rhodopsin
(R*). However, electrophysiological evidence in support of this notion
has come largely from studies of truncated, perfused rod outer segments
and of rods genetically engineered to perturb known steps in R*
deactivation. To test this hypothesis within intact native rods, we
examined the effect of a fixed conditioning flash on rods prepared to
contain 9-demethyl rhodopsin (9dR) in addition to residual rhodopsin.
9dR, an opsin-based photopigment containing 11-cis
9-demethylretinal as its chromophore, exhibits a blue-shifted
excitation spectrum and sluggish deactivation kinetics, properties that
distinguish the signaling activities of photoactivated 9dR (9dR*) from
those of R*. Saturating photocurrent responses mediated preferentially
by R* and 9dR* were obtained with test flash stimulation at 640 and 440
nm, respectively, under dark-adapted conditions (unconditioned
response) and at a fixed time after a 640-nm conditioning flash of
fixed high intensity. At each test wavelength, the decrease in
photocurrent saturation period induced by the conditioning flash was
analyzed to determine ψ, the sensitivity of the conditioned
response relative that of the unconditioned response;
ψ640 /ψ440, the ratio of relative
sensitivities, was then obtained. Data obtained from 12 rods yielded
ψ640 /ψ440 = 0.60 ± 0.13
(mean ± SD). As common pools of transducin and other downstream
components mediate transduction initiated by both R* and 9dR*, the
finding that ψ640 < ψ440 provides
direct evidence for the down-regulation specifically of R*'s
signaling activity during rod light adaptation.
Neural responses to relative speed in the primary visual cortex of
rhesus monkey
Authors: CAO AN , SCHILLER PETER H.
Published: April 2003

Relative motion information, especially relative speed between
different input patterns, is required for solving many complex tasks of
the visual system, such as depth perception by motion parallax and
motion-induced figure/ground segmentation. However, little is known
about the neural substrate for processing relative speed information.
To explore the neural mechanisms for relative speed, we recorded
single-unit responses to relative motion in the primary visual cortex
(area V1) of rhesus monkeys while presenting sets of random-dot arrays
moving at different speeds. We found that most V1 neurons were
sensitive to the existence of a discontinuity in speed, that is, they
showed higher responses when relative motion was presented compared to
homogenous field motion. Seventy percent of the neurons in our sample
responded predominantly to relative rather than to absolute speed.
Relative speed tuning curves were similar at different
center–surround velocity combinations. These relative
motion-sensitive neurons in macaque area V1 probably contribute to
figure/ground segmentation and motion discontinuity detection.
THE DEVIL AND THE SKIRT
Authors: Klein Cecelia F.
Published: April 2003

Similarities in certain paintings and sculptures
created by pre-Conquest and early Colonial Aztec artists
strongly suggest that the original identities and nature
of the tzitzimime changed over the decades following
the Spanish conquest. These images support textual evidence
that Spanish authors, typically mendicants and clergymen,
quickly conflated the tzitzimime with the Devil
and his servants, in the process demonizing and ultimately
masculinizing them as well. Whereas the most important
tzitzimime were apparently female in pre-Hispanic
times, Colonial authors writing after the mid-sixteenth
century described them as exclusively or predominantly
male. The potential for the tzitzimime terrorizing
people during periods of crisis, when the sun's continued
passage through the firmament was perceived as doubtful,
became the sole focus of late-Colonial descriptions of
the role and attributes of the tzitzimime. In
pre-Hispanic times, in contrast, the most important tzitzimime
were ambivalent creator deities whose generative powers
rendered them capable of preventing and curing illness
as well as causing harm. In the beginning, the tzitzimime
apparently were female, the principal tzitzimitl,
Citlalinicue, having passed on her powers to her daughters
and granddaughters. These descendants included the goddess
Cihuacoatl who, like the goddess Citlalinicue, was the
patroness of parturient Aztec women and midwives and closely
associated with the souls of women who had died in childbirth.
Itzpapalotl is another example, to which we can add Tlaltecuhtli,
Coatlicue, and Coatlicue's four self-sacrificing sisters.
It was probably not until the Aztec government was in a
position to rework official history that the national male
deity Huitzilopochtli was inserted into Aztec stories of
the creation in his manifestation as Omitecuhtli, “Bone
Lord.” Like other tzitzimime, however, Omitecuhtli
was petitioned to heal the sick, especially children, and
was subsequently called upon to bestow his generative powers
on newly elected government officials. These magical powers
were embedded in the tzitzimime's garments.
Their capes and skirts were decorated with skulls and crossbones
that were often combined with symbols of stars and, occasionally,
stone knives. This explains why petitions for a tzitzimitl's
assistance were apparently made at a stone platform bearing
these same designs. The platforms represented the sacred
capes and skirts that, legend suggests, were the essence
of the gods. Midwives and curers of both sexes probably
made special use of these platforms, which provided them
direct access to the tzitzimime. Materializing
the sacred garments that embodied the generative essence
of the tzitzimime provided the Aztec with a means
of petitioning their assistance in averting illness and
cosmic destruction.
PRE-HISPANIC MAYA RELIGION
Authors: Vail Gabrielle
Published: April 2003

For much of this century, scholars have tended to
dismiss the Madrid Codex as a resource because
of the large number of apparent scribal errors in the hieroglyphic
text of the manuscript. An examination of naming patterns
and attribute distribution with respect to the codical
deities, however, reveals that many of these so-called
errors are patterned in meaningful ways. These patterns
suggest that our view of the Maya pantheon as consisting
of a series of discrete entities with distinct conceptual
domains is a Western construct, rather than a valid representation
of pre-Hispanic Maya ideology. Reference to ethnohistoric
sources from both within the Maya area and elsewhere in
Mesoamerica (e.g., accounts from central Mexico) provides
a model for conceptualizing Maya deities as members of
overlapping complexes or clusters, each composed of a small
number of underlying divinities characterized by various
aspects, or manifestations.
MAIZE PREPARATION AND THE AZTEC SUBSISTENCE ECONOMY
Authors: Biskowski Martin
Published: April 2003

The study of changes in the social organization of
maize preparation provides an important opportunity to
examine the integration of households into larger systems
of social and economic relationships. Spatial analysis
of the distribution of manos and metates at Otumba demonstrates
a change in maize production from individual, household based
to a more specialized system. It is hypothesized that scarcity
of firewood for cooking was a causal factor for this change,
but more evidence is needed to test this idea.
CERAMIC INDICES OF AZTEC ELITENESS
Authors: Garraty Christopher P.
Published: April 2003

This article explores the complex, multidimensional
nature of Aztec social organization and, specifically,
the concept of “eliteness,” as it applies to
the Aztecs. I discuss both why we can speak of
Aztec “elites” and how we can monitor
them using ceramic data. I argue it is possible to distinguish
elites archaeologically by identifying the ceramic attributes
and variables that best reflect feasting behavior, one
of the primary practices the Aztecs used to socially construct
and reproduce unequal relations of power, wealth, and estate.
Ceramics thus served as one of the primary media through
which politically and socially charged “communication”
occurred among the Aztecs. I define and evaluate six ceramic
indices of eliteness using Late Aztec ceramic data (ca.
a.d. 1350–1520) from Teotihuacan, an Aztec
period altepetl (city-state) located in the northeastern
Basin of Mexico. I use the most effective eliteness indices
to interpret the intrasite spatial patterning of elite
residences at Late Aztec Teotihuacan and infer some observations
about the social and political organization of the altepetl.
PROVENIENCE INVESTIGATION OF CERAMICS AND OBSIDIAN FROM OTUMBA
Authors: Neff Hector , Glascock Michael D. , Charlton Thomas H. , Charlton Cynthia Otis , Nichols Deborah L.
Published: April 2003

Obsidian and ceramic artifacts from the Otumba
project were analyzed by instrumental neutron-activation
analysis. Sources for the obsidian were determined by comparison
to a databank of Central Mexican source analyses. Ceramic
sources were determined by comparison to a series of reference
groups from the Basin of Mexico and by comparison with
raw material samples. Obsidian from the lapidary workshop
(Operation 11) comes predominantly from the Otumba and
Pachuca sources. There is also an unknown compositional
profile present among the artifacts. This profile may derive
from a not-yet-sampled flow within one of several nearby
obsidian-source areas, such as Otumba or Paredon. The majority
of Otumba ceramics fall into a large group derived from clays
of the Teotihuacan-valley alluvium. Aztec II Black-on-Orange
and red-ware samples come from other sources in the eastern
basin. Ceramics from sites along the trade route leading
northeast toward Tulancingo include figurines derived from
Otumba, figurines probably made locally near Tepeapulco
and Tulancingo, and long-handle censers probably made in
the latter two locations.
PRE-HISPANIC OBSIDIAN PROCUREMENT IN THE TUXTLA MOUNTAINS,
SOUTHERN VERACRUZ, MEXICO
Authors: Santley Robert S. , Barrett Thomas P. , Glascock Michael D. , Neff Hector
Published: April 2003

This paper discusses the results of recent instrumental
neutron-activation analysis (INNA) work identifying the obsidian
sources relied upon in the Tuxtla Mountains of southern Veracruz
in pre-Hispanic times. Our research indicates that Guadalupe
Victoria and, secondarily, Zaragoza obsidian were the main sources
imported to the Tuxtlas during the Early and Middle Formative
periods. In contrast, Zaragoza became the dominant source relied
upon from Late Formative times onward. Data on obsidian color
and raw-material quality make it possible to extend the INAA
results to the entire obsidian assemblage from the Tuxtlas.
MAYA SACBEOB
Authors: Shaw Justine M.
Published: April 2003

This article reviews currently available data on Lowland Maya
sacbeob (raised roadways) to create a tripartite system
of road classification and explore why the Maya built such
constructions. Rather than simply classify sacbeob
as “intrasite” or “intersite,” roads
are divided into “local intrasite,”
“core–outlier intrasite,” and
“intersite” based on length and function. This
classification system is then employed on a data set of 190
sacbeob to explore the degree to which it may have
been some sort of a reality for the ancient Maya. The practical
and symbolic aspects of roadways are also discussed, with the
aim of beginning to explain why sacbeob are present
at some sites while absent at others. Possibilities from
environmental to temporal variation are reviewed, as are the
ways in which plazas may or may not have been able to substitute
for constructed routes. The Inka road system is also briefly
summarized to provide an analogy to better understand Maya systems.
Finally, an appeal is made to researchers to view sacbeob
not as a single type of artifact, but as a class of features
with a range of types and functions.
WARFARE, CERAMIC ECONOMY, AND THE ITZA
Authors: Stanton Travis W. , Negrón Tomás Gallareta
Published: April 2003

Models of polity organization in the northern Maya lowlands
are often based on the distribution of ceramic types. These
models do not account for crucial links between the processes
of ceramic production, distribution, use, and discard and
sociopolitical relationships. We discuss several models of ceramic
economy. These models suggest that the distribution of some
serving vessels may encode information concerning sociopolitical
relationships. These models are evaluated in light of stratigraphic
evidence from Yaxuna and Uxmal, in order to elucidate the nature
of polity at Chichen Itza. We argue that the ceramic data are
ambiguous concerning the proposed existence of a large conquest
state centered on the capital.
SALT PRODUCTION IN THE COASTAL AREA OF MICHOACAN, MEXICO: An
ethnoarchaeological study
Authors: Williams Eduardo
Published: April 2003

This study of saltmaking in coastal Michoacan underscores the
value of ethnoarchaeology as a tool for assessing ancient
saltmaking activities. Common salt (sodium chloride) was a
strategic resource of great importance for Mesoamerica during
pre-Hispanic and Colonial times. This study deals with salt
production in La Placita and neighboring areas of coastal Michoacan
and Colima, in western Mexico. The primary goals are to document
traditional saltmaking techniques—in particular, the material
culture, organization of work, ecological setting, and levels
of production observed in the study area, as well as the importance
of salt manufacture and trade for the area's economy and
culture over time. Ethnographic observations together with
ethnohistorical and archaeological data shed light on the
pre-Hispanic production, use, and commerce of salt in the coastal
area of Michoacan, one of the least studied regions in Mesoamerica.
There are three types of sites in the study area: (1) sites
where salt is currently being produced; (2) abandoned sites
where salt production was carried out until some fifty years
ago; and (3) archaeological sites where salt may have been produced
and/or distributed in ancient times. The material evidence of
salt production consists of: (1) terreros, or mounds
of leached soil; (2) eras, or solar evaporation pans;
and (3) specialized pottery types. Finally, this paper uses
archaeological and historical evidence, as well as oral traditions,
to discuss ancient salt exchange and trade networks.
ESTIMATING SEX OF MAYA SKELETONS BY DISCRIMINANT FUNCTION
ANALYSIS OF LONG-BONE MEASUREMENTS FROM THE PROTOHISTORIC MAYA
SITE OF TIPU, BELIZE
Authors: Wrobel Gabriel D. , Danforth Marie E. , Armstrong Carl
Published: April 2003

Discriminant functions were developed using long-bone robusticity
measurements of 82 individuals from the protohistoric Maya site
of Tipu, Belize. All individuals were sexed using nonmetric
morphological indicators, particularly those of the pelvis.
These functions are designed to provide a means of determining
the sex of fragmentary prehistoric Maya skeletons. The equations
ranged in accuracy from 77.5% to 100%. The reliability of these
equations was tested using a jackknife method on the Tipu sample
and by applying the equations to small samples of prehistoric
skeletons from the sites of Seibal, KOB Swamp, Laguna de On,
and Chau Hiix. The vast majority of the equations applied to
the test cases succeeded in correctly estimating the sex based
on pelvic and cranial features. A more reliable technique for
sex determination of poorly preserved skeletal remains will
allow a whole new range of archaeological and bioanthropological
hypotheses concerning sex and gender among the ancient Maya
to be investigated and considered.
RE-CREATING THE FORMATIVE MAYA VILLAGE OF K'AXOB
Authors: McAnany Patricia A. , Varela Sandra L. López
Published: April 2003

Occupation of the lowlands by groups of Mayan-language
speakers during the Archaic and Formative periods is poorly
understood, partly because of a lack of sufficient data.
This problem is exacerbated by the fact that early deposits
often are discovered at the base of deep test excavations
and, as such, yield a “window” to the past
that is limited in terms of understanding settlement colonization,
growth, and differentiation. The southern portion of the
site of K'axob, which is located in northern Belize,
contains substantial Middle and Late Formative period construction
that is relatively accessible under Classic-period plaza
surfaces. The results of seven large-scale excavations
conducted in both large and small platform complexes are
reported here. A suite of radiocarbon assays and ceramic
analysis indicate initial construction at K'axob shortly
after 800 b.c. Ceramic complexes presented here
are typified by a diversity of Middle Formative pottery
types (devoid of jar forms), followed by Late Formative
pottery featuring a significant increase in vessel volume
and local innovations in surface finish. At K'axob,
Middle Formative domiciles were large and well equipped,
and they featured a separate ancillary kitchen structure
to the west. Around 200 b.c., settlement expanded
from a nuclear Middle Formative core, and differentiation
in residential construction became apparent. A significant
aspect of Formative domestic architecture is the inclusion
of human remains, which reveal longitudinal trends in the
elaboration of mortuary ritual indicative of ancestor-linked
social and economic differentiation.
MESOAMERICAN EVIDENCE OF PRE-COLUMBIAN TRANSOCEANIC CONTACTS
Authors: Hristov Romeo , Genovés Santiago
Published: April 2003

In this article we discuss the results of the re-examination
of a terracotta head of supposed Roman origin found in
a pre-Hispanic burial offering near Mexico City. A thermoluminescent
age test performed in 1995 at the Forschungsstelle Archäometrie
in Heidelberg, Germany, set the age limits of the artifact
at 1780 ± 400 b.p., which is consistent with the
Roman-origin hypothesis. A review of the circumstances
of this discovery did not demonstrate any sign of possible
post-Columbian intrusion and permits the acceptance of
the object as the first hard evidence from Mesoamerica
to support pre-Hispanic transoceanic contacts between the
Old and New Worlds.
REVISITING THE CANEK MANUSCRIPT
Authors: Jones Grant D.
Published: April 2003

I conclude that Hanns Prem's article in this
issue is correct in the assessment that the Canek Manuscript
is a forgery. This evaluation resulted from extensive communication
with Prem and from additional research suggesting that
the author of the Canek Manuscript used a 1917 publication
by Philip Ainsworth Means and the writings of Sylvanus
G. Morley as aids in constructing the text of the document.
The forger's references to the Itza capital as Tayasal
and to the Tayasal peninsula follow modern, not seventeenth-century,
conventions, an error that reinforces Prem's conclusions.
The discovery of a family of forgeries, of which the Canek
Manuscript is a particularly convincing one, should make
future researchers wary of single documents that differ
significantly from others of the Colonial era.
The Moral Orientations of Justice and Care among Young Physicians
Authors: SELF DONNIE J. , JECKER NANCY S. , BALDWIN DeWITT C.
Published: April 2003

High moral standards and adherence to a moral code have long
been strong tenets of the profession of medicine, even though
there have been occasional lapses that have led to renewed calls
for a revitalization of moral integrity in medicine. Certainly, a
moral component has generally been held to be an important aspect
of the concept of a physician.
Justice in Residency Placement: Is the Match System an Offense
to the Values of Medicine?
Authors: MURPHY TIMOTHY F.
Published: April 2003

Medical residency—specialty training after the completion
of medical school—is an essential component of medical
education and is required in order to be a licensed, independent
medical practitioner in most jurisdictions. As things currently
stand in the United States, the match between medical school
graduates and residency programs is governed by a match between
rank-order lists prepared by candidates and residencies alike.
An applicant picks a number of residency programs and ranks
them according to order of interest. The residency program prepares
a similar list, ranking the candidates it most wants in its
program. A computer program compares the rankings and makes
assignments according to a certain algorithm. Using these lists,
the match system assigns approximately 24,000 applicants to
approximately 21,000 training positions in pediatrics, obstetrics
and gynecology, internal medicine, and the rest. These assignments
are then announced to all parties on specific days. The system
has been in place since 1952 and is overseen by the National
Residency Match Program (NRMP), a nonprofit organization. This
system has several advantages. First of all, it standardizes
the timetable for decisions, and applicants are in no position
to tie up offers while waiting to hear from other institutions.
Institutions are not held captive, either, in making assignments
while waiting to hear from particular parties.
What Constitutes a Just Match?: A Reply to Murphy
Authors: HESTER D. MICAH
Published: April 2003

In April of 2001 I published a brief commentary in the journal
Academic Medicine questioning the current character
and functioning of the National Residency Matching Program (or
“the match,” as it is known in medical schools and
teaching centers). The purpose of the article was to stimulate a
rethinking of process. At 50 years old, the environment through
which the match operates (and has helped to create) has changed,
and as such I thought it time to ask ourselves whether or not the
match, its algorithm, and, more important, the values it manifests
might well need an overhaul.
From Detached Concern to Empathy: Humanizing Medical
Practice, by Jodi Halpern. London: Oxford University Press,
2001. 165 pp. $37.95.
Authors: Benner Patricia
Published: April 2003

Dr. Jodi Halpern has written a remarkable book articulating
a view of clinical empathy that has practical and philosophical
implications for all helping professionals, as well as for
normative and relational ethics within the helping professions.
Dr. Halpern first carefully deconstructs a detached insight
view of empathy (an intellectualist view) and empathy as
sympathetic merger between two persons.
Prodromal frontal/executive dysfunction predicts incident
dementia in Parkinson's disease
Authors: WOODS STEVEN PAUL , TRÖSTER ALEXANDER I.
Published: April 2003

To identify the cognitive characteristics predictive of incident
dementia in Parkinson's disease (PD), we examined the baseline
neuropsychological profiles of 18 initially non-demented patients
with PD who met diagnostic criteria for dementia (PDD) at one-year
follow-up. PDD participants' baseline neuropsychological
test scores were compared to the baseline performance of 18
patients with PD who did not meet criteria for dementia at one-year
follow-up (PDND) and 18 normal controls (NC). The three groups
were matched on baseline demographic and disease variables.
Relative to the PDND group, the incident PDD participants
demonstrated significantly poorer performance on digits backward
(Wechsler Memory Scale–Revised), word list learning and
recognition (California Verbal Learning Test), and perseverative
errors on the Wisconsin Card Sorting Test. Each of these baseline
neuropsychological variables exhibited adequate diagnostic
classification accuracy in predicting PDD and PDND group membership
at follow-up. These results suggest that subtle frontal/executive
dysfunction is evident during the immediate PDD prodrome and
may be of prognostic value in identifying PD patients at risk
for dementia. Accordingly, neuropsychological evaluation may
facilitate early identification of PDD and thereby inform
appropriate dispositional planning. (JINS, 2003,
9, 17–24.)
What does the WMS–III tell us about memory changes
with normal aging?
Authors: HAALAND KATHLEEN Y. , PRICE LARRY , LARUE ASENATH
Published: April 2003

The standardization sample from the WMS–III (N
= 1250), which varied in age from 16 to 89, was used to determine
whether encoding, retrieval, or storage of verbal and spatial
information was most affected by normal aging. Immediate and
delayed recall and recognition of Logical Memory and Visual
Reproduction were examined. Immediate verbal and spatial recall
significantly deteriorated with increasing age, and the
age-associated deterioration in delayed recall and recognition
was largely explained by poorer immediate memory. These findings,
in concert with the smaller aging effects for percent retention
after a delay, suggest that the aging effect is due to
deterioration in encoding more than retrieval or storage of
new information. While Visual Reproduction deteriorated more
rapidly with age than Logical Memory, the pattern of performance
decrements as a function of age were comparable across both
tests. Decreases in performance were first seen in the fifth
decade with gradual deterioration until the eighth decade when
there was another precipitous drop. These results suggest that
functions that are more dependent on the frontal lobes are more
vulnerable to aging than those that are more dependent on the
temporal lobes. (JINS, 2003, 9, 89–96.)
IN MEMORY OF BRUCE SMITH
Authors: Antinolfi Gaetano
Published: April 2003

Bruce Smith was a brilliant economist who made important contributions in several fields, most notably monetary and financial economics, monetary history, economic growth, business cycle theory, and development economics. Bruce was a prolific author with nearly 100 published papers and about a dozen unpublished papers. I will try in this short article to describe his way of doing economics and being an economist. Even though Bruce's research agenda was wide, his distinctive style was clear on every page of his writings.
An empirical analysis of the investment performance of the Chilean pension system
Authors: MITTELSTAEDT H. FRED , OLSEN JOHN C.
Published: April 2003

The Chilean national pension system is often viewed as the model for moving from a pay-as-you-go system to a prefunded, individual account system. One measure of its success has been its 12% average real rate of return. This study uses monthly return data to examine the source of these returns and to compare the risk-adjusted returns of the pension system to those of Chilean stock indices, debt instruments, and mutual funds. Tests using the Sharpe ratio and the multi-factor Jensen alpha suggest that the pension returns are consistent with the overall riskiness of the Chilean economy. Based on our findings, neither the structure of the Chilean pension system nor the performance of the fund managers should permit the system to earn abnormally high returns in the future.
Effect of pH on Infectivity and Morphology of Ecotropic Moloney Murine Leukemia Virus
Authors: Ye Kaiming , Dhiman Harpreet K. , Suhan Joseph , Schultz Jerome S.
Published: April 2003

A number of factors affect the infectivity of retroviruses. The effect of pH on infectivity and morphology of ecotropic moloney murine leukemia virus (MoMuLV) was determined in this work. The ecotropic MoMuLVs were found to remain infectious at a narrow pH range from 5.5 to 8.0. Our experiments indicated that the viruses were inactivated swiftly at lower or higher pH. Within 5 min of exposure to pH 4 about 95% of the viruses lost infectiousness. The viruses were completely inactivated after exposure to pH < 3 or pH >11 for 5 min. The inactivation of MoMuLV was irreversible. Electron microscopy revealed that ecotropic MoMuLV remained round‐shaped at pH between 7.0 and 5. They became irregular with a convex head at pH < 4. At pH 2, virtually all virion particles were penetrated by stains, causing the accumulation of heavy metals inside the particles. The penetration of heavy metal inside the particles indicated the disassociation of the lipid bilayer of the viruses at low pH. A FACS‐based screening strategy for selecting high‐titer retrovirus producing cell lines is also presented in this report.
Lipase‐Mediated Deacetylation and Oligomerization of Lactonic Sophorolipids
Authors: Hu Yongmei , Ju Lu‐Kwang
Published: April 2003

The direct enzymatic polymerization of lactonic sophorolipids (SLs) was investigated with four lipases, including porcine pancreatic lipase (PPL), immobilized Mucor miehei lipase (MML), lyophilized Candida antarctica lipase (Fraction B, CAL‐B), and lyophilized Pseudomonas sp. lipase (PSL). Several organic solvents, covering a wide range of polarity, were compared for suitability as the reaction medium. Isopropyl ether and toluene were found most effective. According to the quantification and structure identification by HPLC and LC‐MS, the reaction proceeded with the formation of monoacetylated lactonic SLs and the subsequent conversion of the intermediates to oligomers and polymers, presumably through ring‐opening polymerization. Temperature was found to have significant effects on the reaction. Both the conversion of reactant SLs and the subsequent formation of oligomers and polymers from the intermediates were faster at 60 °C than at 50 °C. The substrate selectivity among the three dominant reactant SLs also differed with the temperature. The conversion rate increased with the ring size of the lactones at 60 °C, but it decreased with the size at 50 °C.
Production of Phytase by Mucorracemosus in Solid‐State Fermentation
Authors: Bogar Barbara , Szakacs George , Pandey Ashok , Abdulhameed Sabu , Linden James C. , Tengerdy Robert P.
Published: April 2003

Phytase production was studied by three Mucor and eight Rhizopus strains by solid‐state fermentation (SSF) on three commonly used natural feed ingredients (canola meal, coconut oil cake, wheat bran). Mucor racemosusNRRL 1994 (ATCC 46129) gave the highest yield (14.5 IU/g dry matter phytase activity) on coconut oil cake. Optimizing the supplementation of coconut oil cake with glucose, casein and (NH4)2SO4, phytase production in solid‐state fermentation was increased to 26 IU/g dry matter (DM). Optimization was carried out by Plackett‐Burman and central composite experimental designs. Using the optimized medium phytase, α‐amylase and lipase production of Mucor racemosusNRRL 1994 was compared in solid‐state fermentation and in shake flask (SF) fermentation. SSF yielded higher phytase activity than did SF based on mass of initial substrate. Because this particular isolate is a food‐grade fungus that has been used for sufu fermentation in China, the whole SSF material (crude enzyme, in situ enzyme) may be used directly in animal feed rations with enhanced cost efficiency.
A Novel Correlation for Protein Diffusion Coefficients Based on Molecular Weight and Radius of Gyration
Authors: He Lizhong , Niemeyer Bernd
Published: April 2003

A new correlation is proposed for the prediction of protein diffusion coefficients in free solution. Molecular weight and radius of gyration of proteins are employed as correlation parameters in this method. Both parameters can be easily found in the literature. The correlation works well for diverse proteins with different shapes and extensive molecular weight. Furthermore, this method does not require a preassumption regarding the protein shape while it offers a rapid and convenient calculation with a high accuracy. Also, the proposed correlation can elucidate the estimation deviation of previous correlation methods in the literature.
Enhancement and Prolongation of Baculovirus‐Mediated Expression in Mammalian Cells: Focuses on Strategic Infection and Feeding
Authors: Hu Yu‐Chen , Tsai Chien‐Tai , Chang Yao‐Jen , Huang Jen‐Huang
Published: April 2003

The baculovirus/insect cell system has been widely used for recombinant protein production. Since the finding that baculovirus was able to infect hepatocytes in 1995, various attempts to utilize baculovirus as a gene delivery vehicle into mammalian cells have been reported. In this study, we intended to explore the possibility of utilizing a baculovirus/mammalian cell system as a nonlytic, continuous protein production system. A recombinant baculovirus vector carrying enhanced green fluorescent protein (EGFP) under the control of cytomegalovirus immediate‐early (CMV‐IE) promoter was constructed. This virus was used to infect four common mammalian cell lines, and HeLa was found to yield the highest expression level. Additions of butyrate and valproic acid both enhanced the expression level, but butyrate exhibited a more profound effect. More importantly, HeLa cells were found to be superinfected by baculovirus, a result not observed in the conventional baculovirus/insect cell system. The effects of multiplicity of infection (MOI) and infection timing were also compared. High MOI up to 800 increased the expression in the short term (4 days), but the relatively higher cell death and lower cell density compromised the overall protein yield thereafter. The highest overall expression for a long term was obtained at MOI = 200 when the cells were initially infected at the mid‐exponential phase and superinfected with additional baculovirus (MOI = 200) together with a one‐time supplement of butyrate. In summary, the strategic infection and feeding enhanced the expression level 9‐fold (compared with unsuperinfected culture) and prolonged the duration of expression to 16 days. This study reveals that this baculovirus/mammalian cell system has great potential to become a novel continuous, nonlytic expression system.
Macroaffinity Ligand‐Facilitated Three‐Phase Partitioning (MLFTPP) of α‐Amylases Using a Modified Alginate
Authors: Mondal Kalyani , Sharma Aparna , Lata  , Gupta Munishwar Nath
Published: April 2003

The crude extracts of α‐amylases when mixed with alginate, tert‐butyl alcohol, and ammonium sulfate resulted in an interfacial precipitate containing polymer‐bound amylase. The precipitate was dissolved in 1 M maltose to recover α‐amylase activity. The recovery of α‐amylases were 74%, 77%, and 92% in the case of Bacillus amyloliquefaciens, wheat germ, and porcine pancreas, respectively. All purified preparations showed a single band on SDS‐PAGE.
Co‐Extraction during Reactive Extraction of Phenylalanine using Aliquat 336: Interfacial Mass Transfer
Authors: Pursell Mark R. , Alcina Mendes‐Tatsis M. , Stuckey David C.
Published: April 2003

Reactive liquid‐liquid extraction can be used to separate hydrophilic fermentation products that would not otherwise partition into nonpolar solvents. However, during extraction of the target solute other compounds present in the extraction medium will also react with the ion exchange reagent and are thus co‐extracted. In this study the effect of co‐extraction on the interfacial flux of the target solute phenylalanine has been investigated for reactive extraction using Aliquat 336. The effect of co‐extracting compounds has been included in a new interfacial flux balance, and experimental results reveal that the interfacial concentrations are equal to the final equilibrium conditions of the system. Using this information a simple mass transfer model has been developed from which film mass transfer coefficients may be determined. Co‐extraction of other compounds present in the feed was found to reduce the interfacial flux of the target solute by reducing the driving force. Co‐extraction did not affect the value of the film mass transfer coefficient, and therefore, co‐extraction does not effect the transport properties of the solute to the interface. Extraction from a multicomponent fermentation broth resulted in a reduced flux, which arises from a reduction in the driving force caused by high levels of co‐extraction. Furthermore, the flux was also reduced as the result of a mass transfer resistance caused by soluble surface‐active compounds present in the fermentation broth adsorbing to the interface. The biomass associated with the fermentation broth was also found to reduce the solute flux, and it is believed that this is due to blockage of the interfacial area.
Use of Process Data To Assess Chromatographic Performance in Production‐Scale Protein Purification Columns
Authors: Larson Tina M. , Davis Jeff , Lam Harry , Cacia Jerry
Published: April 2003

Transition analysis was performed on production‐scale chromatography data in order to monitor column performance. Analysis of over 300 transitions from several different chromatography operations demonstrated the utility of the techniques presented. Several of the transitions analyzed occurred on columns with known integrity breaches. The techniques proved sensitive for detection of these breaches. Seven transition calculations are presented, which were combined to produce a single overall integrity value for each column. In addition, principal components analysis (PCA) was used to detect shifts in the transition pattern, including those attributed to integrity breaches. Besides detection of integrity breaches, transition analysis proved useful in monitoring column efficiency over multiple column uses.
Concentric Cylinder Bioreactor for Production of Tissue Engineered Cartilage: Effect of Seeding Density and Hydrodynamic Loading on Construct Development
Authors: Saini Sunil , Wick Timothy M.
Published: April 2003

A concentric cylinder bioreactor has been developed to culture tissue engineered cartilage constructs under hydrodynamic loading. This bioreactor operates in a low shear stress environment, has a large growth area for construct production, allows for dynamic seeding of constructs, and provides for a uniform loading environment. Porous poly‐lactic acid constructs, seeded dynamically in the bioreactor using isolated bovine chondrocytes, were cultured for 4 weeks at three seeding densities (60, 80, 100 × 106 cells per bioreactor) and three different shear stresses (imposed at 19, 38, and 76 rpm) to characterize the effect of chondrocyte density and hydrodynamic loading on construct growth. Construct seeding efficiency with chondrocytes is greater than 95% within 24 h. Extensive chondrocyte proliferation and matrix deposition are achieved so that after 28 days in culture, constructs from bioreactors seeded at the highest cell densities contain up to 15 × 106 cells, 2 mg GAG, and 3.5 mg collagen per construct and exhibit morphology similar to that of native cartilage. Bioreactors seeded with 60 million chondrocytes do not exhibit robust proliferation or matrix deposition and do not achieve morphology similar to that of native cartilage. In cultures under different steady hydrodynamic loading, the data demonstrate that higher shear stress suppresses matrix GAG deposition and encourages collagen incorporation. In contrast, under dynamic hydrodynamic loading conditions, cartilage constructs exhibit robust matrix collagen and GAG deposition. The data demonstrate that the concentric cylinder bioreactor provides a favorable hydrodynamic environment for cartilage construct growth and differentiation. Notably, construct matrix accumulation can be manipulated by hydrodynamic loading. This bioreactor is useful for fundamental studies of construct growth and to assess the significance of cell density, nutrients, and hydrodynamic loading on cartilage development. In addition, studies of cartilage tissue engineering in the well‐characterized, uniform environment of the concentric cylinder bioreactor will develop important knowledge of bioprocessing parameters critical for large‐scale production of engineered tissues.
Application of Multivariate Analysis to Optimize Function of Cultured Hepatocytes
Authors: Chan Christina , Hwang Daehee , Stephanopoulos Gregory N. , Yarmush Martin L. , Stephanopoulos George
Published: April 2003

Understanding the metabolic and regulatory pathways of hepatocytes is important for biotechnological applications involving liver cells, including the development of bioartificial liver (BAL) devices. To characterize intermediary metabolism in the hepatocytes, metabolic flux analysis (MFA) was applied to elucidate the changes in intracellular pathway fluxes of primary rat hepatocytes exposed to human plasma and to provide a comprehensive snapshot of the hepatic metabolic profile. In the current study, the combination of preconditioning and plasma supplementation produced distinct metabolic states. Combining the metabolic flux distribution obtained by MFA with methodologies such as Fisher discriminant analysis (FDA) and partial least squares or projection to latent structures (PLS) provided insights into the underlying structure and causal relationship within the data. With the aid of these analyses, patterns in the cellular response of the hepatocytes that contributed to the separation of the different hepatic states were identified. Of particular interest was the recognition of distal pathways that strongly correlated with a particular hepatic function. The hepatic functions investigated were intracellular triglyceride accumulation and urea production. This study illustrates a framework for optimizing hepatic function and a possibility of identifying potential targets for improving hepatic functions.
Highly Efficient “Tight Fit” Immobilization of α‐Chymotrypsin in Mesoporous MCM‐41: A Novel Approach Using Precursor Immobilization and Activation
Authors: Fadnavis Nitin. W. , Bhaskar Veldurthy , Kantam Mannepalli Lakshmi , Choudary Boyapati Manoranjan
Published: April 2003

The zymogen α‐chymotrypsinogen A is bound to mesoporous silica MCM‐41 with a protein loading of 170 mg/g solid (MCM‐Z) by a simple stirring in aqueous tris‐HCl buffer (pH 7.2). The bound zymogen is then activated with trypsin to obtain α‐chymotrypsin immobilized on MCM‐41 (MCM‐E.I) that displays an effective enzyme activity corresponding to 65 mg protein/g of solid support (3250 BTEE units/g). A direct immobilization of commercially available α‐chymotrypsin (MCM‐E.II) gives lower loading (1250 BTEE units/g). Protein content of the solid support after immobilization is confirmed by thermogravimetric analysis (TGA). The enzyme is tightly bound to the support and can be used over 100 recycles over 1 week in aqueous as well as reverse micellar media. The immobilized enzyme (MCM‐E.I) has been used for resolution of N‐acetyl‐dl‐amino acid esters and racemic trans‐4‐methoxy‐3‐phenylglycidic acid (PGA) methyl ester.
Comparative Genomic Analysis of dha Regulon and Related Genes for Anaerobic Glycerol Metabolism in Bacteria
Authors: Sun Jibin , van den Heuvel Joop , Soucaille Philippe , Qu Yinbo , Zeng An‐Ping
Published: April 2003

The dihydroxyacetone ( dha) regulon of bacteria encodes genes for the anaerobic metabolism of glycerol. In this work, genomic data are used to analyze and compare the dha regulon and related genes in different organisms in silico with respect to gene organization, sequence similarity, and possible functions. Database searches showed that among the organisms, the genomes of which have been sequenced so far, only two, i.e., Klebsiella pneumoniaeMGH 78578 and Clostridium perfringens contain a complete dha regulon bearing all known enzymes. The components and their organization in the dha regulon of these two organisms differ considerably from each other and also from the previously partially sequenced dha regulons in Citrobacter freundii, Clostridium pasteurianum, and Clostridium butyricum. Unlike all of the other organisms, genes for the oxidative and reductive pathways of anaerobic glycerol metabolism in C. perfringens are located in two separate organization units on the chromosome. Comparisons of deduced protein sequences of genes with similar functions showed that the dha regulon components in K. pneumoniae and C. freundii have high similarities (80–95%) but lower similarities to those of the Clostridium species (30–80%). Interestingly, the protein sequence similarities among the dha genes of the Clostridium species are in many cases even lower than those between the Clostridium species and K. pneumoniae or C. freundii, suggesting two different types of dharegulon in the Clostridium species studied. The in silico reconstruction and comparison of dha regulons revealed several new genes in the microorganisms studied. In particular, a novel dha kinase that is phosphoenolpyruvate‐dependent is identified and experimentally confirmed for K. pneumoniaein addition to the known ATP‐dependent dha kinase. This finding gives new insights into the regulation of glycerol metabolism in K. pneumoniaeand explains some hitherto not well understood experimental observations.