bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Essential Role for Thymic Mesenchyme in Early T Cell Development
Authors: Suniara Ravinder K. , Jenkinson Eric J. , Owen John J.T. 
Published: July 2002

We show that the mesenchymal cells that surround the 12-d mouse embryo thymus are necessary for T cell differentiation. Thus, epithelial lobes with attached mesenchyme generate all T cell populations in vitro, whereas lobes from which mesenchyme has been removed show poor lymphopoiesis with few cells progressing beyond the CD4−CD8− stage of development. Interestingly, thymic mesenchyme is derived from neural crest cells, and extirpation of the region of the neural crest involved results in impaired thymic development and craniofacial abnormalities similar to the group of clinical defects found in the DiGeorge syndrome.
Previous studies have suggested an inductive effect of mesenchyme on thymic epithelial morphogenesis. However, we have found that mesenchyme-derived fibroblasts are still required for early T cell development in the presence of mature epithelial cells, and hence mesenchyme might have a direct role in lymphopoiesis. We provide an anatomical basis for the role of mesenchyme by showing that mesenchymal cells migrate into the epithelial thymus to establish a network of fibroblasts and associated extracellular matrix. We propose that the latter might be important for T cell development through integrin and/or cytokine interactions with immature thymocytes.
The Effect of Novel Attributes on Product Evaluation
Authors: Mukherjee Ashesh , Hoyer Wayne D. 
Published: July 2002

Abstract
Many technological innovations introduce attributes that are novel or completely unknown to a large number of consumers. For example, recently introduced attributes such as GPS in cars or I-Link in computers are likely to have been novel to many consumers. Past research suggests that the addition of novel attributes is likely to improve product evaluation and sales, since consumers interpret these attributes as additional benefits provided by the manufacturer. However, this article demonstrates that the positive effect of novel attributes holds only in the case of low-complexity products. In the case of high-complexity products, the addition of novel attributes can actually reduce product evaluation because of negative learning-cost inferences about these attributes. Further, the positive and negative effects of novel attributes on product evaluation are accentuated by external search for information when the information discovered through search is ambiguous in nature. Finally, it is shown that the negative effect of novel attributes on the evaluation of high-complexity products can persist even after consumers are given explicit information about the benefits of novel attributes. A key marketing implication of these findings is that novel attributes may contribute to technophobia, or consumer resistance toward technological innovation.
Order 𝑝 automorphisms of the open disc of a 𝑝-adic field
Authors: Green Barry , Matignon Michel 
Published: July 2002

Let

k
k

be an algebraically closed field of characteristic

p
>
0
,

p>0,

W
(
k
)

W(k)

the ring of Witt vectors and

R
R

a complete discrete valuation ring dominating

W
(
k
)

W(k)

and containing

ζ
,

\zeta ,

a primitive

p
p

-th root of unity. Let

π
\pi

denote a uniformizing parameter for

R
.

R.

We study order

p
p

automorphisms of the formal power series ring

R
[
[
Z
]
]
,

R[[Z]],

which are defined by a series

σ
(
Z
)
=
ζ
Z
(
1
+

a

1

Z
+
⋯
+

a

i

Z

i

+
⋯
)
∈
R
[
[
Z
]
]
.

\begin{equation*}\sigma (Z)=\zeta Z(1+a_{1}Z+\cdots +a_{i}Z^{i}+\cdots )\in R[[Z]].\end{equation*}

The set of fixed points of

σ
\sigma

is denoted by

F

σ

F_{\sigma }

and we suppose that they are

K
K

-rational and that

|

F

σ

|

=
m
+
1

|F_{\sigma }|=m+1

for

m
≥
0.

m\geq 0.

Let

D

o

{\mathcal {D}}^{o}

be the minimal semi-stable model of the

p
p

-adic open disc over

R
R

in which

F

σ

F_{\sigma }

specializes to distinct smooth points. We study the differential data that can be associated to each irreducible component of the special fibre of

D

o

.

{\mathcal {D}}^{o}.

Using this data we show that if

m
>
p

m>p

, then the fixed points are equidistant, and that there are only a finite number of conjugacy classes of order

p
p

automorphisms in

Aut

R

⁡
(
R
[
[
Z
]
]
)

\operatorname {Aut}_{R}(R[[Z]])

which are not the identity

mod
⁡
(
π
)
.

\operatorname {mod} (\pi ).
Repeated Hospitalizations and Self-rated Health among the Elderly: A Multivariate Failure Time Analysis
Authors: Kennedy Byron S. , Kasl Stanislav V. , Vaccarino Viola 
Published: July 2002

Abstract
The purpose of this study was to determine to what extent a single measure, self-rated health (SRH), independently predicts long-term hospitalizations due to all causes and to cardiovascular diseases by using both the standard Cox proportional hazards model and a more robust events model. The study cohort consisted of 2,812 elderly subjects residing in New Haven, Connecticut, who were followed from 1982 to 1996 as part of the Established Populations for Epidemiologic Study of the Elderly. After adjustment for baseline risk factors, using the Cox model, a favorable SRH was associated with a significantly lowered risk for a first hospitalization for all causes (risk ratio (RR) = 0.850, 95% confidence interval (CI): 0.774, 0.934) and congestive heart failure (RR = 0.599, 95% CI: 0.426, 0.841) but not for myocardial infarction (RR = 0.882, 95% CI: 0.565, 1.379). With the adjusted robust events model, a positive SRH was associated with a decreased risk in both a first (RR = 0.813, 95% CI: 0.744, 0.889) and a second (RR = 0.870, 95% CI: 0.782, 0.968) hospitalization for any cause. These results indicate that a single measurement of SRH predicts long-term patterns of hospitalization, especially for heart failure, among older adults.
Association between Physical Activity and Markers of Inflammation in a Healthy Elderly Population
Authors: Geffken Dominic F. , Cushman Mary , Burke Gregory L. , Polak Joseph F. , Sakkinen Pamela A. , Tracy Russell P. 
Published: July 2002

Abstract
Higher levels of physical activity are associated with lower risk of cardiovascular disease. There is growing evidence that the development of the atherosclerotic plaque is associated with inflammation. In this study, the authors investigated the cross-sectional association between physical activity and markers of inflammation in a healthy elderly population. Data obtained in 1989–1990 and 1992–1993 from the Cardiovascular Health Study, a cohort of 5,888 men and women aged ≥65 years, were analyzed. Concentrations of the inflammation markers–C-reactive protein, fibrinogen, Factor VIII activity, white blood cells, and albumin–were compared cross-sectionally by quartile of self-reported physical activity. Compared with persons in the lowest quartile, those in the highest quartile of physical activity had 19%, 6%, 4%, and 3% lower concentrations of C-reactive protein, white blood cells, fibrinogen, and Factor VIII activity, respectively, after adjustment for gender, the presence of cardiovascular disease, age, race, smoking, body mass index, diabetes, and hypertension. Multivariate regression models suggested that the association of higher levels of physical activity with lower levels of inflammation markers may be mediated by body mass index and glucose. There was no association between physical activity and albumin. Higher levels of physical activity were associated with lower concentrations of four out of five inflammation markers in this elderly cohort. These data suggest that increased exercise is associated with reduced inflammation. Prospective studies will be required for verification of these findings.
Menstrual History and Risk of Hip Fractures in Postmenopausal Women The Iowa Women's Health Study
Authors: Nicodemus Kristin K. , Folsom Aaron R. , Anderson Kristin E. 
Published: July 2002

Abstract
The authors examined prospectively between 1986 and 1997 the relation of irregular menstrual cycles and irregular menstrual bleeding duration earlier in life with risk of hip fracture in 33,434 postmenopausal Iowa women. Over the 318,522 person-years of follow-up, 523 hip fractures were reported. Adjusted for age, smoking, body mass index, waist/hip ratio, and estrogen use, the relative risk of hip fracture in women who reported always having irregular menstrual cycles, compared with women who never had irregular cycles, was 1.36 (95% confidence interval (CI): 1.03, 1.78). Women who reported having irregular menstrual bleeding duration had a 1.40-fold (95% CI: 1.10, 1.78) increased risk of hip fracture compared with women with regular bleeding duration. In addition, women who reported having both irregular menstrual cycles and irregular menstrual bleeding had a 1.82-fold (95% CI: 1.55, 2.15) higher risk of hip fracture than did women who reported neither irregularity. Women who reported only one menstrual disturbance did not have a risk of hip fracture that was significantly different from women who reported no menstrual disturbances. The authors conclude that women with menstrual irregularities are at increased risk of hip fracture, probably because they are estrogen or progesterone deficient.
Maternal Exposure to Nitrate from Drinking Water and Diet and Risk for Neural Tube Defects
Authors: Croen Lisa A. , Todoroff Karen , Shaw Gary M. 
Published: July 2002

Abstract
In this population-based case-control study conducted in California between June 1989 and May 1991, the authors investigated the association between maternal periconceptional exposure to nitrate from drinking water and diet and risk for neural tube defects. The mothers of 538 cases and 539 nonmalformed controls were interviewed regarding residential history, consumption of tap water at home, and dietary intake during the periconceptional period. Dietary nitrate exposure was not associated with increased risk for neural tube defects. Exposure to nitrate in drinking water at concentrations above the 45 mg/liter maximum contaminant level was associated with increased risk for anencephaly (odds ratio (OR) = 4.0, 95% confidence interval (CI): 1.0, 15.4), but not for spina bifida. Increased risks for anencephaly were observed at nitrate levels below the maximum contaminant level among groundwater drinkers only (OR = 2.1, 95% CI: 1.1, 4.1 for 5–15 mg/liter; OR = 2.3, 95% CI: 1.1, 4.5 for 16–35 mg/liter; and OR = 6.9, 95% CI: 1.9, 24.9 for 36–67 mg/liter compared with &lt;5 mg/liter). Adjustment for identified risk factors for anencephaly did not substantially alter these associations, nor did control for maternal dietary nitrate, total vitamin C intake, and quantity of tap water consumed. The lack of an observed elevation in risk for anencephaly in association with exposure to mixed water containing nitrate at levels comparable with the concentration in groundwater may indicate that something other than nitrate accounts for these findings.
Fingerprint Ridge-Count Difference between Adjacent Fingertips (dR45) Predicts Upper-Body Tissue Distribution: Evidence for Early Gestational Programming
Authors: Kahn Henry S. , Ravindranath Roopa , Valdez Rodolfo , Venkat Narayan K. M. 
Published: July 2002

Abstract
Fingerprint ridge counts, which remain constant from the 19th week of pregnancy, are related to fingertip growth during early gestation. Each finger corresponds neurologically to a spinal-cord segment ranging from C6 (thumb, relatively cephalad) to C8 (fifth finger, relatively caudad). The authors hypothesized that large ridge-count differences between fingertips (cephalad &gt; caudad) might reflect fetal inhibition of caudal growth. Among 69 male Atlanta, Georgia, military recruits (1994–1997; aged 17–22 years), they tested associations of the anthropometric waist-to-thigh ratio with 20 ridge-count differences. Waist-to-thigh ratio was associated with the ridge-count difference between the right fourth and fifth fingertips only (dR45; r = 0.36, p = 0.003). The race-adjusted standardized regression coefficient was 0.22 (95% confidence interval: 0.03, 0.41). Since upper-body tissue distribution indicates disease risk, the authors then tested the association of age (an indicator of survivorship) with dR45 in a sample of 135 male patients from Bangalore, India (1989–1990; aged 38–82 years). Age was inversely associated with dR45 (r = −0.17, p = 0.04), notably among the 75 men with diabetes (r = −0.22, p = 0.06). An increased dR45 predicts an upper-body tissue distribution originating before the midpoint of pregnancy. The cause of this developmental pattern is unknown, but it may lead to reduced survivorship.
Coffee Consumption and Serum Lipids: A Meta-Analysis of Randomized Controlled Clinical Trials
Authors: Jee Sun Ha , He Jiang , Appel Lawrence J. , Whelton Paul K. , Suh II , Klag Michael J. 
Published: July 2002

Abstract
Coffee drinking has been associated with increased serum cholesterol levels in some, but not all, studies. A Medline search of the English-language literature published prior to December 1998, a bibliography review, and consultations with experts were performed to identify 14 published trials of coffee consumption. Information was abstracted independently by two reviewers using a standardized protocol. With a random-effects model, treatment effects were estimated by pooling results from individual trials after weighting the results by the inverse of total variance. A dose-response relation between coffee consumption and both total cholesterol and LDL cholesterol was identified (p &lt; 0.01). Increases in serum lipids were greater in studies of patients with hyperlipidemia and in trials of caffeinated or boiled coffee. Trials using filtered coffee demonstrated very little increase in serum cholesterol. Consumption of unfiltered, but not filtered, coffee increases serum levels of total and LDL cholesterol.
Invited Commentary: Arsenic and Cancer of the Urinary Tract
Authors: Cantor Kenneth P. 
Published: July 2002

Abstract
Inorganic arsenic in drinking water is a recognized cause of cancers of the skin, lung, and bladder. In the absence of an animal model for studying arsenic carcinogenesis, epidemiologic studies provide the only quantitative data for guiding risk assessment at levels that commonly occur in drinking water. To date, most estimates of risk at low and moderate levels of exposure (&lt;200 µg/liter) have been based on extrapolation from ecologic studies of populations exposed to much higher levels. Epidemiologic data from the prospective cohort study by Chiou et al. that appears in this issue of the Journal (Am J Epidemiol 2001;153:411–18) make an important contribution to improving the precision of the estimated risk of transitional cell carcinoma of the urinary tract associated with ingested arsenic from drinking water. The great strength of the study derives from having individually based measures of exposure and cancer diagnoses. Arsenic in water is a topic of great concern and controversy, and epidemiologic studies will continue to provide crucial information about the risks of cancer and other diseases associated with ingested arsenic.
Multivariate Logistic Regression for Familial Aggregation of Two Disorders. I. Development of Models and Methods
Authors: Hudson James I. , Laird Nan M. , Betensky Rebecca A. 
Published: July 2002

Abstract
The question of whether two disorders cluster together, or coaggregate, within families often arises. This paper considers how to analyze familial aggregation of two disorders and presents two multivariate logistic regression methods that model both disorder outcomes simultaneously. The first, a proband predictive model, predicts a relative's outcomes (the presence or absence of each of the two disorders) by using the proband's disorder status. The second, a family predictive model derived from the quadratic exponential model, predicts a family member's outcomes by using all of the remaining family members' disorder statuses. The models are more realistic, flexible, and powerful than univariate models. Methods for estimation and testing account for the correlation of outcomes among family members and can be implemented by using commercial software.
Incidence of Guillain-Barré Syndrome following Infection with Campylobacter jejuni
Authors: McCarthy Noel , Giesecke Johan 
Published: July 2002

Abstract
Evidence of recent or ongoing Campylobacter jejuni infection has been found in approximately one out of every four cases of Guillain-Barré syndrome (GBS). It is increasingly accepted that C. jejuni infection is an important causal factor for GBS. However, the likelihood of GBS' occurring following an episode of C. jejuni gastroenteritis has not been measured. The authors measured the incidence of GBS in a large cohort of persons with laboratory-confirmed C. jejuni infection. Cases of C. jejuni infection were derived from the Swedish national laboratory reporting system for the years 1987–1995. Follow-up for GBS was carried out using the Swedish national hospital inpatient register. Nine cases of GBS were detected in the cohort, which comprised 29,563 cases of C. jejuni infection—a rate of 30.4 per 100,000 (95% confidence interval: 13.9, 57.8). This compares with an expected incidence of 0.3 per 100,000 in a 2-month period in the general population. GBS is an important but rare complication of C. jejuni infection. The risk of developing GBS during the 2 months following a symptomatic episode of C. jejuni infection is approximately 100 times higher than the risk in the general population.
ProbeDesigner: for the design of probesets for branched DNA (bDNA) signal amplification assays.
Authors: Bushnell S , Budde J , Catino T , Cole J , Derti A , Kelso R , Collins M L , Molino G , Sheridan P , Monahan J , Urdea M 
Published: July 2002

Abstract
MOTIVATION: The sensitivity and specificity of branched DNA (bDNA) assays are derived in part through the judicious design of the capture and label extender probes. To minimize non-specific hybridization (NSH) events, which elevate assay background, candidate probes must be computer screened for complementarity with generic sequences present in the assay. RESULTS: We present a software application which allows for rapid and flexible design of bDNA probesets for novel targets. It includes an algorithm for estimating the magnitude of NSH contribution to background, a mechanism for removing probes with elevated contributions, a methodology for the simultaneous design of probesets for multiple targets, and a graphical user interface which guides the user through the design steps. AVAILABILITY: The program is available as a commercial package through the Pharmaceutical Drug Discovery program at Chiron Diagnostics.
Efficient large-scale sequence comparison by locality-sensitive

hashing
Authors: Buhler Jeremy 
Published: July 2002

Abstract
Motivation: Comparison of multimegabase genomic DNA sequences is a popular technique for finding and annotating conserved genome features. Performing such comparisons entails finding many short local alignments between sequences up to tens of megabases in length. To process such long sequences efficiently, existing algorithms find alignments by expanding around short runs of matching bases with no substitutions or other differences. Unfortunately, exact matches that are short enough to occur often in significant alignments also occur frequently by chance in the background sequence. Thus, these algorithms must trade off between efficiency and sensitivity to features without long exact matches.
Results: We introduce a new algorithm, lsh-all-pairs, to find ungapped local alignments in genomic sequence with up to a specified fraction of substitutions. The length and substitution rate of these alignments can be chosen so that they appear frequently in significant similarities yet still remain rare in the background sequence. The algorithm finds ungapped alignments efficiently using a randomized search technique, locality-sensitive hashing. We have found lsh-all-pairsto be both efficient and sensitive for finding local similarities with as little as 63% identity in mammalian genomic sequences up to tens of megabases in length
Availability: Contact the author at the address below.
Contact: jbuhler@cs.washington.edu
Supplementary information: The sequences and local alignment data described in this work are available at http://bio.cs.washington.edu/jbuhler-bioinformatics-2001/.
Tumor classification by partial least squares using microarray
gene expression data
Authors: Nguyen Danh V. , Rocke David M. 
Published: July 2002

Abstract
Motivation: One important application of gene expression microarray data is classification of samples into categories, such as the type of tumor. The use of microarrays allows simultaneous monitoring of thousands of genes expressions per sample. This ability to measure gene expression en masse has resulted in data with the number of variables p(genes) far exceeding the number of samples N. Standard statistical methodologies in classification and prediction do not work well or even at all when N &lt; p. Modification of existing statistical methodologies or development of new methodologies is needed for the analysis of microarray data.
Results: We propose a novel analysis procedure for classifying (predicting) human tumor samples based on microarray gene expressions. This procedure involves dimension reduction using Partial Least Squares (PLS) and classification using Logistic Discrimination (LD) and Quadratic Discriminant Analysis (QDA). We compare PLS to the well known dimension reduction method of Principal Components Analysis (PCA). Under many circumstances PLS proves superior; we illustrate a condition when PCA particularly fails to predict well relative to PLS. The proposed methods were applied to five different microarray data sets involving various human tumor samples: (1) normal versus ovarian tumor; (2) Acute Myeloid Leukemia (AML) versus Acute Lymphoblastic Leukemia (ALL); (3) Diffuse Large B-cell Lymphoma (DLBCLL) versus B-cell Chronic Lymphocytic Leukemia (BCLL); (4) normal versus colon tumor; and (5) Non-Small-Cell-Lung-Carcinoma (NSCLC) versus renal samples. Stability of classification results and methods were further assessed by re-randomization studies.
Availability: The methodology can be implemented using a combination of standard statistical methods, available, for example, in SAS. Illustrative SAS code is available from the first author.
Contact: nguyen@wald.ucdavis.edu; dmrocke@ucdavis.edu
* To whom correspondence should be addressed.