bluuebunny/crossref_metadata_2025_split huggingface dataset:
On nonexistence of Baras–Goldstein type for higher-order parabolic equations with singular potentials
Authors: Galaktionov V. , Kamotski I. 
Published: April 2010

The celebrated result by Baras and Goldstein (1984) established that the heat equation with singular inverse square potential in a smooth bounded domain

Ω
⊂

R

N

\Omega \subset \mathbb {R}^N

,

N
≥
3

N \ge 3

, such that

0
∈
Ω

0 \in \Omega

,
\[

u
t

=
Δ
u
+

c

|

x

|

2

u

in

Ω
×
(
0
,
T
)
,

u

|

∂
Ω

=
0
,

u_t= \Delta u + \frac c{|x|^2} u \;\; \text {in} \;\; \Omega \times (0,T), \;\; u \big |_{\partial \Omega }=0,

\]
in the supercritical range
\[

c
>

c

H
a
r
d
y

(
1
)
=

(

N
−
2

2

)

2

,

c > c_{\mathrm {Hardy}}(1) = \big (\frac {N-2}2\big )^2,

\]
does not have a solution for any nontrivial

L
1

L^1

initial data

u
0

(
x
)
≥
0

u_0(x) \ge 0

in

Ω
\Omega

or for a positive measure. Namely, it was proved that a regular approximation of a possible solution by a sequence

{

u
n

(
x
,
t
)
}

\{u_n(x,t)\}

of classical solutions of uniformly parabolic equations with bounded truncated potentials given by
\[

V
(
x
)
=

c

|

x

|

2

↦

V
n

(
x
)
=
min

{

c

|

x

|

2

,

n

}

(
n
≥
1
)

V(x) = \frac c{|x|^2} \mapsto V_n(x)=\min \big \{ \frac c{|x|^2}, \, n \big \} \,\,\, (n \ge 1)

\]
diverges, and, as

n
→
∞

n \to \infty

,
\[

u
n

(
x
,
t
)
→
+
∞

in

Ω
×
(
0
,
T
)
.

u_n(x,t) \to +\infty \quad \mbox {in} \quad \Omega \times (0,T).

\]
In the present paper, we reveal the connection of this “very singular” evolution with a spectrum of some “limiting” operator. The proposed approach allows us to consider more general higher-order operators (for which Hardy’s inequalities were known since Rellich, 1954) and initial data that are not necessarily positive. In particular it is established that, under some natural hypothesis, the divergence result is valid for any

2
m

2m

th-order parabolic equation with singular potential
\[

u
t

=
−
(
−
Δ

)
m

u
+

c

|

x

|

2
m

u

i
n

Ω
×
(
0
,
T
)
,

w
h
e
r
e

c
>

c

H

(
m
)
,

;
m
≥
1
,

u_t = -(-\Delta )^m u + \frac c{|x|^{2m}}\, u \;\; \mathrm {in} \;\; \Omega \times (0,T), \;\; \mathrm {where} \;\; c>c_{\mathrm {H}}(m), \,; m \ge 1,

\]
with zero Dirichlet conditions on

∂
Ω

\partial \Omega

and for a wide class of initial data. In particular, typically, the divergence holds for any data satisfying
\[

u
0

(
x
)

is continuous at

x
=
0

and

u
0

(
0
)
>
0

.

u_0(x) \;\; \text {is continuous at $x=0$ and $u_0(0)>0$}.

\]
Similar nonexistence (i.e., divergence as

ε
→
0

\varepsilon \to 0

) results are also derived for time-dependent potentials

ε

−
2
m

q
(

x
ε

,

t

ε

2
m

)

\varepsilon ^{-2m}q(\frac {x}{\varepsilon }, \frac {t}{\varepsilon ^{2m}})

and nonlinear reaction terms

|

u

|

p

ε

2
m

+

|

x

|

2
m

\frac {|u|^p}{\varepsilon ^{2m}+|x|^{2m}}

with

p
>
1

p>1

. Applications to other, linear and semilinear, Schrödinger and wave PDEs are discussed.
A signal–noise model for significance analysis of ChIP-seq with negative control
Authors: Xu Han , Handoko Lusy , Wei Xueliang , Ye Chaopeng , Sheng Jianpeng , Wei Chia-Lin , Lin Feng , Sung Wing-Kin 
Published: April 2010

AbstractMotivation:ChIP-seq is becoming the main approach to the genome-wide study of protein–DNA interactions and histone modifications. Existing informatics tools perform well to extract strong ChIP-enriched sites. However, two questions remain to be answered: (i) to which extent is a ChIP-seq experiment able to reveal the weak ChIP-enriched sites? (ii) are the weak sites biologically meaningful? To answer these questions, it is necessary to identify the weak ChIP signals from background noise.Results: We propose a linear signal–noise model, in which a noise rate was introduced to represent the fraction of noise in a ChIP library. We developed an iterative algorithm to estimate the noise rate using a control library, and derived a library-swapping strategy for the false discovery rate estimation. These approaches were integrated in a general-purpose framework, named CCAT (Control-based ChIP-seq Analysis Tool), for the significance analysis of ChIP-seq. Applications to H3K4me3 and H3K36me3 datasets showed that CCAT predicted significantly more ChIP-enriched sites that the previous methods did. With the high sensitivity of CCAT prediction, we revealed distinct chromatin features associated to the strong and weak H3K4me3 sites.Availability: http://cmb.gis.a-star.edu.sg/ChIPSeq/tools.htmContact: sungk@gis.a-star.edu.sg; asflin@ntu.edu.sgSupplementary Information: Supplementary data are available at Bioinformatics online.
Modular analysis of gene expression data with R
Authors: Csárdi Gábor , Kutalik Zoltán , Bergmann Sven 
Published: April 2010

Abstract
Summary: Large sets of data, such as expression profiles from many samples, require analytic tools to reduce their complexity. The Iterative Signature Algorithm (ISA) is a biclustering algorithm. It was designed to decompose a large set of data into so-called ‘modules’. In the context of gene expression data, these modules consist of subsets of genes that exhibit a coherent expression profile only over a subset of microarray experiments. Genes and arrays may be attributed to multiple modules and the level of required coherence can be varied resulting in different ‘resolutions’ of the modular mapping. In this short note, we introduce two BioConductor software packages written in GNU R: The isa2 package includes an optimized implementation of the ISA and the eisa package provides a convenient interface to run the ISA, visualize its output and put the biclusters into biological context. Potential users of these packages are all R and BioConductor users dealing with tabular (e.g. gene expression) data.
Availability: http://www.unil.ch/cbg/ISA
Contact: sven.bergmann@unil.ch
Multi-threaded vectorized distance matrix computation on the CELL/BE and x86/SSE2 architectures
Authors: Wirawan Adrianto , Kwoh Chee Keong , Schmidt Bertil 
Published: March 2010

Abstract
Summary: Multiple sequence alignment is an important tool in bioinformatics. Although efficient heuristic algorithms exist for this problem, the exponential growth of biological data demands an even higher throughput. The recent emergence of multi-core technologies has made it possible to achieve a highly improved execution time for many bioinformatics applications. In this article, we introduce an implementation that accelerates the distance matrix computation on x86 and Cell Broadband Engine, a homogeneous and heterogeneous multi-core system, respectively. By taking advantage of multiple processors as well as Single Instruction Multiple Data vectorization, we were able to achieve speed-ups of two orders of magnitude compared to the publicly available implementation utilized in ClustalW.
Availability and Implementation: Source codes in C are publicly available at https://sourceforge.net/projects/distmatcomp/
Contact: adri0004@ntu.edu.sg
Comparison of Surgical Stress Index-guided Analgesia with Standard Clinical Practice during Routine General Anesthesia
Authors: Chen Xinzhong , Thee Carsten , Gruenewald Matthias , Wnent Jan , Illies Christoph , Hoecker Jan , Hanss Robert , Steinfath Markus , Bein Berthold 
Published: April 2010

Background
Surgical stress index (SSI), a novel multivariate index, has recently been proven to react well to surgical nociceptive stimuli and analgesic drug concentration changes during general anesthesia. We investigated the feasibility of application of SSI for guidance of remifentanil administration during propofol-remifentanil anesthesia.

Methods
Eighty patients scheduled for elective ear-nose-throat surgery were randomized into two groups, SSI-guided analgesia group (SSI group) and standard practice analgesia group (control group). In both groups, anesthesia was maintained with a propofol target-controlled infusion and adjusted stepwise by 0.5 microg/ml to keep bispectral index values between 40 and 60. In the SSI group, the predicted effect-site concentration of remifentanil was adjusted stepwise by 1 ng/ml to keep SSI values between 20 and 50, whereas in the control group, predicted effect-site concentration of remifentanil was adjusted according to traditional inadequate analgesia criteria. Anesthetics consumption, recovery times, and incidence of unwanted events were recorded.

Results
Remifentanil consumption (average normalized infusion rate) was lower in the SSI group than in the control group (mean +/- SD, 9.5 +/- 3.8 microg . kg(-1) . h(-1) vs. 12.3 +/- 5.2 microg . kg(-1) . h(-1); P < 0.05). The number of unwanted events was less in the SSI group (84) than in the control group (556; P < 0.01). Recovery times were comparable between groups. No patient reported intraoperative recall.

Conclusions
SSI-guided anesthesia resulted in lower remifentanil consumption, more stable hemodynamics, and a lower incidence of unwanted events.
A New Technique to Assist Epidural Needle Placement
Authors: Ting Chien-Kun , Tsou Mei-Yung , Chen Pin-Tarng , Chang Kuang-Yi , Mandell M. Susan , Chan Kwok-Hon , Chang Yin 
Published: April 2010

Background
Up to 10% of epidurals fail due to incorrect catheter placement. We describe a novel optical method to assist epidural catheter insertion in a porcine model.

Methods
Optical emissions were tested on ex vivo tissues from porcine paravertebral tissues to identify optical reflective spectra. The wavelengths of 650 and 532 nm differentiated epidural space from the ligamentum flavum. We then used a hollow stylet that contained optical fibers to place epidural needles in anesthetized pigs. Real-time data were displayed on an oscilloscope and stored for analysis. A total of 50 punctures were done in four laboratory pigs. Data were expressed as mean +/- SD.

Results
Paired t test shows significant optical differences between the epidural space and the ligamentum flavum at both 650 nm (P < 0.001) and 532 nm (P = 0.014). Mean magnitudes for 650 nm, 532 nm, and their ratio were 3.565 +/- 0.194, 2.542 +/- 0.145, and 0.958 +/- 0.172 at epidural space and 3.842 +/- 0.191, 2.563 +/- 0.131, and 1.228 +/- 0.244 at ligamentum flavum, respectively. There were no differences in the optical characteristics of the ligamentum flavum and epidural space at different levels in the lumbar and thoracic region (two-way ANOVA P > 0.05).

Conclusions
This is the first study to introduce a new optical method to localize epidural space in a porcine model. Epidural space could be identified by the changes in the reflective pattern of light emitted at 650 nm, which were specific for the ligamentum flavum and dural tissue. Real-time optical information successfully guided a modified Tuohy needle into the epidural space.
Ketamine Activates Cell Cycle Signaling and Apoptosis in the Neonatal Rat Brain
Authors: Soriano Sulpicio G. , Liu Qian , Li Jing , Liu Jia-Ren , Han Xiao Hui , Kanter Jennifer L. , Bajic Dusica , Ibla Juan C. 
Published: April 2010

Background
Prolonged exposure to ketamine results in accelerated neurodegeneration and neurocognitive deficits in the neonatal rats. Experimental models of neurodegeneration have implicated reentry of postmitotic neurons into the cell cycle, leading to cell death. The authors hypothesize that the ketamine-induced neuroapoptosis is partially due to aberrant cycle cell reentry. To explore this hypothesis, the authors characterized the effect of ketamine on the cell cycle signaling pathway in the developing rodent brain in vivo and in vitro.

Methods
Postnatal day 7 rat pups and primary neurons were used for the experiments. Each rat pup received five intraperitoneal doses of either saline or ketamine (5, 10, and 20 mg/kg/dose) at 90-min intervals over 6 h. Primary neurons were exposed to varying concentrations of ketamine to determine the dose and duration effects. The expression of cell cycle proteins (cyclin D1, cyclin-dependent kinase 4, and E2F1), Bcl2-interacting mediator of cell death (Bim), and activated caspase-3 was determined. The effect of cyclin D1 knockdown by small interfering RNA was also examined in primary neurons incubated in ketamine.

Results
Ketamine mediated a dose- and time-dependent increase in expression of cell cycle proteins and activated caspase-3. Cyclin D1, cyclin-dependent kinase 4, E2F1, Bim, and cleaved caspase-3 expression increased at 12 h and peaked at 24 h in vitro. Knockdown of cyclin D1 by small interfering RNA attenuated Bim and cleaved caspase-3 expression.

Conclusion
These findings support a model in which ketamine induces aberrant cell cycle reentry, leading to apoptotic cell death in the developing rat brain.
Association of Perioperative Risk Factors and Cumulative Duration of Low Bispectral Index with Intermediate-term Mortality after Cardiac Surgery in the B-Unaware Trial
Authors: Kertai Miklos D. , Pal Nirvik , Palanca Ben J. A. , Lin Nan , Searleman Sylvia A. , Zhang Lini , Burnside Beth A. , Finkel Kevin J. , Avidan Michael S. 
Published: April 2010

Background
Current data suggest that mortality after noncardiac surgery may be associated with persistent hypotension and the cumulative duration of low processed electroencephalogram-based bispectral index (BIS). This study assessed the relationships among cumulative duration of low BIS (BIS < 45), intermediate-term mortality, and anesthetic dose after cardiac surgery.

Methods
The authors studied 460 patients (mean age, 63.0 +/- 13.1 yr; 287 men) who underwent cardiac surgery between September 2005 and October 2006 at Washington University Medical Center, St Louis, Missouri. By using multivariable Cox regression analysis, perioperative factors were evaluated for their potential association with intermediate-term all-cause mortality.

Results
A total of 82 patients (17.8%) died during a median follow-up of 3 yr (interquartile range, 2.7-3.3 yr). Comparing patients who died with those who survived, there was no statistically significant difference in the relationship between end-tidal anesthetic gas concentrations during the anesthetic maintenance phase and the BIS. Cumulative duration of low BIS was independently associated with intermediate-term mortality. The 1.29 adjusted hazard ratio (95% CI, 1.12-1.49) for intermediate-term mortality with cumulative duration of low BIS translated into a 29% increased risk of death for every cumulative hour spent with a BIS less than 45. The final multivariable Cox regression model showed a good discriminative ability (c-index of 0.78).

Conclusions
This study found an association between cumulative duration of low BIS and mortality in the setting of cardiac surgery. Notably, this association was independent of both volatile anesthetic concentration and duration of anesthesia, suggesting that intermediate-term mortality after cardiac surgery was not causally related to excessive anesthetic dose.
Mapping Plant Interactomes Using Literature Curated and Predicted Protein–Protein Interaction Data Sets
Authors: Lee KiYoung , Thorneycroft David , Achuthan Premanand , Hermjakob Henning , Ideker Trey 
Published: April 2010

Abstract
Most cellular processes are enabled by cohorts of interacting proteins that form dynamic networks within the plant proteome. The study of these networks can provide insight into protein function and provide new avenues for research. This article informs the plant science community of the currently available sources of protein interaction data and discusses how they can be useful to researchers. Using our recently curated IntAct Arabidopsis thaliana protein–protein interaction data set as an example, we discuss potentials and limitations of the plant interactomes generated to date. In addition, we present our efforts to add value to the interaction data by using them to seed a proteome-wide map of predicted protein subcellular locations.
Convergent Evolution of Syringyl Lignin Biosynthesis via Distinct Pathways in the Lycophyte Selaginella and Flowering Plants
Authors: Weng Jing-Ke , Akiyama Takuya , Bonawitz Nicholas D. , Li Xu , Ralph John , Chapple Clint 
Published: April 2010

Abstract
Phenotypic convergence in unrelated lineages arises when different organisms adapt similarly under comparable selective pressures. In an apparent example of this process, syringyl lignin, a fundamental building block of plant cell walls, occurs in two major plant lineages, lycophytes and angiosperms, which diverged from one another more than 400 million years ago. Here, we show that this convergence resulted from independent recruitment of lignin biosynthetic cytochrome P450-dependent monooxygenases that route cell wall monomers through related but distinct pathways in the two lineages. In contrast with angiosperms, in which syringyl lignin biosynthesis requires two phenylpropanoid meta-hydroxylases C3′H and F5H, the lycophyte Selaginella employs one phenylpropanoid dual meta-hydroxylase to bypass several steps of the canonical lignin biosynthetic pathway. Transgenic expression of the Selaginella hydroxylase in Arabidopsis thaliana dramatically reroutes its endogenous lignin biosynthetic pathway, yielding a novel lignin composition not previously identified in nature. Our findings demonstrate a unique case of convergent evolution via distinct biochemical strategies and suggest a new way to genetically reconstruct lignin biosynthesis in higher plants.
Moderator effects of organizational tenure on the relationship between psychological climate and affective commitment
Authors: English Brian , Morrison David , Chalon Christopher 
Published: April 2010

PurposePrevious research is equivocal about: whether affective organizational commitment increases or decreases with increasing tenure; and which psychological climate variables correlated with affective commitment are important as tenure increases. The study's purpose is to examine whether the relationship between psychological climate and affective commitment is moderated by tenure.Design/methodology/approachThe total workforce of a public sector agency in Western Australia (n=1,117) was surveyed with a response rate of 53 per cent. The moderating role of tenure was examined for employees with less than one year's tenure (n=87), one to nine years (n=232) and more than nine years (n=258).FindingsAffective commitment was found to be stronger for employees with longer tenure; however, perceptions of psychological climate appear to be less positive for these employees. The finding of a moderation effect for tenure appeared to be attributable to the importance of supervisor involvement to affective commitment for employees with one to nine years' tenure.Practical implicationsBuilding affective commitment is an important issue for managers as it is strongly related to withdrawal cognitions and employee turnover. The findings of the study suggest that the criteria against which an organization is assessed by employees tends to shift with time and impacts on affective commitment.Originality/valueThe three‐way relationship between tenure, psychological climate and affective commitment has received little attention. The findings of the study suggest that the strength of affective commitment may depend on the extent to which the specific interests and capabilities of individual employees at different stages of tenure are met.
Performance measurement in the food supply chain: a balanced scorecard approach
Authors: Bigliardi Barbara , Bottani Eleonora 
Published: April 2010

PurposeThe primary objective of this paper is to develop a balanced scorecard (BSC) model that is designed and delimited for performance measurement in the food supply chain.Design/methodology/approachThe research methodology is a combination of literature analysis, Delphi technique and case study‐based research. Starting from the literature concerning performance measurement and metrics, the food industry and the BSC model, the relevant financial and non‐financial indicators, suitable to be used for companies belonging to the food industry, were first identified. Indicators were submitted to a panel of experts, which operated following the Delphi technique, to gather possible suggestions or amendments. In its final form, the resulting BSC model was tested on two companies operating in the food industry, for a final validation.FindingsResults of the case studies show that the companies examined have a similar view for three of the four perspectives of the BSC, which can be thus considered as validated. Conversely, some diverging results were observed concerning the learning and growth perspective.Research limitations/implicationsBy focusing on the specific context of the food supply chain, this study completes previous works, which proposed a generic BSC model for supply chain management. On the other hand, the fact that a specific industry field was examined could be seen as a limitation of the work as the results presented are not suitable to be generalized or extended to other contexts, although some extrapolations can be made.Originality/valueThe paper provides a structured performance measurement system tailored for the food supply chain. The BSC model developed could serve as a reference for the food industry, to establish applicable performance appraisal indicators, and it is believed that both researchers and practitioners would benefit from the tool developed.
Haematological emergencies managing hypercalcaemia in adults and children with haematological disorders
Authors: Sargent Jeremy T. S. , Smith Owen P. 
Published: April 2010

SummaryHypercalcaemia is a common metabolic complication of malignant disease often requiring emergency intervention. Although it is more frequently associated with solid tumours, malignancy‐associated hypercalcaemia (MAH) is seen in a significant number of patients with blood diseases. Its association with myeloma and adult T‐cell leukaemia/lymphoma is well recognized but the incidence of hypercalcaemia in other haematological neoplasms, affecting adults and children, is less clearly defined. Haematologists need to be familiar with the clinical manifestations of, the differential diagnosis to be considered and the most effective management strategies that are currently available for MAH. The key components of management of MAH include aggressive rehydration, specific therapy to inhibit bone resorption and, crucially, treatment of the underlying malignancy. Bisphosphonates have revolutionized the management of MAH over the last 20 years, however the elucidation of molecular pathways implicated in MAH is facilitating the development of more targeted approaches to treatment.