bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generalized stability of classical polynomial functional equation of order n
Authors: Eungrasamee Tippaporn , Udomkavanich Patanee , Nakmahachalasint Paisan 
Published: August 2012

Abstract
We study a general n th order polynomial functional equation

Δ
y
n

f
(
x
)
=
n
!
f
(
y
)

on linear spaces and prove its generalized stability.

MSC:39B52, 39B82.
Opposing effects of Notch-signaling in maintaining the proliferative state of follicle cells in the telotrophic ovary of the beetle Tribolium
Authors: Bäumer Daniel , Ströhlein Nadi M , Schoppmeier Michael 
Published: August 2012

Abstract

Introduction
Establishment of distinct follicle cell fates at the early stages of Drosophila oogenesis is crucial for achieving proper morphology of individual egg chambers. In Drosophila oogenesis, Notch-signaling controls proliferation and differentiation of follicular cells, which eventually results in the polarization of the anterior-posterior axis of the oocyte. Here we analyzed the functions of Tribolium Notch-signaling factors during telotrophic oogenesis, which differs fundamentally from the polytrophic ovary of Drosophila.

Results
We found Notch-signaling to be required for maintaining the mitotic cycle of somatic follicle cells. Upon Delta RNAi, follicle cells enter endocycle prematurely, which affects egg-chamber formation and patterning. Interestingly, our results indicate that Delta RNAi phenotypes are not solely due to the premature termination of cell proliferation. Therefore, we monitored the terminal/stalk cell precursor lineage by molecular markers. We observed that upon Delta RNAi terminal and stalk cell populations were absent, suggesting that Notch-signaling is also required for the specification of follicle cell populations, including terminal and stalk precursor cells.

Conclusions
We demonstrate that with respect to mitotic cycle/endocycle switch Notch-signaling in Tribolium and Drosophila has opposing effects. While in Drosophila a Delta-signal brings about the follicle cells to leave mitosis, Notch-signaling in Tribolium is necessary to retain telotrophic egg-chambers in an “immature” state. In most instances, Notch-signaling is involved in maintaining undifferentiated (or preventing specialized) cell fates. Hence, the role of Notch in Tribolium may reflectthe ancestral function of Notch-signaling in insect oogenesis.
The functions of Notch-signaling in patterning the follicle cell epithelium suggest that Tribolium oogenesis may - analogous to Drosophila - involve the stepwise determination of different follicle cell populations. Moreover, our results imply that Notch-signaling may contribute at least to some aspects of oocyte polarization and AP axis also in telotrophic oogenesis.
Non structural protein of avian influenza A (H11N1) virus is a weaker suppressor of immune responses but capable of inducing apoptosis in host cells
Authors: Mukherjee Sanjay , Majumdar Shamik , Vipat Veena C , Mishra Akhilesh C , Chakrabarti Alok K 
Published: August 2012

Abstract

Background
The Non-Structural (NS1) protein of Influenza A viruses is an extensively studied multifunctional protein which is commonly considered as key viral component to fight against host immune responses. Even though there has been a lot of studies on the involvement of NS1 protein in host immune responses there are still ambiguities regarding its role in apoptosis in infected cells. Interactions of NS1 protein with host factors, role of NS1 protein in regulating cellular responses and apoptosis are quite complicated and further studies are still needed to understand it completely.

Results
NS1 genes of influenza A/Chicken/India/WBNIV2653/2008 (H5N1) and A/Aquatic bird/India/NIV-17095/2007(H11N1) were cloned and expressed in human embryonic kidney (293T) cells. Microarray based approach to study the host cellular responses to NS1 protein of the two influenza A viruses of different pathogenicity showed significant differences in the host gene expression profile. NS1 protein of H5N1 resulted in suppression of IFN-β mediated innate immune responses, leading to down-regulation of the components of JAK-STAT pathway like STAT1 which further suppressed the expression of pro-inflammatory cytokines like CXCL10 and CCL5. The degree of suppression of host immune genes was found considerable with NS1 protein of H11N1 but was not as prominent as with H5N1-NS1. TUNEL assay analyses were found to be positive in both the NS1 transfected cells indicating both H5N1 as well as H11N1 NS1 proteins were able to induce apoptosis in transfected cells.

Conclusions
We propose that NS1 protein of both H5N1 and H11N1 subtypes of influenza viruses are capable of influencing host immune responses and possess necessary functionality to support apoptosis in host cells. H11N1, a low pathogenic virus without any proven evidence to infect mammals, contains a highly potential NS1 gene which might contribute to greater virus virulence in different gene combinations.
Methods of staining and visualization of sphingolipid enriched and non-enriched plasma membrane regions of Arabidopsis thaliana with fluorescent dyes and lipid analogues
Authors: Blachutzik Jörg O , Demir Fatih , Kreuzer Ines , Hedrich Rainer , Harms Gregory S 
Published: August 2012

Abstract

Background
Sterols and Sphingolipids form lipid clusters in the plasma membranes of cell types throughout the animal and plant kingdoms. These lipid domains provide a medium for protein signaling complexes at the plasma membrane and are also observed to be principal regions of membrane contact at the inception of infection. We visualized different specific fluorescent lipophilic stains of the both sphingolipid enriched and non-sphingolipid enriched regions in the plasma membranes of live protoplasts of Arabidopsis thaliana.

Results
Lipid staining protocols for several fluorescent lipid analogues in plants are presented. The most emphasis was placed on successful protocols for the single and dual staining of sphingolipid enriched regions and exclusion of sphingolipid enriched regions on the plasma membrane of Arabidopsis thaliana protoplasts. A secondary focus was placed to ensure that these staining protocols presented still maintain cell viability. Furthermore, the protocols were successfully tested with the spectrally sensitive dye Laurdan.

Conclusion
Almost all existing staining procedures of the plasma membrane with fluorescent lipid analogues are specified for animal cells and tissues. In order to develop lipid staining protocols for plants, procedures were established with critical steps for the plasma membrane staining of Arabidopsis leaf tissue and protoplasts. The success of the plasma membrane staining protocols was additionally verified by measurements of lipid dynamics by the fluorescence recovery after photobleaching technique and by the observation of new phenomena such as time dependent lipid polarization events in living protoplasts, for which a putative physiological relevance is suggested.
Correlation of serum C-reactive protein, white blood count and neutrophil percentage with histopathology findings in acute appendicitis
Authors: Xharra Shefki , Gashi-Luci Lumturije , Xharra Kumrije , Veselaj Fahredin , Bicaj Besnik , Sada Fatos , Krasniqi Avdyl 
Published: August 2012

Abstract

Background
Acute appendicitis is one of the most common surgical emergencies. Accurate diagnosis of acute appendicitis is based on careful history, physical examination, laboratory and imaging investigation. The aim of the study is to analyze the role of C-reactive protein (CRP), white blood count (WBC) and Neutrophil percentage (NP) in improving the accuracy of diagnosis of acute appendicitis and to compare it with the intraoperative assessment and histopathology findings.

Materials and methods
This investigation was a prospective double blinded clinical study. The study was done on 173 patients surgically treated for acute appendicitis. The WBC, NP, and measurement of CRP were randomly collected pre-operatively from all involved patients. Macroscopic assessment was made from the operation. Appendectomy and a histopathology examination were performed on all patients. Gross description was compared with histopathology results and then correlated with CRP, WBC, and NP.

Results
The observational accuracy was 87,3%, as compared to histopathological accuracy which was 85.5% with a total of 173 patients that were operated on. The histopathology showed 25 (14.5%) patients had normal appendices, and 148 (85.5%) patients had acutely inflamed, gangrenous, or perforated appendicitis. 52% were male and 48% were female, with the age ranging from 5 to 59 with a median of 19.7. The gangrenous type was the most frequent (52.6%). The WBC was altered in 77.5% of the cases, NP in 72.3%, and C-reactive protein in 76.9% cases. In those with positive appendicitis, the CRP and WBC values were elevated in 126 patients (72.8%), whereas NP was higher than 75% in 117 patients (67.6%). Out of 106 patients with triple positive tests, 101 (95.2%) had appendicitis. The sensitivity, specificity, and positive predictive values of the 3 tests in combination were 95.3%, 72.2%, and 95.3%, respectively.

Conclusion
The raised value of the CRP was directly related to the severity of inflammation (p-value <0.05). CRP monitoring enhances the diagnostic accuracy of acute appendicitis. The diagnostic accuracy of CRP is not significantly greater than WBC and NP. A combination of these three tests significantly increases the accuracy. We found that elevated serum CRP levels support the surgeon's clinical diagnosis.
Late decompressive craniectomyafter traumatic brain injury: neurological outcome at 6 months after ICU discharge
Authors: Cianchi Giovanni , Bonizzoli Manuela , Zagli Giovanni , di Valvasone Simona , Biondi Simona , Ciapetti Marco , Perretta Lucia , Mariotti Furio , Peris Adriano 
Published: August 2012

Abstract

Introduction
The choice of optimal treatment in traumatic brain injured (TBI) patients is a challenge. The aim of this study was to verify the neurological outcome of severe TBI patients treated with decompressive craniectomy (early < 24 h, late > 24 h), compared to conservative treatment, in hospital and after 6-months.

Methods
A total of 186 TBI patients admitted to the ICU of the Emergency Department of a tertiary referral center (Careggi Teaching Hospital, Florence, Italy) from 2005 through 2009 were retrospectively studied. Patients treated with decompressive craniectomy were divided into 2 groups: “early craniectomy group” (patients who underwent to craniectomy within the first 24 hours); and “late craniectomy group” (patients who underwent to craniectomy later than the first 24 hours). As a control group, patients whose intracranial hypertension was successfully controlled by medical treatment were included in the “no craniectomy group”.

Results
Groups included 41 patients who required early decompressive craniectomy, 21 patients treated with late craniectomy (7.7 days after trauma, on average), and 124 patients for whom intracranial hypertension was successfully controlled through conservative treatment. Groups were comparable in age and trauma/critical illness scores, except for a significantly higher Marshall score in early craniectomized patients. The Glasgow Outcome Scale was comparable between groups at ICU, at the time of hospital discharge and at 6 months.

Conclusions
In our sample, a late craniectomy in patients with refractory intracranial hypertension produced a comparable 6-months neurological outcome if compared to patients responder to standard treatment. This data must be reproduced and confirmed before considering as goal-treatment in refractory intracranial hypertension.
Roles of CREB in the regulation of FMRP by group I metabotropic glutamate receptors in cingulate cortex
Authors: Wang Hansen , Morishita Yoshikazu , Miura Daiki , Naranjo Jose R , Kida Satoshi , Zhuo Min 
Published: August 2012

Abstract

Background
Fragile X syndrome is caused by lack of fragile X mental retardation protein (FMRP) due to silencing of the FMR1 gene. The metabotropic glutamate receptors (mGluRs) in the central nervous system contribute to higher brain functions including learning/memory, mental disorders and persistent pain. The transcription factor cyclic AMP-responsive element binding protein (CREB) is involved in important neuronal functions, such as synaptic plasticity and neuronal survival. Our recent study has shown that stimulation of Group I mGluRs upregulated FMRP and activated CREB in anterior cingulate cortex (ACC), a key region for brain cognitive and executive functions, suggesting that activation of Group I mGluRs may upregulate FMRP through CREB signaling pathway.

Results
In this study, we demonstrate that CREB contributes to the regulation of FMRP by Group I mGluRs. In ACC neurons of adult mice overexpressing dominant active CREB mutant, the upregulation of FMRP by stimulating Group I mGluR is enhanced compared to wild-type mice. However, the regulation of FMRP by Group I mGluRs is not altered by overexpression of Ca2+-insensitive mutant form of downstream regulatory element antagonist modulator (DREAM), a transcriptional repressor involved in synaptic transmission and plasticity.

Conclusion
Our study has provided further evidence for CREB involvement in regulation of FMRP by Group I mGluRs in ACC neurons, and may help to elucidate the pathogenesis of fragile X syndrome.
Oocyte-like cells induced from mouse spermatogonial stem cells
Authors: Wang Lu , Cao Jinping , Ji Ping , Zhang Di , Ma Lianghong , Dym Martin , Yu Zhuo , Feng Lixin 
Published: August 2012

Abstract

Background
During normal development primordial germ cells (PGCs) derived from the epiblast are the precursors of spermatogonia and oogonia. In culture, PGCs can be induced to dedifferentiate to pluripotent embryonic germ (EG) cells in the presence of various growth factors. Several recent studies have now demonstrated that spermatogonial stem cells (SSCs) can also revert back to pluripotency as embryonic stem (ES)-like cells under certain culture conditions. However, the potential dedifferentiation of SSCs into PGCs or the potential generation of oocytes from SSCs has not been demonstrated before.

Results
We report that mouse male SSCs can be converted into oocyte-like cells in culture. These SSCs-derived oocytes (SSC-Oocs) were similar in size to normal mouse mature oocytes. They expressed oocyte-specific markers and gave rise to embryos through parthenogenesis. Interestingly, the Y- and X-linked testis-specific genes in these SSC-Oocs were significantly down-regulated or turned off, while oocyte-specific X-linked genes were activated. The gene expression profile appeared to switch to that of the oocyte across the X chromosome. Furthermore, these oocyte-like cells lost paternal imprinting but acquired maternal imprinting.

Conclusions
Our data demonstrate that SSCs might maintain the potential to be reprogrammed into oocytes with corresponding epigenetic reversals. This study provides not only further evidence for the remarkable plasticity of SSCs but also a potential system for dissecting molecular and epigenetic regulations in germ cell fate determination and imprinting establishment during gametogenesis.
Differential effects of Th1 versus Th2 cytokines in combination with hypoxia on HIFs and angiogenesis in RA
Authors: Larsen Helene , Muz Barbara , Khong Tak L , Feldmann Marc , Paleolog Ewa M 
Published: August 2012

Abstract
Introduction
Hypoxia and T-helper cell 1 (Th1) cytokine-driven inflammation are key features of rheumatoid arthritis (RA) and contribute to disease pathogenesis by promoting angiogenesis. The objective of our study was to characterise the angiogenic gene signature of RA fibroblast-like synoviocytes (FLS) in response to hypoxia, as well as Th1 and T-helper cell 2 (Th2) cytokines, and in particular to dissect out effects of combined hypoxia and cytokines on hypoxia inducible transcription factors (HIFs) and angiogenesis.

Methods
Human angiogenesis PCR arrays were used to screen cDNA from RA FLS exposed to hypoxia (1% oxygen) or dimethyloxalylglycine, which stabilises HIFs. The involvement of HIF isoforms in generating the angiogenic signature of RA FLS stimulated with hypoxia and/or cytokines was investigated using a DNA-binding assay and RNA interference. The angiogenic potential of conditioned media from hypoxia-treated and/or cytokine-treated RA FLS was measured using an in vitro endothelial-based assay.

Results
Expression of 12 angiogenic genes was significantly altered in RA FLS exposed to hypoxia, and seven of these were changed by dimethyloxalylglycine, including ephrin A3 (EFNA3), vascular endothelial growth factor (VEGF), adipokines angiopoietin-like (ANGPTL)-4 and leptin. These four proangiogenic genes were dependent on HIF-1 in hypoxia to various degrees: EFNA3 >ANGPTL-4 >VEGF >leptin. The Th1 cytokines TNFα and IL-1β induced HIF-1 but not HIF-2 transcription as well as activity, and this effect was additive with hypoxia. In contrast, Th2 cytokines had no effect on HIFs. IL-1β synergised with hypoxia to upregulate EFNA3 and VEGF in a HIF-1-dependent fashion but, despite strongly inducing HIF-1, TNFα suppressed adipokine expression and had minimal effect on EFNA3. Supernatants from RA FLS subjected to hypoxia and TNFα induced fewer endothelial tubules than those from FLS subjected to TNFα or hypoxia alone, despite high VEGF protein levels. The Th2 cytokine IL-4 strongly induced ANGPTL-4 and angiogenesis by normoxic FLS and synergised with hypoxia to induce further proangiogenic activity.

Conclusion
The present work demonstrates that Th1 cytokines in combination with hypoxia are not sufficient to induce angiogenic activity by RA FLS despite HIF-1 activation and VEGF production. In contrast, Th2 cytokines induce angiogenic activity in normoxia and hypoxia, despite their inability to activate HIFs, highlighting the complex relationships between hypoxia, angiogenesis and inflammation in RA.
Uncertainty in Fluid Substitution using Gassmann's Equation and Implication for DHI analysis and Time-lapse Monitoring
Authors: Ileka Okey 
Published: August 2012

Abstract
Gassmann's equation may not be directly applicable for amplitude variation with offset (AVO) modeling due to the violation of its assumptions (low permeability, highly compressible mineral components, invasion and dispersion), the high sensitivity to input parameters which may be in error, the variations in rock frame porosity and compressibility between gas and brine saturated rocks due to the lateral or vertical geological variability or differences in digenesis or cementation due to different pore fluids, the chemical effects at very low effective stress, frame hardening or softening and the heterogeneous fluid distribution spatially and between pores of various sizes and shapes, possible in applicability of wood's equation.
This study investigates the uncertainty in gassmann's equation and the implication in direct hydrocarbon indicator (DHI) analysis and time lapse monitoring. Gassmann's equations are only applicable to clean, highly permeable reservoir rocks. When gas is substituted for brine using gassmann's equations, predicted compressional wave velocity exhibits a wide range of possible values. This range is larger than the expected change in velocity. A single deterministic gassmann result is only one of many possible stochastic realizations. The maximum, mean, median, modal and minimum values of the many stochastic realization of fluid modulus, fluid density, bulk modulus, compressional wave velocity, acoustic impedance, shear impedance and fluid factor can be used in the interpretation.
The resulting range of possible stochastic realizations of modelled compressional wave velocity ratio between the two bounding media, possible stochastic realizations of modelled density ratio between the two bounding media, possible stochastic realizations of poisson's ratio in the upper medium and possible stochastic realizations of poisson's ratio in the lower media gives rise to various possible stochastic realizations for direct hydrocarbon indicator (DHI) prestack data and time lapse post stack data.
Case Study: Numerical Simulation of a Tight Gas Reservoir with Multifractured Horizontal Wells
Authors: Feng Yang , Zhengfu Ning , Xinwei Liao , Huiqing Liu , Hongmei Liao 
Published: August 2012

Abstract
Tight gas reservoirs have amounted to almost 50% of the newly proved natural gas reserves of PetroChina Co., Ltd. in the past five years. Horizontal wells with multiple hydraulically fractures have been proved an effective method to promote the development performance in tight gas reservoirs, which can extend the reservoir contact, reduce the flow resistance, and enhance the well deliverability. This paper summarizes the design, optimization, results, and reservoir modeling of a tight gas reservoir with fractured horizontal wells. A 3-D reservoir model by using multi-scale data is established to optimize future field development performance. Numerical simulation combining well test interpretation and dynamic analysis results is the primary method to define the various impacting factors, such as orientation of horizontal well, hydraulic fracture spacing, number of fractures along the horizontal well, fracture length, etc. Pilot results have been history matched with a numerical model to reconcile reservoir characterization interpretations and provide prediction of ultimate recovery. The simulation results show that with the average productivity of 5.52×104m3/d of a single fractured horizontal well, the tight gas reservoir can product stably for 3 years, and the periodical recovery will be 16.85%, the ultimate cumulative gas production will be 25.52×108m3.
Re-defining The Refusal Standard For Stovepipe Installation
Authors: Alabi Tunde , Iyua Donald 
Published: August 2012

Abstract
The installation of stovepipe is necessary to provide a circulating system for the drilling fluid, prevent incompetent surface soils from being eroded by drilling fluid, and guide drill string and other casing strings into the hole. It is an integral and routine part of the well construction process. The stovepipe also bears much of the loads of the subsequent casing strings that are installed in the well. To be able to withstand the loads it bears, the stovepipe needs to be driven to a competent refusal depth. For a number of decades, SPDC drilling standard for onshore well construction required stovepipes to be driven with a Delmag D22 hammer to a defined refusal blow count of 110 blows/ft. Most of the time, a satisfactory competent formation was reached. At that time 26" OD, ¾" thickness stovepipes were used. Over time, however, changes were made to the hammer specifications. Also, the sizes of stovepipes were changed. Albeit there was no corresponding engineered translation to new refusal standards for the revised stovepipe and drive hammer specifications. Though the equipment changes did not prompt a return to first principles to re-define the standards, the resulting challenges, particularly in the GB field, did
This paper presents the engineering principles used to derive the new standard and the results achieved in applying the standard.