bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Operational Mesogamma-Scale Analysis and Forecast System of the U.S. Army Test and Evaluation Command. Part IV: The White Sands Missile Range Auto-Nowcast System
Authors: Saxen Thomas R. , Mueller Cynthia K. , Warner Thomas T. , Steiner Matthias , Ellison Edward E. , Hatfield Eric W. , Betancourt Terri L. , Dettling Susan M. , Oien Niles A. 
Published: May 2008

Abstract
During the summer months at the U.S. Army Test and Evaluation Command’s (ATEC) White Sands Missile Range (WSMR), forecasting thunderstorm activity is one of the primary duties of the range forecasters. The safety of personnel working on the range and the protection of expensive test equipment depend critically on the quality of forecasts of thunderstorms and associated hazards, including cloud-to-ground lightning, hail, strong winds, heavy rainfall, flash flooding, and tornadoes. The National Center for Atmospheric Research (NCAR) Auto-Nowcast (ANC) system is one of the key forecast tools in the ATEC Four-Dimensional Weather System (4DWX) at WSMR, where its purpose is to aid WSMR meteorologists in their mission of very short term thunderstorm forecasting. Besides monitoring the weather activity throughout the region and warning personnel of potentially hazardous thunderstorms, forecasters play a key role in assisting with the day-to-day planning of test operations on the range by providing guidance with regard to weather conditions favorable to testing. Moreover, based on climatological information about the local weather conditions, forecasters advise their range customers about scheduling tests at WSMR months in advance. This paper reviews the NCAR ANC system, provides examples of the ANC system’s use in thunderstorm forecasting, and describes climatological analyses of WSMR summertime thunderstorm activity relevant for long-range planning of tests. The climatological analysis illustrates that radar-detected convective cells with reflectivity of ≥35 dBZ at WSMR are 1) short lived, with 76% having lifetimes of less than 30 min; 2) small, with 67% occupying areas of less than 25 km2; 3) slow moving, with 79% exhibiting speeds of less than 4 m s−1; 4) moderately intense, with 80% showing reflectivities in excess of 40 dBZ; and 5) deep, with 80% of the storms reaching far enough above the freezing level to be capable of generating lightning.
Biogeography of Tropical Montane Cloud Forests. Part I: Remote Sensing of Cloud-Base Heights
Authors: Welch Ronald M. , Asefi Salvi , Zeng Jian , Nair Udaysankar S. , Han Qingyuan , Lawton Robert O. , Ray Deepak K. , Manoharan Vani Starry 
Published: May 2008

AbstractCloud-base heights over tropical montane cloud forests are determined using Moderate Resolution Imaging Spectroradiometer (MODIS) cloud products and National Centers for Environmental Prediction global tropospheric final analysis (FNL) fields. Cloud-base heights are computed by subtracting cloud thickness estimates from cloud-top height estimates. Cloud-top pressures determined from the current MODIS retrieval algorithm often have serious cloud-top pressure retrieval errors at pressures &gt; 700 hPa. The problem can be easily remedied by matching cloud-top temperature derived from the 11-μm channel to the dewpoint temperature profile (instead of the temperature profile) obtained from the FNL dataset. The FNL dataset at 1° spatial resolution produced results that were nearly equivalent to those derived from radiosonde measurements. The following three different approaches for estimating cloud thickness are examined: 1) the constant liquid water method, 2) the empirical method, and 3) the adiabatic model method. The retrieval technique is applied first for stratus clouds over U.S. airports for 12 cases, with cloud-base heights compared with ceilometer measurements. Mean square errors on the order of 200 m result. Then, the approach is applied to orographic clouds over Monteverde, Costa Rica, with estimated cloud-base heights compared with those derived from photographs. Mean square errors on the order of 100 m result. Both the empirical and adiabatic model approaches produce superior results when compared with the constant liquid water (CLW) approach. This is due to the fact that CLW is more sensitive to natural variations in cloud optical thickness.
A Method to Derive the Multispectral Surface Albedo Consistent with MODIS from Historical AVHRR and VGT Satellite Data
Authors: Trishchenko Alexander P. , Luo Yi , Khlopenkov Konstantin V. , Wang Shusen 
Published: May 2008

Abstract
Multispectral surface albedo and bidirectional properties are required for accurate determination of the surface and atmosphere solar radiation budget. A method is developed here to obtain time series of these surface characteristics consistent with the Moderate Resolution Imaging Spectroradiometer (MODIS) using historical satellite observations with limited spectral coverage available from NOAA Advanced Very High Resolution Radiometer (AVHRR) and VEGETATION/Satellite pour l’Observation de la Terre (SPOT). A nonlinear regression model was developed that relates retrievals from four spectral channels of VEGETATION/SPOT or three spectral channels of NOAA AVHRR with retrieval from each of the seven MODIS channels designed for land applications. The model also takes into account the surface land cover type, the normalized difference vegetation index, and the seasonal cycle. It was applied to generate surface albedo and bidirectional parameters of the seven MODIS-like spectral channels at a 10-day interval for the 1995–2004 period over the U.S. southern Great Plains. The relative retrieval accuracy for the MODIS channels replicated from AVHRR or VEGETATION/SPOT data was typically better than 5%. Correlation coefficients between replicated and original data varied from 0.92 to 0.98 for all channels except MODIS channel 5, where it was lower (0.77–0.84). The developed method provides valuable information for parameterization of spectral albedo in global climate models and can be extended to generate global multispectral data compatible with MODIS from historical AVHRR and VEGETATION/SPOT observations for the pre-MODIS era.
Comparison of Revision Surgery with Primary Anterior Cruciate Ligament Reconstruction and Outcome of Revision Surgery between Different Graft Materials
Authors: Ann Jin Hwan , Lee Yong Seuk , Ha Hae Chan 
Published: May 2008

Background The number of primary anterior cruciate ligament reconstructions is increasing rapidly; the number of failing grafts and need for revision surgery have also risen. Hypothesis Revision anterior cruciate ligament reconstruction will produce similar results to those of primary reconstruction, and there may be different results according to graft materials. Study Design Case control study; Level of evidence, 3. Methods Fifty-nine revision surgeries were performed at 1 institution between January 1997 and October 2005. Fifty-five patients (56 operations) were followed. The results of 117 patients (117 knees) treated with arthroscopic primary anterior cruciate ligament reconstruction using double-looped semitendinosus and gracilis autograft from September 2001 to November 2002 were also evaluated. Clinical and stability results between primary and revision anterior cruciate reconstruction were compared. For the revision surgery, 21 (37.5%) knees had revision reconstruction with previously unharvested ipsilateral double-looped semitendinosus and gracilis autograft. Twenty (35.7%) were bone-patellar tendon-bone allograft, and 15 (26.8%) were Achilles allograft. The details of the technique varied according to the original graft choice and the abnormality encountered. Concomitant procedures were necessary in 32 (57.1%) of 56 knees. Clinical and stability results according to the different graft materials were also compared. Results There were significant improvements in the scores for subjective, objective forms ( P < .001), and stability ( P < .001). However, the clinical results of revision surgery were inferior to primary reconstruction ( P < .001), but as regards stability, the difference between primary and revision cases was not significant (P = .338). There was no difference in clinical and stability results in different groups of graft material ( P = .160-.690). Conclusion Revision anterior cruciate ligament reconstruction could improve clinical and stability results, but the clinical results Were inferior to those of primary reconstruction. This study also demonstrated that the success of the operation did not depend on the choice of graft materials.
Tibiofemoral Contact Pressures and Osteochondral Microtrauma during Anterior Cruciate Ligament Rupture Due to Excessive Compressive Loading and Internal Torque of the Human Knee
Authors: Meyer Eric G. , Baumer Timothy G. , Slade Jill M. , Smith Walter E. , Haut Roger C. 
Published: May 2008

Background The knee is one of the most frequently injured joints, including 80 000 anterior cruciate ligament (ACL) tears in the United States each year. Bone bruises are seen in over 80% of patients with ACL injuries, and have been associated with an overt loss of cartilage overlying those regions within 6 months of injury. Hypothesis The level of contact pressure developed in the human knee joint and the extent of articular cartilage and underlying subchondral bone injuries will depend on the mechanism of applied loads/moments during rupture of the ACL. Study Design Controlled laboratory study. Methods Seven knee pairs, flexed to 30°, were loaded in compression or internal torsion until injury. Pressure-sensitive film recorded the magnitude and location of contact. Histologic analysis and magnetic resonance imaging were used to document microtrauma to the tibial plateau cartilage and subchondral bone. Results All specimens suffered ACL injury, either in the form of a midsubstance rupture or avulsion fracture. The contact area and pressures were higher for compression than torsion experiments. After being loaded, the articular cartilage in the central and posterior regions of the medial tibial plateau showed increased magnetic resonance imaging signal intensity, corresponding to an increased susceptibility to absorb water. Histologically, there were more microcracks in the subchondral bone and more articular cartilage damage in the compression than torsion experiments. Conclusion Significant damage occurs to the articular cartilage and underlying subchondral bone during rupture of the ACL. The types and extent of these tissue injuries are a function of the mechanism of ACL rupture. Clinical Relevance Patients suffering an ACL injury may be at risk of osteochondral damage, especially if the mechanism of injury involves a high compressive loading component, such as during a jump landing.
SALL4 is a key regulator of survival and apoptosis in human leukemic cells
Authors: Yang Jianchang , Chai Li , Gao Chong , Fowles Taylor C. , Alipio Zaida , Dang Hien , Xu Dan , Fink Louis M. , Ward David C. , Ma Yupo 
Published: May 2008

AbstractIncreasing studies suggest that SALL4 may play vital roles in leukemogenesis and stem cell phenotypes. We have mapped the global gene targets of SALL4 using chromatin immunoprecipitation followed by microarray hybridization and identified more than 2000 high-confidence, SALL4-binding genes in the human acute promyelocytic leukemic cell line, NB4. Analysis of SALL4-binding sites reveals that genes involved in cell death, cancer, DNA replication/repair, and cell cycle were highly enriched (P < .05). These genes include 38 important apoptosis-inducing genes (TNF, TP53, PTEN, CARD9, CARD11, CYCS, LTA) and apoptosis-inhibiting genes (Bmi-1, BCL2, XIAP, DAD1, TEGT). Real-time polymerase chain reaction has shown that expression levels of these genes changed significantly after SALL4 knockdown, which ubiquitously led to cell apoptosis. Flow cytometry revealed that reduction of SALL4 expression in NB4 and other leukemia cell lines dramatically increased caspase-3, annexin V, and DNA fragmentation activity. Bromodeoxyuridine-incorporation assays showed decreased numbers of S-phase cells and increased numbers of G1- and G2-phase cells indicating reduced DNA synthesis, consistent with results from cell proliferation assays. In addition, NB4 cells that express low levels of SALL4 have significantly decreased tumorigenecity in immunodeficient mice. Our studies provide a foundation in the development of leukemia stem cell–specific therapy by targeting SALL4.
Segmental uniparental disomy is a commonly acquired genetic event in relapsed acute myeloid leukemia
Authors: Raghavan Manoj , Smith Lan-Lan , Lillington Debra M. , Chaplin Tracy , Kakkas Ioannis , Molloy Gael , Chelala Claude , Cazier Jean-Baptiste , Cavenagh James D. , Fitzgibbon Jude , Lister T. Andrew , Young Bryan D. 
Published: May 2008

AbstractDespite advances in the curative treatment of acute myeloid leukemia (AML), recurrence will occur in the majority of cases. At diagnosis, acquisition of segmental uniparental disomy (UPD) by mitotic recombination has been reported in 15% to 20% of AML cases, associated with homozygous mutations in the region of loss of heterozygosity. This study aimed to discover if clonal evolution from heterozygous to homozygous mutations by mitotic recombination provides a mechanism for relapse. DNA from 27 paired diagnostic and relapsed AML samples were analyzed using genotyping arrays. Newly acquired segmental UPDs were observed at relapse in 11 AML samples (40%). Six were segmental UPDs of chromosome 13q, which were shown to lead to a change from heterozygosity to homozygosity for internal tandem duplication mutation of FLT3 (FLT3 ITD). Three further AML samples had evidence of acquired segmental UPD of 13q in a subclone of the relapsed leukemia. One patient acquired segmental UPD of 19q that led to homozygosity for a CEBPA mutation 207C>T. Finally, a single patient with AML acquired segmental UPD of chromosome 4q, for which the candidate gene is unknown. We conclude that acquisition of segmental UPD and the resulting homozygous mutation is a common event associated with relapse of AML.
Estimating the size of the solution space of metabolic networks
Authors: Braunstein Alfredo , Mulet Roberto , Pagnani Andrea 
Published: May 2008

Abstract

Background
Cellular metabolism is one of the most investigated system of biological interactions. While the topological nature of individual reactions and pathways in the network is quite well understood there is still a lack of comprehension regarding the global functional behavior of the system. In the last few years flux-balance analysis (FBA) has been the most successful and widely used technique for studying metabolism at system level. This method strongly relies on the hypothesis that the organism maximizes an objective function. However only under very specific biological conditions (e.g. maximization of biomass for E. coli in reach nutrient medium) the cell seems to obey such optimization law. A more refined analysis not assuming extremization remains an elusive task for large metabolic systems due to algorithmic limitations.

Results
In this work we propose a novel algorithmic strategy that provides an efficient characterization of the whole set of stable fluxes compatible with the metabolic constraints. Using a technique derived from the fields of statistical physics and information theory we designed a message-passing algorithm to estimate the size of the affine space containing all possible steady-state flux distributions of metabolic networks. The algorithm, based on the well known Bethe approximation, can be used to approximately compute the volume of a non full-dimensional convex polytope in high dimensions. We first compare the accuracy of the predictions with an exact algorithm on small random metabolic networks. We also verify that the predictions of the algorithm match closely those of Monte Carlo based methods in the case of the Red Blood Cell metabolic network. Then we test the effect of gene knock-outs on the size of the solution space in the case of E. coli central metabolism. Finally we analyze the statistical properties of the average fluxes of the reactions in the E. coli metabolic network.

Conclusion
We propose a novel efficient distributed algorithmic strategy to estimate the size and shape of the affine space of a non full-dimensional convex polytope in high dimensions. The method is shown to obtain, quantitatively and qualitatively compatible results with the ones of standard algorithms (where this comparison is possible) being still efficient on the analysis of large biological systems, where exact deterministic methods experience an explosion in algorithmic time. The algorithm we propose can be considered as an alternative to Monte Carlo sampling methods.
PPARalpha-mediated effects of dietary lipids on intestinal barrier gene expression
Authors: de Vogel-van den Bosch Heleen M , Bünger Meike , de Groot Philip J , Bosch-Vermeulen Hanneke , Hooiveld Guido JEJ , Müller Michael 
Published: May 2008

Abstract

Background
The selective absorption of nutrients and other food constituents in the small intestine is mediated by a group of transport proteins and metabolic enzymes, often collectively called 'intestinal barrier proteins'. An important receptor that mediates the effects of dietary lipids on gene expression is the peroxisome proliferator-activated receptor alpha (PPARα), which is abundantly expressed in enterocytes. In this study we examined the effects of acute nutritional activation of PPARα on expression of genes encoding intestinal barrier proteins. To this end we used triacylglycerols composed of identical fatty acids in combination with gene expression profiling in wild-type and PPARα-null mice. Treatment with the synthetic PPARα agonist WY14643 served as reference.

Results
We identified 74 barrier genes that were PPARα-dependently regulated 6 hours after activation with WY14643. For eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and oleic acid (OA) these numbers were 46, 41, and 19, respectively. The overlap between EPA-, DHA-, and WY14643-regulated genes was considerable, whereas OA treatment showed limited overlap. Functional implications inferred form our data suggested that nutrient-activated PPARα regulated transporters and phase I/II metabolic enzymes were involved in a) fatty acid oxidation, b) cholesterol, glucose, and amino acid transport and metabolism, c) intestinal motility, and d) oxidative stress defense.

Conclusion
We identified intestinal barrier genes that were PPARα-dependently regulated after acute activation by fatty acids. This knowledge provides a better understanding of the impact dietary fat has on the barrier function of the gut, identifies PPARα as an important factor controlling this key function, and underscores the importance of PPARα for nutrient-mediated gene regulation in intestine.
18-month occurrence of severe events among early diagnosed HIV-infected children before antiretroviral therapy in Abidjan, Côte d'Ivoire: A cohort study
Authors: Harambat Jérôme , Fassinou Patricia , Becquet Renaud , Touré Pety , Rouet François , Dabis François , Msellati Philippe , Blanche Stéphane , Timité-Konan Marguerite , Salamon Roger , Leroy Valériane ,   ANRS 1201/1202 Ditrame Plus Study Group
Published: May 2008

Abstract

Objective
To assess the 18-month field effectiveness on severe events of a pediatric package combining early HIV-diagnosis and targeted cotrimoxazole prophylaxis in HIV-infected children from age six-week before the antiretroviral era, in Abidjan, Côte d'Ivoire.

Methods
Data from two consecutive prevention of HIV mother-to-child transmission programs were compared: the ANRS 1201/1202 Ditrame-Plus cohort (2001–2005) and the pooled data of the ANRS 049a Ditrame randomized trial and its following open-labeled cohort (1995–2000), used as a reference group. HIV-infected pregnant women ≥ 32–36 weeks of gestation were offered a short-course peri-partum antiretroviral prophylaxis (ZDV in Ditrame, and ZDV ± 3TC+single-dose (sd) NVP in Ditrame-Plus). Neonatal prophylaxis was provided in Ditrame-Plus only: 7-day ZDV and sdNVP 48–72 h after birth. A 6-week pediatric HIV-RNA diagnosis was provided on-line in the Ditrame-Plus while it was only oriented on clinical symptoms in Ditrame. Six-week HIV-infected children received a daily cotrimoxazole prophylaxis in Ditrame-Plus while no prophylaxis was provided in Ditrame. The determinants of severe events (death or hospitalization > 1 day) were assessed in a Cox regression model.

Results
Between 1995 and 2003, 98 out of the 1121 live-births were diagnosed as HIV-infected in peri-partum: 45 from Ditrame-Plus and 53 from Ditrame. The 18-month Kaplan-Meier cumulative probability of presenting a severe event was 66% in Ditrame-Plus (95% confidence interval [95%CI]: 50%–81%) and 77% in Ditrame (95%CI: 65%–89%), Log Rank test: p = 0.47. After adjustment on maternal WHO clinical stage, maternal death, 6-week pediatric viral load, birth-weight, and breastfeeding exposure, the 18-month risk of severe event was lower in Ditrame-Plus than in Ditrame (adjusted Hazard Ratio (aHR): 0.55, 95%CI: 0.3–1.1), although the difference was not statistically significant; p = 0.07). Maternal death was the only variable determinant of the occurrence of severe events in children (aHR: 3.73; CI: 2.2–11.2; p = 0.01).

Conclusion
Early cotrimoxazole from 6 weeks of age in HIV-infected infants seemed to reduce probability of severe events but the study lacked statistical power to prove this. Even with systematic cotrimoxazole prophylaxis, infant morbidity and mortality remained high pointing towards a need for early pediatric HIV-diagnosis and antiretroviral treatment in Africa.
Informed consent in Sri Lanka: A survey among ethics committee members
Authors: Sumathipala Athula , Siribaddana Sisira , Hewage Suwin , Lekamwattage Manura , Athukorale Manjula , Siriwardhana Chesmal , Murray Joanna , Prince Martin 
Published: May 2008

Abstract

Background
Approval of the research proposal by an ethical review committee from both sponsoring and host countries is a generally agreed requirement in externally sponsored research.
However, capacity for ethics review is not universal. Aim of this study was to identify opinions and views of the members serving in ethical review and ethics committees in Sri Lanka on informed consent, essential components in the information leaflet and the consent form.

Methods
We obtained ethical approval from UK and Sri Lanka. A series of consensus generation meetings on the protocol were conducted. A task oriented interview guide was developed. The interview was based on open-ended questionnaire. Then the participants were given a WHO checklist on informed consent and requested to rate the items on a three point scale ranging from extremely important to not important.

Results
Twenty-nine members from ethics committees participated. Majority of participants (23), believed a copy of the information leaflet and consent form, should accompany research proposal. Opinions about the items that should be included in the information leaflets varied. Participants identified 18 criteria as requirements in the information leaflet and 19 for the consent form.
The majority, 20 (69%), believed that all research need ethical approval but identified limited human resource, time and inadequate capacity as constraints. Fifteen (52%) believed that written consent is not required for all research. Verbal consent emerged as an alternative to written consent. The majority of participants rated all components of the WHO checklist as important.

Conclusion
The number of themes generated for the consent form (N = 18) is as many as for the information leaflet (N = 19) and had several overlaps. This suggests that the consent form should be itemized to reflect the contents covered in the information leaflet. The participants' opinion on components of the information leaflets and consent forms proved to be similar with WHO checklist on informed consent.