bluuebunny/crossref_metadata_2025 huggingface dataset:
REST selectively represses a subset of RE1-containing neuronal genes in mouse embryonic stem cells
Authors: Jørgensen Helle F. , Terry Anna , Beretta Chiara , Pereira C. Filipe , Leleu Marion , Chen Zhou-Feng , Kelly Claire , Merkenschlager Matthias , Fisher Amanda G.
Published: February 2009

REST is a transcriptional repressor that targets a group of neuronal genes in non-neuronal cells. In embryonic stem (ES) cells, REST has been implicated in controlling the expression of transcription factor genes that are crucial for lineage determination and for maintaining ES cell potential. Here, we asked whether REST directly regulates neural-specifying genes in mouse ES cells using siRNA-mediated REST knockdown and ES cells that lack functional REST protein as a result of gene targeting. Loss of REST did not affect the expression of any of ten transcription factor genes known to promote neural commitment and did not affect the expression of several microRNAs, including miR-21, a putative REST target in ES cells. REST-deficient ES cells retained the ability to self-renew and to undergo appropriate differentiation towards mesoderm, endoderm and ectoderm lineages upon LIF withdrawal. Genome-wide expression profiling showed that genes that were deregulated in the absence of REST were preferentially expressed in the brain and highly enriched for the presence of canonical REST binding sites (RE1). Chromatin immunoprecipitation studies confirmed these genes as direct targets of REST in ES cells. Collectively, these data show that REST selectively silences a cohort of neuronal genes in ES cells.
EphA4as an effector ofTwist1in the guidance of osteogenic precursor cells during calvarial bone growth and in craniosynostosis
Authors: Ting Man-Chun , Wu Nancy L. , Roybal Paul G. , Sun Jingjing , Liu Liqiong , Yen Youzhen , Maxson Robert E.
Published: February 2009

Heterozygous loss of Twist1 function causes coronal synostosis in both mice and humans. We showed previously that in mice this phenotype is associated with a defect in the neural crest-mesoderm boundary within the coronal suture, as well as with a reduction in the expression of ephrin A2(Efna2), ephrin A4 (Efna4) and EphA4 in the coronal suture. We also demonstrated that mutations in human EFNA4 are a cause of non-syndromic coronal synostosis. Here we investigate the cellular mechanisms by which Twist1, acting through Eph-ephrin signaling,regulates coronal suture development. We show that EphA4 mutant mice exhibit defects in the coronal suture and neural crest-mesoderm boundary that phenocopy those of Twist1+/- mice. Further, we demonstrate that Twist1 and EphA4 interact genetically: EphA4expression in the coronal suture is reduced in Twist1 mutants, and compound Twist1-EphA4 heterozygotes have suture defects of greater severity than those of individual heterozygotes. Thus, EphA4 is a Twist1 effector in coronal suture development. Finally, by DiI labeling of migratory osteogenic precursor cells that contribute to the frontal and parietal bones, we show that Twist1 and EphA4are required for the exclusion of such cells from the coronal suture. We suggest that the failure of this process in Twist1 and EphA4mutants is the cause of craniosynostosis.
A Kullback-Leibler View of Linear and Log-Linear Pools
Authors: Abbas Ali E.
Published: February 2009

Linear and log-linear pools are widely used methods for aggregating expert belief. This paper frames the expert aggregation problem as a decision problem with scoring rules. We propose a scoring function that uses the Kullback-Leibler (KL) divergence measure between the aggregate distribution and each of the expert distributions. The asymmetric nature of the KL measure allows for a convenient scoring system for which the linear and log-linear pools provide the optimal assignment. We also propose a “goodness-of-fit” measure that determines how well each opinion pool characterizes its expert distributions, and also determines the performance of each pool under this scoring function. We work through several examples to illustrate the approach.
An Encoding in Metaheuristics for the Minimum Communication Spanning Tree Problem
Authors: Rothlauf Franz
Published: February 2009

Problem-specific encodings can improve the performance of metaheuristics, such as genetic algorithms or simulated annealing. This paper studies the link-biased (LB) encoding, which is a tree representation, and applies metaheuristics using this encoding to the minimum communication spanning tree (MCST) problem. Given the communication requirements of the nodes, the MCST problem seeks a communication spanning tree with minimum total cost. Optimal solutions for MCST problems are similar to minimum spanning trees (MSTs), and the LB encoding exploits this property by encoding trees similar to MSTs with higher probability. The paper investigates how to systematically design problem-specific encodings for MCST problems and how to set the encoding-specific parameter that controls the bias of the LB encoding towards MSTs; it then presents performance results for various MCST problems.
Significance of the cyclic structure and of arginine residues for the antibacterial activity of arenicin-1 and its interaction with phospholipid and lipopolysaccharide model membranes
Authors: Andrä Jörg , Hammer Malte U. , Grötzinger Joachim , Jakovkin Igor , Lindner Buko , Vollmer Ekkehard , Fedders Henning , Leippe Matthias , Gutsmann Thomas
Published: February 2009

Arenicin-1 (Ar-1) is a β-sheeted antimicrobial peptide from the marine lugworm Arenicola marina. To elucidate the significance of its unique 18-residue cyclic structure and of six cationic arginines for its biological activity and its interaction with biomembranes, we synthesized one linear peptide in which the two cysteines were exchanged for serines (C/S-Ar-1) and a cyclic peptide in which all arginines were replaced by lysines (R/K-Ar-1). We addressed antibacterial and hemolytic activities, the impact of the peptides on bacterial morphology, and their binding to, intercalation into, and permeabilization of model membranes composed of phospholipids or lipopolysaccharide (LPS). In accordance with high salt concentration in sea water, the antibacterial activity of Ar-1 was almost insensitive to high NaCl concentrations. In contrast, the linear derivative lost activity under these conditions against polymyxin B-resistant Proteus mirabilis. Ar-1 intercalated into phospholipid and LPS membranes and formed heterogeneous and short-lived lesions. However, when the peptide was present in both membrane leaflets, it formed defined pores. This characteristic was not observed for the linear derivative C/S-Ar-1. Apparently, the disulfide bond provides conforma-tional stability, which has an impact on salt tolerance, prevents fast degradation by trypsin, and is a prerequisite for the formation of structurally defined pores.
Developmental alterations of the prefrontal cerebral cortex in sudden unexplained perinatal and infant deaths
Authors: Lavezzi Anna Maria , Mauri Maria , Mecchia Donatella , Matturri Luigi
Published: February 2009

The aim of this study was to investigate the developmental patterns of the human prefrontal cortex involved in breathing control in a wide cohort of fetal and infant death victims, aged from the 22nd gestational week to 10 months of life, and to evaluate whether morpho-functional disorders are present in this specific cortical area in victims of sudden unexplained death. A further aim was to determine whether prenatal absorption of nicotine could also affect the maturational processes of the prefrontal cortex. A pronounced radial organization of the cerebral wall was evident from the 26th gestational week. By 36 gestational weeks this columnar structure disappeared, coinciding with the formation of a laminar cyto-architecture. The mature cortex, observable from the 4th month of life, was organized horizontally into six laminae. In 33% of the sudden death victims the prefrontal cortex showed morphological alterations with anomalous laminar patterns and delayed neuronal maturation. A significant correlation with prenatal cigarette exposure was found.
Immunologic and infectious consequences of immediate versus delayed umbilical cord clamping in premature infants: A prospective, randomized, controlled study
Authors: Kugelman Amir , Borenstein-Levin Liron , Kessel Aharon , Riskin Arieh , Toubi Elias , Bader David
Published: February 2009

Aim: To evaluate the immunologic and infectious consequences of delayed versus immediate cord clamping in premature infants (<35 weeks) during the neonatal period.

Methods: This was a prospective, masked, randomized, controlled, single-center study. Prior to delivery 35 infants were randomly assigned to immediate cord clamping (ICC) at 5–10 s and 30 infants to delayed cord clamping (DCC), at 30–45 s (14 and 15 infants in each group were <1500 g, respectively).

Results: Neonatal characteristics of the ICC and DCC groups were comparable. There was no significant difference between the ICC and DCC groups in the complement or in the immunoglobulin levels. All were within the normal range for age. All infectious parameters (events of sepsis or “rule-out sepsis”, days of antibiotic therapy, and number of antibiotic courses during hospitalization and infections within the first month of life in cases of earlier discharge) were comparable in both groups. Similar results were found in the subgroup of infants <1500 g. Gender analysis showed only modest differences.

Conclusions: Delayed compared to immediate cord clamping did not affect the immunologic or the infectious status of infants born at <35 weeks during the neonatal period.
Statistical model predicting a short duration to birth in women with preterm labor at 22–35 weeks' gestation: the importance of large vaginal Gram-positive rods
Authors: Usui Rie , Ohkuchi Akihide , Matsubara Shigeki , Suzuki Mitsuaki
Published: February 2009

Aims: To identify risk factors for a short interval to birth in women with preterm labor, and to construct a statistical model to predict birth within seven days from the diagnosis of preterm labor at 22–35 weeks of gestation.

Methods: Vaginal flora was obtained from 126 singleton pregnant women hospitalized for preterm labor at 22–35 weeks' gestation. The amount of vaginal large Gram-positive rods (GPR) was counted in a bright field under ×400 magnification and classified semiquantitively as loss of GPRs, decreased GPRs (<10), and normal flora (10 or more). The effects of vaginal GPRs, cervical dilatation, and previous history of preterm birth on the subsequent occurrence of birth were analyzed using proportional hazards model, and the effects on birth within seven days from the diagnosis of preterm labor were analyzed using multivariate logistic regression.

Results: Fifty-four women (42.9%) delivered preterm. Both loss of GPRs and decreased GPRs were independent risk factors for a short interval from threatened preterm labor to birth, after adjusting the effect of cervical dilatation and past history of preterm birth (hazard ratio 3.4 [95% CI 2.0–5.5] and 2.0 [95% CI 1.1–3.6], respectively). Cervical dilatation of <4.0 cm and 2.0–3.9 cm, and past history of preterm birth were also independent risk factors for a short interval to birth. Loss of GPRs and decreased GPRs, and cervical dilatation of <4.0 cm and 2.0–3.9 cm were independently associated with birth within seven days from the diagnosis of preterm labor (OR 26 [95% CI 5.3–130], 11 [1.9–69], 76 [8.0–720], and 6.4 [1.5–27], respectively).

Conclusions: Loss of GPRs and decreased GPRs may be independently important for developing birth in women with preterm labor.
Evaluation of normal neurological development of human fetuses from 21 to 30 weeks' gestation through fetal auditory evoked response
Authors: Luz Sérgio Hecker , Vasconcellos Fabiano Candal , Kreling Tatiana , Pacheco Fernanda Silva , Fagundes Chaves Márcia Lorena
Published: February 2009

Objectives: To evaluate the neurological maturation of fetuses between 21 and 30 weeks' gestation by the auditory evoked response.

Methods: The auditory evoked responses of 25 normal singleton fetuses were observed once a week from 21 to 30 weeks' gestation. The stimulus consisted of five pulses of sinusoidal waves, for 2 s, at 1500 cycles/s, with a sound pressure of 125 dB.

Results: Fetal auditory evoked response increased with neurological maturation, presenting two main points of positive discontinuity. The two points in the heart response were detected between the 24th/25th and the 27th/28th week. From the 27th week on, fetal motor response (FMR) was always present. Initial fetal heart response presented a fluctuation pattern between the 21st and the 30th week, with a tendency to increase as gestational age advanced. Fetal heart response also increased with gestational age. Late response (LR) fluctuated until the 29th week, and was always present after that period.

Conclusions: The maturation of the fetal nervous system is clearly demonstrated by changes in the auditory evoked responses in different gestational ages, and presents some discontinuity points.
Access to level III perinatal care for pregnancies of very short duration (<32 weeks)
Authors: Di Napoli Anteo , Di Lallo Domenico , Franco Francesco , Scapillati Maria Eleonora , Zocchetti Carlo , Agostino Rocco , Orzalesi Marcello
Published: February 2009

Aims: To evaluate to which extent pregnancies of very short duration (<32 weeks' gestation) are concentrated in level III centers.

Methods: Area-based study in the 57 maternity units of the Lazio Region (Italy), years 2003–2004, including: 1012 live births (gestational age 22–31 weeks), 261 fetal losses (22–31 weeks) and 209 induced abortions (22–25 weeks). Variables associated with access to a level III unit were evaluated through multivariable logistic regression models.

Results: 83.7% of all pregnancies <32 weeks (88.8% of live births, 71.6% of fetal losses and 75.1% of induced abortions) were admitted to a level III perinatal center; 23.4% of live newborns, delivered in a level III hospital, were subsequently transferred to a same level facility. The probability that a fetal loss was not treated in a level III perinatal unit was higher for women without pregnancy complication, with lower education level, and living outside the metropolitan area.

Conclusions: Regionalization of perinatal care in Lazio is not satisfactory. Concentration of high-risk deliveries in level III centers is good, but in utero transfer is insufficient. This study can help to define the effectiveness of different organizational systems on access to locally available perinatal facilities and to optimize general organizational patterns of perinatal care.
Translational and Rotational Accelerations Generated During Reconstructed Ice Hockey Impacts on a Hybrid III Head Form
Authors: Coulson N. R. , Foreman S. G. , Hoshizaki T. B.
Published: February 2009

In this study, the relationship between flagrant impacts to the head and peak translational and rotational accelerations in reconstructed ice hockey impacts was examined. A Hybrid III head-neck complex attached to a sliding table and equipped with nine accelerometers was fitted with an ice hockey helmet and impacted under various striking conditions through the head form’s center of mass. Eight right-hand-dominant male ice hockey players carried out three maximal impacts for each of the striking techniques, and peak translational and rotational accelerations were measured. It was found that the highest mean translational and rotational accelerations were generated during the slashing trials to a static head form (138 g and 14,100 rad/s2, respectively), while the lowest mean translational and rotational accelerations were produced in the static crosschecking (26.5 g) and moving crosschecking trials (2,260 rad/s2), respectively. The reconstruction of illegal impacts reflecting flagrant fouls in ice hockey can generate peak translational and rotational accelerations great enough to cause concussive injuries. Accordingly, these types of injurious infractions must be prevented.
Sylvester Graham's Imperial Dietetics
Authors: tompkins kyla wazana
Published: February 2009

In ““Bodies Made of Bread”” I theorize eating as an intimate site through which power, in particular, the power that upheld the nineteenth-century United States' investment in imperial rhetoric and action, was both instantiated and undermined. Using the dietetic writings of nineteenth-century reformer and anti-masturbation campaigner Sylvester Graham, I assess the body politics that lurk behind the highly socialized but insistently naturalized act of eating. Eating in Graham's work is a quotidian act through which fictions of racial and gendered embodiment are upheld; through comparison to South Pacific islanders and other European colonists, Graham imagines an ideal American-ness which is founded upon the imperial fantasy of Euro-American indigeneity and regulated through the daily consumption of wheat and other ““farinaceous”” foods.
Chapulines and Food Choices in Rural Oaxaca
Authors: cohen jeffrey h. , sáánchez nydia delhi mata , montiel-ishino francisco
Published: February 2009

Grasshoppers (chapulines) are an important part of rural Oaxacan (Mexico) cuisine and they play a key role in the local diet and market. In this paper, and using data collected over several years of interviewing and ethnographic research in the state, we describe how rural Oaxacan women manage the harvest and prepare chapulines. Second, we examine how chapulines are consumed in the rural households and their nutritional value. Finally, we turn to the important role chapulines play in the market system and entrepreneurial activities of rural Oaxacan women who sell this much valued food source.
Advantages of object-oriented finite-element analysis
Authors: Mackie R. I.
Published: February 2009

Over the last 20 years or so object-oriented programming has become the predominant paradigm in software engineering. Finite-element analysis (FEA) is the most powerful computational tool used in engineering, particularly for structures. It has been in use for some 50 years and as a result there is a massive legacy of tried-and-tested software, mostly written in Fortran. Therefore, the impact of object-oriented programming has been less than in other areas. Even so, there has been much research in this area. This paper describes the advantages that can be gained from using object-oriented methods in finite-element software design. From the user perspective there are two primary concerns—ease of use and computational speed. In addition, the flexibility, maintainability and robustness of software are of indirect importance to the end-user, and clearly of major importance to software developers. The paper will demonstrate how object-oriented methods make positive contributions to all these areas.
Modeling arsenic desorption from herbicide-contaminated soils
Authors: Qi Yongqiang , Donahoe Rona J.
Published: February 2009

The application of arsenical herbicides has created legacy environmental problems by contaminating soil in some agricultural areas and at various industrial sites. Numerous previous studies have suggested that the adsorption of arsenic by common soil components is largely controlled by kinetic factors. Four arsenic-contaminated soil samples collected from industrial sites were characterized and subjected to sequential leaching using a synthetic acid rain solution in order to study the release of arsenic. A dual-site numerical sorption-desorption model was constructed that describes arsenic desorption from these soils in terms of two different release mechanisms: Release from type I (equilibrium) and type II (kinetic) sorption sites. Arsenic held on both type I and II sorption sites is accessible through extensive acid rain leaching. Arsenic desorption from these sites follows a linear Kd model; the manner of approaching the Kd model, however, differs. Arsenic desorption from type I sites reached equilibrium with the aqueous phase under the physical environment provided by the experiment (shaking for 24 h at 25°C), while desorption from type II sites followed a first-order kinetic pattern when approaching equilibrium. During synthetic acid rain sequential leaching of the soils, type I sites released their sorbed arsenic rapidly and subsequent desorption was dominated by the kinetic release of arsenic from type II sites. This shift in desorption mechanism dominance generated data corresponding to two intersecting straight lines in the n-logC dimension for all four soils. The dual-site desorption model was solved analytically and proven to be successful in simulating sorption processes where two different mechanisms are simultaneously controlling the aqueous concentration of a trace element.
The Economic Impact of Exposure to Secondhand Smoke in Minnesota
Authors: Waters Hugh R. , Foldes Steven S. , Alesci Nina L. , Samet Jonathan
Published: February 2009

Objectives. Using the risk categories established by the 2006 US surgeon general's report, we estimated medical treatment costs related to exposure to secondhand tobacco smoke (SHS) in the state of Minnesota.

Methods. We estimated the prevalence and costs of treated medical conditions related to SHS exposure in 2003 with data from Blue Cross and Blue Shield (Minnesota's largest insurer), the Current Population Survey, and population attributable risk estimates for these conditions reported in the scientific literature. We adjusted treatment costs to the state level by health insurance category by using the Medical Expenditure Panel Survey.

Results. The total annual cost of treatment in Minnesota for conditions for which the 2006 surgeon general's report found sufficient evidence to conclude a causal link with exposure to SHS was $228.7 million in 2008 dollars—equivalent to $44.58 per Minnesota resident. Sensitivity analyses showed a range from $152.1 million to $330.0 million.

Conclusions. The results present a strong rationale for regulating smoking in public places and were used to support the passage of Minnesota's Freedom to Breathe Act of 2007.
Mexican Americans and Frailty: Findings From the Hispanic Established Populations Epidemiologic Studies of the Elderly
Authors: Ottenbacher Kenneth J. , Graham James E. , Al Snih Soham , Raji Mukaila , Samper-Ternent Rafael , Ostir Glenn V. , Markides Kyriakos S.
Published: February 2009

Objectives. We examined the prevalence of frailty among Mexican American older adults and explored the correlates associated with becoming frail to determine their affect on disability and morbidity in this population.

Methods. We studied the trajectory of frailty over 10 years in 2049 Mexican Americans participating in the Hispanic Established Populations Epidemiologic Studies of the Elderly. We constructed a frailty index based on weight loss, exhaustion, grip strength, walking speed, and physical activity and collected data on sociodemographic and health status, comorbidities, and functional measures of performance.

Results. The sample was 58% female, with a mean age of 74.43 years (SD = 6.04) at baseline. Fifty-five percent of participants at baseline and 75% of the surviving sample at follow-up (n = 777) were classified as prefrail or frail. Of persons identified as frail at baseline, 84% died by the end of follow-up. Baseline age, diabetes, arthritis, smoking status, body mass index, cognition, negative affect, and number of comorbid conditions were predictors of frailty at follow-up (R2 = 0.29; P < .05).

Conclusions. Further research into ways to reduce the number of Mexican American older adults who become frail and disabled and therefore lose their independence is needed. Future studies should continue to examine the trajectory of frailty as a dynamic process that includes psychosocial and cognitive components.
Speciation and Isotopic Exchangeability of Nickel in Soil Solution
Authors: Nolan Annette L. , Ma Yibing , Lombi Enzo , McLaughlin Mike J.
Published: February 2009

Knowledge of trace metal speciation in soil pore waters is important in addressing metal bioavailability and risk assessment of contaminated soils. In this study, free Ni2+ activities were determined in pore waters of long‐term Ni‐contaminated soils using a Donnan dialysis membrane technique. The pore water free Ni2+ concentration as a percentage of total soluble Ni ranged from 21 to 80% (average 53%), and the average amount of Ni bound to dissolved organic matter estimated by Windermere Humic Aqueous Model VI was ≤17%. These data indicate that complexed forms of Ni can constitute a significant fraction of total Ni in solution. Windermere Humic Aqueous Model VI provided reasonable estimates of free Ni2+ fractions in comparison to the measured fractions (R2 = 0.83 with a slope of 1.0). Also, the isotopically exchangeable pools (E value) of soil Ni were measured by an isotope dilution technique using water extraction, with and without resin purification, and 0.1 mol L−1 CaCl2 extraction, and the isotopic exchangeability of Ni species in soil water extracts was investigated. The concentrations of isotopically non‐exchangeable Ni in water extracts were <9% of total water soluble Ni concentrations for all soils. The resin E values expressed as a percentage of the total Ni concentrations in soil showed that the labile Ni pool ranged from 0.9 to 32.4% (average 12.4%) of total soil Ni. Therefore the labile Ni pool in these well‐equilibrated contaminated soils appears to be relatively small in relation to total Ni concentrations.
Integrated Assessment of Nitrogen Losses from Agriculture in EU‐27 using MITERRA‐EUROPE
Authors: Velthof G.L. , Oudendag D. , Witzke H.P. , Asman W.A.H. , Klimont Z. , Oenema O.
Published: February 2009

The high N inputs to agricultural systems in many regions in 27 member states of the European Union (EU‐27) result in N leaching to groundwater and surface water and emissions of ammonia (NH3), nitrous oxide (N2O), nitric oxide (NO), and dinitrogen (N2) to the atmosphere. Measures taken to decreasing these emissions often focus at one specific pollutant, but may have both antagonistic and synergistic effects on other N emissions. The model MITERRA‐EUROPE was developed to assess the effects and interactions of policies and measures in agriculture on N losses and P balances at a regional level in EU‐27. MITERRA‐EUROPE is partly based on the existing models CAPRI and GAINS, supplemented with a N leaching module and a module with sets of measures. Calculations for the year 2000 show that denitrification is the largest N loss pathway in European agriculture (on average 44 kg N ha−1 agricultural land), followed by NH3 volatilization (17 kg N ha−1), N leaching (16 kg N ha−1) and emissions of N2O (2 kg N ha−1) and NOX (2 kg N ha−1). However, losses between regions in the EU‐27 vary strongly. Some of the measures implemented to abate NH3 emission may increase N2O emissions and N leaching. Balanced N fertilization has the potential of creating synergistic effects by simultaneously decreasing N leaching and NH3 and N2O emissions. MITERRA‐EUROPE is the first model that quantitatively assesses the possible synergistic and antagonistic effects of N emission abatement measures in a uniform way in EU‐27.
Effects of Burn Temperature on Ash Nutrient Forms and Availability from Cattail (Typha domingensis) and Sawgrass (Cladium jamaicense) in the Florida Everglades
Authors: Qian Y. , Miao S. L. , Gu B. , Li Y. C.
Published: February 2009

Plant ash derived from fire plays an important role in nutrient balance and cycling in ecosystems. Factors that determine the composition and availability of ash nutrients include fire intensity (burn temperature and duration), plant species, habitat nutrient enrichment, and leaf type (live or dead leaf). We used laboratory simulation methods to evaluate temperature effects on nutrient composition and metals in the residual ash of sawgrass (Cladium jamaicense) and cattail (Typha domingensis), particularly on post‐fire phosphorus (P) availability in plant ash. Live and dead leaf samples were collected from Water Conservation Area 2A in the northern Everglades along a soil P gradient, where prescribed fire may be used to accelerate recovery of this unique ecosystem. Significant decreases in total carbon and total nitrogen were detected with increasing fire temperature. Organic matter combustion was nearly complete at temperatures ≥450°C. HCl‐extractable P (average, 50% of total P in the ash) and NH4Cl‐extractable P (average, 33% of total P in the ash) were the predominant P fractions for laboratory‐burned ash. Although a low‐intensity fire could induce an elevation of P availability, an intense fire generally resulted in decreased water‐soluble P. Significant differences in nutrient compositions were observed between species, habitat nutrient status, and leaf types. More labile inorganic P remained in sawgrass ash than in cattail ash; hence, sawgrass ash has a greater potential to release available P than cattail. Fire intensity affected plant ash nutrient composition, particularly P availability, and the effects varied with plant species and leaf type. Therefore, it is important to consider fire intensity and vegetation community when using a prescribed fire for ecosystem management.
Fertilization and Blending Alternatives for Irrigation with Desalinated Water
Authors: Ben‐Gal Alon , Yermiyahu Uri , Cohen Shabtai
Published: February 2009

In arid‐zone agriculture where available irrigation water is saline, desalination is becoming an attractive method for increasing yields and reducing negative environmental consequences. However, irrigation with desalinated water can be problematic if essential nutrients, including Ca, Mg, and S, removed during reverse osmosis, are not reintroduced. We evaluated two strategies for supplying these nutrients — direct fertilization and blending of desalinated with saline groundwater —experimentally in a greenhouse and in a model for a case study regarding pepper (Capsicum annuumL.) production. Reducing salinity from electrical conductivity (EC) 3.20 to EC 0.40 dS m−1by reverse‐osmosis desalination increased maximum yields by almost 50% while allowing a reduction of applied irrigation water to half of that with the saline water, but the associated cost of fertilizing with Ca, Mg, and S minerals was high (around .50 m−3). Blending 30% saline water with 70% desalinated water brought Ca, Mg, and S minerals to satisfactory levels while producing water with salinity of EC = 1.35 dS m−1Comparison of relative pepper yields and analysis of simulated results showed that irrigation with blended water maintained yields greater than 90% compared to irrigation with fully desalinated water, but only as irrigation rates were increased by more than 50%. The environmental cost of the increase in irrigation‐water salinity from EC 0.40 to EC 1.35 dS m−1in the blended water was shown to be substantial as it involved five times greater loading (into the soil) and leaching (beyond the root zone) of salts and other contaminants.
Greenhouse Gas Emissions and Global Warming Potential of Reclaimed Forest and Grassland Soils
Authors: Shrestha Raj K. , Lal Rattan , Penrose Chris
Published: February 2009

Although greenhouse gas (GHG) emissions from soils are important, reclaimed mine soil (RMS) ecosystems are not widely assessed. Postreclamation land uses (forest, hay, and pasture) were investigated to: (i) monitor the magnitude of GHG fluxes, (ii) estimate their global warming potential (GWP), (iii) identify the relationship between GHG fluxes and soil properties, and (iv) develop a soil quality index by principal component analysis (PCA). The GHG fluxes were measured for 1 yr cycle and simultaneous measurements were also made for soil moisture and temperature. The RMS‐forest, ‐hay, and ‐pasture land uses had weighted average fluxes of 1.16, 1.66, and 3.06 g CO2–C m−2 d−1; 0.33, 0.48 and 1.1 mg CH4–C m−2 d−1; and 0.33, 0.70, and 1.06 mg N2O‐N m−2 d−1, respectively. The CO2, CH4, and N2O fluxes were consistently high in the RMS‐pasture and low in the RMS‐forest. The GWP (CO2–C equivalent) of the postreclamation land uses was in the order of RMS‐forest (4.5 Mg ha−1 yr−1) = RMS‐hay (6.8 Mg ha−1 yr−1) < RMS‐pasture (12.3 Mg ha−1 yr−1). The PCA showed that four PCs with eigenvalues > 1 explained 88.8% of the total variance in the soil properties. The first PC is mostly characterized by soil physical properties and the second by chemical properties. Soil and air temperatures were positively correlated with CO2, CH4, and N2O fluxes. The results suggest that GWP from RMS can be minimized by establishing forest land use.
Characterization of Condensed Organic Matter in Soils and Sediments
Authors: Ran Yong , Sun Ke , Xing Baoshan , Shen Chengde
Published: February 2009

Condensed organic matter (OM) such as nonhydrolyzable C (NHC) is important in C cycling and the sorption and fate of hydrophobic organic contaminants in soils and sediments, but its structural components are rarely known. Nonhydrolyzable C in three contaminated soils and 22 bulk and size‐fractionated sediments from the Pearl River delta and estuary in China were measured following treatment with an HCl–HF–trifluoroacetic acid method. It was characterized using elemental analysis, radiocarbon accelerated mass spectroscopy, and Raman microspectrometry. The results show that NHC is an important or even dominating component of the organic C (OC) in the investigated soils and sediments. The NHC contents in this study are highly correlated with the OC contents, with a slope of 0.647 for the 25 soil and sediment samples, which is higher than previously reported NHC–OC correlations in the soils. The radiocarbon analysis demonstrates the importance of ancient OM in the NHC samples. The NHC fractions are chemically and structurally different from the biopolymer and humic substances in the soils and sediments, and originated from different thermally matured bitumen or kerogens, polymethylene C (algaenan, cutan, cutin, cuticle, and lipid), aged terrigenous OM (lignin and humin), and black carbon.
Illinois Soil Nitrogen Test for Prediction of Fertilizer Nitrogen Needs of Corn in Virginia
Authors: Spargo John T. , Alley Marcus M. , Thomason Wade E. , Nagle Steven M.
Published: February 2009

Current N needs for corn (Zea mays L.) in Virginia are estimated based on expected yield and are adjusted to account for the estimated amounts of N mineralized from organic sources such as manures, biosolids, and legumes. The dynamic nature of soil N creates significant uncertainty in estimates of N availability from these sources. Accurate quantification of organic N mineralization during the corn growing season should improve the precision of fertilizer N recommendations. The Illinois soil N test (ISNT) has shown promise as a tool for estimating mineralizable soil N and predicting corn fertilizer N needs. Other research has found the ISNT to be poorly related to labile soil N and unrelated to corn response to fertilizer N. The objective of this study was to determine if the ISNT predicts the fertilizer N response of corn grown in a diverse set of Virginia agroecosystems. We conducted 29 on‐farm fertilizer N response trials in major corn‐producing regions of Virginia. The ISNT was significantly related to estimated yield without fertilizer N (R2 = 0.57, P < 0.0001) and relative yield (R2 = 0.64, P < 0.0001). We also found that the ISNT extracted a consistent percentage of total soil N (16.3 ± 0.7%), suggesting that it is a poor indicator of labile N. In fact, total soil N did as well as the ISNT at predicting yield without fertilizer N (R2 = 0.53, P = 0.0002) and relative yield (R2 = 0.64, P < 0.0001). The ISNT offered no more information about corn yield response to fertilizer N than did total soil N content.
Soil Organic Matter Effects on Phosphorus Sorption: A Path Analysis
Authors: Kang Jihoon , Hesterberg Dean , Osmond Deanna L.
Published: February 2009

While P sorption in mineral soils has been extensively studied, P sorption behavior in organic‐rich soils is less known. This study was conducted to determine the relationships between Langmuir P sorption maxima (Smax) and selected physicochemical properties of soils, with particular emphasis on organic matter (OM) content. TheSmaxvalues were determined for 72 soil samples from the North Carolina Coastal Plain, along with pH, clay and OM contents, oxalate‐extractable P (Pox), Al (Alox), and Fe (Feox), and Mehlich 3 extractable P (PM3), Al (AlM3), and Fe (FeM3). Path analysis was used to examine direct and indirect effects of soil properties onSmaxIn the oxalate path analysis, the direct effects of clay, Alox, and FeoxonSmaxwere significant in the order Alox> clay > Feox(P< 0.05). TheSmaxwas highly influenced by the indirect effect of Aloxand Feoxthrough OM content. A two‐piece segmented linear relationship existed betweenSmaxand OM and the regression slope in soils with OM ≤ 49 g kg−1was 10‐fold greater than that for soils with OM > 49 g kg−1This finding suggested that noncrystalline or organically bound Al and Fe in the soils with OM > 49 g kg−1is less effective for P sorption than in the soils with lower OM content. In the Mehlich 3 path analysis, the direct effects of clay, OM, and AlM3onSmaxwere significant in the order AlM3> OM > clay (P< 0.05) while the direct effect of FeM3onSmaxwas not significant. Oxalate may be better suited than Mehlich 3 as an extractant for predicting P sorption capacity in the Coastal Plain soils.
Cotton Response to Poultry Litter Applied by Subsurface Banding Relative to Surface Broadcasting
Authors: Tewolde Haile , Armstrong Shalamar , Way Thomas R. , Rowe Dennis E. , Sistani Karamat R.
Published: February 2009

Dry poultry litter is typically land applied by surface broadcasting, a practice that exposes certain litter nutrients to volatilization loss. Applying litter with a new, experimental implement that places the litter in narrow bands below the soil surface may reduce or eliminate such losses but has not been tested experimentally. The objective of this research was to quantify cotton (Gossypium hirsutum L.) lint yield and fiber quality improvements when fertilized with broiler litter applied in narrow subsurface bands at planting or after crop establishment compared with the traditional surface broadcast and standard inorganic fertilization. Applying litter at 6.7 Mg ha−1 increased lint yield from 984 kg ha−1 when applied by surface broadcast to an average of 1052 kg ha−1 when applied by subsurface band at planting or 1 mo later. Applying the same litter rate by subsurface banding 1 mo after planting had the added benefit of improving fiber properties, fiber length in particular. Chlorophyll index measurements showed that plants received greater N nutrition, suggesting that litter‐derived N was conserved when the litter was applied by subsurface banding relative to surface broadcast. These results demonstrate that applying dry poultry litter in narrow subsurface bands with this implement conserves litter‐derived N and may lead to a reduction in the litter application rate relative to the conventional surface broadcast method, with an added benefit of improved fiber quality when the litter is applied after crop establishment.
Evaluation of Polymer‐Coated Urea for Direct‐Seeded, Delayed‐Flood Rice Production
Authors: Golden B.R. , Slaton N.A. , Norman R.J. , Wilson C.E. , DeLong R.E.
Published: February 2009

Rice (Oryza sativa L.) cultivated with the direct‐seeded, delayed‐flood production system relies heavily on post‐emergence aerial application of N. The availability of a controlled‐release N fertilizer suitable for preplant application would offer rice growers an alternative N‐fertilization method and reduce the aerial application costs of N fertilization. Our objectives were to determine grain yield and N uptake of rice receiving preplant incorporated polymer‐coated urea (PCU) compared with urea applied preflood at the five‐leaf stage and characterize the N release of two PCUs. Field trials were conducted at five site‐years to evaluate rice performance when fertilized with preplant‐applied Environmentally Smart Nitrogen (ESN) and Duration Type 5 (D5) and preflood‐applied urea across N rates ranging from 0 to 168 kg N ha−1 Nitrogen release from PCU was evaluated in field incubations using a buried‐bag method at two site‐years. Nitrogen release was nonlinear across time and similar between site‐years but different between PCUs. The nonlinear relationships predicted that 75% of PCU N content was released by 36 d for D5 and 25 d for ESN. Nitrogen recovery at panicle differentiation averaged 30% for D5, 26% for ESN, and 72% for urea and at heading averaged 47% for D5, 37% for ESN, and 101% for urea. As the N rate increased, yields increased nonlinearly for rice receiving D5 preplant and urea preflood and linearly for rice receiving ESN preplant. Yield predictions for D5 were always lower than for urea at the same N rates. Results suggest that the N release from D5 and ESN is too rapid for rice cultivated in the direct‐seeded, delayed‐flood method.
Abundant but Neglected: Awards as Incentives
Authors: Frey Bruno S. , Neckermann Susanne
Published: February 2009

Economists traditionally focus on monetary compensation when examining incentives, but awards are of immense practical relevance as can be inferred from their prevalence in the form of state orders, decorations and prizes, according to Bruno Frey and Susanne Neckermann.
Assessing Glycemic Control in Maintenance Hemodialysis Patients With Type 2 Diabetes
Authors: Kazempour-Ardebili Sara , Lecamwasam Varunika L. , Dassanyake Thushara , Frankel Andrew H. , Tam Frederick W.K. , Dornhorst Anne , Frost Gary , Turner Jeremy J.O.
Published: February 2009

OBJECTIVE

Optimizing glycemic control in diabetic patients undergoing maintenance hemodialysis requires accurate assessment. We hypothesize that 1) 48-h continuous glucose monitoring (CGM) provides additional, clinically relevant, information to that provided by the A1C measurement and 2) glycemic profiles differ significantly between day on and day off dialysis.

RESEARCH DESIGN AND METHODS

With the use of GlucoDay S, 48-h CGM was performed in 19 type 2 diabetic subjects undergoing hemodialysis to capture consecutive 24-h periods on and off dialysis. Energy intake was calculated using food diaries. A1C was assayed by a high-performance liquid chromatography method.

RESULTS

CGM data were available for 17 subjects (13 male) with a mean (range) age of 61.5 years (42–79 years) and diabetes duration of 18.8 years (4–30 years). The 24-h CGM area under the glucose curve and 24-h mean glucose values were significantly higher during the day off dialysis than on dialysis (5,932.1 ± 2,673.6 vs. 4,694 ± 1,988.0 mmol · 3 min−1 · l−1, P = 0.022, and 12.6 ± 5.6 vs. 9.8 ± 3.8 mmol/l, P = 0.013, respectively), independent of energy intake. Asymptomatic hypoglycemia occurred in 4 subjects, 3 within 24 h of dialysis, and the glucose nadir in 14 subjects occurred within 24 h of dialysis.

CONCLUSIONS

Glucose values are significantly lower on dialysis days than on nondialysis days despite similar energy intake. The risk of asymptomatic hypoglycemia was highest within 24 h of dialysis. Physicians caring for patients undergoing hemodialysis need to be aware of this phenomenon and consider enhanced glycemic monitoring after a hemodialysis session. CGM provides glycemic information in addition to A1C, which is potentially relevant to clinical management.
Mortality Risk of Charcot Arthropathy Compared With That of Diabetic Foot Ulcer and Diabetes Alone
Authors: Sohn Min-Woong , Lee Todd A. , Stuck Rodney M. , Frykberg Robert G. , Budiman-Mak Elly
Published: February 2009

OBJECTIVE

The purpose of this study was to compare mortality risks of patients with Charcot arthropathy with those of patients with diabetic foot ulcer and those of patients with diabetes alone (no ulcer or Charcot arthropathy).

RESEARCH DESIGN AND METHODS

A retrospective cohort of 1,050 patients with incident Charcot arthropathy in 2003 in a large health care system was compared with patients with foot ulcer and those with diabetes alone. Mortality was determined during a 5-year follow-up period. Patients with Charcot arthropathy were matched to individuals in the other two groups using propensity score matching based on patient age, sex, race, marital status, diabetes duration, and diabetes control.

RESULTS

During follow-up, 28.0% of the sample died; 18.8% with diabetes alone and 37.0% with foot ulcer died compared with 28.3% with Charcot arthropathy. Multivariable Cox regression shows that, compared with Charcot arthropathy, foot ulcer was associated with 35% higher mortality risk (hazard ratio 1.35 [95% CI 1.18–1.54]) and diabetes alone with 23% lower risk (0.77 [0.66–0.90]). Of the patients with Charcot arthropathy, 63% experienced foot ulceration before or after the onset of the Charcot arthropathy. Stratified analyses suggest that Charcot arthropathy is associated with a significantly increased mortality risk independent of foot ulcer and other comorbidities.

CONCLUSIONS

Charcot arthropathy was significantly associated with higher mortality risk than diabetes alone and with lower risk than foot ulcer. Patients with foot ulcers tended to have a higher prevalence of peripheral vascular disease and macrovascular diseases than patients with Charcot arthropathy. This finding may explain the difference in mortality risks between the two groups.
Obesity and Albuminuria Among Adults With Type 2 Diabetes
Authors: Kramer Holly , Reboussin David , Bertoni Alain G. , Marcovina Santica , Lipkin Edward , Greenway Frank L. , Brancati Frederick L. ,   the Look Ahead Research Group
Published: February 2009

OBJECTIVE

To determine the association between obesity measures and albuminuria in adults with type 2 diabetes.

RESEARCH DESIGN AND METHODS

In the Look AHEAD (Action for Health in Diabetes) Study, BMI and waist circumference were measured among 4,985 participants while total percent body fat was measured by whole-body DEXA scans among 1,351 participants. Odds of albuminuria by quartiles of BMI, waist circumference, and percent total body fat were calculated using logistic regression analysis while adjusting for covariates.

RESULTS

The highest quartile of BMI (odds ratio [OR] 1.72 [95% CI 1.40–2.11]) and waist circumference (OR 1.75 [95% CI 1.42–2.15]) was significantly associated with albuminuria compared with the lowest quartile after adjustment for covariates. No associations were noted between quartiles of percent total body fat and albuminuria in any model.

CONCLUSIONS

Increased BMI and abdominal obesity are associated with albuminuria in overweight and obese adults with type 2 diabetes.
Investigation of the effect of fluid elasticity on a cake filtration process
Authors: Surý Alexander , Machač Ivan
Published: February 2009

The paper is concerned with the constant pressure cake filtration of suspensions in viscoelastic fluids. The filtration equations, based on the capillary hybrid model for power law fluid flow, were used for the description of this type of filtration. Filtration experiments with suspensions of nearly spherical polystyrene particles Krasten in viscoelastic aqueous solutions of polyacrylamide Praestol were carried out at constant pressure in a laboratory cylindrical filtration unit. The fluid rheological properties were measured on a rotational rheometer Haake RheoStress 150. Elastic effects manifested themselves predominantly at the early period of the filtration due to higher filtration velocity which resulted in an evidently increased filtration resistance. Analysing the experimental data, procedures for the evaluation of the effective specific filter cake resistance γ ef, filter screen resistance R fs, and the elongation flow coefficient E have been proposed. The filtration process predicted using the proposed filtration equation agrees very well with that determined experimentally.