bluuebunny/crossref_metadata_2025_split huggingface dataset:
Precision equipment for symmetrical bending— Part 1. The loading system
Authors: Bereqvist B. 
Published: January 2009

The design and performance of precision bending equipment for testing straight beams with constant rectangular section under a pure bending moment is described. Part 1 deals with the loading arrangements and Part 2 with the rig for measuring beam deflection. The methods for recording deflection of strain gauges applied on the beam have been described elsewhere.1–4The reactions to the deadweight gravity loads are taken via ball bearings. The total bending moment inaccuracy, i.e. the sum of estimated systematic errors and random errors, the latter expressed as the 2Ga confidence interval about the mean (2Gcim), is about ± 25 x. 10‐4%, for 23 tests with a steel beam with 15 mm × 75 mm cross sectional dimensions, loaded to 1‐1.5 mm/m strain.The measuring rig stands on the beam via hardened and polished spherical segment feet and uses a capacitive transducer system with less than 5nm resolution. Various application tasks are described. The total inaccuracy of the measured deflection, i.e. apart from bending moment inaccuracy, is about ± 35 times 104% for about 10 reproduced, not repeated, tests with the same steel beam. The deflection for such a beam is of the order of 2 to 4 mm.
Velocity and force measurements in the splash zone
Authors: Easson W. J. 
Published: January 2009

A method for measuring fluid velocity in waves in the splash zone is demonstrated. The method uses Laser Anemometry coupled to accurate microcomputer control of the wave generation. Results are presented for the developing flow field in a plunging breaking wave in deep water.The phenomenon of slam when waves hit members of offshore structures causes large forces with small rise times. The design of a rig capable of measuring such forces in laboratory produced breaking waves is presented. Measurements on a small cylinder show that maximum forces are present at the height where the plunging spout forms and that these forces can be up to five times the drag force.
Regenerating Topsoil Functionality in Four Drastically Disturbed Soil Types by Compost Incorporation
Authors: Curtis Matthew J. , Claassen Victor P. 
Published: January 2009

Abstract The low water‐holding capacity and low nutrient levels of roadcuts in northern California cause many of these disturbed areas to remain chronically barren. Yard waste compost was incorporated into four nonvegetated substrates found along roadcuts (decomposed granite [DG], lahar, serpentine, and sandstone) in order to regenerate topsoil infiltration, water‐holding capacity, and nutrient availability. Soil physical and chemical properties, as well as the vegetative response of a native perennial grass, were compared between treatments (non‐tilled, tilled, and tilled with compost amendment). Tillage and compost addition decreased soil bulk density compared to the non‐tilled treatment, and the compost treatment increased the soil carbon and nitrogen contents compared to the non‐tilled and tilled treatments. Tillage alone resulted in an increase in saturated hydraulic conductivity in soils that did not contain a large amount of coarse fragments. Tillage also reduced sediment loss in all soils except the DG. Foliar C13 content did not predict water stress consistently between treatments. The incorporation of yard waste compost increased plant available water in coarse but not in fine‐textured soils, and aboveground plant biomass was significantly greater in the compost treatment than in either of the other treatments. Although the incorporation of yard waste compost generated the greatest revegetation success, tillage alone may be a sufficient treatment if residual soils have adequate nutrient levels.
Ecophysiology of Species with Distinct Leaf Morphologies: Effects of Plastic and Shadecloth Tree Guards
Authors: Close Dugald C. , Ruthrof Katinka X. , Turner Shane , Rokich Deanna P. , Dixon Kingsley W. 
Published: January 2009

Abstract Ecological restoration using seedling tubestock is challenging under a Mediterranean‐type climate of hot, dry summers. We investigated the ecophysiological effects of plastic tree guards and shadecloth tree guards during seedling establishment of four co‐occurring tree species that differ in leaf morphology. Average temperature was 6.7°C higher in plastic guards than controls over a summer, with a maximum of 53.5°C compared to 47.9°C in controls. Light levels were 2‐fold lower in both tree guard treatments relative to control. In spring, photosynthesis and specific leaf area were significantly elevated in shadecloth tree guards relative to other treatments. In summer, photosynthetic rate was significantly lower, and midday photochemical efficiency was significantly higher, in both tree guard treatments relative to controls. The effect of elevated temperature in plastic tree guards may partially explain our results of higher mortality of seedling in plastic tree guards. The relatively elevated spring photosynthesis of seedlings in shadecloth tree guards may partially explain the result of reduced mortality and increased growth in this treatment. We conclude that shadecloth tree guards create a microclimate more favorable for seedling establishment in a Mediterranean‐type environment than plastic tree guards and control treatments. Our results may have wide applicability to the range of restoration settings where seedling tubestock is planted, except in environments where low temperature is limiting to plant growth.
Generating Quantitative Regional Plant Community Descriptions for Restoration
Authors: Lane Cynthia P. , Texler Hannah D. 
Published: January 2009

Abstract Information from reference sites is often used as an aid for planning and assessing native plant community restorations. However, restorations often proceed with inadequate reference information because there are insufficient resources to locate suitable sites and/or collect the data. As one means of providing reference information, we developed methods for using a large existing dataset to develop quantitative reference community descriptions for three ecological subsections in east‐central Minnesota. We used data gathered from remnant plant communities within the same region as potential restoration sites. Our data source was 325 vegetation plots (or “relevés”) and the results of recent cluster analysis work that grouped relevés into native plant communities for the region. The remnant natural areas sampled were distributed throughout the study area and varied in patch size. For each community type, we calculated the average frequency and abundance for each species. We also calculated an index of commonness as a product of frequency and abundance. Using this methodology, we generated lists for 31 native plant communities. We discuss the use of these lists to set restoration goals, guide restoration strategies, and/or assess restoration efforts and present some of the strengths and weaknesses of our approach.
Canopy Composition and Forest Structure Provide Restoration Targets for Low‐Order Riparian Ecosystems
Authors: Rheinhardt Richard D. , McKenney‐Easterling M. , Brinson Mark M. , Masina‐Rubbo Jennifer , Brooks Robert P. , Whigham Dennis F. , O’Brien David , Hite Jeremy T. , Armstrong Brian K. 
Published: January 2009

AbstractMany programs are in place to protect and restore low‐order streams and riparian zones. However, information on riparian zone forests is sparse for many biogeographical regions, especially compositional and structural data that would provide useful targets for restoration. This study provides quantitative data on riparian zone composition and forest structure from three physiographic provinces of eastern United States. Data from 219 low‐order (first‐ to fourth‐order) forested reaches were arranged by three basal area (BA) categories meant to represent successional categories and variations in forest structure. Detrended correspondence analysis (DCA) was used to illustrate differences among successional categories and physiographic provinces. The DCA ordination separated stands into four physiographic subregions, based on the species composition of late‐successional stands. Many early to mid‐successional stands (<30 m2/ha) were similar in composition to late‐successional reference stands (BA ≥ 30 m2/ha) in the same physiographic subregion. In such sites, natural successional processes would likely be sufficient to restore the compositional and structural attributes inherent in late‐successional stands if provided long‐term protection. Other sites with dissimilar compositions may have been recovering from more intensive types of alterations, such as mechanized land clearing. In such sites, restoration to historic compositions could benefit functionally by planting oaks (Quercusspp. L.) and other heavy mast species.
Diversity of Regenerating Plants in Reforestations withAraucaria angustifolia(Bertol.) O. Kuntze of 12, 22, 35, and 43 Years of Age in Paraná State, Brazil
Authors: Barbosa Carlos Eduardo de A. , Benato Taís , Cavalheiro Alba L. , Torezan José Marcelo D. 
Published: January 2009

AbstractIn the current context of intense forest fragmentation and consequent loss of biodiversity, commercial reforestations have gained special attention in conservation biology because the colonization of the understory in these wooded areas may result in a considerable number of species. A record was made of the regenerating species in the understory of reforestations withAraucaria angustifoliaat planting ages of 12, 22, 35, and 43 years, located in the central east region of Paraná State, Brazil. In total, an area of 1,200 m2was sampled, with 231 recorded species belonging to 60 botanical families. Species diversity and richness increased with planting age up to 35 years. Canopy cover was the variable that best explained the colonization of the understory in some stages. Maintenance activities in the reforestations over the years selected species capable of germinating or sprouting and growing rapidly. However, our results show thatA. angustifoliacommercial reforestations are home to many native plant species. Thus, the objectives of commercial reforestation can be harmonized with the interests of conservation biology, applying management alternatives with the aim of changing current forestry models.
Rehabilitation of Stream Ecosystem Functions through the Reintroduction of Coarse Particulate Organic Matter
Authors: Aldridge Kane T. , Brookes Justin D. , Ganf George G. 
Published: January 2009

Abstract In streams, coarse particulate organic matter (CPOM) acts as a substrate for microbial activity, which promotes nutrient retention. However, in urban areas, increased peak flows within streams lead to decreased retention of CPOM. The aim of this study was to investigate whether the reintroduction of CPOM, in the form of leaf litter, into a degraded urban stream would increase biofilm activity and phosphorus retention, two ecosystem functions that reflect the integrity of the ecosystem. Stream metabolism and nutrient retention were assessed in treated (T) and control (C) channels of the Torrens River Catchment, South Australia, before and after CPOM addition. Gross primary production and community respiration (CR) were measured as oxygen production and consumption within benthic chambers. Phosphorus retention was measured through a series of short‐term filterable reactive phosphorus (FRP) addition experiments. Before CPOM addition, there were no differences in CR, but C retained 6.8% more FRP than T. After CPOM addition, CR was greater in T than in C (572 and 276 mg O2·m−2·day−1, respectively), and T retained 7.7% more FRP than C. The increase in FRP retention in T compared to C was attributed to phosphorus limitation of the CPOM and increased demand for phosphorus of the attached microbial heterotrophic community. The reintroduction of CPOM into degraded streams will be an important step in the restoration of stream metabolism and nutrient retention. Maintenance of CPOM may be achieved through restoration of riparian vegetation, a reduction in the increased peak flows, and rehabilitation of stream morphology.
Role of Soil Organisms in the Maintenance of Species‐Rich Seminatural Grasslands through Mowing
Authors: Ilmarinen Katja , Mikola Juha , Nissinen Kari , Vestberg Mauritz 
Published: January 2009

Abstract To preserve species‐rich grasslands, management practices such as mowing are often required. Mowing is known to promote aboveground conditions that help to maintain plant species richness, but whether belowground effects are important as well is not known. We hypothesized that if mowing decreases belowground carbon transfer by reducing root mass, this will reduce the abundance and activity of soil decomposers and lead to diminished nutrient availability in soil. In grasslands, this would provide a means to mitigate the negative effects of nitrogen enrichment on plant species richness. We established experimental plots on grassland with one‐third of plots growing untouched, one‐third mowed once a summer, and one‐third mowed twice a summer for three growing seasons. Root and soil attributes were measured at each plot 1 month after each mowing. Mowing decreased root mass but had few effects on belowground biota and soil NH4‐N, NO3‐N, and PO4‐P concentrations. Mowing did not affect root N concentrations. Our results show that despite reducing root mass, mowing may have few effects on those soil biota that control nutrient supply and, as a result, have no clear‐cut effects on nutrient availability in soil. This suggests that the effects of mowing on soil decomposers and soil nutrient availability may not provide an effective means to mitigate N enrichment and enhance plant species richness in grasslands in a timescale of a few years. Whether such effects could, however, be achieved with longer lasting mowing remains open.
Grasshopper Herbivory Affects Native Plant Diversity and Abundance in a Grassland Dominated by the Exotic Grass Agropyron cristatum
Authors: Branson David H. , Sword Gregory A. 
Published: January 2009

Abstract The indirect effects of native generalist insect herbivores on interactions between exotic and native grassland plants have received limited attention. Crested wheatgrass (Agropyron cristatum) is the most common exotic rangeland grass in western North America. Crested wheatgrass communities are resistant to colonization by native plant species and have strong competitive effects on native species, imposing problems for the restoration of native grasslands. Grasshoppers are generalist herbivores that are often abundant in Crested wheatgrass–dominated sites in the northern Great Plains. We conducted two experiments in a Crested wheatgrass–dominated grassland in western North Dakota to test the hypothesis that grasshopper herbivory influences local Crested wheatgrass community composition by impeding native seedlings. Grasshopper herbivory negatively affected the species richness, abundance, and Shannon diversity of native plants in 3 of 4 years. Although additional research is needed to determine if grasshoppers actively select native plants, the effects of grasshopper herbivory may be an important consideration in the restoration of Crested wheatgrass areas. Our findings illustrate the importance of understanding the impact of native generalist invertebrate herbivores on the relationships between exotic and native plants.
Hyperhomocysteinemia in patients with epilepsy: Does it play a role in the pathogenesis of brain atrophy? A preliminary report
Authors: Gorgone Gaetano , Caccamo Daniela , Pisani Laura Rosa , Currò Monica , Parisi Giulia , Oteri Giancarla , Ientile Riccardo , Rossini Paolo Maria , Pisani Francesco 
Published: January 2009

SummaryPurpose:  Brain atrophy (BA) is observed in 20–50% of patients with epilepsy. Hyper‐total‐homocysteinemia (hyper‐tHcy), which occurs in 10–40% of patients, is considered to be a risk factor for cardiovascular diseases and BA. The present study was aimed at investigating the possible association of hyper‐tHcy with BA in a population of patients with epilepsy.Methods:  Fifty‐eight patients (33 M/25 F, 43.5 ± 13.1 years of age) chronically treated with antiepileptic drugs (AEDs) and 60 controls matched for age and sex were enrolled. All participants underwent determination of plasma tHcy, folate, vitamin B12, and C677T methylene‐tetrahydrofolate‐reductase (MTHFR) polymorphism genotyping, and brain magnetic resonance imaging (MRI).Results:  Patients exhibited significantly higher tHcy and lower folate levels than controls; hyper‐tHcy was significantly associated with the variables group (patients vs. controls), MTHFR genotype, and their interaction terms. BA was observed in 30.1% of patients and was significantly associated with hyper‐tHcy (β = 0.45, p = 0.003) and polytherapy (β = 0.31, p < 0.001).Discussion:  Our investigation suggests that hyper‐tHcy plays a role in the development of BA in patients with epilepsy. Although the real origin of this phenomenon is not yet fully elucidated, experimental data support the hypothesis of a link of the neuronal Hcy‐mediated damage with oxidative stress and excitotoxicity.
Diffusion‐weighted magnetic resonance imaging in patients with partial status epilepticus
Authors: Di Bonaventura Carlo , Bonini Francesca , Fattouch Jinane , Mari Francesco , Petrucci Simona , Carnì Marco , Tinelli Emanuele , Pantano Patrizia , Bastianello Stefano , Maraviglia Bruno , Manfredi Mario , Prencipe Massimiliano , Giallonardo Anna T. 
Published: January 2009

SummaryPurpose:  Diffusion‐weighted magnetic resonance imaging (DWI) is used to detect changes in the distribution of water molecules in regions affected by various pathologies. Like other conditions, ictal epileptic activity, such as status epilepticus (SE), can cause regional vasogenic/cytotoxic edema that reflects hemodynamic and metabolic changes. This study describes the electroclinical and neuroimaging findings in 10 patients with partial SE whose DWI evaluation disclosed periictal changes related to sustained epileptic activity.Patients and Methods:  In this retrospective study we selected 10 patients with partial SE of different etiologies (six acute symptomatic SE; four with previous epilepsy and concomitant precipitating factors) who underwent video‐EEG (electroencephalography) monitoring and a DWI study during the periictal phase. We analyzed ictal electroclinical features and DWI changes in the acute phase and during the follow‐up period.Results:  DWI images revealed significant signal alterations in different brain regions depending on the location of ictal activity. DWI changes were highly concordant with the electroclinical findings in all 10 patients. As the SE resolved and the clinical conditions improved, DWI follow‐up showed that the signal alterations gradually disappeared, thereby documenting their close relationship with ictal activity.Conclusions:  This study confirms the usefulness of DWI imaging in clinical practice for a more accurate definition of the hemodynamic/metabolic changes occurring during sustained epileptic activity.
Anemia screening in potential female blood donors: comparison of two different quantitative methods
Authors: Mendrone Jr Alfredo , Sabino Ester Cerdeira , Sampaio Luciana , Neto César Almeida , Schreiber George B. , De Alencar Fischer Chamone Dalton , Dorlhiac‐Llacer Pedro Enrique 
Published: January 2009

BACKGROUND: Anemia screening before blood donation requires an accurate, quick, practical, and easy method with minimal discomfort for the donors. The aim of this study was to compare the accuracy of two quantitative methods of anemia screening: the HemoCue 201+ (Aktiebolaget Leo Diagnostics) hemoglobin (Hb) and microhematocrit (micro‐Hct) tests.STUDY DESIGN AND METHODS: Two blood samples of a single fingerstick were obtained from 969 unselected potential female donors to determine the Hb by HemoCue 201+ and micro‐Hct using HemataSTAT II (Separation Technology, Inc.), in alternating order. From each participant, a venous blood sample was drawn and run in an automatic hematology analyzer (ABX Pentra 60, ABX Diagnostics). Considering results of ABX Pentra 60 as true values, the sensitivity and specificity of HemoCue 201+ and micro‐Hct as screening methods were compared, using a venous Hb level of 12.0 g per dL as cutoff for anemia.RESULTS: The sensitivities of the HemoCue 201+ and HemataSTAT II in detecting anemia were 56 percent (95% confidence interval [CI], 46.1%‐65.5%) and 39.5 percent (95% CI, 30.2%‐49.3%), respectively (p < 0.001). Analyzing only candidates with a venous Hb level lower than 11.0 g per dL, the deferral rate was 100 percent by HemoCue 201+ and 77 percent by HemataSTAT II. The specificities of the methods were 93.5 and 93.2 percent, respectively.CONCLUSION: The HemoCue 201+ showed greater discriminating power for detecting anemia in prospective blood donors than the micro‐Hct method. Both presented equivalent deferral error rates of nonanemic potential donors. Compared to the micro‐Hct, HemoCue 201+ reduces the risk of anemic female donors giving blood, specially for those with lower Hb levels, without increasing the deferral of nonanemic potential donors.
Evidence of acute primary occult hepatitis B virus infection in an Italian repeat blood donor
Authors: Manzini Paola , Abate Maria Lorena , Valpreda Chiara , Milanesi Paola , Curti Franco , Rizzetto Mario , Smedile Antonina 
Published: January 2009

BACKGROUND: Preliminary evidence of cases of acute occult hepatitis B virus (HBV) infection (OBI) has been recently reported in the literature. Furthermore, OBI definition has been the object of an international consensus conference.STUDY DESIGN AND METHODS: A case of acute primary OBI was identified and followed up in a repeat female blood donor using a highly sensitive nucleic acid test (NAT; Procleix Ultrio on Tigris, Chiron). Genotyping and sequencing of virus isolates from donor and contact cases were performed.RESULTS: The blood donor never developed detectable hepatitis B surface antigen (HBsAg) until seroconversion to antibody to hepatitis B surface antigen/antibody to hepatitis B core antigen. A very low viral load was observed during the infection course (<50 IU/mL). Donor HBV DNA sequencing consistently showed a CCA deletion leading to amino acid T116 deletion in the small envelope protein (S). Other sequence features showed high homology between donor and contact case, suggesting a sexual transmission.DISCUSSION: The main explanation for HBsAg undetectability relies on the very low level of viremia observed. The single‐amino‐acid deletion found in the S protein cannot account for HBsAg detection failure, because the capture antibody of the assay used is targeted to a different sequence epitope (aa121‐124). Meanwhile, CCA deletion may have impacted the virus replication efficiency since it affects the overlapping reverse transcriptase “finger” domain of the polymerase gene. These findings define this case as an acute primary OBI, confirming the existence of this condition. NAT with high sensitivity is the only screening enabling prevention of HBV transmission by transfusion in such cases.