bluuebunny/crossref_metadata_2025_split huggingface dataset:
Baseline articular contact stress levels predict incident symptomatic knee osteoarthritis development in the MOST cohort
Authors: Segal Neil A. , Anderson Donald D. , Iyer Krishna S. , Baker Jennifer , Torner James C. , Lynch John A. , Felson David T. , Lewis Cora E. , Brown Thomas D. 
Published: June 2009

AbstractWe studied whether contact stress estimates from knee magnetic resonance images (MRI) predict the development of incident symptomatic tibiofemoral osteoarthritis (OA) 15 months later in an at‐risk cohort. This nested case‐control study was conducted within a cohort of 3,026 adults, age 50 to79 years. Thirty cases with incident symptomatic tibiofemoral OA by their 15 month follow‐up visit were randomly selected and matched with 30 control subjects. Symptomatic tibiofemoral OA was defined as daily knee pain/stiffness and Kellgren‐Lawrence Grade ≥2 on weight bearing, fixed‐flexion radiographs. Tibiofemoral geometry was segmented on baseline knee MRI, and contact stresses were estimated using discrete element analysis. Linear mixed models for repeated measures were used to examine the association between articular contact stress and case/control status. No significant intergroup differences were found for age, sex, BMI, weight, height, or limb alignment. However, the maximum articular contact stress was 0.54 ± 0.77 MPa (mean ± SD) higher in incident OA cases compared to that in control knees (p = 0.0007). The interaction between case‐control status and contact stress was significant above 3.20 MPa (p < 0.0001). The presence of differences in estimated contact stress 15 months prior to incidence suggests a biomechanical mechanism for symptomatic tibiofemoral OA and supports the ability to identify risk by subject‐specific biomechanical modeling. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1562–1568, 2009
Changes in total and labile carbon and nitrogen contents in a sandy soil after the conversion of a succession fallow to cultivated land
Authors: Böhm Christian , Landgraf Dirk , Makeschin Franz 
Published: June 2009

AbstractThe content of soil organic matter (SOM) can be considered as an important factor for evaluating soil fertility, crop yields, and environmental effects. Sensitive measurements for the assessment of quantitative changes in SOM shortly after the conversion of the management practice would be helpful to understand the SOM‐transformation cycle in more detail. Changes in SOM are reflected in modifications of total organic‐carbon (TOC) and total organic‐nitrogen (TON) contents. They are initially detectable in the readily decomposable fraction. We used hot water–extractable carbon (HWC) and nitrogen (HWN) as measurement of labile pools of SOM and aimed to quantify changes in contents of these C and N fractions in a sandy soil already few years after changing management strategy. In this context, we examined the impact of the conversion of a succession fallow (F) to organic (O) and intensive (I) agriculture on TOC, total N (TN), HWC, and HWN. The conversion of succession fallow to cultivated land resulted in a significant decrease of TOC, TN, and HWC at 0–10 cm soil depth. On average, TOC decreased approx. 0.70 g C kg–1 (approx. 9% of initial TOC), TN decreased approx. 0.13 g N kg–1 (approx. 17% of initial TN), and HWC decreased approx. 0.05 g C kg–1 (approx. 12% of initial HWC) within 3 years. Relatively rapid changes in TOC and TN contents indicated comparatively high proportions of decomposable C and N. These were reflected in comparable high HWC (ranging from 0.37 to 0.59 g C kg–1 at 0–30 cm soil depth) and HWN (ranging from 0.04 to 0.10 g N kg–1 at 0–30 cm) contents. These high contents as well as the high HWC : TOC and organic hot water–extractable N (HWNorg) : TN ratios (both between 5% and 7%) implied that the soil investigated has a high ability to provide short‐term available organic C and N compounds. Long‐lasting applications of high quantities of organic fertilizer in the past and high quantities of rhizodepositions were assumed as reasons for the high capability of soil to provide short‐term to medium‐term available C and N. Changes in the HWN content due to the fertilization or crop rotation were mainly based on changes in its inorganic part. This ranged between 10% and 30% of HWN. By discriminant function analysis, it could be shown that the HWN represents a suitably sensitive measurement for the determination of management‐specific impacts in terms of the N, but also of the C cycle. In combination with other C and particularly with other N parameters, the HWN allowed a statistically significant separation of comparable sites varying in management practice already 2 years after the conversion of the management system.
Determination of the fate of regularly applied13C‐labeled‐artificial‐exudates C in two agricultural soils
Authors: Marx Marc , Buegger Franz , Gattinger Andreas , Zsolnay Ádám , Charles Munch Jean 
Published: June 2009

AbstractExudates are part of the total rhizodeposition released by plant roots to soil and are considered as a substantial input of soil organic matter. Exact quantitative data concerning the contribution of exudates to soil C pools are still missing. This study was conducted to reveal effects of13C‐labeled exudate (artificial mixture) which was regularly applied to upper soil material from two agricultural soils. The contribution of exudate C to water‐extractable organic C (WEOC), microbial biomass C (MBC), and CO2‐C evolution was investigated during a 74 d incubation. The WEOC, MBC, and CO2‐C concentrations and the respective δ13C values were determined regularly. In both soils, significant incorporation of artificial‐exudate‐derived C was observed in the WEOC and MBC pool and in CO2‐C. Up to approx. 50% of the exudate‐C amounts added were recovered in the order WEOC << MBC < CO2‐C in both soils at the end of the incubation. Newly built microbial biomass consisted mainly of exudates, which substituted soil‐derived C. Correspondingly, the CO2‐C evolved from exudate‐treated soils relative to the controls was dominated by exudate C, showing a preferential mineralization of this substrate. Our results suggest that the remaining 50% of the exudate C added became stabilized in non‐water‐extractable organic fractions. This assumption was supported by the determination of the total organic C in the soils on the second‐last sampling towards the end of the incubation. In the exudate‐treated soils, significantly more soil‐derived C compared to the controls was found in the WEOC on almost all samplings and in the MBC on the first sampling. This material might have derived from exchange processes between the added exudate and the soil matrix. This study showed that easily available substrates can be stabilized in soil at least in the short term.
Applicability of ground‐penetrating radar as a tool for nondestructive soil‐depth mapping on Pleistocene periglacial slope deposits
Authors: Gerber Rolf , Felix‐Henningsen Peter , Behrens Thorsten , Scholten Thomas 
Published: June 2009

AbstractSoil depth plays a decisive role in determining soil properties in mountainous regions for ecological site assessment. To evaluate the use of ground‐penetrating radar (GPR) for fast and high‐resolution mapping within mountainous regions, we examined the possibilities and limitations of GPR to determine soil depth over bedrock and to delineate individual substrate layers formed during the Pleistocene in a periglacial environment (Pleistocene periglacial slope deposits, PPSD). Selected catenae in representative subregions of the study area (Dill catchment, SE Rhenish Massif, Germany) have been successfully mapped using GPR. A practicable method was developed using a 400 MHz antenna to reach a mean penetration depth of 1.5 m and to map different substrates and layers of PPSD based on calibrations of the GPR at soil pits along 12 catenae. Colluvium, the three types of PPSD layers, as well as the in situ bedrock could be distinguished in most sections of the GPR surveys. Characteristic GPR facies caused by intrinsic material properties of the different substrates, such as stone content and soil moisture content, could be distinguished in different geomorphologic and lithological settings. A layer‐based velocity distribution was determined for characteristic substrate layers at soil pits enabling us to considerably enhance the accuracy of soil‐depth prediction. Compared to traditionally surveyed soil profiles, our results demonstrate an accuracy of layer thickness surveying within a standard deviation of approx. 0.1 m. It is demonstrated that the combination of GPR with conventional soil‐pit mapping is an efficient and valid method to produce high‐resolution data of substrate distribution.
Root–shoot communication of field‐grown maize drought‐stressed at different rates as modified by atmospheric conditions
Authors: Asch Folkard , Bahrun Andi , Jensen Christian R. 
Published: June 2009

AbstractMaize is often grown in drought‐prone environments and, thus, drought resistance is an important trait. In order to minimize production losses, plants need to respond and adapt early and fast to moisture loss in the root zone. From experiments under controlled conditions, constituents of the xylem sap, such as the plant hormone abscisic acid (ABA), or xylem pH have long been recognized to act as signals in root–shoot communication. To investigate early signals of field‐grown maize under conditions of progressive drought, a field trial was set up in a field lysimeter for two consecutive years. Although the experimental set‐up was very similar in the two years, plant responses to moisture loss were significantly different in both, the cascade of events and the intensity of responses. The main difference between the two years was in atmospheric vapor‐pressure deficit (VPD), accelerating the drying rate of the soil in the second year. In contrast to observations during the first year, the sudden increase in VPD in the second year caused a strong, transient peak in xylem sap ABA concentration, but no change in xylem pH or leaf ABA concentration was observed. Whereas the water relations of the maize plants remained stable in the first year, they were severely unbalanced in the second. It is argued that the strong xylem‐ABA signal triggered a change from adaptation mechanisms to survival mechanisms. Modulations due to VPD of constituents of the signal cascade induced by drought are discussed with regard to possible resistance strategies, their initiation, and their modification by combining primary environmental signals.
Summer temperature variations in Lapland during the Medieval Warm Period and the Little Ice Age relative to natural instability of thermohaline circulation on multi‐decadal and multi‐centennial scales
Authors: Helama Samuli , Timonen Mauri , Holopainen Jari , Ogurtsov Maxim G. , Mielikäinen Kari , Eronen Matti , Lindholm Markus , Meriläinen Jouko 
Published: June 2009

AbstractNew tree ring‐based analysis for climate variability at a regional scale is presented for high latitudes of Europe. Our absolutely dated temperature reconstruction seeks to characterise the summer temperatures since AD 750. The warmest and coolest reconstructed 250‐year periods occurred at AD 931–1180 and AD 1601–1850, respectively. These periods share significant temporal overlap with the general hemispheric climate variability due to the Medieval Warm Period (MWP) and the Little Ice Age (LIA). Further, we detect a multi‐decadal (ca. 50‐ to 60‐year) rhythm, attributable to instability of the North Atlantic Deep Water, in the regional climate during the MWP but not during the LIA. Intensified formation of the North Atlantic Deep Water further appeared coincident to the initiation and continuation of MWP, the mid‐LIA transient warmth occurring during the period AD 1391–1440, and to recent warming. Our results support the view that the internal climate variability (i.e. thermohaline circulation) could have played a role in the earlier start of the MWP in several proxy reconstructions compared to the externally forced model simulations. Copyright © 2009 John Wiley & Sons, Ltd.
Palaeoceanography and climate changes off North Iceland during the last millennium: comparison of foraminifera, diatoms and ice‐rafted debris with instrumental and documentary data
Authors: Knudsen Karen Luise , Eiríksson Jón , Jiang Hui , Jónsdóttir Ingibjörg 
Published: June 2009

AbstractPlanktonic and benthic foraminifera data, as well as ice‐rafted debris data, from a 210Pb‐dated multicore (B05‐2006‐MC04) covering the last ca. 130 a on the North Icelandic shelf (∼450 m water depth) are compared with instrumental data and with the Sea Ice Index for the area. There is indication of a strong connection between atmospheric and oceanic changes. A pronounced rise in the sea surface temperature is documented by the proxy data to occur at AD 1910, which is shortly before the rise in the air temperature in the region at ca. AD 1920 but coinciding with the first rise in instrumentally measured annual sea surface temperature. The Great Salinity Anomaly in the 1960s and early 1970s is, however, not clearly expressed in the environmental proxies. There has been a mean sedimentation rate of about 300 cm ka−1 at the core site, based on a tephrochronological age model for the core MD99‐2275. The foraminifera and diatom assemblages show increased influence of Atlantic water masses during the time interval ca. AD 800–1300 (the so‐called Medieval Warm Period or Medieval Climatic Anomaly), whereas the interval ca. AD 1300–1910 (encompassing the Little Ice Age) was characterised by decreased sea surface temperatures due to intensified influence of Arctic waters of the East Icelandic Current. Copyright © 2009 John Wiley & Sons, Ltd.
A 1000‐year record of dry conditions in the eastern Canadian prairies reconstructed from oxygen and carbon isotope measurements on Lake Winnipeg sediment organics
Authors: Buhay William Mark , Simpson Shawna , Thorleifson Harvey , Lewis Mike , King John , Telka Alice , Wilkinson Paul , Babb Jeff , Timsic Sandra , Bailey Dan 
Published: June 2009

AbstractA short sediment core (162 cm), covering the period AD 920–1999, was sampled from the south basin of Lake Winnipeg for a suite of multi‐proxy analyses leading towards a detailed characterisation of the recent millennial lake environment and hydroclimate of southern Manitoba, Canada. Information on the frequency and duration of major dry periods in southern Manitoba, in light of the changes that are likely to occur as a result of an increasingly warming atmosphere, is of specific interest in this study. Intervals of relatively enriched lake sediment cellulose oxygen isotope values (δ18Ocellulose) were found to occur from AD 1180 to 1230 (error range: AD 1104–1231 to 1160–1280), 1610–1640 (error range: AD 1571–1634 to 1603–1662), 1670–1720 (error range: AD 1643–1697 to 1692–1738) and 1750–1780 (error range: AD 1724–1766 to 1756–1794). Regional water balance, inferred from calculated Lake Winnipeg water oxygen isotope values (δ18Oinf‐lw), suggest that the ratio of lake evaporation to catchment input may have been 25–40% higher during these isotopically distinct periods. Associated with the enriched δ18Ocellulose intervals are some depleted carbon isotope values associated with more abundantly preserved sediment organic matter (δ13COM). These suggest reduced microbial oxidation of terrestrially derived organic matter and/or subdued lake productivity during periods of minimised input of nutrients from the catchment area. With reference to other corroborating evidence, it is suggested that the AD 1180–1230, 1610–1640, 1670–1720 and 1750–1780 intervals represent four distinctly drier periods (droughts) in southern Manitoba, Canada. Additionally, lower‐magnitude and duration dry periods may have also occurred from 1320 to 1340 (error range: AD 1257–1363), 1530–1540 (error range: AD 1490–1565 to 1498–1572) and 1570–1580 (error range: AD 1531–1599 to 1539–1606). Copyright © 2009 John Wiley & Sons, Ltd.
Comparative analysis between a proxy‐based climate reconstruction and GCM‐based simulation of temperatures over the last millennium in China
Authors: Tan Ming , Shao Xuemei , Liu Jian , Cai Binggui 
Published: June 2009

AbstractThe application of general circulation models (GCMs) could improve our understanding of climate forcing. Furthermore, longer climate records spanning a wider range of climate states could help in assessing the skill of the models for simulating climates different from the present. We first attempt to find a way to combine proxy records which are affected by different seasonal temperatures, and then present a large‐scale temperature reconstruction over the last millennium for China by combining the Beijing stalagmite layer series and the Qilian tree ring sequence to compare with the GCM‐based ECHO‐G simulated millennial temperature record for China. The correlation coefficient between the simulated and the reconstructed temperature records is 0.61 based on a 31‐year running mean (exceedingP < 0.01). An asymmetricalV‐like low‐frequency variation shown both by the combined proxy record and the simulated series is the major long‐term pattern in the last millennial temperature in China, suggesting that solar irradiance as well as greenhouse gases could explain much of the low‐frequency variations in the climate. However, there still exist high‐frequency discrepancies between the two time series, which may be due to (1) the overestimated climatic effect of volcanoes within the GCM and/or (2) proxies which are not sensitive enough to respond to the volcanic eruptions. Copyright © 2009 John Wiley & Sons, Ltd.
A thousand‐year record of temperature variations for Germany and Central Europe based on documentary data
Authors: Glaser Rüdiger , Riemann Dirk 
Published: June 2009

AbstractThis paper presents a temperature reconstruction of the past 1000 years for Central Europe, based on chronological records. The advantages and limitations of this hermeneutic, text‐based approach are discussed and the statistic methodology is introduced. Historical documents represent direct observation of weather and atmospheric conditions with highest temporal resolution available and precise dating. A major advantage of these extensive data is that they allow the reconstruction of large numbers of variables such as winter temperature, precipitation, pressure patterns or climate extremes as well as floods or storms. Within this hermeneutic climatological research approach, even human impacts and social dimensions of climate development can be examined. In order to quantify the historical information, statistical methods are applied, based on an index approach. Copyright © 2009 John Wiley & Sons, Ltd.
Photocolorimetric determination of yolk colour in relation to selected quality parameters of eggs
Authors: Dvořák Petr , Doležalová Jana , Suchý Pavel 
Published: June 2009

AbstractBACKGROUND: Determination of egg yolk colourity and colour was carried out by means of a new photocolorimetric methodology based on the CIELAB system. Measurements (after gloss elimination) were performed using a Color Guide Sphere Spex photocolorimeter. For comparison, a standard method according to the Yolk Colour Fan® (Roche) was used.RESULTS: Yolk colourity was measured in 252 eggs from layers of Isa Brown breed (aged 51–80 weeks). The colourity parameter L* ranged from 43.42 to 68.51. The parameter a* ranged from 0.05 to 13.49 and the parameter b* ranged from 22.38 to 48.18. The normal (Gaussian) distribution curve for the individual parameters was validated. The resulting number of 8700 combinations of yolk colour parameters was given by multiplication of possible results in the experiment while taking into account the instrumental accuracy. All results according to the Yolk Colour Fan® (Roche) scale represented a range of three colour stripes.CONCLUSION: The photocolorimetric determination is more precise than the Yolk Colour Fan® (Roche) method. No correlation between yolk colourity parameters and yolk cholesterol concentration was found. The highest correlation (r = −0.919) was observed between yolk colourity parameter b* (yellow colour) and total egg weight. Copyright © 2009 Society of Chemical Industry
Help on the way: Senior leaders can benefit from working with a mentor
Authors: Zachary Lois J. , Fischler Lory A. 
Published: June 2009

AbstractAs leaders gain seniority, many of them view their days of being a mentee as behind them. They see mentoring as a developmental activity designed primarily to help new or emerging leaders. But mentoring can be a powerful tool for helping leaders at all levels grow and develop. Finding and working successfully with the right mentor requires commitment and following the correct steps.
Skin fluorescence controlled photodynamic photorejuvenation (wrinkle reduction)
Authors: Bjerring Peter , Christiansen Kaare , Troilius Agneta , Bekhor Philip , de Leeuw Jaap 
Published: June 2009

AbstractBackgroundIdentical skin fluorescence can be obtained after one hour spraying with 0.5% liposome‐encapsulated 5‐ALA and after 0.5 hour application of 20% 5‐ALA in a cream base. In this study the clinical outcome and side effects using the 0.5% 5‐ALA in Caucasian skin are investigated and compared to earlier reported non‐ablative treatments for wrinkles and improvements of skin texture using 20% ALA photodynamic photorejuvenation.Methods and Materials37 healthy Caucasian female patients participated in a randomized, prospective split face study. Two different intense pulsed light (IPL) treatment modalities were investigated; both employed a pre‐treatment of approximately one hour of spraying with 0.5% liposome encapsulated 5‐ALA. One modality combined type I photorejuvenation with wrinkle reduction (C‐PDT) using a waveband from 530 to 750 nm and short pulse durations (7 J/cm2, 2 × 2.5 ms, delay 10 ms). The other modality (PDT alone) emitted a band of wavelengths from 400 to 720 nm, three passes were performed (3.5 J/cm2, 30 ms pulse duration).ResultsAfter a series of three C‐PDT or PDT‐alone treatments, the patients obtained statistically significant (P< 5 × 10‐5) reductions in periorbital and perioral wrinkles. Using the Fitzpatrick wrinkle scale, periorbital wrinkles were reduced by 1.2 grades (SD: 1.1) and 1.1 (SD: 1.1), respectively and perioral wrinkles were reduced by 0.8 grades (SD: 1.0) and 0.7 (SD: 0.9) respectively. The difference in treatment efficacy between. C‐PDT and PDT alone treated sides was not statistically significant (P = 0.224).ConclusionThe present study shows that statistically significant improvements in wrinkle reduction and skin texture, equivalent to previously reported results obtained with 20% ALA, can be obtained with 0.5% liposome encapsulated 5‐ALA. Only minor and infrequent side effects were registered at the 0.5% 5‐ALA treated areas. Skin fluorescence monitoring during pre‐treatrnent with 5‐ALA may improve clinical efficacy, reduce time consumption and increase safety of the treatment. Lasers Surg. Med. 41:327–336, 2009. © 2009 Wiley‐Liss, Inc.