bluuebunny/crossref_metadata_2025 huggingface dataset:
Fat content and fatty acids profile of colostrum and milk of primitive Konik horses (Equus caballus gmeliniAnt.) during six months of lactation
Authors: Pikul Jan , Wójtowski Jacek , Danków Romualda , Kuczyńska Beata , Łojek Jacek
Published: August 2008

The effect of the stage of lactation, the number of foals and age of the mare on changes in the fat content and fatty acid composition of colostrum and milk of primitive Konik horses was investigated. Colostrum and milk samples from 12 lactating mares were collected at the beginning of lactation, on the days 1 and 2 after foaling and then, starting from the first month of lactation, at 4-week intervals up to the sixth month of lactation. Significant differences were observed in fat content as well as the composition of some analysed fatty acids between colostrum and milk of mares of the Konik breed. The number of foalings and the age of mares did not have a statistically significant effect on the fat content in milk and had only a slight effect on the fatty acid composition. Milk produced by mares of the Konik breed is characterized by a considerable content of polyene fatty acids with 18 carbon atoms, a low ratio of n-6 fatty acids to n-3 fatty acids as well as low, highly advantageous values of atherogenic and thrombogenic indices.
Isomerisation of cis-9 trans-11 conjugated linoleic acid (CLA) to trans-9 trans-11 CLA during acidic methylation can be avoided by a rapid base catalysed methylation of milk fat
Authors: Lee Michael R F , Tweed John K S
Published: August 2008

This study investigated the evolution of trans-9 trans-11 conjugated linoleic acid (CLA) from cis-9 trans-11 CLA during methylation and its avoidance through a rapid base methylation of milk fat. The study examined three conditions shown to result in loss of cis-9 trans-11 CLA during methylation namely: temperature, methylation time, water contamination in old reagents and acidic conditions. Three techniques currently used for the conversion of milk fat into fatty acid methyl esters for analysis of CLA content by gas liquid chromatography and a fourth procedure designed to eliminate acidic conditions and to limit methylation temperature and time were used. The four methods were: (i) acidic methylation (AM); (ii) acidic and basic bimethylation with fresh reagents (FBM); (iii) acidic and basic bimethylation with pre-prepared reagents (PBM) and (iv) basic methylation (BM). Each regime was carried out on six milk samples over two periods and methylated 1 ml freeze-dried milk (n=12 per regime). Total CLA was not different across methylation regimes (0·30 mg/ml). Isomer cis-9 trans-11 was higher (P<0·01) with BM than the other regimes and lowest with AM: 21·2, 17·8, 18·8 and 14·7 mg/100 ml for BM, FBM, PBM and AM, respectively. The inverse relationship was shown for trans-9 trans-11 with higher (P<0·001) amounts with AM than the other regimes and lowest with BM: 0·57, 2·55, 2·36 and 3·69 mg/100 ml for BM, FBM, PBM and AM, respectively. The trans-10 cis-12 isomer was also shown to alter with methylation procedure being higher (P<0·001) with AM than the other regimes: 0·43, 0·47, 0·29 and 1·20 mg/100 ml for BM, FBM, PBM and AM, respectively. Validation with known CLA free fatty acid and triacylglycerol standards confirmed that AM resulted in conversion of cis-9 trans-11 to trans-9 trans-11, and also elevated trans-10 cis-12 whilst BM of triacylglycerol CLA did not isomerise cis-9 trans-11 and was comparable to FBM.
Reproductive biology of the slipper lobster Scyllarides deceptor (Decapoda: Scyllaridae) along the southern Brazilian coast
Authors: Oliveira Gabriela , Freire Andrea S. , Bertuol Paulo R.K.
Published: August 2008

The reproductive biology of Scyllarides deceptor was studied along the southern Brazilian coast (27°S 48°W) from December 2002 to December 2003. Samples were collected monthly at Xavier Island, where animals were caught and marked. Fecundity and egg size were estimated from ovigerous females caught also in two adjacent islands, Arvoredo and Aranhas. A total of 98 females was recorded at Xavier Island during the sampling period, 24 of these were recaptured and presented time-at-liberty ranging from 14 to 297 days. Ovigerous females were observed during spring and summer, with the moulting period lasting from late winter to spring. Size at sexual maturity was assessed from 66 females caught during the breeding season and estimated in 85.33 mm of carapace length (CL). Mean fecundity of S. deceptor was estimated in 191,262 eggs (±17,811, SE) for females, on average, 94.74 mm long (±1.86 mm SE) (CL). Fecundity was significantly related to CL (R2 = 0.90) Mean egg size was 0.67 mm (±0.005 mm SE) and did not correlate significantly to CL (P = 0.78). The rocky bottom of Xavier Island was favourable for reproduction, presenting shelter and foraging grounds for the ovigerous females. For management purposes, our results suggest the closure of the S. deceptor fishery from November to January and the capture-size of females to be restricted to animals larger than 90 mm (CL).
Divine hiddenness and the value of divine–creature relationships
Authors: TUCKER CHRIS
Published: August 2008

Apparently, relationships between God (if He exists) and His creatures would be very valuable. Appreciating this value raises the question of whether it can motivate a certain premise in John Schellenberg's argument from divine hiddenness, a premise which claims, roughly, that if some capable, non-resistant subject fails to believe in God, then God does not exist. In this paper, I argue that the value of divine–creature relationships can justify this premise only if we have reason to believe that the counterfactuals of freedom work out in certain ways. Unfortunately, we can't acquire such a reason, at least not without relying on other successful arguments (if there are any) for the relevant premise of Schellenberg's hiddenness argument.
The impact of the Clandestine Marriages Act: three case-studies in conformity
Authors: PROBERT REBECCA , BROWN LIAM D'ARCY
Published: August 2008

This article examines the extent of compliance with the Clandestine Marriages Act 1753 through three parish studies. It demonstrates that the vast majority of the sample cohort of parents whose children were baptized in church, and indeed of couples living together, had married in church as required by the 1753 Act, and shows how the proportion of marriages traced rises as more information about the parties becomes available. Through a study of settlement examinations, the article posits an explanation of why some marriages have not been traced, and argues that researchers should be cautious in inferring non-compliance from the absence of a record in a specific parish. It is also argued that the reason for such high rates of compliance has less to do with the power of statute and more to do with the fact that the 1753 Act was not such a radical break with the past as has been assumed.
Compromise between seabird enjoyment and disturbance: the role of observed and observers
Authors: MARTÍNEZ-ABRAÍN ALEJANDRO , ORO DANIEL , CONESA DAVID , JIMÉNEZ JUAN
Published: August 2008

Natural areas are increasingly visited by people, and urban human visitors expect to watch wildlife as close as possible, but this may have associated disturbance costs. Here, effects of number of visitors and bird density on flight initiation distance (FID) as a proxy of disturbance vulnerability were evaluated in the large ground-nesting yellow-legged gull,Larus michahellis. Mean FID decreased with increasing number of visitors and with increasing gull densities, suggesting that (1) ground-nesting gulls habituate to massive human presence, while retaining their antipredatory mechanisms, and (2) dense groups of gulls were more reluctant to fly away. This density effect may be due to the increased risk of clutch predation by conspecifics at high densities and, if so, FID is a reliable metric of disturbance vulnerability in ground-nesting gulls. In conclusion, set-back distances are specific to local populations and it is unnecessary to ban or restrict human visits to ground-nesting gull colonies; redistributing visits, taking into account both the number of visitors and gull density, is preferable.
Ecosystem model predictions of fishery and conservation trade-offs resulting from marine protected areas in the East China Sea
Authors: JIANG HONG , CHENG HE-QIN , LE QUESNE WILLIAM J.F. , XU HAI-GEN , WU JUN , DING HUI , ARREGUÍN-SÁNCHEZ FRANCISCO
Published: August 2008

The East China Sea (ECS) supports a highly productive fishery and is rich in biodiversity, but economic development in China and peripheral countries has led to intensifying anthropogenic impacts in the ECS. In response to this the Chinese government has introduced a range of marine spatial management measures. A spatial ecosystem model (Ecospace) of the ECS was developed to examine (1) the likely nature of trade-offs between fishery and conservation goals resulting from the marine protected areas (MPAs) and (2) possible trade-offs within the fishery sector resulting from the MPAs. The results suggest that overall the fishery has benefited from all of the simulated MPAs, whereas, although they defy categorical interpretation, effects of the MPAs on biodiversity and ecosystem structure are variable. Simultaneous application of several metrics of ecosystem status indicates that the perceived effect of an MPA on ecosystem status can depend on which metrics for ecosystem status are used, and how these metrics are interpreted. The simulations indicate that a fisheries and conservation outcome beneficial to all is possible, but not guaranteed, with the creation of an MPA. Total landings and profitability are predicted to have increased as a result of each of the MPAs, albeit at the cost of reduced landings and profits to some sectors of the fishery. This study demonstrates the benefits of the additional information relating to biodiversity, ecosystem structure and within fishery dynamics available from spatial ecosystem models compared to the single species models typically used to examine MPA effects. However, the use of a more complex ecosystem model introduces additional uncertainty in model interpretation.
Deforestation dynamics in a fragmented region of southern Amazonia: evaluation and future scenarios
Authors: MICHALSKI FERNANDA , PERES CARLOS A. , LAKE IAIN R.
Published: August 2008

The ‘arc of deforestation’ of southern Amazonia has one of the highest deforestation rates documented anywhere in the world. Landscape changes in a poorly studied but strategically important region in the Brazilian Amazon were studied using biennial Landsat TM/ETM+ images from 1984 to 2004. Deforestation rate for the period 1984–2004 was 2.47% yr−1in the 7295 km2study area, but decreased to 1.99% and 2.15% in 2000–2002 and 2002–2004, respectively. Landscape structure changes were characterized by smaller forest patches that were further apart, but increasingly complex in shape. Deforestation was mainly driven by cattle ranching, which in turn was affected by distance to roads, with forest cover increasing at greater distances from roads. A multi-layer perceptron was used to develop future scenarios based on Markov Chain analysis. Based on current land use, forest cover in the region will decline from 42% in 2004 to 21% by 2016. Results indicate a critical threshold at 51% of forest cover in which landscape structure and connectivity changes abruptly. This suggests that the region requires greater efforts in environmental law enforcement, land-use planning and education programmes to maintain the remaining forest cover near this threshold.
Control effects as a modality
Authors: THIELECKE HAYO
Published: August 2008

We combine ideas from types for continuations, effect systems and monads in a very simple setting by defining a version of classical propositional logic in which double-negation elimination is combined with a modality. The modality corresponds to control effects, and it includes a form of effect masking. Erasing the modality from formulas gives classical logic. On the other hand, the logic is conservative over intuitionistic logic.
CASE NOTES AND CLINICIANS: GALEN’S COMMENTARY ON THE HIPPOCRATIC EPIDEMICS IN THE ARABIC TRADITION*
Authors: PORMANN PETER E.
Published: August 2008

Galen’s Commentaries on the Hippocratic Epidemics constitute one of the most detailed studies of Hippocratic medicine from Antiquity. The Arabic translation of the Commentaries by Ḥunayn ibn Isḥāq (d. c. 873) is of crucial importance because it preserves large sections now lost in Greek, and because it helped to establish an Arabic clinical literature. The present contribution investigate the translation of this seminal work into Syriac and Arabic. It provides a first survey of the manuscript tradition, and explores how physicians in the medieval Muslim world drew on it both to teach medicine to students, and to develop a framework for their own clinical research.
Turbulence transport throughout the heliosphere
Authors: Breech B. , Matthaeus W. H. , Minnie J. , Bieber J. W. , Oughton S. , Smith C. W. , Isenberg P. A.
Published: August 2008

We employ a turbulence transport model to compute distributions of turbulence throughout the heliosphere. The model determines the radial dependence of three (coupled) quantities that characterize interplanetary turbulence, the energy per unit mass, the cross helicity or Alfvénicity, and a similarity length scale. A fourth integrated quantity, the plasma temperature, is modified by heat deposition due to turbulent dissipation. The model includes advection, expansion, and reflection effects as well as the tendency toward dynamic alignment, and a von Kármán type dissipation function that represents decay of turbulence due to cascade to small scales. Two types of forcing are also featured, one a simple model of stream shear, and the other a driving in the outer heliosphere associated with wave energy injection due to pickup protons of interstellar origin. Parameters for the model have been tuned using observation data from Voyager and Ulysses. We analyze the constraining observations to provide boundary conditions and parameters that vary with heliocentric latitude, with some extrapolations. The fully assembled model permits the computation of the distribution of turbulence throughout the entire heliosphere, and we present solutions for several appropriate parameter sets.
The spatial distribution of upstream ion events from the Earth's bow shock measured by ACE, Wind, and STEREO
Authors: Desai M. I. , Mason G. M. , Müller‐Mellin R. , Korth A. , Mall U. , Dwyer J. R. , von Rosenvinge T. T.
Published: August 2008

Using simultaneous measurements of >40 keV upstream ions observed at ACE, Wind, and STEREO‐A during the solar minimum period of 2007, day 1 through 2007, day 181, we investigate their spatial distributions by calculating their occurrence probabilities as a function of lateral and radial separation between L1 and STEREO‐A. Our main results are given as follows: (1) STEREO‐A observed upstream events even when it was separated from Earth by ∼1750 RE and ∼3800 RE in the radial and lateral directions, respectively. (2) The occurrence probability (∼20–30%) for measuring simultaneous upstream events at L1 and STEREO‐A was far greater than that expected from accidental coincidences. (3) The occurrence rate of simultaneous upstream events at L1 and STEREO‐A is significantly higher inside rarefaction regions of high‐speed solar wind flows (>500 km s−1) that follow corotating compression regions and when there exist antisunward propagating Alfvén waves. These new results confirm the global nature of the source region and place limits on the spatial size of the interplanetary structures that could either accelerate the ions in the first place or at the very least provide them with easier access by facilitating their scatter‐free transport from the Earth's foreshock into the far upstream regions traversed by STEREO‐A. We suggest that the existence of large amplitude Alfvén waves with spatial scales of the order of 0.03 AU that are embedded in and get convected past the Earth by high‐speed solar wind streams plays a critical and necessary role in the occurrence of upstream ion events near the Earth.
Synthetic radio maps of CME‐driven shocks below 4 solar radii heliocentric distance
Authors: Schmidt J. M. , Gopalswamy N.
Published: August 2008

We present 2 1/2 D numerical MagnetoHydroDynamic (MHD) simulations of coronal mass ejections (CMEs) in conjunction with plasma simulations of radio emission from the CME‐driven shocks. The CME‐driven shock extends to an almost spherical shape during the temporal evolution of the CME. Our plasma simulations can reproduce the dynamic spectra of coronal type II radio bursts, with the frequency drift rates corresponding to the shock speeds. We find further, that the CME‐driven shock is an effective radio emitter at metric wavelengths, when the CME has reached a heliocentric distance of about two solar radii (). We apply our simulation results to explain the radio images of type II bursts obtained by radio heliographs, in particular to the banana‐shaped images of radio sources associated with fast CMEs.
A conceptual model for hydrocarbon accumulation and seepage processes around Chapopote asphalt site, southern Gulf of Mexico: From high resolution seismic point of view
Authors: Ding Feng , Spiess Volkhard , Brüning Markus , Fekete Noemi , Keil Hanno , Bohrmann Gerhard
Published: August 2008

As part of the German R/V Meteor M67/2 expedition in 2006 to the southern Gulf of Mexico, a set of 2D high resolution seismic profiles was acquired across the Chapopote knoll to study seafloor asphalt occurrences. On the basis of regional seismostratigraphic studies and DSDP drilling, a more highly reflective, coarse‐grained sediment unit of late Miocene age is identified as a potential shallow hydrocarbon reservoir. Although a unit of that age would typically be buried by Pliocene and Pleistocene sediment cover, at Chapopote, local salt tectonism has highly elevated the structure since the late Miocene, and the Miocene reservoir is locally above present‐day regional datum. The elevation resulted in a thin (100–200 m), fine grained sediment cover on the crest of the knoll above the reservoir. Because oil and gas production can be expected at depth in Jurassic, Cretaceous and Tertiary source rocks, the presence of high‐amplitude reflector packages within the reservoir unit is interpreted as an evidence of hydrocarbons. This is variously supported by observations of crosscutting reflectors, polarity reversal, and drops in instantaneous frequency. The thin seal above the reservoir unit facilitates leakage of trapped hydrocarbons. Hydrocarbons apparently invaded into the seal sediments in the wider vicinity around the crest of the knoll, even extending beyond the area where seafloor asphalt is known. The asphalt site thus may be a currently active spot, while the rest of the crest may be temporarily sealed by solid phase hydrocarbons. We propose that a shallow, large reservoir with deeply sourced, relatively heavy petroleum is principally responsible for the formation of asphalts on the seafloor.
On the dynamics of the South China Sea Warm Current
Authors: Yang Jiayan , Wu Dexing , Lin Xiaopei
Published: August 2008

The South China Sea Warm Current (SCSWC) flows northeastward over the shelf and continental slope in the northern South China Sea (SCS). This current persists in its northeastward direction in all seasons despite the fact that the annually averaged wind stress is decisively southwestward against it. Two major mechanisms have been proposed in previous studies, one attributing it directly to the wind stress forcing within the SCS and the other to the Kuroshio intrusion through the Luzon Strait. In this study we use a simple model to demonstrate that neither of them is the leading forcing mechanism. Instead, the SCSWC is a source‐ and sink‐driven flow induced by the Taiwan Strait Current (TSC), a year‐round northward flow through the Taiwan Strait. The two previously suggested mechanisms are important but secondary. The model simulations show that the local wind stress alone would force a current in the opposite direction to the SCSWC. Blocking the Kuroshio intrusion through the Luzon Strait, on the other hand, only weakens the SCSWC. The SCSWC vanishes when the Taiwan Strait is closed in the model.
Advantages of fine resolution SSTs for small ocean basins: Evaluation in the Black Sea
Authors: Kara A. B. , Barron C. N. , Wallcraft A. J. , Oguz T. , Casey K. S.
Published: August 2008

This paper examines monthly variability of climatological mean sea surface temperature (SST) in the Black Sea. A total of eight products, including observation‐ and model‐based SST climatologies, are formed and compared with each other. Some of the observation‐based SST data sets include only satellite measurements, while others combine in situ temperatures, such as those from moored and drifter buoys, with satellite data. Climatologies for numerical weather prediction (NWP) model‐based data sets are formed using high temporal resolution (6 hourly) surface temperatures. Spatial resolution of these SST products varies greatly (≈ 4 km to 280 km), with the observation‐based climatologies typically finer than the NWP‐based climatologies. In the interior, all data sets are in general agreement, with annual mean SST biases typically within ±0.2°C in comparison to the finest resolution (4 km) satellite‐based Pathfinder climatology. Major differences are near the land‐sea boundaries where model‐based SSTs pose serious biases (as much as >5°C). Such errors are due to improper contamination of surface temperatures over land since coarse resolution model‐based products cannot distinguish land and sea near the coastal boundaries. A creeping sea‐fill interpolation improves accuracy of coastal SSTs from NWP climatologies, such as European Centre for Medium‐Range Weather Forecast. All climatologies are also evaluated against historical in situ SSTs during 1942–2007. These comparisons confirm the relatively better accuracy of the observation‐based climatologies.
Abrupt rainfall transitions over the Greater Horn of Africa: Observations and regional model simulations
Authors: Riddle Emily E. , Cook Kerry H.
Published: August 2008

We examine the yearly occurrence of a monsoon jump of approximately 20° latitude during the boreal spring and summer rainy seasons over the Greater Horn of Africa (GHA). This jump is in contrast with a simple model of a smoothly varying ITCZ over the region. The rainfall jump is observed annually during April and May in three precipitation data sets and in regional climate model simulations using the PSU/NCAR Mesoscale Model (MM5). The MM5 simulations show the rainfall jump to be roughly coincident with abrupt circulation changes that occur as the Somali jet develops during April, May, and June. In particular, the cross‐equatorial (meridional) branch of the Somali jet forms along the East African coast in April, bringing moisture (and rainfall) northward to the southern slopes of the Ethiopian plateau. This meridional branch forms well before the northern zonal branch of the jet, which diverts moisture eastward from southern Ethiopia and feeds the Indian monsoon. These results establish a framework for understanding the precipitation cycle over the GHA, and provide a foundation for improving subseasonal forecasts over drought‐prone regions of eastern Africa.
Atmospheric circuit influences on ground‐level pressure in the Antarctic and Arctic
Authors: Burns G. B. , Tinsley B. A. , French W. J. R. , Troshichev O. A. , Frank‐Kamenetsky A. V.
Published: August 2008

Pressure variations at 11 Antarctic sites and 7 Arctic sites have been examined and show significant correlations with a daily proxy for the output of the meteorological generators of the global atmospheric circuit. This proxy is derived from vertical electric field measurements made at Vostok on the Antarctic ice plateau. Taken with the finding of proportionate pressure variations correlated with atmospheric circuit changes owing to coupling with the interplanetary electric field, particularly for the Antarctic plateau (magnetic latitude > 83°) region, this provides experimental evidence that a small portion of the surface pressure variations are due to the influence of the global atmospheric circuit. The response to the interplanetary electric field is an example of Sun‐weather coupling. To evaluate it, the daily average interplanetary magnetic field (IMF) east‐west component (By) is used as a proxy for the north–south interplanetary electric field, which produces opposite ionospheric potential changes in the northern and southern polar caps. The correlation with IMF By for the pressure variations for the Antarctic sites for a solar cycle (1995–2005) is small (0.9% average covariance for the magnetic latitude > 83° sites) but significant (99.7% confidence level). The Arctic stations show a negative regression between pressure variations and IMF By, a relationship expected if the linkage process operates by the atmospheric circuit, but it is only found when the interval is restricted to the peak of the sunspot cycle (1999–2002).
Influence of oceanic dimethyl sulfide emissions on cloud condensation nuclei concentrations and seasonality over the remote Southern Hemisphere oceans: A global model study
Authors: Korhonen Hannele , Carslaw Kenneth S. , Spracklen Dominick V. , Mann Graham W. , Woodhouse Matthew T.
Published: August 2008

We use a global chemical transport model with size‐resolved aerosol microphysics to investigate the sources of cloud condensation nuclei (CCN) in the Southern Hemisphere remote marine boundary layer (MBL). Long‐term observations of CCN number at Cape Grim (40°41′S, 144°41′E) show a clear seasonal cycle with a 2–3 times higher concentration in summer than in winter, which has been attributed to seasonal changes in the dimethyl sulfide (DMS) ocean‐to‐atmosphere flux. We find that this cycle at Cape Grim and also throughout the 30°–45°S latitude band is caused mostly by changes in the regional‐scale DMS ocean water concentration. In this latitude band, DMS emissions increase the simulated CCN concentrations from November to April, with a maximum effect of 46% in January (calculated at 0.23% supersaturation). Farther south, the impact of DMS on CCN is apparent only from December to February and increases the CCN concentration at most by 18% at 45°–60°S and by 40% at 60°–75°S. These model‐derived contributions of DMS to Southern Ocean summertime CCN are smaller than the 80% derived from correlations between satellite‐observed chlorophyll and column CCN, which we explain in terms of nonlinear behavior of CCN from the free troposphere (FT). We show that the main microphysical pathway of DMS influence on CCN number is nucleation of DMS‐derived H2SO4 in the FT and subsequent growth of formed particles by condensation and coagulation during entrainment into the MBL. Our simulations suggest that >90% of the increase in MBL CCN when DMS is added to the model is formed in this way. The growth of ultrafine sea spray particles to CCN sizes due to condensation of DMS‐derived H2SO4 in the MBL affects the simulated CCN concentrations by less than 6%. Overall, entrainment of nucleated sulfate aerosol into the MBL from the FT accounts for 43–65% of the summer zonal mean CCN concentrations but only 7–20% of the winter CCN over the Southern Hemisphere oceans.
An investigation of the flow and scour mechanisms around isolated spur dikes in a shallow open channel: 2. Conditions corresponding to the final stages of the erosion and deposition process
Authors: Koken Mete , Constantinescu George
Published: August 2008

Large eddy simulation (LES) is used to investigate the flow around a vertical spur dike in a straight channel with equilibrium scour bathymetry and the scour mechanisms in the later stages of the erosion deposition process. The equilibrium bathymetry is obtained from an experiment conducted at the same relatively low channel Reynolds number (Re = 18,000). Flow visualizations are used to complement the information obtained from the numerical simulation. The present investigation demonstrates that large‐scale bimodal oscillations of the primary necklace vortex are the main reason for the amplification of the turbulence inside the scour hole. The nature of these oscillations is similar to the one observed in the horseshoe vortex (HV) system forming in the flow past bluff bodies (e.g., spur dikes) mounted on flat surfaces. The presence of the scour hole stabilizes the HV system compared to the case when the bed is flat. It is observed that random ejection of vorticity patches from the legs of the necklace structures takes place at random times. The axis of the vorticity patch remains approximately parallel to the bed. These patches of high vorticity move predominantly against the mean slope of the scour hole and can cause sediment entrainment as they are convected over the bed before they dissipate. This mechanism explains, at least partially, the lateral growth of the scour hole in the later stages of the scouring process. As a result of merging phenomena, some of the eddies convected in the detached shear layer (DSL) can also induce large local value of the bed shear stress. The variation in the mean shape of the DSL as the bed is approached is another phenomenon observed in the current study. Close to the bed, at some time instances the DSL tends to curve toward the back of the spur dike, whereas at higher elevations the DSL regains the shape typically encountered in the flow over a surface‐mounted wall of infinite width. In the near‐bed region, the DSL is observed to oscillate between these two extreme positions. This explains how the scour hole grows in the region situated just behind the spur dike and how the entrained sediment is then transported in the deposition area behind the spur dike. The role of the two streamwise‐oriented vortices, present in between the elongated submerged deposition hill and the channel sidewall, in the sediment transport processes inside the wake region is discussed. The predicted mean bed shear stress distribution around the spur dike is consistent with the equilibrium conditions present in the experiment.
The 7–13 March 2006 dust storm over West Africa: Generation, transport, and vertical stratification
Authors: Tulet Pierre , Mallet Marc , Pont Véronique , Pelon Jacques , Boone Aaron
Published: August 2008

Several studies have shown the importance of desert dust aerosols in weather forecast models. Nevertheless, desert dust has been poorly represented in such models and is the source of some prediction errors, in particular for tropical and subtropical regions. The purpose of this paper is to illustrate the formation and the three‐dimensional transport of a severe dust storm which occurred in March 2006 over West Africa. An intense dust haze was transported southward over the Gulf of Guinea thereby generating an aerosol optical thickness (AOT) greater than 4 over Nigeria. The MesoNH mesoscale atmospheric model coupled with new dust parameterization schemes has been used to illustrate the three‐dimensional transport of the dust plume and the vertical layering of this desert air mass above the lower atmosphere monsoon flux layer. It is modeled that more than 50 g m−2 of dust was emitted during this event from the surface by a strong Harmattan wind over the Sahel region. It is also shown that when the dust layer is located over the boundary layer, it can modify the atmospheric stability by as much as 9.5 K in terms of potential temperature in the lowest 2000 m of the atmosphere.
Diversity and temporal sequences of forms of DOC and NO3‐discharge responses in an intermittent stream: Predictable or random succession?
Authors: Butturini Andrea , Alvarez Marta , Bernal Susana , Vazquez Eusebi , Sabater Francesc
Published: August 2008

Storm events have major implications for biogeochemical cycles at local and regional scales and they provide an excellent opportunity to study the hydro‐biogeochemical functioning of catchments. However, concentration‐discharge (C‐Q) responses have only been studied in detail for short periods or a few selected events. In consequence, it is difficult to quantify the diversity ofC‐Qresponses in a hydrological system and impossible to assess whether the succession of forms ofC‐Qresponses follows a predictable sequence or not. Bearing in mind these shortfalls, the variability of dissolved organic carbon (DOC) and nitrate (NO3) pulses during storms is analyzed in a detailed 4‐year series from an intermittent Mediterranean stream. In this study, each DOC and NO3‐Qresponse is synthesized by two descriptors that summarize its trend (ΔC; dilution/flushing/no change) and shape (ΔR; linear/nonlinear response). We observe thatC‐Qresponses are widely distributed along the two‐dimensional ΔRversus ΔCcontinuum. Furthermore, the temporal succession of forms of DOC and NO3‐Qresponses follow a random pattern, and only the dynamics of the ΔR(NO3)descriptor show periodicity. The long‐term data set reveals that it is impossible to predict with reasonable precision the full properties of DOC and NO3‐Qresponses. Thus, a “typical”C‐Qresponse does not really exist at our study site, and this apparent diversity of responses has to be handled with a probabilistic approach that allows synthesis of the complexity of the hydro‐biogeochemical functioning of a specific catchment.
High‐throughput Screening of Mouse Knockout Lines Identifies True Lean and Obese Phenotypes
Authors: Brommage Robert , Desai Urvi , Revelli Jean‐Pierre , Donoviel Dorit B. , Fontenot Gregory K. , DaCosta Christopher M. , Smith Deon D. , Kirkpatrick Laura L. , Coker Kenneth J. , Donoviel Michael S. , Eberhart Derek E. , Holt Kathleen H. , Kelly Michael R. , Paradee William J. , Philips Anne V. , Platt Kenneth A. , Suwanichkul Adisak , Hansen Gwenn M. , Sands Arthur T. , Zambrowicz Brian P. , Powell David R.
Published: August 2008

We developed a high‐throughput approach to knockout (KO) and phenotype mouse orthologs of the 5,000 potential drug targets in the human genome. As part of the phenotypic screen, dual‐energy X‐ray absorptiometry (DXA) technology estimates body‐fat stores in eight KO and four wild‐type (WT) littermate chow‐fed mice from each line. Normalized % body fat (nBF) (mean KO % body fat/mean WT littermate % body fat) values from the first 2322 lines with viable KO mice at 14 weeks of age showed a normal distribution. We chose to determine how well this screen identifies body‐fat phenotypes by selecting 13 of these 2322 KO lines to serve as benchmarks based on their published lean or obese phenotype on a chow diet. The nBF values for the eight benchmark KO lines with a lean phenotype were ≥1 s.d. below the mean for seven (perilipin, SCD1, CB1, MCH1R, PTP1B, GPAT1, PIP5K2B) but close to the mean for NPY Y4R. The nBF values for the five benchmark KO lines with an obese phenotype were >2 s.d. above the mean for four (MC4R, MC3R, BRS3, translin) but close to the mean for 5HT2cR. This screen also identifies novel body‐fat phenotypes as exemplified by the obese kinase suppressor of ras 2 (KSR2) KO mice. These body‐fat phenotypes were confirmed upon studying additional cohorts of mice for KSR2 and all 13 benchmark KO lines. This simple and cost‐effective screen appears capable of identifying genes with a role in regulating mammalian body fat.
A quantitative human monoclonal antibody immunoassay using anti‐idiotypic antibody as a membrane antigen surrogate with surface‐plasmon‐resonance detection
Authors: Wong Rosie B. , Lee An‐Horng , Rangan Vangipuram S. , Cheng Kuang‐Chuan
Published: August 2008

Biologically active membrane proteins are difficult to isolate. Very often the isolated membrane proteins have low binding affinity or no biological integrity at all. Despite some success in isolation, one has to overcome the hurdles of obtaining sufficient quantity of the proteins and maintaining biological activity upon coating them on surfaces for developing an ELISA. Thus an alternative approach may be useful. The present study describes a quantification assay method for a therapeutic hmAb‐1 (human monoclonal antibody‐1) that recognizes a cell‐surface protein employing an anti‐ID (anti‐idiotypic antibody) to hmAb‐1 as a surrogate antigen in an immunoassay format using surface‐ plasmon‐resonance technology. This assay is applicable for quantification of hmAb‐1 in process streams, final drug‐product quality control, as well as low‐concentration drug substances in intravenous‐solution bags. The surrogate nature of the anti‐ID was confirmed by demonstrating that the anti‐ID displaced the interaction between the hmAb‐1 and its membrane antigen in a FACS titration test. The assay format involves first capturing hmAb‐1 on the flow‐cell surface, which then binds quantitatively to anti‐ID in a mixture of increasing quantity of hmAb‐1 in solution. An inverse dose–response relation between this anti‐ID bound signal (or resonance units) and hmAb‐1 concentration was established. The dose–response range of the calibration curve for hmAb‐1 was between 20 and 300 ng/ml. The precision, accuracy and specificity of the assay are reported in the present paper.
Detection and characterization of proteinase K-sensitive disease-related prion protein with thermolysin
Authors: Cronier Sabrina , Gros Nathalie , Tattum M. Howard , Jackson Graham S. , Clarke Anthony R. , Collinge John , Wadsworth Jonathan D. F.
Published: August 2008

Disease-related PrPSc [pathogenic PrP (prion protein)] is classically distinguished from its normal cellular precursor, PrPC(cellular PrP) by its detergent insolubility and partial resistance to proteolysis. Although molecular diagnosis of prion disease has historically relied upon detection of protease-resistant fragments of PrPSc using PK (proteinase K), it is now apparent that a substantial fraction of disease-related PrP is destroyed by this protease. Recently, thermolysin has been identified as a complementary tool to PK, permitting isolation of PrPSc in its full-length form. In the present study, we show that thermolysin can degrade PrPC while preserving both PK-sensitive and PK-resistant isoforms of disease-related PrP in both rodent and human prion strains. For mouse RML (Rocky Mountain Laboratory) prions, the majority of PK-sensitive disease-related PrP isoforms do not appear to contribute significantly to infectivity. In vCJD (variant Creutzfeldt–Jakob disease), the human counterpart of BSE (bovine spongiform encephalopathy), up to 90% of total PrP present in the brain resists degradation with thermolysin, whereas only ∼15% of this material resists digestion by PK. Detection of PK-sensitive isoforms of disease-related PrP using thermolysin should be useful for improving diagnostic sensitivity in human prion diseases.
Hydrolytic cleavage ofN6-substituted adenine derivatives by eukaryotic adenine and adenosine deaminases
Authors: PospíŠilová Hana , Šebela Marek , Novák Ondřej , Frébort Ivo
Published: August 2008

Homogeneous adenine deaminases (EC 3.5.4.2) from the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe and a putative ADA (adenosine deaminase; EC 3.5.4.4) from Arabidopsis thaliana were obtained for the first time as purified recombinant proteins by molecular cloning of the corresponding genes and their overexpression in Escherichia coli. The enzymes showed comparable molecular properties with well-known mammalian ADAs, but exhibited much lower kcat values. Adenine was the most favoured substrate for the yeast enzymes, whereas the plant enzyme showed only very low activities with either adenine, adenosine, AMP or ATP. Interestingly, the yeast enzymes also hydrolysed N6-substituted adenines from cytokinins, a group of plant hormones, cleaving them to inosine and the corresponding side chain amine. The hydrolytic cleavage of synthetic cytokinin 2,6-di-substituted analogues that are used in cancer therapy, such as olomoucine, roscovitine and bohemine, was subsequently shown for a reference sample of human ADA1. ADA1, however, showed a different reaction mechanism to that of the yeast enzymes, hydrolysing the compounds to an adenine derivative and a side chain alcohol. The reaction products were identified using reference compounds on HPLC coupled to UV and Q-TOF (quadrupole–time-of-flight) detectors.

The ADA1 activity may constitute the debenzylation metabolic route already described for bohemine and, as a consequence, it may compromise the physiological or therapeutic effects of exogenously applied cytokinin derivatives.
The Illegal Economy in the Restaurant Sector in Denmark
Authors: Hjalager Anne-Mette
Published: August 2008

This paper discusses some of the known illegal methods used in the restaurant business, for example tax fiddles, employment of illegal or undeclared labour, and illegal import of supplies. In Denmark, with its high tax and wage levels, the temptation to fiddle is possibly bigger than in other countries. This paper estimates the economic importance and employment consequences of shadow activities in the Danish restaurant sector. The authorities employ various methods in their continuing struggle against the underground economy, for example control actions and raids. Licensing and self-control launched by trade associations or public agencies is another way of limiting such behaviour. Deregulation and the lowering of taxes are supposed to have similar effects. In time, pressure by informed consumers might become a potent remedy. This paper discusses the efficiency in a European context. Fraud has a number of consequences, the loss of tax receipts being the most often mentioned. This paper also addresses problems such as the distortion of competition, inequality of access to cheaper services and the negative effects on the quality of products and services. For enterprises, participation in shadow activities may lead to growth trapping. If substantial proportions of restaurants' activities are not openly accounted for, it will put obstacles in the way of certain types of recognised business trajectories, and it will be difficult for public and trade associations to push for the continual professionalisation of the industry.
The determination of the metal-dielectric interface barrier height from the open-circuit isothermal charging current
Authors: Neagu E. R. , Neagu R. M. , Dias C. J. , Carmo Lança M. , Marat-Mendes J. N.
Published: August 2008

There is a sustained interest both from theoretical and from practical points of view to understand the isothermal charging and the isothermal discharging currents in dielectrics. The measured currents are analyzed either in terms of polarization mechanisms or in terms of charge injection/extraction at the metal-dielectric interface and the conduction current through the dielectric material. As long as we do not know the nature of the origin of the current, it is not clear what information we can get by analyzing the experimental data. We propose to measure the open-circuit isothermal charging and discharging currents just to overpass the difficulties related to the analysis of the conduction mechanisms in dielectric materials. We demonstrate that besides a polarization current, there is a current related with charge injection or extraction at the metal-dielectric contact and a reverse current related to the charge trapped into the superficial trap states of the dielectric and that can jump at the interface in a reverse way. An analytical expression for the current is proposed. By fitting the experimental data to this analytical equation, two important parameters can be determined: (i) the highest value of the relaxation time for the polarization mechanisms still involved into the transient current and (ii) the height of the potential barrier W0 at the metal-dielectric interface at the initial time when the step voltage is applied. The value obtained for Al-polyethylene terephthalate interface is (0.43±0.02) eV. For a charging voltage of 220 V there are 6×1014 trapped electrons/m2.
Theoretical study of stable structures and photoelectron spectra of mass-selected Al12Cs−, Al11Cs2−, and Al10Cs3− clusters
Authors: Shimada Hiroyuki , Matsuzawa Hidenori
Published: August 2008

The geometric and electronic structures of the ground and low-lying states for the Al12Cs−, Al11Cs2−, and Al10Cs3− clusters were examined using the density functional theory. Semi-icosahedral structures of the Al12Cs− and Al11Cs2− clusters were found as the ground state. The most stable structure of the Al10Cs3− cluster is a distorted icosahedron structure. The vertical detachment energy of these clusters and the anion photoelectron spectra (PES) were compared. The peaks of the anion PES were assigned on the basis of the shell model. The single peak of 3.1–3.2 or 2.5–2.7eV for the Al12Cs− or Al11Cs2− cluster, respectively, is observed due to the electron detachment from the 2p or 1f or 1f+2p shells. Two large peaks of 2.1eV and 3.1–3.3eV correspond to the electron detachments from the 1f+2p and 2p, and 1d+1f shells, respectively. It was found that a second peak appears with the hybridization of the 1d and 1f shells due to the distortion from the icosahedral structure in the Al10Cs3− cluster.
Excitation enhancement of CdSe quantum dots by single metal nanoparticles
Authors: Chen Yeechi , Munechika Keiko , Jen-La Plante Ilan , Munro Andrea M. , Skrabalak Sara E. , Xia Younan , Ginger David S.
Published: August 2008

We study plasmon-enhanced fluorescence from CdSe∕CdS∕CdZnS∕ZnS core/shell quantum dots near a variety of Ag and Au nanoparticles. The photoluminescence excitation (PLE) spectrum of quantum dots closely follows the localized surface plasmon resonance (LSPR) scattering spectrum of the nanoparticles. We measure excitation enhancement factors of ∼3 to 10 for different shapes of single metal nanoparticles.
Optical properties of thermally annealed hafnium oxide and their correlation with structural change
Authors: Park Jun-Woo , Lee Do-Kyu , Lim D. , Lee Hosun , Choi Suk-Ho
Published: August 2008

We studied the optical properties of hafnium oxide as its structure changed. The shoulderlike feature that appears in crystalline HfO2 near the energy trough of the optical absorption edge after thermal anneal was found to have a direct correlation with the crystallization of the film. A luminescence feature near 4.1 eV could also be observed for some of the crystallized hafnium oxide films, but it did not have a direct correlation with crystallization or the shoulderlike feature. Our experimental results do not support the recently proposed self-trapped exciton (STE) model, where the shoulderlike absorption and the UV luminescence features are both attributed to STE. Simultaneous measurements of structural and optical properties of thermally annealed hafnium oxide films revealed that the shoulderlike feature is not related to defects, but rather is intrinsic to crystallized hafnium oxides. We discuss some possible origins of the shoulderlike feature based on our experimental results. Nevertheless, the UV luminescence feature seems to be related to oxygen defects in crystalline hafnium oxide.
Electrically controlled Kerr effect in magnetophotonic crystals based on nematic liquid crystals
Authors: Da H. X. , Xu P. , Wu J. C. , Li Z. Y.
Published: August 2008

An electrically controllable Kerr effect in magnetophotonic crystals consisting of magnetic materials and nematic liquid crystals is presented by considering the properties of nematic liquid crystals. Numerical results show that the Kerr effect is changed remarkably by adjusting the permittivity of liquid crystal, and the maximum value of the Kerr rotation angle is enhanced with the increase in the permittivity of liquid crystal. Such properties demonstrate the possibility of tunable magneto-optical devices based on nematic liquid crystals.