bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of straw treatment and nitrogen supplementation on digestibility, intake and physiological responses of water intake as well as urine and faecal characteristics
Authors: Ghasemi E. , Khorvash M. , Ghorbani G. R. , Elmamouz F. 
Published: February 2013

SummaryThis study investigates the effects of feeding diet based on untreated (UT) or ensiled alkali‐treated (ET) barley straw with either urea or casein supplementation, on feed intake, digestibility, ruminal pH, water intake and faecal and urinary characteristics. Four sheep fitted with ruminal cannulas were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Barley straw was treated by the dry (spraying) method in pH adjusted of hydrogen peroxide (pH 11.5), ensiled for 6 weeks and included at 65% of the diet dry matter (DM). The results showed that straw pH reduced from 11.58 to 8.60 after 6 weeks of ensilage. The ET diet increased average DM digestibility and intake by 19% and 43% respectively. Total water intake was similar across treatments, while the water/DM intake ratio was 23% higher with the UT diet than with the ET one. Ruminal (6.73 vs. 6.84) and faecal (8.67 vs. 9.05) pH decreased but urinary pH (6.14 vs. 8.13) increased as a result of feeding animals on the ET diet compared with the UT diet. Compared with the UT diet, the ET one decreased faecal fibre (12%), moisture (32%) and water holding capacity, while it increased faecal ash (10%) and density (20%). The volume of urine excreted by the sheep fed with the ET diet increased by 67%, but their urine specific gravity (SG) decreased. No significant effects were observed for the dietary N supplementation and interactions between straw type × N supplementation with regard to any of the measured characteristics except for DM intake, which reduced due to the casein supplementation in the ET diet. These results indicate that the alkali treatment and ensilage of barley straw increased digestibility, intake, faecal consistency and urinary pH and dilution but decreased straw alkalinity as well as ruminal and faecal pH.
The effect of very low food intake on digestive physiology and forage digestibility in horses
Authors: Clauss M. , Schiele K. , Ortmann S. , Fritz J. , Codron D. , Hummel J. , Kienzle E. 
Published: February 2013

SummaryEquid digestion is often conceptualized as a high‐throughput/low‐efficiency system, in particular compared with ruminants. It is commonly assumed that ruminants have an advantage when resources are limited; the effect of low food intake on digestive physiology of horses has, however, not been explored to our knowledge. We used four adult ponies [initial body mass (BM) 288 ± 65 kg] in two subsequent trials with grass hay‐only diets [in dry matter (DM): hay1, mid‐early cut, crude protein (CP) 10.5%, neutral detergent fibre (NDF) 67.6%; hay2, late cut, CP 5.8%, NDF 69.5%], each fed subsequently at four different dry matter intake (DMI) levels: ad libitum and at 75, 55 and 30 g/kg0.75/day. We particularly expected digesta mean retention times (MRT) to increase, and hence fibre digestibility to increase, with decreasing DMI. Ponies maintained BM on the first, but lost BM and body condition on DMI55 and DMI30. MRTs were negatively correlated to DMI and ranged (for particles <2 mm) from 23/31 h (hay1/2) on the ad libitum to 38/48 h on DMI30. Digestibilities of DM, nutrients and fibre components decreased from DMI75 to DMI30; apparent digestibilities of organic matter and NDF (hay1/2) dropped from 47/43% and 42/37%, respectively, on the ad libitum DMI to 35/35% and 30/28% on DMI30. Additional differences evident between the two hays included a higher estimated ‘true’ protein digestibility for hay1 and finer faecal particles on hay2; there were no differences in faecal particle size between intake levels. The results suggest that below a certain food intake threshold, the major digestive constraint is not fermentation time but nutrient supply to gut bacteria. The threshold for such an effect probably varies between feeds and might differ between ruminants and equids.
History of the invasion of the anther smut pathogen on Silene latifolia in North America
Authors: Fontaine Michael C. , Gladieux Pierre , Hood Michael E. , Giraud Tatiana 
Published: February 2013

Summary

Understanding the routes of pathogen introduction contributes greatly to efforts to protect against future disease emergence.

Here, we investigated the history of the invasion in North America by the fungal pathogen Microbotryum lychnidis‐dioicae, which causes the anther smut disease on the white campion Silene latifolia. This system is a well‐studied model in evolutionary biology and ecology of infectious disease in natural systems.

Analyses based on microsatellite markers show that the introduced American M. lychnidis‐dioicae probably came from Scotland, from a single population, and thus suffered from a drastic bottleneck compared with genetic diversity in the native European range. The pattern in M. lychnidis‐dioicae contrasts with that found by previous studies in its host plant species S. latifolia, also introduced in North America. In the plant, several European lineages have been introduced from across Europe. The smaller number of introductions for M. lychnidis‐dioicae probably relates to its life history traits, as it is an obligate, specialized pathogen that is neither transmitted by the seeds nor persistent in the environment.

The results show that even a nonagricultural, biotrophic, and insect‐vectored pathogen suffering from a very strong bottleneck can successfully establish populations on its introduced host.
Foraminiferal record of marine transgression during deposition of the Middle Miocene Badenian evaporites in Central Paratethys (Borków section, Polish Carpathian Foredeep)
Authors: Peryt Danuta 
Published: February 2013

AbstractBenthic and planktonic foraminifera from a marly clay intercalation sandwiched between mid‐Badenian (Middle Miocene) gypsum deposited in an environment of an evaporitic shoal (<1 m deep) at Borków (southern Poland) indicate a major marine flooding event in the previously isolated Carpathian Foredeep Basin (Central Paratethys). After this very short‐term environmental change, benthic foraminifers started to colonize a new niche which was previously defaunated, and the pattern of benthic foraminiferal colonization is similar to that related to the reflooding which terminated the Badenian evaporite deposition. The benthic foraminifer assemblages are composed of pioneer, opportunistic, r‐selected species dominated by elphidiids. The connection of the Carpathian Foredeep Basin with the marine reservoir was short‐lived. The marly clay intercalations in evaporite sequences originating in bared basins can thus register major environmental changes.
Impacts of Trade and the Environment on Clustered Multilateral Environmental Agreements
Authors: H. Egger Peter , Jessberger Christoph , Larch Mario 
Published: February 2013

AbstractMany countries align their environmental policy and environmental regulation by way of multilateral environmental agreements (MEAs). Previous work in economics provided insights in the economic and political determinants ofMEAs at large. This paper distinguishesMEAs by the main issues covered and classifies them in five clusters: biodiversity; atmosphere; land; chemicals and hazardous wastes; and seas. Then the role of environmental, economic, and political factors and of dynamic and cross‐cluster effects is studied at the level ofMEAclusters. Two findings stand out from this empirical analysis. First, economic size and multilateral trade liberalisation of countries are found to be the most important drivers ofMEAparticipation across all clusters. Second, adjustment costs turn out to deter and, in particular, cross‐cluster spillovers turn out to stimulateMEAparticipation across countries and clusters.
Development of XFCT imaging strategy for monitoring the spatial distribution of platinum‐based chemodrugs: Instrumentation and phantom validation
Authors: Kuang Yu , Pratx Guillem , Bazalova Magdalena , Qian Jianguo , Meng Bowen , Xing Lei 
Published: February 2013

Purpose:Developing an imaging method to directly monitor the spatial distribution of platinum‐based (Pt) drugs at the tumor region is of critical importance for early assessment of treatment efficacy and personalized treatment. In this study, the authors investigated the feasibility of imaging platinum (Pt)‐based drug distribution using x‐ray fluorescence (XRF, a.k.a. characteristic x ray) CT (XFCT).Methods:A 5‐mm‐diameter pencil beam produced by a polychromatic x‐ray source equipped with a tungsten anode was used to stimulate emission of XRF photons from Pt drug embedded within a water phantom. The phantom was translated and rotated relative to the stationary pencil beam in a first‐generation CT geometry. The x‐ray energy spectrum was collected for 18 s at each position using a cadmium telluride detector. The spectra were then used for the K‐shell XRF peak isolation and sinogram generation for Pt. The distribution and concentration of Pt were reconstructed with an iterative maximum likelihood expectation maximization algorithm. The capability of XFCT to multiplexed imaging of Pt, gadolinium (Gd), and iodine (I) within a water phantom was also investigated.Results:Measured XRF spectrum showed a sharp peak characteristic of Pt with a narrow full‐width at half‐maximum (FWHM) (FWHMKα1 = 1.138 keV, FWHMKα2 = 1.052 keV). The distribution of Pt drug in the water phantom was clearly identifiable on the reconstructed XRF images. Our results showed a linear relationship between the XRF intensity of Pt and its concentrations (R2 = 0.995), suggesting that XFCT is capable of quantitative imaging. A transmission CT image was also obtained to show the potential of the approach for providing attenuation correction and morphological information. Finally, the distribution of Pt, Gd, and I in the water phantom was clearly identifiable in the reconstructed images from XFCT multiplexed imaging.Conclusions:XFCT is a promising modality for monitoring the spatial distribution of Pt drugs. The technique may be useful in tailoring tumor treatment regimen in the future.
Gantry and isocenter displacements of a linear accelerator caused by an add‐on micromultileaf collimator
Authors: Riis Hans L. , Zimmermann Sune J. , Hjelm‐Hansen Mogens 
Published: February 2013

Purpose:The delivery of high quality stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) treatments to the patient requires knowledge of the position of the isocenter to submillimeter accuracy. To meet the requirements the deviation between the radiation and mechanical isocenters must be less than 1 mm. The use of add‐on micromultileaf collimators (μMLCs) in SRS and SRT is an additional challenge to the anticipated high‐level geometric and dosimetric accuracy of the treatment. The aim of this work was to quantify the gantry excursions during rotation with and without an add‐on μMLC attached to the gantry head. In addition, the shift in the position of the isocenter and its correlation to the kV beam center of the cone‐beam CT system was included in the study.Methods:The quantification of the gantry rotational performance was done using a pointer supported by an in‐house made rigid holder attached to the gantry head of the accelerator. The pointer positions were measured using a digital theodolite. To quantify the effect of an μMLC of 50 kg, the measurements were repeated with the μMLC attached to the gantry head. The displacement of the isocenter due to an add‐on μMLC of 50 kg was also investigated. In case of the pointer measurement the μMLC was simulated by weights attached to the gantry head. A method of least squares was applied to determine the position and displacement of the mechanical isocenter. Additionally, the displacement of the radiation isocenter was measured using a ball‐bearing phantom and the electronic portal image device system. These measurements were based on 8 MV photon beams irradiated onto the ball from the four cardinal angles and two opposed collimator angles. The measurements and analysis of the data were carried out automatically using software delivered by the manufacturer.Results:The displacement of the mechanical isocenter caused by a 50 kg heavy μMLC was found to be (−0.01 ± 0.05, −0.10 ± 0.03, −0.26 ± 0.05) mm in lateral, longitudinal, and vertical direction, respectively. Similarly, the displacement of the radiation isocenter was found to be (0.00 ± 0.03, −0.08 ± 0.06, −0.32 ± 0.02) mm. Good agreement was found between the displacement of the two isocenters. A displacement of the kV cone‐beam CT beam center due to the attached weight of 50 kg could not be detected.Conclusions:General characteristics of the gantry arm excursions and displacements caused by an add‐on μMLC have been reported. A 50 kg heavy add‐on μMLC results in a isocenter displacement downward of 0.26–0.32 mm. The authors recommend that the beam center of the kV cone‐beam CT image system should be matched to the isocenter related to the weight of the μMLC. Consequently, the imperfections in isocenter localizations are transferred to the conventional radiotherapy where the clinical consequences of uncertainties in the submillimeter regime are negligible.
Monte Carlo assessment of CT dose equilibration in PMMA and water cylinders with diameters from 6 to 55 cm
Authors: Li Xinhua , Zhang Da , Liu Bob 
Published: February 2013

Purpose:In multidetector CT, the dose integralDIL of single scan dose profile over the integration interval (−L/2, L/2) can predict the accumulated dose DL(0) at the center of the scan range (−L/2, L/2) for a helical scan of pitch = 1. Both DIL and DL(0) increase with L until the limiting levels (DI∞ and Deq) are reached. The DL(0) equilibration is related to the DIL equilibration. The aim of this study was to evaluate the DIL/DI∞ growth curve, and its variations with factors such as phantom diameter, phantom axis (center or periphery), material (PMMA or water), tube voltage, and bowtie filter (head or body).Methods:A Geant4‐based Monte Carlo program was used to simulate single axial scans on a clinical CT scanner, and to compute axial dose profiles in the cylinders of 90 cm in length, and 6–50 cm (PMMA) and 6–55 cm (water) in diameters.DIL/DI∞ ratios were calculated over a range of integration lengths, and were fitted to a mathematical model: f(L) = 1 − α × exp[− (L/d)n], where α, d, and n were fitting parameters. The minimum length required for DIL to approach within 2% of DI∞ was referred to as the equilibrium length Leq. It could be directly derived from data, and was also calculated from the fits.Results:TheLeq results of the above two approaches were consistent (deviation: 1.4% on average, and 3.6% maximum). When the other conditions (such as tube voltage, bowtie filter, and phantom material) were the same, DI∞ increased with the reduced phantom diameters. The center/periphery DI∞ ratio was greater than 1 for small phantoms, and increased with larger phantoms until their diameters were above about 16 cm. Dose to water was substantially higher than that to PMMA, especially at the centers of large phantoms. As phantom diameter increased, α, n, and Leq increased on the central axis, and initially increased and then saturated [α ≈ 0.555 (PMMA and water), n ≈ 0.81 (PMMA) and 0.80 (water), and Leq ≈ 29 cm (PMMA) and 30 cm (water)] on the peripheral axis. Bowtie filter and tube voltage affected dose, but had small effects on α, n, and Leq. Leq was almost constant on the central or peripheral phantom axis for beam widths from 0.1 to 40 mm.Conclusions:The mathematical model can represent theDIL/DI∞ curve from a single axial CT scan. Generally, n ≠ 1. The equilibrium dose, α, n, and Leq exhibit strong dependencies on phantom diameter and location in the phantom. On the other hand, α, n, and Leq have relatively weak dependencies on material (PMMA or water), tube voltage (80–140 kVp), and bowtie filter, and Leq is also insensitive to beam width (⩽4 cm). A weak dependency of the DIL/DI∞ curve on CT scanner using 80–140 kVp and beam width up to 4 cm is consistent with the results of this study and previous publications. The dose equilibration data provided in this paper can be useful for CT dose evaluation. A framework is presented for assessing dose at any point in infinitely long PMMA and water cylinders undergoing multidetector CT examinations.
Antimicrobial Susceptibilities of Clinical Isolates of HACEK Organisms
Authors: Coburn Bryan , Toye Baldwin , Rawte Prasad , Jamieson Frances B. , Farrell David J. , Patel Samir N. 
Published: February 2013

ABSTRACT
The “HACEK” organisms are a group of fastidious Gram-negative bacteria that cause a variety of infections, including infective endocarditis. Antimicrobial susceptibility testing is not universally available, and therapy for these infections is often empirical. We report the antimicrobial susceptibilities of 70 clinical HACEK isolates to 18 antimicrobials. All isolates were susceptible to ceftriaxone and levofloxacin, indicating that these agents remain appropriate empirical choices for the treatment of infections with this group of organisms.
Risk Factors for a Low Linezolid Trough Plasma Concentration in Acute Infections
Authors: Morata Laura , Cuesta Marta , Rojas Jhon F. , Rodriguez Sebastian , Brunet Merce , Casals Gregori , Cobos Nazareth , Hernandez Cristina , Martínez José A. , Mensa Josep , Soriano Alex 
Published: February 2013

ABSTRACT

Linezolid is an antibiotic with time-dependent activity, and both the percentage of time that plasma concentrations exceed the MIC and the area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC
24
/MIC ratio) are associated with clinical response. The aim of this study was to analyze the linezolid trough plasma concentration (
C
min
) and to determine factors associated with a
C
min
< 2 mg/liter and other clinically relevant thresholds. Characteristics of 78 patients receiving 600 mg/12 h of linezolid with a
C
min
determination at the steady state and within the first 10 days of treatment were retrospectively reviewed. Concentrations were measured using high-pressure liquid chromatography. Univariate and multivariate analysis were performed to identify risk factors of low
C
min
. A total of 29.5% of patients had a
C
min
< 2 mg/liter. The percentage was significantly higher in patients with an estimated glomerular filtration (eGF) > 80 ml/min, in intensive care unit (ICU) patients, and in patients with an infection due to
Staphylococcus aureus
. The independent predictors of
C
min
< 2 mg/liter were an eGF > 80 ml/min (odds ratio [OR], 10; 95% confidence interval [CI], 2.732 to 37.037;
P
= 0.001) and infection due to
S. aureus
(OR, 5.906; 95% CI, 1.651 to 21.126;
P
= 0.006). A linezolid
C
min
of <2 mg/liter was found in 29.5% of cases, and the risk was significantly higher among those with an eGF > 80 ml/min and in infections due to
S. aureus
. In patients with severe sepsis, a loading dose or continuous infusion and drug monitoring could improve the pharmacodynamic parameters associated with linezolid efficacy.
Single-Dose Safety, Tolerability, and Pharmacokinetics of the Antibiotic GSK1322322, a Novel Peptide Deformylase Inhibitor
Authors: Naderer Odin J. , Dumont Etienne , Zhu John , Kurtinecz Milena , Jones Lori S. 
Published: February 2013

ABSTRACT

GSK1322322 is a potent inhibitor of peptide deformylase, an essential bacterial enzyme required for protein maturation. GSK1322322 is active against community-acquired skin and respiratory tract pathogens, including methicillin-resistant
Staphylococcus aureus
, multidrug-resistant
Streptococcus pneumoniae
, and atypical pathogens. This phase I, randomized, double-blind, placebo-controlled, 2-part, single-dose, dose escalation study (first time in humans) evaluated the safety, tolerability, and pharmacokinetics of GSK1322322 (powder-in-bottle formulation) in healthy volunteers. In part A, dose escalation included GSK1322322 doses of 100, 200, 400, 800, and 1,500 mg under fasting conditions and 800 mg administered with a high-fat meal. In part B, higher doses of GSK1322322 (2,000, 3,000, and 4,000 mg) were evaluated under fasting conditions. Of the 39 volunteers enrolled in the study, 29 and 10 volunteers were treated with GSK1322322 and placebo, respectively. Upon single-dose administration, GSK1322322 was absorbed rapidly, with median times to maximum plasma concentration (
T
max
) ranging from 0.5 to 1.0 h. The maximum observed plasma concentration (
C
max
) and exposure (area under the concentration-time curve [AUC]) of GSK1322322 were greater than dose proportional between 100 and 1,500 mg and less than dose proportional between 1,500 and 4,000 mg. Administration of the drug with a high-fat meal reduced the rate of absorption (reduced
C
max
and delayed
T
max
) without affecting the extent of absorption (no effect on AUC). GSK1322322 was generally well tolerated, with all adverse events being mild to moderate in intensity during both parts of the study. The most frequently reported adverse event was headache. Data from this study support further evaluation of GSK1322322.
Monte Carlo Simulations Based on Phase 1 Studies Predict Target Attainment of Ceftobiprole in Nosocomial Pneumonia Patients: a Validation Study
Authors: Muller Anouk E. , Schmitt-Hoffmann Anne H. , Punt Nieko , Mouton Johan W. 
Published: February 2013

ABSTRACT

Monte Carlo simulation (MCS) of antimicrobial dosage regimens during drug development to derive predicted target attainment values is frequently used to choose the optimal dose for the treatment of patients in phase 2 and 3 studies. A criticism is that pharmacokinetic (PK) parameter estimates and variability in healthy volunteers are smaller than those in patients. In this study, the initial estimates of exposure from MCS were compared with actual exposure data in patients treated with ceftobiprole in a phase 3 nosocomial-pneumonia (NP) study (NTC00210964). Results of MCS using population PK data from ceftobiprole derived from 12 healthy volunteers were used (J. W. Mouton, A. Schmitt-Hoffmann, S. Shapiro, N. Nashed, N. C. Punt, Antimicrob. Agents Chemother. 48:1713–1718, 2004). Actual individual exposures in patients were derived after building a population pharmacokinetic model and were used to calculate the individual exposure to ceftobiprole (the percentage of time the unbound concentration exceeds the MIC [percent
fT
> MIC]) for a range of MIC values. For the ranges of percent
fT
> MIC used to determine the dosage schedule in the phase 3 NP study, the MCS using data from a single phase 1 study in healthy volunteers accurately predicted the actual clinical exposure to ceftobiprole. The difference at 50%
fT
> MIC at an MIC of 4 mg/liter was 3.5% for PK-sampled patients. For higher values of percent
fT
> MIC and MICs, the MCS slightly underestimated the target attainment, probably due to extreme values in the PK profile distribution used in the simulations. The probability of target attainment based on MCS in healthy volunteers adequately predicted the actual exposures in a patient population, including severely ill patients.