The impact of the association between Val16Ala-SOD2 SNP and SOD2 immunohistochemistry expression in the prognosis of patients with esophageal cancer.

INTRODUCTION: Esophageal cancer is an extensive public health issue worldwide, warranting the search for biomarkers related to its risk and progression. Previous studies have indicated an association between Val16AlaSOD2 single nucleotide polymorphism in the gene encoding the enzyme superoxide dismutase 2 and esophageal cancer. However, further investigations are needed to clarify its role in disease risk and progression. OBJECTIVE: To investigate the role of Val16AlaSOD2-SNP in esophageal cancer progression and in the survival of patients METHODS: Tumor samples were utilized for Val16Ala-SNP genotyping, while SOD2 expression levels in tissue were assessed using immunohistochemistry. A SOD2 Val16Ala-SNP database was used to obtain information on the genotype of healthy individuals. Risk and overall survival analyzes were performed. RESULTS: The Val16Ala SNP was associated with an increased risk of esophageal cancer (RR 2.18, 95%CI 1.23-3.86), regardless of age and gender, but did not have a significant effect on patient survival. In contrast, weak SOD2 expression demonstrated a significantly associated with poor overall survival after treatment, independent of other clinicopathological variables (HR, 0.41; 95% CI, 0.22-0.79 P = 0.007). CONCLUSIONS: Val16Ala SNP was positively associated with esophageal cancer, and the expression of SOD2 was an independent prognostic marker.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples.

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

ROMA: A Database of Rock Reflectance Spectra for Martian In Situ Exploration.

The ROMA database (ROck reflectance for MArtian in situ exploration, https://roma.univ-lyon1.fr) provides the reflectance spectra between 0.4 and 3-4 µm of various terrestrial, Martian, and synthetic samples, as a means to document reference measurements for comparison with data acquired by visible and near-infrared spectrometers on planetary surfaces, with a focus on current and future Martian observations by the Perseverance (Mars 2020 mission) and Rosalind Franklin (ExoMars) rovers. The main specificity of this database is to include a significant fraction of spectra of unprocessed rock, which are more realistic analogs and often have different spectral features than the fine powders more commonly analyzed in reflectance spectroscopy. Additionally, these measurements were acquired with a spectrometer whose spot size is similar to those of the SuperCam instrument (Mars 2020 mission) at a few meters from a target. Supplementary information are provided in the ROMA database: higher-level data (such as absorption band parameters) as well as sample mineralogy estimated by whole-rock X-ray diffraction analyses. Future comparisons with this database will help improve the interpretation of spectral measurements acquired on the Martian surface. This work introduces the aim of the library and its current state, but additional data on intact natural rock surfaces will likely be added in the future.

Homogeneity assessment of the SuperCam calibration targets onboard rover perseverance.

The SuperCam instrument, onboard the Perseverance rover (Mars 2020 mission) is designed to perform remote analysis on the Martian surface employing several spectroscopic techniques such as Laser Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman (TRR), Time-Resolved Fluorescence (TRF) and Visible and Infrared (VISIR) reflectance. In addition, SuperCam also acquires high-resolution images using a color remote micro-imager (RMI) as well as sounds with its microphone. SuperCam has three main subsystems, the Mast Unit (MU) where the laser for chemical analysis and collection optics are housed, the Body Unit (BU) where the different spectrometers are located inside the rover, and the SuperCam Calibration Target (SCCT) located on the rover's deck to facilitate calibration tests at similar ambient conditions as the analyzed samples. To perform adequate calibrations on Mars, the 22 mineral samples included in the complex SCCT assembly must have a very homogeneous distribution of major and minor elements. The analysis and verification of such homogeneity for the 5-6 replicates of the samples included in the SCCT has been the aim of this work. To verify the physic-chemical homogeneity of the calibration targets, micro Energy Dispersive X-ray Fluorescence (EDXRF) imaging was first used on the whole surface of the targets, then the relative abundances of the detected elements were computed on 20 randomly distributed areas of 100 × 100 µm. For those targets showing a positive Raman response, micro-Raman spectroscopy imaging was performed on the whole surface of the targets at a resolution of 100 × 100 µm. The %RSD values (percent of relative standard deviation of mean values) for the major elements measured with EDXRF were compared with similar values obtained by two independent LIBS set-ups at spot sizes of 300 µm in diameter. The statistical analysis showed which elements were homogeneously distributed in the 22 mineral targets of the SCCT, providing their uncertainty values for further calibration. Moreover, nine of the 22 targets showed a good Raman response and their mineral distributions were also studied. Those targets can be also used for calibration purposes of the Raman part of SuperCam using the wavenumbers of their main Raman bands proposed in this work.

Divergent abiotic spectral pathways unravel pathogen stress signals across species.

Plant pathogens pose increasing threats to global food security, causing yield losses that exceed 30% in food-deficit regions. Xylella fastidiosa (Xf) represents the major transboundary plant pest and one of the world's most damaging pathogens in terms of socioeconomic impact. Spectral screening methods are critical to detect non-visual symptoms of early infection and prevent spread. However, the subtle pathogen-induced physiological alterations that are spectrally detectable are entangled with the dynamics of abiotic stresses. Here, using airborne spectroscopy and thermal scanning of areas covering more than one million trees of different species, infections and water stress levels, we reveal the existence of divergent pathogen- and host-specific spectral pathways that can disentangle biotic-induced symptoms. We demonstrate that uncoupling this biotic-abiotic spectral dynamics diminishes the uncertainty in the Xf detection to below 6% across different hosts. Assessing these deviating pathways against another harmful vascular pathogen that produces analogous symptoms, Verticillium dahliae, the divergent routes remained pathogen- and host-specific, revealing detection accuracies exceeding 92% across pathosystems. These urgently needed hyperspectral methods advance early detection of devastating pathogens to reduce the billions in crop losses worldwide.

Detection of Xylella fastidiosa in almond orchards by synergic use of an epidemic spread model and remotely sensed plant traits.

The early detection of Xylella fastidiosa (Xf) infections is critical to the management of this dangerous plan pathogen across the world. Recent studies with remote sensing (RS) sensors at different scales have shown that Xf-infected olive trees have distinct spectral features in the visible and infrared regions (VNIR). However, further work is needed to integrate remote sensing in the management of plant disease epidemics. Here, we research how the spectral changes picked up by different sets of RS plant traits (i.e., pigments, structural or leaf protein content), can help capture the spatial dynamics of Xf spread. We coupled a spatial spread model with the probability of Xf-infection predicted by a RS-driven support vector machine (RS-SVM) model. Furthermore, we analyzed which RS plant traits contribute most to the output of the prediction models. For that, in almond orchards affected by Xf (n = 1426 trees), we conducted a field campaign simultaneously with an airborne campaign to collect high-resolution thermal images and hyperspectral images in the visible-near-infrared (VNIR, 400-850 nm) and short-wave infrared regions (SWIR, 950-1700 nm). The best performing RS-SVM model (OA = 75%; kappa = 0.50) included as predictors leaf protein content, nitrogen indices (NIs), fluorescence and a thermal indicator (Tc), alongside pigments and structural parameters. Leaf protein content together with NIs contributed 28% to the explanatory power of the model, followed by chlorophyll (22%), structural parameters (LAI and LIDFa), and chlorophyll indicators of photosynthetic efficiency. Coupling the RS model with an epidemic spread model increased the accuracy (OA = 80%; kappa = 0.48). In the almond trees where the presence of Xf was assayed by qPCR (n = 318 trees), the combined RS-spread model yielded an OA of 71% and kappa = 0.33, which is higher than the RS-only model and visual inspections (both OA = 64-65% and kappa = 0.26-31). Our work demonstrates how combining spatial epidemiological models and remote sensing can lead to highly accurate predictions of plant disease spatial distribution.

SuperCam Calibration Targets: Design and Development.

SuperCam is a highly integrated remote-sensing instrumental suite for NASA's Mars 2020 mission. It consists of a co-aligned combination of Laser-Induced Breakdown Spectroscopy (LIBS), Time-Resolved Raman and Luminescence (TRR/L), Visible and Infrared Spectroscopy (VISIR), together with sound recording (MIC) and high-magnification imaging techniques (RMI). They provide information on the mineralogy, geochemistry and mineral context around the Perseverance Rover. The calibration of this complex suite is a major challenge. Not only does each technique require its own standards or references, their combination also introduces new requirements to obtain optimal scientific output. Elemental composition, molecular vibrational features, fluorescence, morphology and texture provide a full picture of the sample with spectral information that needs to be co-aligned, correlated, and individually calibrated. The resulting hardware includes different kinds of targets, each one covering different needs of the instrument. Standards for imaging calibration, geological samples for mineral identification and chemometric calculations or spectral references to calibrate and evaluate the health of the instrument, are all included in the SuperCam Calibration Target (SCCT). The system also includes a specifically designed assembly in which the samples are mounted. This hardware allows the targets to survive the harsh environmental conditions of the launch, cruise, landing and operation on Mars during the whole mission. Here we summarize the design, development, integration, verification and functional testing of the SCCT. This work includes some key results obtained to verify the scientific outcome of the SuperCam system.

Global plant trait relationships extend to the climatic extremes of the tundra biome.

The majority of variation in six traits critical to the growth, survival and reproduction of plant species is thought to be organised along just two dimensions, corresponding to strategies of plant size and resource acquisition. However, it is unknown whether global plant trait relationships extend to climatic extremes, and if these interspecific relationships are confounded by trait variation within species. We test whether trait relationships extend to the cold extremes of life on Earth using the largest database of tundra plant traits yet compiled. We show that tundra plants demonstrate remarkably similar resource economic traits, but not size traits, compared to global distributions, and exhibit the same two dimensions of trait variation. Three quarters of trait variation occurs among species, mirroring global estimates of interspecific trait variation. Plant trait relationships are thus generalizable to the edge of global trait-space, informing prediction of plant community change in a warming world.

Chlorophyll content estimation in an open-canopy conifer forest with Sentinel-2A and hyperspectral imagery in the context of forest decline.

With the advent of Sentinel-2, it is now possible to generate large-scale chlorophyll content maps with unprecedented spatial and temporal resolution, suitable for monitoring ecological processes such as vegetative stress and/or decline. However methodological gaps exist for adapting this technology to heterogeneous natural vegetation and for transferring it among vegetation species or plan functional types. In this study, we investigated the use of Sentinel-2A imagery for estimating needle chlorophyll (Ca+b) in a sparse pine forest undergoing significant needle loss and tree mortality. Sentinel-2A scenes were acquired under two extreme viewing geometries (June vs. December 2016) coincident with the acquisition of high-spatial resolution hyperspectral imagery, and field measurements of needle chlorophyll content and crown leaf area index. Using the high-resolution hyperspectral scenes acquired over 61 validation sites we found the CI chlorophyll index R750/R710 and Macc index (which uses spectral bands centered at 680 nm, 710 nm and 780 nm) had the strongest relationship with needle chlorophyll content from individual tree crowns (r2 = 0.61 and r2 = 0.59, respectively; p < 0.001), while TCARI and TCARI/OSAVI, originally designed for uniform agricultural canopies, did not perform as well (r2 = 0.21 and r2 = 0.01, respectively). Using lower-resolution Sentinel-2A data validated against hyperspectral estimates and ground truth needle chlorophyll content, the red-edge index CI and the Sentinel-specific chlorophyll indices CI-Gitelson, NDRE1 and NDRE2 had the highest accuracy (with r2 values >0.7 for June and >0.4 for December; p < 0.001). The retrieval of needle chlorophyll content from the entire Sentinel-2A bandset using the radiative transfer model INFORM yielded r2 = 0.71 (RMSE = 8.1 µg/cm2) for June, r2 = 0.42 (RMSE = 12.2 µg/cm2) for December, and r2 = 0.6 (RMSE = 10.5 µg/cm2) as overall performance using the June and December datasets together. This study demonstrates the retrieval of leaf Ca+b with Sentinel-2A imagery by red-edge indices and by an inversion method based on a hybrid canopy reflectance model that accounts for tree density, background and shadow components common in sparse forest canopies.

The intrinsic vulnerability of networks to epidemics.

Contact networks are convenient models to investigate epidemics, with nodes and links representing potential hosts and infection pathways, respectively. The outcomes of outbreak simulations on networks are driven both by the underlying epidemic model, and by the networks' structural properties, so that the same pathogen can generate different epidemic dynamics on different networks. Here we ask whether there are general properties that make a contact network intrinsically vulnerable to epidemics (that is, regardless of specific epidemiological parameters). By conducting simulations on a large set of modelled networks, we show that, when a broad range of network topologies is taken into account, the effect of specific network properties on outbreak magnitude is stronger than that of fundamental pathogen features such as transmission rate, infection duration, and immunization ability. Then, by focusing on a large set of real world networks of the same type (potential contacts between field voles, Microtus agrestis), we showed how network structure can be used to accurately assess the relative, intrinsic vulnerability of networks towards a specific pathogen, even when those have limited topological variability. These results have profound implications for how we prevent disease outbreaks; in many real world situations, the topology of host contact networks can be described and used to infer intrinsic vulnerability. Such an approach can increase preparedness and inform preventive measures against emerging diseases for which limited epidemiological information is available, enabling the identification of priority targets before an epidemic event.

Previsual symptoms of Xylella fastidiosa infection revealed in spectral plant-trait alterations.

Plant pathogens cause significant losses to agricultural yields and increasingly threaten food security1, ecosystem integrity and societies in general2-5. Xylella fastidiosa is one of the most dangerous plant bacteria worldwide, causing several diseases with profound impacts on agriculture and the environment6. Primarily occurring in the Americas, its recent discovery in Asia and Europe demonstrates that X. fastidiosa's geographic range has broadened considerably, positioning it as a reemerging global threat that has caused socioeconomic and cultural damage7,8. X. fastidiosa can infect more than 350 plant species worldwide9, and early detection is critical for its eradication8. In this article, we show that changes in plant functional traits retrieved from airborne imaging spectroscopy and thermography can reveal X. fastidiosa infection in olive trees before symptoms are visible. We obtained accuracies of disease detection, confirmed by quantitative polymerase chain reaction, exceeding 80% when high-resolution fluorescence quantified by three-dimensional simulations and thermal stress indicators were coupled with photosynthetic traits sensitive to rapid pigment dynamics and degradation. Moreover, we found that the visually asymptomatic trees originally scored as affected by spectral plant-trait alterations, developed X. fastidiosa symptoms at almost double the rate of the asymptomatic trees classified as not affected by remote sensing. We demonstrate that spectral plant-trait alterations caused by X. fastidiosa infection are detectable previsually at the landscape scale, a critical requirement to help eradicate some of the most devastating plant diseases worldwide.

Understanding the temporal dimension of the red-edge spectral region for forest decline detection using high-resolution hyperspectral and Sentinel-2a imagery.

The operational monitoring of forest decline requires the development of remote sensing methods that are sensitive to the spatiotemporal variations of pigment degradation and canopy defoliation. In this context, the red-edge spectral region (RESR) was proposed in the past due to its combined sensitivity to chlorophyll content and leaf area variation. In this study, the temporal dimension of the RESR was evaluated as a function of forest decline using a radiative transfer method with the PROSPECT and 3D FLIGHT models. These models were used to generate synthetic pine stands simulating decline and recovery processes over time and explore the temporal rate of change of the red-edge chlorophyll index (CI) as compared to the trajectories obtained for the structure-related Normalized Difference Vegetation Index (NDVI). The temporal trend method proposed here consisted of using synthetic spectra to calculate the theoretical boundaries of the subspace for healthy and declining pine trees in the temporal domain, defined by CItime=n/CItime=n+1 vs. NDVItime=n/NDVItime=n+1. Within these boundaries, trees undergoing decline and recovery processes showed different trajectories through this subspace. The method was then validated using three high-resolution airborne hyperspectral images acquired at 40 cm resolution and 260 spectral bands of 6.5 nm full-width half-maximum (FWHM) over a forest with widespread tree decline, along with field-based monitoring of chlorosis and defoliation (i.e., 'decline' status) in 663 trees between the years 2015 and 2016. The temporal rate of change of chlorophyll vs. structural indices, based on reflectance spectra extracted from the hyperspectral images, was different for trees undergoing decline, and aligned towards the decline baseline established using the radiative transfer models. By contrast, healthy trees over time aligned towards the theoretically obtained healthy baseline. The applicability of this temporal trend method to the red-edge bands of the MultiSpectral Imager (MSI) instrument on board Sentinel-2a for operational forest status monitoring was also explored by comparing the temporal rate of change of the Sentinel-2-derived CI over areas with declining and healthy trees. Results demonstrated that the Sentinel-2a red-edge region was sensitive to the temporal dimension of forest condition, as the relationships obtained for pixels in healthy condition deviated from those of pixels undergoing decline.

A photonumeric scale for the assessment of atrophic facial photodamage.

BACKGROUND: Photonumeric scales have consistently shown superiority over descriptive equivalents. They have the advantage of providing a consistent visual frame of reference by minimizing variability in perception and subjectivity. A photonumeric scale to assess hypertrophic facial photodamage already exists. However, there is currently no objective measure for atrophic facial photodamage. To address this, we have devised a nine-point photonumeric standardized scale. OBJECTIVES: To design, test and validate a photonumeric scale for the assessment of atrophic facial photodamage against a descriptive scale for the same indication. METHODS: A pool of 393 facial photographs (en face and 45° oblique) from 131 individuals with atrophic facial photodamage was created. Five photographic standards were selected and assigned grades zero through to eight, where zero is no photodamage and eight is severe atrophic photodamage, thus making a nine-point scale. Twenty photographs spanning the entire range of values were selected to test the scale. Testing was performed alongside a descriptive equivalent. A panel of 10 dermatologists, 10 nondermatology clinicians and 14 dermatology scientists marked the two scales; marking was repeated 1 week later. RESULTS: There was a significantly greater agreement between the graders using the photonumeric scale than the descriptive scale (kappa values 0·71 and 0·37 with standardized errors of 0·57 and 0·17, respectively) with no significant difference in repeatability between the two methods (P < 0·05). CONCLUSIONS: The study describes a new photonumeric scale for atrophic photodamage. This would be a useful adjunct in both the clinical and research settings.

Grazing management of mixed alfalfa bermudagrass pastures.

Rotational grazing management is commonly recommended to improve persistence of legumes interseeded into bermudagrass, but impacts on animal performance are poorly understood. Steers (n = 365, BW = 249 ± 22.9 kg) grazed mixed alfalfa (Medicago sativa L.)/bermudagrass (Cynodon dactylon [L.] Pers.) pastures (n = 10; 1.6-ha) with either continuous grazing (CONT) or rotational grazing (ROT) management over 3 yr. Initial stocking rate was set at 6.25 steers/ha. When forage allowance of CONT became limiting in mid-July each year, 2 randomly selected steers were removed from all pastures to maintain equal stocking rates in CONT and ROT. Rotational grazing pastures were divided into 8 paddocks with 3-d grazing and 21-d rest between grazing events. Initial, final, and interim (28-d) BW were collected following a 16-h removal from feed and water. Data were analyzed as a repeated measures experiment with completely random design using the mixed procedure of SAS (SAS Inst. Inc., Cary, NC) using pasture within treatment by year in the random statement. Across years, steer BW did not differ (P ≥ 0.47) at the midpoint or end of the grazing season. Daily BW gains during the early summer period tended (P = 0.10) to be 0.11 kg greater for CONT than ROT in yr 1, but did not differ (P ≥ 0.24) in yr 2 and 3. In the late summer, ADG was 0.15 kg less (P < 0.01) for CONT than ROT in yr 1, were not different (P = 0.23) in yr 2, and were 0.29 kg less (P < 0.01) for CONT than ROT in yr 3. Over the entire experimental period, ADG did not differ (P ≥ 0.67) in yr 1 or 2, but tended (P = 0.09) to be 0.10 kg greater for ROT than CONT in yr 3. Forage mass of ROT was greater (P < 0.01) than CONT throughout the grazing season. Because stocking rates were maintained at the same level, ROT pastures provided greater (P < 0.01) forage allowance during the grazing season than CONT explaining differences in ADG between treatments. Alfalfa stand percentage did not differ (P = 0.79) at the beginning of the experiment, but was less (P ≤ 0.03) for CONT than ROT at all other sampling dates. These data indicate that at equal stocking rates, ROT can maintain greater alfalfa persistence, forage nutritive quality, and forage allowance compared with continuous grazing and provided increased animal performance during the late summer when the alfalfa stand was reduced in CONT pastures.

Acceleration of sub-relativistic electrons with an evanescent optical wave at a planar interface.

We report on a theoretical and experimental study of the energy transfer between an optical evanescent wave, propagating in vacuum along the planar boundary of a dielectric material, and a beam of sub-relativistic electrons. The evanescent wave is excited via total internal reflection in the dielectric by an infrared (λ = 2 µm) femtosecond laser pulse. By matching the electron propagation velocity to the phase velocity of the evanescent wave, energy modulation of the electron beam is achieved. A maximum energy gain of 800 eV is observed, corresponding to the absorption of more than 1000 photons by one electron. The maximum observed acceleration gradient is 19 ± 2 MeV/m. The striking advantage of this scheme is that a structuring of the acceleration element's surface is not required, enabling the use of materials with high laser damage thresholds that are difficult to nano-structure, such as SiC, Al2O3 or CaF2.

The effects of pregnancy on the pharmacokinetics of infliximab and adalimumab in inflammatory bowel disease.

BACKGROUND: Transplacental transfer of infliximab and adalimumab results in detectable drug levels in the cord blood and infant. AIM: To determine if pregnancy influenced the pharmacokinetics of anti-TNF agents in women with inflammatory bowel disease. METHODS: Twenty-five women from the University of Calgary inflammatory bowel disease(IBD) pregnancy clinic on maintenance infliximab or adalimumab were recruited prospectively with serum bio-banking performed each trimester. Infliximab trough and adalimumab steady-state levels were the outcomes of interest and were analysed using the ANSER infliximab and adalimumab assays. Multivariate linear mixed-effects models were constructed to assess infliximab and adalimumab drug levels during pregnancy adjusting for the clinical covariates of albumin, BMI and CRP. RESULTS: Fifteen women (eight Crohn's disease, seven ulcerative colitis) received infliximab and 10 women with 11 pregnancies were treated with adalimumab. Median age was 29.6 years (IQR: 27.6-31.2 years). Median disease duration was 9.2 years (IQR: 3.16-15.0 years). Median trough infliximab concentrations were 8.50 µg/mL (IQR: 7.23-10.07 µg/mL), 10.31 µg/mL (IQR: 7.66-15.63 µg/mL) and 21.02 µg/mL (IQR: 16.01-26.70 µg/mL) at trimesters 1, 2 and 3 respectively. Significant changes in albumin and BMI (P < 0.05) but not CRP (P > 0.05) were documented throughout pregnancy. After adjusting for albumin, BMI and CRP, infliximab trough levels increased during pregnancy, by 4.2 µg/mL per trimester (P = 0.02), while adalimumab drug levels remained stable (P > 0.05). CONCLUSIONS: Infliximab levels rise during pregnancy, whereas adalimumab levels remain stable after accounting for changes in albumin, BMI and CRP. Therapeutic drug monitoring in the second trimester may be useful in guiding dosing in the third trimester.

Effects of stocking rate, forage management, and grazing management on performance and economics of cow-calf production in Southwest Arkansas.

The objective this research was to determine the effect of application of multiple grazing management practices at 2 stocking rates (SR) on the productivity and economics of the cow-calf enterprise in the Southeastern United States over a 4-yr period. Pasture management systems included: continuous grazing management at a moderate SR (0.8 ha/cow; CG) without additional forage management, rotational grazing management at a moderate SR (0.8 ha/cow (MR) with addition of stockpiled bermudagrass [ (L.) Pers.] and complementary cool season annuals, and rotational grazing management similar to MR but with a high SR (0.4 ha/cow; HR). Stockpiling in MR and HR was managed by fertilization of 0.2 ha/cow of bermudagrass in early August with 168 kg ammonium nitrate and deferring grazing until November. Wheat (; 112 kg/ha) and annual ryegrass ( Lam.; 28 kg/ha) were interseeded (0.2 ha/cow) in HR and MR with a no-till drill in the fall. Cow and calf performance and economics data were analyzed by ANOVA using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC) and pregnancy percentage was analyzed using the GLIMMIX procedure of SAS; pasture was the experimental unit and year was the random block. Hay feeding days decreased ( < 0.01) from 107 ± 10.9 d for CG to 37 ± 10.9 d for HR, which was further reduced ( = 0.01) to 15 ± 10.9 d for MR. Pregnancy percentage did not differ ( = 0.20) among treatments. Weaning BW in CG (237 ± 7.3 kg) tended ( = 0.09) to be greater than in MR (227 ± 7.3 kg) and were greater ( < 0.01) than in HR (219 ± 7.3 kg). However, total weaning BW per hectare was 89% greater ( < 0.01) for HR compared with CG and MR, which did not differ ( = 0.31). With rotational stocking, there was the opportunity to harvest excess forage as hay in both MR and HR with a net value of US$52.90/ha ± 25.73 and $15.50/ha ± 25.73, respectively. Net returns per hectare did not differ ( = 0.30) between CG ($429 ± 63.0/ha) and MR ($479 ± 63.0/ha) but were increased ( < 0.01) by 107% by HR ($1,024 ± 63.0/ha). Using rotational grazing, stockpiled bermudagrass, and complementary cool-season annual grasses can drastically reduce winter feed requirements and simultaneously increase carrying capacity and net return.

Effect of mature body weight and stocking rate on cow and calf performance, cow herd efficiency, and economics in the southeastern United States.

Eight 4-ha mixed warm-season grass pastures in southwestern Arkansas (33°40'4″ N, 93°35'24″ W, and elevation 107 m) were stocked with either large mature size (571 kg [SD 55.2] BW) or small mature size (463 kg [SD 58.2] BW) spring-calving cows at 4 stocking rates (SR; 1, 1.5, 2, or 2.5 cow-calf pairs/ha) over 4 yr to test the effects of SR and mature body size on cow and calf performance and system economics. Each pasture received 112 kg/ha N as ammonium nitrate in May and was broadcast seeded to annual ryegrass ( Lam.) in mid October each fall along with 112 kg/ha N as ammonium nitrate. Data were analyzed by regression to determine the effects of cow size and SR on calf performance, cow BW change, calf gain, weaning weight per hectare, hay feeding requirements, and net returns. As SR increased, cow BW and BCS at weaning decreased ( < 0.01) by 26 kg and 0.36 condition scores, respectively, for each additional cow stocked per hectare ( = 0.44). Calf BW at weaning in October increased ( < 0.01) 19 kg for each 100-kg increase in cow BW but was not affected ( = 0.66) by SR. As cow BW increased, calf BW at weaning per 100 kg cow BW decreased ( < 0.01) 6.7 kg for each 100-kg increase in cow BW but was not affected ( = 0.44) by SR. Neither cow BW nor SR affected ( ≥ 0.53) pregnancy percentage, which averaged 88% over the 4-yr experiment. Calf BW weaned per hectare was not affected ( = 0.75) by cow BW but linearly increased ( < 0.01) by 217 kg for each additional cow per hectare SR. Hay feeding days and cost of hay per cow increased ( ≤ 0.05) and kilograms of hay offered per cow tended ( = 0.09) to linearly increase with increasing SR, yet cow BW had no effects ( > 0.22). Although there were no effects ( ≥ 0.38) of cow BW on carrying cost or net returns, increasing SR decreased ( < 0.01) total expenses by US$102/cow and increased net returns by $70/cow and $438/ha for each cow per hectare increase in SR. These data indicate that increasing cow size can increase weaning BW of calves but does not affect total production per hectare or profitability, even though weaning weight efficiency ratios were reduced. Increasing SR reduced cow BW and BCS at weaning and increased feeding of conserved forages but did not affect pregnancy rates and led to increases in total calf BW weaned per hectare and net returns.

Unique microbial-derived volatile organic compounds in portal venous circulation in murine non-alcoholic fatty liver disease.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease is now the leading liver disease in North America. The progression of non-alcoholic fatty liver disease to the inflammatory condition, non-alcoholic steatohepatitis is complex and currently not well understood. Intestinal microbial dysbiosis has been implicated in the development of non-alcoholic fatty liver disease and progression of non-alcoholic steatohepatitis. Volatile organic compounds are byproducts of microbial metabolism in the gut that may enter portal circulation and have hepatotoxic effects contributing to the pathogenesis of non-alcoholic steatohepatitis. To test this hypothesis, we measured volatile organic compounds in cecal luminal contents and portal venous blood in a mouse model of non-alcoholic steatohepatitis. METHODS: Gas chromatography-mass spectrometry analysis was conducted on cecal content and portal vein blood for volatile organic compound detection from mice fed a methionine and choline deficient diet, which induces non-alcoholic steatohepatitis. The colonic microbiome was studied by 16S rRNA gene amplification using the Illumina MiSeq platform. RESULTS: Sixty-eight volatile organic compounds were detected in cecal luminal content, a subset of which was also present in portal venous blood. Importantly, differences in portal venous volatile organic compounds were associated with diet-induced steatohepatitis establishing a biochemical link between gut microbiota-derived volatile organic compounds and increased susceptibility to non-alcoholic steatohepatitis. CONCLUSION: Our model creates a novel tool to further study the role of gut-derived volatile organic compounds in the pathogenesis of non-alcoholic steatohepatitis.