bluuebunny/crossref_metadata_2025 huggingface dataset:
RdgBα reciprocally transfers PA and PI at ER–PM contact sites to maintain PI(4,5)P2 homoeostasis during phospholipase C signalling in Drosophila photoreceptors
Authors: Cockcroft Shamshad , Garner Kathryn , Yadav Shweta , Gomez-Espinoza Evelyn , Raghu Padinjat
Published: February 2016

Phosphatidylinositol (PI) is the precursor lipid for the synthesis of PI 4,5-bisphosphate [PI(4,5)P2] at the plasma membrane (PM) and is sequentially phosphorylated by the lipid kinases, PI 4-kinase and phosphatidylinositol 4-phosphate (PI4P)-5-kinase. Receptor-mediated hydrolysis of PI(4,5)P2 takes place at the PM but PI resynthesis occurs at the endoplasmic reticulum (ER). Thus PI(4,5)P2 resynthesis requires the reciprocal transport of two key intermediates, phosphatidic acid (PA) and PI between the ER and the PM. PI transfer proteins (PITPs), defined by the presence of the PITP domain, can facilitate lipid transfer between membranes; the PITP domain comprises a hydrophobic cavity with dual specificity but accommodates a single phospholipid molecule. The class II PITP, retinal degeneration type B (RdgB)α is a multi-domain protein and its PITP domain can bind and transfer PI and PA. In Drosophila photoreceptors, a well-defined G-protein-coupled phospholipase Cβ (PLCβ) signalling pathway, phototransduction defects resulting from loss of RdgBα can be rescued by expression of the PITP domain provided it is competent for both PI and PA transfer. We propose that RdgBα proteins maintain PI(4,5)P2 homoeostasis after PLC activation by facilitating the reciprocal transport of PA and PI at ER–PM membrane contact sites.
Study on the maximum calculation height and the maximum propagation angle of the troposcatter wide‐angle parabolic equation method
Authors: Li Lei , Lin Le‐Ke , Wu Zhen‐Sen , Zhao Zhen‐Wei
Published: February 2016

In this study, a method to choose the maximum calculation height and the maximum propagation angle of the split‐step troposcatter wide‐angle parabolic equation (TWAPE) method is presented. The method is implemented with the height and the scatter angle of the troposcatter common volume. The performance of this method is then demonstrated with a few examples which rely heavily on the choosing of the maximum calculation height and the maximum propagation angle. These examples include the comparison of calculated results of TWAPE for choosing different maximum calculated height and maximum propagation angle at frequencies of 3 and 1 GHz, path lengths of 300 and 500 km, respectively. Finally, the seasonal variation mechanism of the troposcatter propagation loss is discussed based on the seasonal variation of the refractive‐index structure parameter.
Best for pleasure, not for business: evaluating recreational marine fisheries in West Africa using unconventional sources of data
Authors: Belhabib Dyhia , Campredon Pierre , Lazar Najih , Sumaila U. Rashid , Baye Braham Cheikh , Kane Elimane Abou , Pauly Daniel
Published: February 2016

West African recreational fisheries, previously overlooked, are often assumed to be insignificant, yet they are increasingly present on social media given anglers’ tendencies to document their experiences. It is important to catch the trend early on as recreational fisheries develop in order to support their sustainable development and to make the most of the alternative economic opportunities that they offer. Here, the recreational fisheries of 11 West African countries are assessed using tourist records from YouTube, blogs and other unconventional records. We introduce the concept of “Recreational-to-Commercial Ratio (RCR)”, that is, the market-equivalent value per tonne of recreational fish injected to the economy, which is similar to “willingness to pay” for fish caught for recreation. Since the recreational fisheries of West African countries gained popularity in the last few years, catches increased and reached a total of 34,000 t annually, none of which was reported in official fisheries statistics. Recreational catches through a total annual revenue of US$152 million had an RCR of approximately 7, which means that developing recreational fisheries would increase the value of fish (whether caught or released) sevenfold. These findings could have major implications for the economy and conservation of fish stocks in West African countries.
Detection of third-hand smoke on clothing fibers with a surface acoustic wave gas sensor
Authors: Cheng Chi-Yung , Huang Shih-Shen , Yang Chia-Min , Tang Kea-Tiong , Yao Da-Jeng
Published: February 2016

Third-hand smoke (THS) is a new cigarette-related issue defined as the residual contamination from cigarette smoke after a cigarette is extinguished. To detect THS on three commonly used clothing fibers—wool, cotton, and polyester, we applied two methods to measure the adsorption of THS: one was the gain of mass with an analytical balance after exposure to cigarette smoke; and the other was to detect the THS chemical compounds such as nicotine and 3-ethenylpyridine with a surface acoustic wave (SAW) sensor composed of coated oxidized hollow mesoporous carbon nanospheres. In the mass measurement, the gain of mass decreased in the order wool, cotton, and polyester; the latter gain was about one tenth that of wool. In the SAW detection, the frequency shift decreased in the same order—wool, cotton, and polyester. The residence period of THS on natural fiber (wool and cotton) is greater than on synthetic polyester fiber. These two tests provide quantitative results of THS on varied clothing fibers, to assess their risk after exposure to cigarette smoke.
Charged vanadium-benzene multidecker clusters: DFT and quantum Monte Carlo study
Authors: Tokár K. , Derian R. , Mitas L. , Štich I.
Published: February 2016

Using explicitly correlated fixed-node quantum Monte Carlo and density functional theory (DFT) methods, we study electronic properties, ground-state multiplets, ionization potentials, electron affinities, and low-energy fragmentation channels of charged half-sandwich and multidecker vanadium-benzene systems with up to 3 vanadium atoms, including both anions and cations. It is shown that, particularly in anions, electronic correlations play a crucial role; these effects are not systematically captured with any commonly used DFT functionals such as gradient corrected, hybrids, and range-separated hybrids. On the other hand, tightly bound cations can be described qualitatively by DFT. A comparison of DFT and quantum Monte Carlo provides an in-depth understanding of the electronic structure and properties of these correlated systems. The calculations also serve as a benchmark study of 3d molecular anions that require a balanced many-body description of correlations at both short- and long-range distances.
SnTe microcrystals: Surface cleaning of a topological crystalline insulator
Authors: Saghir M. , Walker M. , McConville C. F. , Balakrishnan G.
Published: February 2016

Investigating nanometer and micron sized materials thought to exhibit topological surface properties that can present a challenge, as clean surfaces are a pre-requisite for band structure measurements when using nano-ARPES or laser-ARPES in ultra-high vacuum. This issue is exacerbated when dealing with nanometer or micron sized materials, which have been prepared ex-situ and so have been exposed to atmosphere. We present the findings of an XPS study where various cleaning methods have been employed to reduce the surface contamination and preserve the surface quality for surface sensitive measurements. Microcrystals of the topological crystalline insulator SnTe were grown ex-situ and transferred into ultra high vacuum (UHV) before being treated with either atomic hydrogen, argon sputtering, annealing, or a combination of treatments. The samples were also characterised using the scanning electron microscopy, both before and after treatment. It was found that atomic hydrogen cleaning with an anneal cycle (200 °C) gave the best clean surface results.
Vectorial mapping of noncollinear antiferromagnetic structure of semiconducting FeSe surface with spin-polarized scanning tunneling microscopy
Authors: Zhang K. F. , Zhang Xiaole , Yang Fang , Song Y. R. , Chen Xianfeng , Liu Canhua , Qian Dong , Luo Weidong , Gao C. L. , Jia Jin-Feng
Published: February 2016

Antiferromagnetic semiconductors gain increasing interest due to their possible application in spintronics. Using spin polarized scanning tunneling microscopy operating in a vector field, we mapped the noncollinear antiferromagnetic spin structure of a semiconducting hexagonal FeSe surface on the atomic scale. The surface possesses an in-plane compensated Néel structure which is further confirmed by first-principles calculations.
Extracting conformational information from single molecule photon statistics
Authors: Peng Yonggang , Yang Chuanlu , Zheng Yujun
Published: February 2016

In this paper, we describe the approach of resonant trajectories of photon emission (Traj〈N〉 and TrajQ) in the conformational coordinate X and external field frequency ωL space to extract the conformational information of single molecule. The Smoluchowski equation is employed to describe the conformational dynamics of the single molecule in complex environments. This approach is applied to single Thioflavin T (ThT) molecule, and our results are in excellent agreement with the results of ab initio simulations.
Entropic screening preserves non-equilibrium nature of nematic phase while enthalpic screening destroys it
Authors: Dan K. , Roy M. , Datta A.
Published: February 2016

The present manuscript describes the role of entropic and enthalpic forces mediated by organic non-polar (hexane) and polar (methanol) solvents on the bulk and microscopic phase transition of a well known nematic liquid crystalline material MBBA (N-(4-methoxybenzylidene)-4-butylaniline) through Differential Scanning calorimetry (DSC), UV-Visible (UV–Vis), and Fourier Transform Infrared (FTIR) spectroscopy. DSC study indicates continuous linear decreases in both nematic-isotropic (N-I) phase transition temperature and enthalpy of MBBA in presence of hexane while both these parameters show a saturation after an initial decay in methanol. These distinct transitional behaviours were explained in terms of the “depletion force” model for entropic screening in hexane and “screening-self-screening” model for methanol. Heating rate dependent DSC studies find that non-Arrhenius behaviour, characteristic of pristine MBBA and a manifestation of non-equilibrium nature [Dan et al., J. Chem. Phys. 143, 094501 (2015)], is preserved in presence of entropic screening in the hexane solution, while it changes to Arrhenius behaviour (signifying equilibrium behaviour) in presence of enthalpic screening in methanol solution. FTIR spectra show similar dependence on the solvent induced screening in the intensities of the imine (—C = N) stretch and the out-of-plane distortion vibrations of the benzene rings of MBBA with hexane and methanol as in DSC, further establishing our entropic and enthalpic screening models. UV–Vis spectra of the electronic transitions in MBBA as a function of temperature also exhibit different dependences of intensities on the solvent induced screening, and an exponential decrease is observed in presence of hexane while methanol completely changes the nature of interaction to follow a linear dependence.
The effect of dipole-dipole interactions on coercivity, anisotropy constant, and blocking temperature of MnFe2O4 nanoparticles
Authors: Aslibeiki B. , Kameli P. , Salamati H.
Published: February 2016

Superparamagnetic manganese ferrite nanoparticles with mean size of 〈D〉 = 6.5(±1.5) nm were synthesized through a solvothermal method using Tri-ethylene glycol as a solvent. The peak temperature of zero field cooled measurements of magnetization and AC magnetic susceptibility curves shifted toward higher temperatures by applying different pressures from 0 to 1 kbar and increasing the powders compaction. The frequency dependence of AC susceptibility measurements indicated the presence of weak dipole-dipole interactions between nanoparticles. By increasing the powders compaction and interactions strength, the coercive field (Hc) increased and squareness (Mr/Ms) decreased. The obtained effective anisotropy constant (Keff), by susceptibility measurements, was from 1.72 × 106 to 2.36 × 106 ergs/cm3 for pressure of 0 to 1 kbar. These values are larger than those obtained from hysteresis loops at 5 K (0.14 × 106 to 0.34 × 106 erg/cm3). Also, the Keff was two orders of magnitude greater than that of bulk MnFe2O4. Size, surface effects, and total energy barrier between equilibrium states were reported as the main causes of large anisotropy. Below 75 K, a signature of weak surface spin glass was observed. However, memory effect experiment indicated that there is no collective superspin glass state in the samples. This study suggests the role of powders compaction on properties of a magnetic nanoparticles system. Furthermore, the coercivity, the anisotropy constant, and the blocking temperature are affected by changing nanoparticles compaction.
Even nanomechanical modes transduced by integrated photonics
Authors: Westwood-Bachman J. N. , Diao Z. , Sauer V. T. K. , Bachman D. , Hiebert W. K.
Published: February 2016

We demonstrate the actuation and detection of even flexural vibrational modes of a doubly clamped nanomechanical resonator using an integrated photonics transduction scheme. The doubly clamped beam is formed by releasing a straight section of an optical racetrack resonator from the underlying silicon dioxide layer, and a step is fabricated in the substrate beneath the beam. The step causes uneven force and responsivity distribution along the device length, permitting excitation and detection of even modes of vibration. This is achieved while retaining transduction capability for odd modes. The devices are actuated via optical force applied with a pump laser. The displacement sensitivities of the first through third modes, as obtained from the thermomechanical noise floor, are 228 fm Hz−1/2, 153 fm Hz−1/2, and 112 fm Hz−1/2, respectively. The excitation efficiency for these modes is compared and modeled based on integration of the uneven forces over the mode shapes. While the excitation efficiency for the first three modes is approximately the same when the step occurs at about 38% of the beam length, the ability to tune the modal efficiency of transduction by choosing the step position is discussed. The overall optical force on each mode is approximately 0.4 pN μm−1 mW−1, for an applied optical power of 0.07 mW. We show a potential application that uses the resonant frequencies of the first two vibrational modes of a buckled beam to measure the stress in the silicon device layer, estimated to be 106 MPa. We anticipate that the observation of the second mode of vibration using our integrated photonics approach will be useful in future mass sensing experiments.
Temperature dependence of magneto-transport properties in Co2Fe(Ga0.5Ge0.5)/Cu lateral spin valves
Authors: Ikhtiar  , Kasai S. , Takahashi Y. K. , Furubayashi T. , Mitani S. , Hono K.
Published: February 2016

The non-local spin signals of Co2Fe(Ga0.5Ge0.5)/Cu lateral spin valves with sub-micron size dimensions were measured with varying temperatures. The non-local spin signal reaches 54 mΩ at 4 K, while it degrades down to 13 mΩ at room temperature. Analysis based on the one-dimensional spin diffusion model clarifies the dominant source for degrading of the spin signal is suppression of the spin diffusion length in Cu, not the spin polarization, indicating Co2Fe(Ga0.5Ge0.5) keeps half-metallic nature even at room temperature. The temperature dependence of non-local spin signal was found to exhibit a downturn at 36 K. The presence of magnetic impurities, detrimental effect of which becomes more pronounced for diffusive transport in long Cu wires, is suggested to cause the observed downturn in non-local spin signals.
Chemisorption-induced n-doping of MoS2 by oxygen
Authors: Qi Long , Wang Ying , Shen Lei , Wu Yihong
Published: February 2016

Both chemisorption and physisorption affect the electronic properties of two-dimensional materials, such as MoS2, but it remains a challenge to probe their respective roles experimentally. Through repeated in-situ electrical measurements of few-layer MoS2 field-effect transistors in an ultrahigh vacuum system with well-controlled oxygen partial pressure (6 × 10−8 mbar–3 × 10−7 mbar), we were able to study the effect of chemisorption on surface defects separately from physically adsorbed oxygen molecules. It is found that chemisorption of oxygen results in n-doping in the channel but negligible effect on mobility and on/off ratio of the MoS2 transistors. These results are in disagreement with the previous reports on p-doping and degradation of the device's performance when both chemisorption and physisorption are present. Through the analysis of adsorption-desorption kinetics and the first-principles calculations of electronic properties, we show that the experimentally observed n-doping effect originates from dissociative adsorption of oxygen at the surface defects of MoS2, which lowers the conduction band edge locally and makes the MoS2 channel more n-type-like as compared to the as-fabricated devices.
Enhanced Pr3+ photoluminescence by energy transfer in SrF2 : Eu2+, Pr3+ phosphor
Authors: Yagoub M. Y. A. , Swart H. C. , Bergman P. , Coetsee E.
Published: February 2016

Efficient energy transfer was demonstrated in the SrF2 : Eu2+, Pr3+ phosphor synthesized by the co-precipitation method. Results obtained with X-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray spectroscopy (XPS), photoluminescence (PL) and decay curves proposed the UV-Vis energy transfer process. The energy transfer process between the Eu2+ and Pr3+ ions in SrF2 was investigated to evaluate the potential of the Eu2+ ion as a sensitizer for the Pr3+ ion. The results proposed that Eu2+ could be a good sensitizer for absorbing the UV photons and efficiently enhancing the Pr3+ emission intensity. The energy transfer process was effective until concentration quenching for the Pr3+ ions occurred. The concentration quenching was attributed to cross-relaxation between the Pr3+ ions.
An evaluation of carbon offset supplementation options for beef production systems on coastal speargrass in central Queensland, Australia
Authors: Cottle D. , Eckard R. , Bray S. , Sullivan M.
Published: February 2016

In 2014, the Australian Government implemented the Emissions Reduction Fund to offer incentives for businesses to reduce greenhouse gas (GHG) emissions by following approved methods. Beef cattle businesses in northern Australia can participate by applying the ‘reducing GHG emissions by feeding nitrates to beef cattle’ methodology and the ‘beef cattle herd management’ methods. The nitrate (NO3) method requires that each baseline area must demonstrate a history of urea use. Projects earn Australian carbon credit units (ACCU) for reducing enteric methane emissions by substituting NO3 for urea at the same amount of fed nitrogen. NO3 must be fed in the form of a lick block because most operations do not have labour or equipment to manage daily supplementation. NO3 concentrations, after a 2-week adaptation period, must not exceed 50 g NO3/adult animal equivalent per day or 7 g NO3/kg dry matter intake per day to reduce the risk of NO3 toxicity. There is also a ‘beef cattle herd management’ method, approved in 2015, that covers activities that improve the herd emission intensity (emissions per unit of product sold) through change in the diet or management. The present study was conducted to compare the required ACCU or supplement prices for a 2% return on capital when feeding a low or high supplement concentration to breeding stock of either (1) urea, (2) three different forms of NO3 or (3) cottonseed meal (CSM), at N concentrations equivalent to 25 or 50 g urea/animal equivalent, to fasten steer entry to a feedlot (backgrounding), in a typical breeder herd on the coastal speargrass land types in central Queensland. Monte Carlo simulations were run using the software @risk, with probability functions used for (1) urea, NO3 and CSM prices, (2) GHG mitigation, (3) livestock prices and (4) carbon price. Increasing the weight of steers at a set turnoff month by feeding CSM was found to be the most cost-effective option, with or without including the offset income. The required ACCU prices for a 2% return on capital were an order of magnitude higher than were indicative carbon prices in 2015 for the three forms of NO3. The likely costs of participating in ERF projects would reduce the return on capital for all mitigation options.
Carbon footprint of milk production under smallholder dairying in Anand district of Western India: a cradle-to-farm gate life cycle assessment
Authors: Garg M. R. , Phondba B. T. , Sherasia P. L. , Makkar H. P. S.
Published: February 2016

In recent years, the concept of life cycle assessment (LCA) has proven to be useful because of its potential to assess the integral environmental impacts of agricultural products. Developing countries such as India are good candidates for LCA research because of the large contribution of smallholder dairy system to the production of agricultural products such as milk. Therefore, the aim of the present study was to explore the carbon footprint of milk production under the multi-functional smallholder dairy system in Anand district of Gujarat state, western India. A cradle-to-farm gate LCA was performed by covering 60 smallholder dairy farms within 12 geographically distinct villages of the district. The average farm size was 4.0 animals per farm, and the average number of each category of animal was 2.5 lactating cows, 1.4 lactating buffaloes, 1.8 replacement cows, 1.6 replacement buffaloes, 2.0 retired cows, 1.3 retired buffaloes and 1.0 ox per farm. The emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) on CO2-equivalent (CO2-eq) basis from feed production, enteric fermentation and manure management were allocated to fat- and protein-corrected milk (FPCM) on the basis of mass balance, price and digestibility. Emissions of CO2, CH4 and N2O from cattle contributed 11.0%, 75.4% and 13.6%, respectively, to the total greenhouse gas (GHG) emissions. The contribution of CO2, CH4 and N2O from buffalo was 8.2%, 80.5% and 11.3%, respectively, to the total GHG emissions of farms. The average carbon footprint (CF) of cow milk was 2.3, 1.9 and 2.0 kg CO2-eq/kg FPCM on mass, economic and digestibility basis, respectively, whereas for buffalo, milk CF was 3.0, 2.5 and 2.7 kg CO2-eq/kg FPCM, respectively. On the basis of digestibility allocation, emissions from retired (>10 years of age and incapable of or ceased producing milk) cows and buffaloes were 1571.3 and 2556.1 kg CO2-eq/retirement year, respectively. Overall, the CF of milk production under the smallholder dairy system in Anand district was 2.2 kg CO2-eq/kg FPCM, which reduced to 1.7 kg CO2-eq/kg FPCM when milk, manure, finance and insurance were considered as economic functions of the smallholder system. The CF was lower by 65% and 22% for cow and buffalo milk, respectively, than were the estimates of FAO for southern Asia, and this was mainly attributed to difference in the sources of GHG emissions, manure management systems, feed digestibility and milk production data used by FAO.
Prediction and evaluation of enteric methane emissions from lactating dairy cows using different levels of covariate information
Authors: Santiago-Juarez B. , Moraes L. E. , Appuhamy J. A. D. R. N. , Pellikaan W. F. , Casper D. P. , Tricarico J. , Kebreab E.
Published: February 2016

The dairy sector contributes to global warming through enteric methane (CH4) emissions. Methane is also a loss of energy to the ruminant. Several studies have developed CH4 prediction models to assess mitigation strategies to reduce emissions. However, the majority of these models have low predictive ability or require numerous inputs that are often not readily available in commercial dairy operations. In this context, the objective of the present paper was to develop CH4 prediction models by using varying levels of information available at the farm level. The seven complexity levels used the following information: (1) dietary nutrient composition, (2) milk yield and composition, (3) Levels 1 and 2, (4) Level 3 plus dry matter intake (DMI), (5) Level 4 plus bodyweight, (6) Level 2 plus DMI, and (7) DMI only. Models were fitted to 489 individual enteric-CH4 measurements from 30 indirect calorimetry studies and evaluated with an independent database comprising 215 treatment means from 62 studies collected from the literature. Within each complexity level, all possible mixed-effect models were fitted and those with the lowest values of Akaike or Bayesian information criteria were selected using lme4 package in R. Models were evaluated using mean square prediction error (MSPE) based statistic, root MSPE (RMSPE) to observation standard deviation ratio, concordance correlation coefficient and Nash–Sutcliffe efficiency methods. All fitted models performed well with an acceptable error estimates (RMSPE as a percentage of observed mean (RMSPE%) = 16–24%), with more than two-thirds of total error originating from random bias. Overall, models with DMI were more accurate (RMSPE% = 16–20%) than those without (RMSPE% = 20–24%). Although the best prediction model (RMSPE% = 16%) was developed using Level 5 information, a model using Level 2 information is recommended for on-farm methane estimates if DMI is not measured. The proposed models offer easy and practical tools to dairy producers for predicting CH4 emissions and evaluating CH4 mitigation strategies.
Effect of dicyandiamide (DCD) on nitrous oxide emissions from cow urine deposited on a pasture soil, as influenced by DCD application method and rate
Authors: Luo J. , Ledgard S. , Wise B. , Lindsey S.
Published: February 2016

Animal urine deposited on pastoral soils during grazing is recognised as a dominant source of nitrous oxide (N2O) emissions. The nitrification inhibitor, dicyandiamide (DCD), is a potential mitigation technology to control N2O emissions from urine patches on grazed pastures. One delivery option is to include DCD in animal feed so that the DCD is targeted directly in the urine patch when excreted in the animal urine. The hypothesis tested in the present study was that DCD in urine, excreted by cows that were orally administered with DCD, would have the same effect as DCD added to urine after the urine is excreted. The study also aimed to determine the most effective DCD rate for reducing N2O emissions. Fresh dairy cow urine (700 kg N per ha) was applied to a free-draining silt loam pastoral soil in Waikato, New Zealand, in May (late autumn) or July (winter) of 2014, and was mixed with DCD at rates of 0, 10, 30 and 60 kg/ha. In late autumn, there was an equivalent treatment of urine (containing 60 kg DCD per ha) from DCD-treated cows. A static chamber technique was used to determine gaseous N2O emissions. An annual emission factor (EF3; the percentage of applied urine N lost as N2O-N) of 0.23% or 0.21% was found following late-autumn or winter applications of urine without DCD. Late-autumn application of urine containing DCD from oral administration to cows had the same significant reduction effect on N2O emissions as did DCD that was mixed with urine after excretion, at the equivalent DCD application rate of 60 kg/ha. Application of urine with DCD mixed with the urine after excretion at varying DCD rates showed a significant (P < 0.05) linear decrease in both N2O emissions and EF3 values.
Dung and farm dairy effluent affect urine patch nitrous oxide emissions from a pasture
Authors: Li J. , Luo J. , Shi Y. , Li Y. , Ma Y. , Ledgard S. , Wang L. , Houlbrooke D. , Bo L. , Lindsey S.
Published: February 2016

Urine patches in grazed pastures have been identified as important sources of nitrous oxide (N2O) emissions. An increase in N2O emissions is possible where urine patches coincide with dung patches and farm dairy effluent (FDE) applications. The aim of the present study was to quantify the effects of dung additions and fresh FDE applications on N2O emissions from urine patches. A field experiment was conducted on a pasture site at the AgResearch’s Ruakura dairy farm in Hamilton, New Zealand. A closed soil chamber technique was used to measure the N2O emissions from a free-draining volcanic soil that received urine (492 kg N/ha, simulated urine patches), with or without dung (1146 kg N/ha) and fresh FDE (100 kg N/ha) and to compare these with controls receiving no urine. The addition of dung delayed the peak N2O fluxes from the urine patches by ~30 days. This could be due to temporary nitrogen (N) immobilisation during decomposition of carbon from the dung. However, over the whole measurement period (271 days), dung addition increased the N2O emission factor (EF, % of applied N emitted as N2O) for the urine from 1.02% to 2.09%. The application of fresh FDE increased the EF to 1.40%. The effluent- or dung-induced increases in N2O emissions from the urine patches were possibly caused both by the direct input of N from effluent or dung and through the indirect priming effect of addition of dung or effluent on the availability of N from urine patches for N2O production. We conclude that when EFs are used in calculations of N2O emissions from urine, consideration should be given to the likelihood of coincidence with dung or FDE applications.
A novel and effective technology for mitigating nitrous oxide emissions from land-applied manures
Authors: Hill Jaye , Redding Matthew , Pratt Chris
Published: February 2016

Land-applied manures produce nitrous oxide (N2O), a greenhouse gas (GHG). Land application can also result in ammonia (NH3) volatilisation, leading to indirect N2O emissions. Here, we summarise a glasshouse investigation into the potential for vermiculite, a clay with a high cation exchange capacity, to decrease N2O emissions from livestock manures (beef, pig, broiler, layer), as well as urea, applied to soils. Our hypothesis is that clays adsorb ammonium, thereby suppressing NH3 volatilisation and slowing N2O emission processes. We previously demonstrated the ability of clays to decrease emissions at the laboratory scale. In this glasshouse work, manure and urea application rates varied between 50 and 150 kg nitrogen (N)/ha. Clay : manure ratios ranged from 1 : 10 to 1 : 1 (dry weight basis). In the 1-year trial, the above-mentioned N sources were incorporated with vermiculite in 1 L pots containing Sodosol and Ferrosol growing a model pasture (Pennisetum clandestinum or kikuyu grass). Gas emissions were measured periodically by placing the pots in gas-tight bags connected to real-time continuous gas analysers. The vermiculite achieved significant (P ≤ 0.05) and substantial decreases in N2O emissions across all N sources (70% on average). We are currently testing the technology at the field scale; which is showing promising emission decreases (~50%) as well as increases (~20%) in dry matter yields. This technology clearly has merit as an effective GHG mitigation strategy, with potential associated agronomic benefits, although it needs to be verified by a cost–benefit analysis.
Soybean oil suppresses ruminal methane production and reduces content of coenzyme F420 in vitro fermentation
Authors: Wang Mengzhi , Jing Yujia , Liu Shimin , Gao Jian , Shi Liangfeng , Vercoe Phil
Published: February 2016

This experiment examined which type of oils was a superior suppressor to methane mitigation in ruminants. Four oils, peanut, rapeseed, corn and soybean oils, varying in the contents of unsaturated fatty acids as indicated by their iodine values, were used to investigate their effects on methane production and on the content of the F420 enzyme of ruminal methanogens in an in vitro fermentation. The control group was added with calcium palmitate (100% saturated 16C fatty acid). The results showed that the total gas production over a period of 36 h varied from 20.61 mL to 39.67 mL, and were lower in rapeseed, corn and soybean oil treatments than the control (P < 0.05), but not in the peanut oil treatment. The methane concentration in the total gas differed significantly among groups (P < 0.05), and decreased with the increases of unsaturation degree of the oils. The coenzyme F420 content, as indicated by F420 fluorescence intensity in supernatant of the medium, was significantly lower in the oil treatments than in the control (P < 0.05), and the intensity values decreased with the increases of unsaturation degree of the oils, except for the rapeseed oil treatment. Furthermore, there was a close correlation between F420 content and methane production (r = 0.916). By comparison, soybean oil treatment had higher dehydrogenase activity and bacteria density than the other groups (P < 0.05); but was lower in methanogens and genus entodinium (P < 0.05), except for the rapeseed oil treatment. Overall, soybean oil contained a high level of unsaturated fatty acids, and could be used as an ingredient of ruminant diets for methane suppression.
Supplementation with Calliandra calothyrsus improves nitrogen retention in cattle fed low-protein diets
Authors: Korir D. , Goopy J. P. , Gachuiri C. , Butterbach-Bahl K.
Published: February 2016

Ruminant productivity in the tropical Africa has remained low despite decades of research on animal nutrition and introduction of new breeds of animals mainly because of low-quality feeds available, especially during the dry season that is inefficiently utilised. This results in prolonged time for animals to mature and increased nutrient excretion to the environment. We conducted a study using yearling steers (n = 12, liveweight (LW) = 161.8 ± 10.89 kg) in a 3 × 3 Latin square to evaluate the effect of protein supplementation and supplementation frequency on intake, digestibility, nitrogen (N) retention and microbial N supply in cattle consuming low-protein diets. The steers were maintained on ad libitum wheat straw (DM = 877 ± 5 g/kg, crude protein (CP) = 20.0 ± 1.1 g/kg), with supplemental protein supplied as air-dried Calliandra calothyrsus leaves (DM = 897 ± 3 g/kg, CP = 257.5 ± 4.1 g/kg on a DM basis). Samples of basal diet, supplement, refusals, faecal matter and urine were collected and analysed per treatment. Supplementation increased intakes by the steers (P < 0.001), with no difference between the two supplementation frequencies (P > 0.404). Steers lost bodyweight (P < 0.05) on all treatments, but less so when supplemented. Nitrogen losses was reduced (P < 0.001) with supplementation (–33.3% vs 15.7%, s.e.m. 0.06). The increased N balance in animals receiving supplemented diets indicated that N retention actually improves with increased protein supplementation in animals fed low-protein diets, implying that improving protein supply to animals fed submaintenance diets will not only ameliorate production losses, but will actually decrease non-enteric greenhouse gas production and environmental N losses per animal product unit obtained.
Repeatability of methane emission measurements in Australian beef cattle
Authors: Donoghue K. A. , Bird-Gardiner T. , Arthur P. F. , Herd R. M. , Hegarty R. S.
Published: February 2016

Records on 175 young Angus heifer and bull progeny from 46 sires, measured for methane production in respiration chambers, were used to evaluate the repeatability of methane measurement over short- and long-term periods. The traits assessed were dry matter intake (DMI), methane production rate (MPR), methane yield (MPR per unit DMI), and four residual methane (RMP) traits. The RMP traits were computed as actual MPR minus expected MPR, where the expected MPR for the first three RMP traits were calculated from three different published and widely used equations. The expected MPR for the fourth was computed by regressing MPR on DMI, using the data from the study. Animals underwent an initial (first) methane measurement test for 48 h, and one repeat methane measurement test up to 450 days after the first test. Repeat tests were classified into four different time periods: tested across consecutive days; re-tested within 60 days of first test; re-tested 61–120 days after first test; and re-tested 121–450 days after first test. Repeatabilities were calculated for all traits across all time periods, and phenotypic correlations for the same trait measured over time were obtained from bivariate analyses. Methane traits from tests conducted over consecutive days were highly repeatable (0.75–0.94) and highly phenotypically correlated (0.85–0.95). Repeatabilities from tests conducted within 60 days of the first test were moderate to high (0.59–0.91), whereas phenotypic correlations were, in general, moderate (0.30–0.44), with the exception of MPR (0.78). Results for both longer-term time periods (61–120 days and 121–450 days after the first test) were very similar, with low estimates of repeatabilities (0.16–0.27) and phenotypic correlations (0.12–0.27). Correlations between sire progeny means from the first and repeat methane test were moderate (0.46–0.77) for all traits except RMPR (0.19). Results from this study indicate that methane traits from tests conducted either on consecutive days or within a short-term time frame afterward (~60 days) are highly repeatable and highly phenotypically correlated. However, methane tests conducted over longer-term time frames are substantially, but consistently, less repeatable and are lowly phenotypically correlated, which indicates that multiple measures may be required to accurately record methane traits over the life time of an animal.
Intra-ruminal gas-sensing in real time: a proof-of-concept
Authors: Bishop-Hurley Gregory J. , Paull David , Valencia Philip , Overs Leslie , Kalantar-zadeh Kourosh , Wright André-Denis G. , McSweeney Chris
Published: February 2016

An intra-rumen (IR) gas-sensing system incorporating commercially available gas sensors [methane (CH4), carbon dioxide (CO2) and hydrogen (H2)] and a wireless sensor network was developed to measure rumen gas concentrations of grazing animals in real-time. The IR gas-sensing devices also measure temperature and pressure near the sensors and the design isolates the electronics and battery from exposure to gases. Membranes were developed that allow the desired gases to diffuse through to the sensors while excluding corrosive hydrogen sulfide (H2S). Performance of the prototype IR devices was tested in cattle and sheep fed once a day as a proof-of-concept. Concentrations of expired gases from respiration chambers were compared with the concentrations obtained by the IR gas-sensing device within the rumen digesta. Direct measurements of rumen gas cap samples demonstrate a similar gas profile to that observed with the IR gas-sensing device with the ratio of CO2 : CH4 peaking shortly after feeding and CO2 levels nearly 2.5 times greater than those of CH4. The gas ratio then declines over time to a point when at 23 h post-feeding the concentration of CH4 exceeds that of CO2. The H2 gas concentration in the rumen varied throughout the day reaching maximum levels of 2500 ppm after feeding and declining to 250 ppm over the day. Although the IR device was able to detect H2 in the rumen throughout the entire day, expired H2 was often below the limits of detection in the respiration chamber. Current work is focussed on extending the longevity of the devices in the rumen so that replicated trials can be performed on the accuracy and precision of the measurements.
Variation of greenhouse gas emissions and identification of their drivers during the fattening of Belgian Blue White bulls based on a LCA approach
Authors: Mathot Michaël , Elias Eric , Reding Edouard , Vanlierde Amélie , Reuter Werne , Planchon Viviane , Stilmant Didier
Published: February 2016

Greenhouse gas emission intensity (GHGI; kilograms carbon dioxide equivalents/kilograms liveweight gain) have to be reduced so as to limit the impact of human activities on global warming while furnishing food to human. In this respect, performances of 654 Belgian Blue double-muscled bulls (BBdm) during their fattening phase were recorded. On this basis, their greenhouse gas emissions were modelled to estimate variation in GHGI and investigate mitigation options at that level. The relevance of theses option is discussed, taking into account the whole life and production system scales. Large variations (mean (s.d.)) were observed (from 7.2 (0.4) to 10.0 (0.7) kg carbon dioxide equivalents/kg liveweight gain) for, respectively, the 1st- and 4th-quantile groups defined for GHGI. Early culling, low liveweight and age at start of the fattening phase of the bulls would lead to a reduction of GHGI. Nevertheless, more than 32% of the variation remained unexplained. However, decision leading to reduction of GHG intensity at this stage of the life may be compensated in the early stage of BBdm. Attention is drawn on the necessity to encompass the whole life of BBdm for investigating mitigation options and on the sensitivity of the results on models and methodological choices.
Greenhouse-gas mitigation potential of agro-industrial by-products in the diet of dairy goats in Spain: a life-cycle perspective
Authors: Pardo G. , Martin-Garcia I. , Arco A. , Yañez-Ruiz D. R. , Moral R. , del Prado A.
Published: February 2016

Goat milk production is an important agricultural resource in the Mediterranean basin. Market demands and scarcity of pastures during drought periods has led to farms becoming more intensive and based on imported concentrate feeds. The use of alternative feedstuffs from agro-industry can help decrease dependence on external concentrates, while preventing the environmental issues associated with livestock production and by-product disposal. From a life-cycle assessment perspective, we investigated the change on greenhouse-gas (GHG) emissions of replacing a conventional dairy goat diet in southern Spain with two alternative dietary strategies, including tomato waste or olive by-products silages. The effect on enteric methane emissions and milk productivity was assessed through specific feeding trials. Experimental data were integrated within a modelling framework comprising different submodels to describe the farm system and associated production chain. A new model describing carbon and nitrogen losses from solid waste was applied to estimate the emissions associated with the baseline scenarios for food by-product management. The assessment revealed that the two dietary strategies achieve GHG reductions (~12–19% per kg milk). In both cases, nitrous oxide and carbon dioxide emissions from crop production were partially reduced through the displacement of typical concentrate ingredients. An additional mitigation effect was obtained when including tomato wastes in the diet because it reduced the methane emissions from enteric fermentation. Results suggested that use of agro-industrial residues for feeding is a feasible mitigation option in this case. However, as organic by-products could have alternative uses (bioenergy, soil amendment), with different implications for land use and soil carbon stocks, a more complete overview of both scenarios is recommended. Potential trade-offs from non-GHG categories may play an important role in a decision-making process.
Composition of the gut microbiota modulates the severity of malaria
Authors: Villarino Nicolas F. , LeCleir Gary R. , Denny Joshua E. , Dearth Stephen P. , Harding Christopher L. , Sloan Sarah S. , Gribble Jennifer L. , Campagna Shawn R. , Wilhelm Steven W. , Schmidt Nathan W.
Published: February 2016

Significance

Plasmodium
infections cause >200 million cases of malaria and ∼1 million deaths annually. Although these infections result in disease states that range from asymptomatic to life-threatening, factors that contribute to disease severity remain poorly defined. This report demonstrates that the assemblage of microbes in the gut can modulate the severity of malaria. Mice from different vendors with differences in their gut microbiome showed significant differences in pathology after infection with
Plasmodium
. Among the bacterial populations that were different between “resistant” and “susceptible” mice were
Lactobacillus
and
Bifidobacterium
, and treatment of mice with
Lactobacillus
and
Bifidobacterium
resulted in decreased
Plasmodium
burden. These results identify both a previously unidentified risk factor for severe malaria and a potential new avenue of treatment.
Genetic specificity of a plant–insect food web: Implications for linking genetic variation to network complexity
Authors: Barbour Matthew A. , Fortuna Miguel A. , Bascompte Jordi , Nicholson Joshua R. , Julkunen-Tiitto Riitta , Jules Erik S. , Crutsinger Gregory M.
Published: February 2016

Significance

We know that the gain or loss of species can have cascading effects on food-web complexity; however, it is less clear whether the gain or loss of genetic variation within species, an often overlooked component of biodiversity, will similarly affect food-web structure. Here, we empirically identify how genetic variation within a host plant directly and indirectly affects its associated insect food web, resulting in distinct trophic interactions occurring on each host-plant genotype. Moreover, simulations of our empirical data suggest that higher levels of host-plant genetic variation lead to a more complex plant–insect food web. Our results suggest that preserving genetic variation within key species may be critical for maintaining complex and robust food webs under future environmental change.
Structure of the Brd4 ET domain bound to a C-terminal motif from γ-retroviral integrases reveals a conserved mechanism of interaction
Authors: Crowe Brandon L. , Larue Ross C. , Yuan Chunhua , Hess Sonja , Kvaratskhelia Mamuka , Foster Mark P.
Published: February 2016

Significance

Bromodomain and extraterminal domain (BET) proteins recruit a variety of cellular factors to epigenetic marks on chromatin to modulate essential cellular processes, including DNA repair and transcription. To facilitate their recruitment to chromosomal DNA made accessible by epigenetically modified chromatin dynamics, conserved sequences in γ-retroviral integrases bind to the highly conserved extraterminal (ET) domains of BET proteins. The solution structure of the complex between the Brd4 ET domain and a conserved sequence from murine leukemia virus integrase reveals the basis for γ-retroviral integration pattern, with implications for retrovirus-based gene therapy. Moreover, the studies suggest how BET proteins might interact with cognate binding partners involved in a diverse array of cellular phenomena including transcriptional activation, cancer, viral latency, and viral integration.
Ultrasensitive microchip based on smart microgel for real-time online detection of trace threat analytes
Authors: Lin Shuo , Wang Wei , Ju Xiao-Jie , Xie Rui , Liu Zhuang , Yu Hai-Rong , Zhang Chuan , Chu Liang-Yin
Published: February 2016

Significance

Real-time detection of trace threat analytes is critical for global sustainability. The key challenge is how to efficiently convert and amplify the analyte signal into simple readouts. Here we report an ultrasensitive microfluidic platform incorporated with stimuli-responsive smart microgel for real-time detection of trace threat analytes. The microgel swells in response to specific analyte, thus converting trace analyte concentration into significantly amplified signal of flow rate change for highly sensitive, fast, and selective detection, which can be monitored on cell phone for timely warning and terminating of pollution. This work provides a generalizable platform for incorporating myriad microgels to achieve ever-better performance for real-time detection of various trace threat molecules, and may expand the scope of applications of detection techniques.