bluuebunny/crossref_metadata_2025 huggingface dataset:
Increases in Cerebrospinal Fluid Caffeine Concentration are Associated with Favorable Outcome after Severe Traumatic Brain injury in Humans
Authors: Sachse Kathleen T , Jackson Edwin K , Wisniewski Stephen R , Gillespie Delbert G , Puccio Ava M , Clark Robert SB , Dixon C Edward , Kochanek Patrick M
Published: August 2007

Caffeine, the most widely consumed psychoactive drug and a weak adenosine receptor antagonist, can be neuroprotective or neurotoxic depending on the experimental model or neurologic disorder. However, its contribution to pathophysiology and outcome in traumatic brain injury (TBI) in humans is undefined. We assessed serial cerebrospinal fluid (CSF) concentrations of caffeine and its metabolites (theobromine, paraxanthine, and theophylline) by high-pressure liquid chromatography/ultraviolet in 97 ventricular CSF samples from an established bank, from 30 adults with severe TBI. We prospectively selected a threshold caffeine level of ≥1 μmol/L (194 ng/mL) as clinically significant. Demographics, Glasgow Coma Scale (GCS) score, admission blood alcohol level, and 6-month dichotomized Glasgow Outcome Scale (GOS) score were assessed. Mean time from injury to initial CSF sampling was 10.77 ± 3.13 h. On initial sampling, caffeine was detected in 24 of 30 patients, and the threshold was achieved in 9 patients. Favorable GOS was seen more often in patients with CSF caffeine concentration ≥ versus < the threshold (55.6 versus 11.8%, P = 0.028). Gender, age, admission CGS score, admission blood alcohol level, and admission systolic arterial blood pressure did not differ between patients with CSF caffeine concentration ≥ versus < the threshold. Increases in CSF concentrations of the caffeine metabolites theobromine and paraxanthine were also associated with favorable outcome ( P = 0.018 and 0.056, respectively). Caffeine and its metabolites are commonly detected in CSF in patients with severe TBI and in an exploratory assessment are associated with favorable outcome. We speculate that caffeine may be neuroprotective by long-term upregulation of adenosine A1 receptors or acute inhibition of A2a receptors.
General versus Specific Actions of Mild-Moderate Hypothermia in Attenuating Cerebral Ischemic Damage
Authors: Zhao Heng , Steinberg Gary K , Sapolsky Robert M
Published: August 2007

Mild or moderate hypothermia is generally thought to block all changes in signaling events that are detrimental to ischemic brain, including ATP depletion, glutamate release, Ca2+ mobilization, anoxic depolarization, free radical generation, inflammation, blood—brain barrier permeability, necrotic, and apoptotic pathways. However, the effects and mechanisms of hypothermia are, in fact, variable. We emphasize that, even in the laboratory, hypothermic protection is limited. In certain models of permanent focal ischemia, hypothermia may not protect at all. In cases where hypothermia reduces infarct, some studies have overemphasized its ability to maintain cerebral blood flow and ATP levels, and to prevent anoxic depolarization, glutamate release during ischemia. Instead, hypothermia may protect against ischemia by regulating cascades that occur after reperfusion, including blood—brain barrier permeability and the changes in gene and protein expressions associated with necrotic and apoptotic pathways. Hypothermia not only blocks multiple damaging cascades after stroke, but also selectively upregulates some protective genes. However, most of these mechanisms are addressed in models with intraischemic hypothermia; much less information is available in models with postischemic hypothermia. Moreover, although it has been confirmed that mild hypothermia is clinically feasible for acute focal stroke treatment, no definite beneficial effect has been reported yet. This lack of clinical protection may result from suboptimal criteria for patient entrance into clinical trials. To facilitate clinical translation, future efforts in the laboratory should focus more on the protective mechanisms of postischemic hypothermia, as well as on the effects of sex, age and rewarming during reperfusion on hypothermic protection.
Circulating CD34-Positive Cells Provide a Marker of Vascular Risk Associated with Cognitive Impairment
Authors: Taguchi Akihiko , Matsuyama Tomohiro , Nakagomi Takayuki , Shimizu Yoko , Fukunaga Ryuzo , Tatsumi Yoshiaki , Yoshikawa Hiroo , Kikuchi-Taura Akie , Soma Toshihiro , Moriwaki Hiroshi , Nagatsuka Kazuyuki , Stern David M , Naritomi Hiroaki
Published: August 2007

Maintenance of uninterrupted cerebral circulation is critical for neural homeostasis. The level of circulating CD34-positive (CD34+) cells has been suggested as an index of cerebrovascular health, although its relationship with cognitive function has not yet been defined. In a group of individuals with cognitive impairment, the level of circulating CD34+ cells was quantified and correlated with clinical diagnoses. Compared with normal subjects, a significant decrease in circulating CD34+ cells was observed in patients with vascular-type cognitive impairment, although no significant change was observed in patients with Alzheimer's-type cognitive impairment who had no evidence of cerebral ischemia. The level of cognitive impairment was inversely correlated with numbers of circulating CD34+ cells in patients with vascular-type cognitive impairment, but not Alzheimer's type. We propose that the level of circulating CD34+ cells provides a marker of vascular risk associated with cognitive impairment, and that differences in the pathobiology of Alzheimer's- and vascular-type cognitive impairment may be mirrored in levels of circulating CD34+ cells in these patient populations.
Nitrite Does Not Provide Additional Protection to Thrombolysis in a Rat Model of Stroke with Delayed Reperfusion
Authors: Schatlo Bawarjan , Henning Erica C , Pluta Ryszard M , Latour Lawrence L , Golpayegani Nahal , Merrill Marsha J , Lewin Naomi , Chen Yong , Oldfield Edward H
Published: August 2007

An adjuvant therapy to prolong the therapeutic window for stroke patients is urgently needed. This randomized, blinded, placebo-controlled study investigated adjuvant intravenous sodium nitrite with recombinant tissue plasminogen activator (rtPA) in middle cerebral artery occlusion (MCAO) with 6 and 2 h of ischemia followed by reperfusion in Sprague—Dawley rats ( n = 59). Quantitative diffusion, T1-, T2-weighted, and semiquantitative perfusion imaging were performed before and after reperfusion and at 48 h after ischemia to determine the spatiotemporal evolution of stroke. After 48 h animals were killed and examined to evaluate infarct size and evidence of hemorrhagic transformation. Factor VIII immunostaining was performed to assess vessel morphology. Nitrite treatment (6 h group: 37.5 μmol for more than 90 mins; 2 h group: 26.25 and 1.75 μmol for more than 60 mins) did not reduce infarct volume 48 h after MCAO compared with saline-treated placebo groups after 6 or 2 h of MCAO. Stroke progression from baseline to 48 h, based on the apparent diffusion coefficient and relative cerebral blood flow deficits before and after reperfusion and T2-weighted hyperintensity at 48 h, did not differ between treated and control animals. These results suggest that nitrite is not a protective adjuvant therapy to delayed rtPA administration after ischemic stroke in rats.
Cerebral Metabolic Adaptation and Ketone Metabolism after Brain Injury
Authors: Prins Mayumi L
Published: August 2007

The developing central nervous system has the capacity to metabolize ketone bodies. It was once accepted that on weaning, the ‘post-weaned/adult’ brain was limited solely to glucose metabolism. However, increasing evidence from conditions of inadequate glucose availability or increased energy demands has shown that the adult brain is not static in its fuel options. The objective of this review is to summarize the body of literature specifically regarding cerebral ketone metabolism at different ages, under conditions of starvation and after various pathologic conditions. The evidence presented supports the following findings: (1) there is an inverse relationship between age and the brain's capacity for ketone metabolism that continues well after weaning; (2) neuroprotective potentials of ketone administration have been shown for neurodegenerative conditions, epilepsy, hypoxia/ischemia, and traumatic brain injury; and (3) there is an age-related therapeutic potential for ketone as an alternative substrate. The concept of cerebral metabolic adaptation under various physiologic and pathologic conditions is not new, but it has taken the contribution of numerous studies over many years to break the previously accepted dogma of cerebral metabolism. Our emerging understanding of cerebral metabolism is far more complex than could have been imagined. It is clear that in addition to glucose, other substrates must be considered along with fuel interactions, metabolic challenges, and cerebral maturation.
Atlas of two-dimensional irreversible conservative Lagrangian mechanical systems with a second quadratic integral
Authors: Yehia Hamad M.
Published: August 2007

This paper aims at the most comprehensive and systematic construction and tabulation of mechanical systems that admit a second invariant, quadratic in velocities, other than the Hamiltonian. The configuration space is in general a two-dimensional Riemannian or pseudo-Riemannian manifold and the determination of its geometry is a part of the process of solution. Forces acting on the system include a part derived from a scalar potential and a part derived from a vector potential, associated with terms linear in velocities in the Lagrangian function of the system. The last caused time irreversibility of the system. We constructed 41 multiparameter integrable systems of the type described in the title, mostly on Riemannian manifolds. They are mostly new and cover all previously known systems as special cases, corresponding to special values of the parameters. Those include all known cases of motion of a particle in the plane and all known cases in the dynamics of rigid body. In the last field we introduce a new integrable case related to Steklov’s case [Math. Ann. 42, 273 (1893)] of motion of a body in a liquid. Several new cases of motion in the plane, on the sphere, and on the pseudosphere or in the hyperbolic plane are found as special cases. Prospective applications in mathematics and physics are also pointed out.
Photodissociation dynamics of the reaction H2CO→H+HCO via the singlet (S) and triplet (T1) surfaces
Authors: Yin Hong-Ming , Rowling Steven J. , Büll Alexander , Kable Scott H.
Published: August 2007

We have explored the photodissociation dynamics of the reaction H2CO+hν→H+HCO in the range of 810–2600cm−1 above the reaction threshold. Supersonically cooled formaldehyde was excited into selected JKa,Kc rotational states of six vibrational levels (1141, 51, 2261, 2243, 2341, and 2441) in the Ã(A21) state. The laser induced fluorescence spectra of the nascent HCO fragment provided detailed product state distributions. When formaldehyde was excited into the low-lying levels 1141, 51, and 2261, at Eavail<1120cm−1, the product state distribution can be modeled qualitatively by phase space theory. These dynamics are interpreted as arising from a reaction path on the barrierless S0 surface. When the initial states 2243 and 2341 were excited (Eavail=1120–1500cm−1), a second type of product state distribution appeared. This second distribution peaked sharply at low N, Ka and was severely truncated in comparison with those obtained from the lower lying states. At the even higher energy of 2441 (Eavail≈2600cm−1) the sharply peaked distribution appears to be dominant. We attribute this change in dynamics to the opening up of the triplet channel to produce HCO. The theoretical height of the barrier on the T1 surface lies between 1700 and 2100cm−1 and so we consider the triplet reaction to proceed via tunneling at the intermediate energies and proceed over the barrier at the higher energies. Considerable population was observed in the excited (0,0,1) state for all initial H2CO states that lie above the appearance energy. Rotational populations in the (0,0,1) state dropped more rapidly with (N,Ka) than did the equivalent populations in (0,0,0). This indicates that, although individual rotational states are highly populated in (0,0,1), the total v3=1 population might not be so large. Specific population was also measured in the almost isoenergetic Kc and J states. No consistent population preference was found for either asymmetry or spin-rotation component.
Flow around an impulsively arrested circular cylinder
Authors: Sheard G. J. , Leweke T. , Thompson M. C. , Hourigan K.
Published: August 2007

The vortex dynamics of the flow around a suddenly arrested translating circular cylinder is investigated by direct numerical simulation and water tank experiments. In the numerical study, a method of visualization of streaklines in simulated-particle tracking computations is proposed, which is based on a variable-variance two-dimensional Gaussian-weighted summation of particles in the vicinity of each interpolation point, and for which a close similarity with physical dye visualizations is found. This technique is used to identify the trajectory of both the wake vortices, as well as the secondary vortices induced as the original wake convects over the arrested cylinder. Observations show that, in a fashion similar to the flow past an arresting sphere, each wake vortex induces a counter-rotating vortex pair, which subsequently self-propels over a range of sometimes surprising trajectories as the Reynolds number and cylinder translation distance are varied. At low Reynolds numbers and short translation distances, the wake vortices propel past the cylinder, continuing in the direction of the original cylinder motion. At higher Reynolds numbers, the vortices deviate outwards in circular arcs of increasing curvature, even to the extent that the vortex pairs collide behind the cylinder. These trajectory curvatures are analyzed with respect to the circulation of the vortex pairs. At sufficiently long translation distances, a wake instability destroys the reflective symmetry about the wake centerline. This regime is investigated by both comparison with experiment and analysis of the discrepancy between the vorticity and particle fields at large post-arrest times.
Mean first passage time for a class of non-Markovian processes
Authors: Dienst A. , Friedrich R.
Published: August 2007

We determine the probability distribution of the first passage time for a class of non-Markovian processes. This class contains, amongst others, the well-known continuous time random walk (CTRW), which is able to account for many properties of anomalous diffusion processes. In particular, we obtain the mean first passage time for CTRW processes with truncated power-law transition time distribution. Our treatment is based on the fact that the solutions of the non-Markovian master equation can be obtained via an integral transform from a Markovian Langevin process.
Turbulent excitation of plasma oscillations in the acoustic frequency range
Authors: Falchetto G. L. , Ottaviani M. , Garbet X. , Smolyakov A.
Published: August 2007

The impact of geodesic curvature on flux-driven electrostatic ion temperature gradient turbulence in the core of tokamak plasmas is studied by means of three-dimensional fluid global numerical simulations. The emphasis is on the dynamics of the axisymmetric fluctuations. The simulations evolve the equilibrium and the perturbed fields as a whole. The coupling of poloidal harmonics induced by the curvature results, on the one hand, in the presence of neoclassical transport, besides the turbulent one, and on the other, in the generation of oscillations in the acoustic frequency range. The neoclassical thermal conductivity is evaluated for the considered isotropic model, and scales as the plateau conductivity. The computed conductivity is shown to agree perfectly with that theoretical estimate. Geodesic acoustic modes (GAMs) are only observed transiently in the simulations. The GAM oscillations are strongly reduced in the final turbulent stationary state. The main peak in the poloidal velocity spectra is observed at a lower frequency. Detailed analysis of the simulations in the turbulent stationary state, in particular by means of a singular value decomposition of the space-time data, shows that a second linear branch of axisymmetric modes, having a frequency somewhat lower than the acoustic one, is more effectively excited by the turbulence. The result is a quasicoherent mode with a radial wavelength somewhat larger than the ion Larmor radius.
Consistent modeling of interphase turbulent kinetic energy transfer in particle-laden turbulent flows
Authors: Xu Ying , Subramaniam Shankar
Published: August 2007

The interphase transfer of turbulent kinetic energy (TKE) is an important term that affects the evolution of TKE in fluid and particle phases in particle-laden turbulent flow. This work shows that the interphase TKE transfer terms must obey a mathematical constraint, which in the limiting case of statistically homogeneous flow with zero mean velocity in both phases, requires these terms be equal and opposite. In the single-point statistical approach called the two-fluid theory, the interphase TKE transfer terms are unclosed and need to be modeled. Multiphase turbulence models that satisfy this constraint of conservative interphase TKE transfer admit a term-by-term comparison with true direct numerical simulations (DNS) that enforce the exact velocity boundary condition on each particle’s surface. Analysis of three models reveals that not all models satisfy the requirement of conservative interphase TKE transfer. DNS that invoke the point-particle assumption also do not obey this principle of conservative interphase TKE transfer, and this precludes the comparison of model predictions of TKE budgets in each phase with point-particle DNS. This study motivates the development of multiphase turbulence models based on the insights revealed by this analysis, leading to a meaningful comparison of TKE budgets with true DNS.
Universal joint-measurement uncertainty relation for error bars
Authors: Busch P. , Pearson D. B.
Published: August 2007

We formulate and prove a new, universally valid uncertainty relation for the necessary error bar widths in any approximate joint measurement of position and momentum.
Charge retention characteristics of silicon nanocrystal layers by ultrahigh vacuum atomic force microscopy
Authors: Feng Tao , Miller Gerald , Atwater Harry A.
Published: August 2007

The nanoscale charge retention characteristics of both electrons and holes in SiO2 layers containing silicon nanocrystals were investigated with ultrahigh vacuum conductive-tip noncontact atomic force microscopy. The results revealed much longer hole retention time (e.g., >1 day) than that of electrons (e.g., ∼1 h). A three-dimensional electrostatic model was developed for charge quantification and analysis of charge dissipation. Based on the superior retention characteristics of holes, a p-channel nanocrystal memory working with holes is suggested to be an interesting choice in improving data retention or in further device scaling.
Longitudinal relaxation time detection using a high-Tc superconductive quantum interference device magnetometer
Authors: Liao Shu-Hsien , Horng Herng-Er , Yang Hong-Chang , Yang Shieh-Yueh
Published: August 2007

The parameters to optimize the measurement of longitudinal relaxation time detection using a high-Tc superconductive quantum interference device magnetometer are investigated. These parameters include the prepolarization field, Bp, the prepolarization time, TBp, and the delay time, Td, to turn on pulses after turning off the prepolarization field. Furthermore, the decreasing of magnetization with the increasing Td of the applied pulse was analyzed to determine the longitudinal relaxation time. We estimated the longitudinal relaxation time to be 2.11±0.04 s and 2.29±0.04 s, respectively, for water determined from nuclear magnetic resonance signals as a function of TBp and Td at 24 °C in a measuring field of 95 μT. The data are consistent with the derived longitudinal relaxation time of water measured from the increase of magnetization with the duration of the polarizing field.
Comprehensive model for fine Coulomb fission of liquid droplets charged to Rayleigh limit
Authors: Gu Wenhua , Heil Philip Edward , Choi Hyungsoo , Kim Kyekyoon
Published: August 2007

Fine Coulomb fission of liquid droplets charged to the Rayleigh limit is modeled, combining the theories for the flow-limited field-injection electrostatic spraying and the conventional electrostatic spraying. The model gives expressions for the current, flow rate, jet growth rate, and secondary droplet size in the fine Coulomb fission process. The model can explain the reported experimental results and completes the previous model on Coulomb fission.
Scaling effect on the operation stability of short-channel organic single-crystal transistors
Authors: Minari T. , Miyadera T. , Tsukagoshi K. , Hamano T. , Aoyagi Y. , Yasuda R. , Nomoto K. , Nemoto T. , Isoda S.
Published: August 2007

Organic single-crystal transistors allowed the authors to investigate the essential features of short-channel devices. Rubrene single-crystal transistors with channel lengths of 500 and 100nm exhibited good field-effect characteristics under extremely low operation voltages, although space charge limited current degrades the subthreshold properties of 100nm devices. Furthermore, bias-stress measurements revealed the remarkable stability of organic single-crystal transistors regardless of device size. The bias-stress effect was explained by the trapping of gate-induced charges into localized density of states in the single-crystal channel.
Interdigitated back contact silicon heterojunction solar cell and the effect of front surface passivation
Authors: Lu Meijun , Bowden Stuart , Das Ujjwal , Birkmire Robert
Published: August 2007

This letter reports interdigitated back contact silicon heterojunction (IBC-SHJ) solar cells which combine the performance benefits of both back contact and heterojunction technologies while reducing their limitations. Low temperature (<200°C) deposited p- and n-type amorphous silicon used to form interdigitated heteroemitter and contacts in the rear preserves substrate lifetime while minimizes optical losses in the front. The IBC-SHJ structure is ideal for diagnosing surface passivation quality, which is analyzed and measured by internal quantum efficiency and minority carrier lifetime measurements. Initial cells have independently confirmed efficiency of 11.8% under AM1.5 illumination. Simulations indicate efficiencies greater than 20% after optimization.
Scale-factor corrections in large ring lasers
Authors: Pritsch B. , Schreiber K. U. , Velikoseltsev A. , Wells J.-P. R.
Published: August 2007

The authors report on fluctuations of the geometric scale factor of a very large ring laser situated 30m underground in the Cashmere Cavern in Christchurch (New Zealand). Variations in temperature and atmospheric pressure cause thermoelastic deformations to the cavern, which lead to changes of the area and perimeter of the ring laser structure. In situ beam monitoring has been used to partially correct for these effects.
Highly efficient p-i-n-type organic light emitting diodes on ZnO:Al substrates
Authors: Tomita Yuto , May Christian , Toerker Michael , Amelung Joerg , Eritt Michael , Loeffler Frank , Luber Claus , Leo Karl , Walzer Karsten , Fehse Karsten , Huang Qiang
Published: August 2007

Aluminum doped zinc oxide (ZAO) is presented in this letter as an alternative transparent electrode: optimized ZAO films offer excellent parameters for organic light emitting diodes (OLEDs). The ZAO films are applied to various p-i-n-type OLEDs. By using green phosphorescent molecules in a double emitter structure, very high efficiencies were obtained, namely, 54.6cd∕A and 61.5lm∕W for 100cd∕m2 at 2.78V. Additionally, white OLEDs on ZAO demonstrated pure white emission independent of the luminance and high efficiencies of 12.6cd∕A and 14.5lm∕W for 100cd∕m2 at 2.6V, which is comparable to indium-tin-oxide based white OLEDs.
High-efficiency orange and yellow organic light-emitting devices using platinum(II) complexes containing extended π-conjugated cyclometalated ligands as dopant materials
Authors: Yan Bei-Ping , Cheung Cecil C. C. , Kui Steven C. F. , Roy V. A. L. , Che Chi-Ming , Xu Shi-Jie
Published: August 2007

Two luminescent platinum(II) complexes 1 and 2 containing extended π-conjugated cyclometalated ligands have been used as dopant materials for the construction of two high-efficiency organic light-emitting devices I and II. Device I (containing dopant 1) emits orange emission and exhibits a maximum external quantum efficiency of 12.4%, a maximum luminous efficiency of 32.3cd∕A, and a maximum power efficiency of 11.2lm∕W. Device II (containing dopant 2) emits yellow light and exhibits a maximum external quantum efficiency of 16.1%, a maximum luminous efficiency of 51.8cd∕A, and a maximum power efficiency of 23.2lm∕W.
D-Glucosylated Derivatives of Isofagomine and Noeuromycin and Their Potential as Inhibitors of β-Glycoside Hydrolases
Authors: Meloncelli Peter J. , Gloster Tracey M. , Money Victoria A. , Tarling Chris A. , Davies Gideon J. , Withers Stephen G. , Stick Robert V.
Published: August 2007

While isofagomine and noeuromycin have previously been demonstrated to be effective inhibitors of a range of exo-acting glycosidases, they are usually only very weak inhibitors of endo-glycosidases. However, the disaccharide-like 3- and 4-O-β-d-glucopyranosylisofagomines have proven to be strong inhibitors of these endo-acting enzymes that utilize multiple sub-sites. In an attempt to emulate these successes, we have prepared 3- and 4-O-β-d-glucopyranosylnoeuromycin, the former by a selective glycosylation (at O2) of benzyl 4-C-cyano-4-deoxy-α-d-arabinoside (also leading to another synthesis of 3-O-β-d-glucopyranosylisofagomine), the latter by a non-selective glycosylation of benzyl 4-O-allyl-β-l-xyloside with subsequent introduction of the required nitrile group (also leading to another synthesis of 4-O-β-d-glucopyranosylisofagomine). 3-O-β-d-Glucopyranosylnoeuromycin was evaluated as an inhibitor of a family 26 lichenase from Clostridium thermocellum, and 4-O-β-d-glucopyranosylnoeuromycin as an inhibitor of both a family 5 endo-glucanase from Bacillus agaradhaerans and a family 10 endo-xylanase from Cellulomonas fimi. We also report X-ray structural investigations of 3- and 4-O-β-d-glucopyranosylnoeuromycin in complex with the family 26 and family 5 β-glycoside hydrolases, respectively. The two d-glucosylated noeuromycins were indeed able to harness the additional binding energy from the sub-sites of their endo-glycoside hydrolase targets, and were thus excellent inhibitors (in the nanomolar range), binding as expected in the –1 and –2 sub-sites of the enzymes.
Capturing benefits from the bovine genome sequence
Authors: Tellam Ross L.
Published: August 2007

The bovine genome sequence in ‘draft’ form will be complete in 2007. The availability of the sequence and very large numbers of single nucleotide polymorphisms will have profound effects on livestock production. The dairy industry is well positioned to capture the benefits of this enormous and enabling resource because of its comprehensive databases containing phenotypic and pedigree data for large numbers of animals, intense utilisation of genetics in breeding programs and efficient management of reproductive performance. The bovine genome sequence will assist in the development of novel products, especially value-added products, and markedly enhance the rate of genetic gain in the Australian dairy population. The immediate challenge facing the industry is the integration of new technological capabilities into existing breeding programs and production systems.
FutureDairy: a national, multidisciplinary project to assist dairy farmers to manage future challenges - methods and early findings
Authors: García Sergio C. , Fulkerson William J. , Nettle Ruth , Kenny Sean , Armstrong Daniel
Published: August 2007

FutureDairy is a national, multidisciplinary project designed to assist Australian dairy farmers to manage future challenges. FutureDairy is exploring technical, economic and social aspects of technology adoption through an innovative approach that combines methodologies of social research (‘People’), extension (‘System’) and technical research (‘Science’). The technologies being investigated revolve around increasing forage production per unit of land through a complementary forage rotation; evaluating the most efficient use of brought-in feed to increase milk production per ha; and, the incorporation of automatic milking and other technological innovations that would either reduce labour input or allow more precise agriculture. The central strategy of FutureDairy is to utilise ‘knowledge partnerships’ to co-develop knowledge around each of the key areas of investigation; thus a key feature of the project is its linkage with commercial ‘partner’ farmers that explore similar questions to those being investigated at Elizabeth Macarthur Agricultural Institute (NSW Department of Primary Industries), where the technical research is being undertaken. This paper focuses on early findings from the forages module. Work thus far has shown that forage yields in excess of 40 t DM/ha.year are achievable. However, the practicalities of implementing this technology on-farm have already identified new and diverse issues that, unless understood, will jeopardise its effective adaptation by farmers.
Converting genomic discoveries into genetic solutions for dairy pastures - an overview
Authors: Smith K. F. , Forster J. W. , Spangenberg G. C.
Published: August 2007

A range of molecular breeding technologies have been developed for forage plant species including both transgenic and non-transgenic methodologies. The application of these technologies has the potential to greatly increase the range of genetic variation that is available for incorporation into breeding programs and its subsequent delivery to producers in the form of improved germplasm. Further developments in plant functional genomics and in detailing the phenotypic effect of genes and alleles both through research in target species and through inference from results from model species will further refine the delivery of new forage cultivars.
Short term fasting as a tool to design effective grazing strategies for lactating dairy cattle: a review
Authors: Chilibroste P. , Soca P. , Mattiauda D. A. , Bentancur O. , Robinson P. H.
Published: August 2007

Varying the time since the last meal (i.e. fasting) is a means of manipulating foraging behaviour. Management practices that restrict grazing time, and/or change the timing of the grazing session, may be analogous to changes introduced with different fasting regimes, suggesting that the same pattern of responses on foraging behaviour could be expected. Concepts related to eating patterns of grazing dairy cows are briefly reviewed, and impacts of short-term (i.e. within day) fasts on ingestive behaviours are discussed. Finally, several experiments that examined impacts of short-term fasts on eating patterns, ingestive behaviours and performance of lactating dairy cows are reviewed. Management practices that create shorter grazing sessions (i.e. longer fasting periods before grazing), and/or involve afternoon grazing, result in longer initial grazing bouts, higher intake rates, reductions in rumination time during the grazing session, as well as more pronounced changes in rumen pH, concentrations of rumen fermentation metabolites and rumen load. All of these changes have been associated with improvements in performance of grazing dairy cattle. These concepts and findings have implications in defining optimal grazing strategies, as well as allowing cattle performance, sward conditions and nutrient balances to be predicted and analysed in an integrated manner.
A left-in-place group milk sampler can improve disease monitoring in dairy herds
Authors: Clarke T. , Devereaux R. S. , Madison N. , Hannah M. C. , Ridge S. E. , Ryan L. , Wientjes H. A.
Published: August 2007

A novel milk sampler (MilkThief) is described. It can collect representative samples of milk to be used for disease monitoring from groups of cows during a milking session. The maximum dilution of each individual cow’s milk did not exceed a 1 : 45 limit when we tested the sampler in a range of Australian dairies. Such a dilution limit has been shown by others to be efficient for the detection of enzootic bovine leucosis when the ‘Lactelisa’ method is used. The samplers and collection flasks are conveniently left in place for the whole milking session. The sampling volume can be manipulated so that the combined sample collected from up to 10 cows can be held in a flask of 220-mL capacity. The sampler can be easily fitted to any milking machine.
'Dairy Science 2006': a perspective of likely benefits to farmers from new technologies and learning approaches
Authors: Doyle P. T.
Published: August 2007

The dairy industry is an important rural industry and confers significant social and economic benefits to Australia. The future prospects of the dairy industry will depend on making productivity gains to counteract declining terms of trade at the farm level. The ‘Dairy Science 2006’ symposium featured plenary papers on platform technologies forecast to deliver large gains in farm productivity, on a national project designed to accelerate adoption of technologies and on functional foods. This paper summarises the potential benefits this research and development might offer to the dairy industry, and the time it might take to realise these benefits.
Dairy proteins and the regulation of satiety and obesity
Authors: Dunshea Frank R. , Ostrowska Ewa , Ferrari Josie M. , Gill Harsharn S.
Published: August 2007

Over the past decade there has been growing scientific evidence and public acceptance of the role that dietary protein plays in regulation of satiety, feed intake and obesity-related disorders. Dietary protein appears to suppress food intake and delay the return of hunger more than fats or carbohydrates in a manner not due to energy content alone. Also, high-protein diets support the maintenance of muscle mass when subjects reduce their energy intake, ensuring primarily adipose tissue loss. Some protein sources, particularly dairy, contain specific peptides or proteins that may elicit direct effects on satiety. The major proteins present in milk include β-lactalbumin, α-lactoglobulin, immunoglobulins, bovine serum albumin, and the various caseins. In addition, processed whey contains glycomacropeptide, which stimulates pancreatic and gastrointestinal secretion of hormones involved in satiety to a greater extent than whey alone. In the context of the literature, we show that a glycomacropeptide-rich whey protein isolate decreases feed intake and weight gain to a greater extent than a soy protein isolate in obese pigs. Also, insulin sensitivity is improved in pigs consuming high-protein diets, with these effects being independent of protein source. While, high-protein diets may decrease calcium balance and bone strength, it appears that these effects are attenuated by dairy proteins and dairy sources of calcium. These findings suggest that high-protein diets, and in particular those that contain whey proteins, may reduce hunger and food intake, thereby reducing fat deposition and improving insulin sensitivity.
Variation among hexaploid Paspalum dilatatum Poir. regenerants from tissue culture
Authors: Venuto B. C. , Croughan S. S. , Pitman W. D. , Jessup R. W. , Renganayaki K. , Burson B. L.
Published: August 2007

The common biotype of Paspalum dilatatum Poir. (dallisgrass) is a pentaploid obligate apomict and efforts to improve the grass have not been successful because of its asexual reproduction and irregular meiosis. An apomictic hexaploid biotype, known as Uruguayan dallisgrass, is a new source of genetic variation that may be useful in improving dallisgrass. As with common dallisgrass, improvement of this biotype via conventional breeding methods is difficult because of its apomictic reproduction. However, the use of tissue culture to produce somaclonal variation in the Uruguayan biotype has not been reported, and may offer a means for improving the species. The objectives of this research were to: (i) regenerate plants of Uruguayan dallisgrass through tissue culture, (ii) screen the regenerants for useful agronomic variation and evaluate their forage potential and nutritive value, and (iii) determine the genetic relatedness of the regenerants and their explant sources. In total, 178 plants, selected from 2372 regenerants in preliminary screening, were evaluated for forage nutritive value. Thirty-seven of these were planted into replicated field plot trials at two locations. None of these regenerants were superior to the Uruguayan biotype for forage nutritive value. However, two regenerants, 3440 and 3441, produced more forage than either the Uruguayan or common biotypes in evaluation tests for 3 years at one of the two locations. Data from AFLP analyses indicate genetic variation between two of the Uruguayan accessions and these two regenerants. This variation could account for the differences in forage yield between 3440 and 3441 and the Uruguayan accessions.
Nutrient budgeting as an approach to improving nutrient management on Australian dairy farms
Authors: Gourley C. J. P. , Powell J. M. , Dougherty W. J. , Weaver D. M.
Published: August 2007

Dairy farming in Australia continues to intensify. Increased stocking rates have resulted in increased milk production per ha, but have also required greater inputs of purchased feed and fertiliser. The imbalance between nutrient inputs, primarily as feed and fertiliser, and nutrient outputs, in milk and livestock, has resulted in significant nutrient accumulation on dairy farms and, consequently, a greater risk of nutrient loss to the environment. Nutrient budgeting is a technique used to quantify or predict nutrient deficits or surpluses, either at a whole-farm or field scale, in an attempt to improve nutrient use efficiency and reduce nutrient losses from agriculture. A broad range of nutrient budgeting approaches are used internationally, and depending on their purpose, they vary from the very simple to the very complex. Nutrient budgeting has been widely used to assist on-farm nutrient management decisions, in research to identify major nutrient pools, transformations and losses, to enable farmers to access cost-sharing support from governments, and in some countries as a major regulatory tool. The changing nature of Australian dairy operations, the increasing societal pressure on the farming community to reduce nutrient losses to water and air, and the need to provide evidence that farm practices are meeting environmental standards, justifies the need for improved nutrient management practices on Australian dairy farms. This paper describes different types of nutrient budgeting approaches used internationally and assesses the benefits of developing a practical, scientifically rigorous and nationally standardised nutrient budgeting approach for the Australian dairy industry.
A precise, low-cost milk sampler to enable the analysis of fat, protein, lactose and somatic cells in milk from individual cows
Authors: Clarke T. , Hannah M. C. , Wientjes H.
Published: August 2007

Less than half of Australian dairy farmers undertake production recording that normally requires the collection of milk samples for the measurements of fat, protein and lactose percentages and somatic cell count. Usually the milk samples are collected from individual animals on a ‘one-day-per-month’ basis by temporary milk-metering or sampling devices. Farmers who do not participate in production recording programs may be encouraged to do so if they could use a simple, robust, inexpensive, convenient and precise sampler. A sampler has been developed to meet these criteria. In this paper we report on the precision and bias of the new sampler with respect to milk composition and somatic cell count by comparison with samples collected by test buckets. For milk fat, the precision was only 3.1% and bias was +0.002% coefficient of variation. Precision for fat yield over a lactation period increases by only 0.02% when compared with results based on samplers that are approved by the International Committee for Animal Recording. We consider that the combination of low sampler cost and low sampler errors makes the new sampler aptly suited for production recording and monitoring somatic cell count.
Targeting amyloid-β in glaucoma treatment
Authors: Guo Li , Salt Thomas E. , Luong Vy , Wood Nicholas , Cheung William , Maass Annelie , Ferrari Giulio , Russo-Marie Françoise , Sillito Adam M. , Cheetham Michael E. , Moss Stephen E. , Fitzke Frederick W. , Cordeiro M. Francesca
Published: August 2007

The development of the devastating neurodegenerative condition, Alzheimer's disease, is strongly associated with amyloid-β (Aβ) deposition, neuronal apoptosis, and cell loss. Here, we provide evidence that implicates these same mechanisms in the retinal disease glaucoma, a major cause of irreversible blindness worldwide, previously associated simply with the effects of intraocular pressure. We show that Aβ colocalizes with apoptotic retinal ganglion cells (RGC) in experimental glaucoma and induces significant RGC apoptosis
in vivo
in a dose- and time-dependent manner. We demonstrate that targeting different components of the Aβ formation and aggregation pathway can effectively reduce glaucomatous RGC apoptosis
in vivo
, and finally, that combining treatments (triple therapy) is more effective than monotherapy. Our work suggests that targeting the Aβ pathway provides a therapeutic avenue in glaucoma management. Furthermore, our work demonstrates that the combination of agents affecting multiple stages in the Aβ pathway may be the most effective strategy in Aβ-related diseases.
Bound attractant at the leading vs. the trailing edge determines chemotactic prowess
Authors: Herzmark Paul , Campbell Kyle , Wang Fei , Wong Kit , El-Samad Hana , Groisman Alex , Bourne Henry R.
Published: August 2007

We have analyzed chemotaxis of neutrophil-differentiated HL60 cells in microfluidic devices that create exponential gradients of the chemoattractant, f-Met-Leu-Phe (fMLP). Such gradients expose each cell to a difference in fMLP concentration (ΔC) across its diameter that is directly proportional to the ambient concentration (C) at that cell's position in the gradient, so the ratio ΔC/C is constant everywhere. Cells exposed to ambient fMLP concentrations near the constant of dissociation (Kd) for fMLP binding to its receptor (≈10 nM) crawl much less frequently when ΔC/C is 0.05 than when it is 0.09 or 0.13. Hence, cells can detect the gradient across their diameter without moving and, thus, without experiencing temporal changes in attractant concentration. At all ΔC/C ratios tested, the average chemotactic prowess of individual cells (indicated by the distance a cell traveled in the correct direction divided by the length of its migration path) is maximal for cells that start migrating at concentrations near theKdand progressively decreases at higher or lower starting concentrations.
Pattern Recognition Receptors: From the Cell Surface to Intracellular Dynamics
Authors: Altenbach Denise , Robatzek Silke
Published: August 2007

Detection of potentially infectious microorganisms is essential for plant immunity. Microbial communities growing on plant surfaces are constantly monitored according to their conserved microbe-associated molecular patterns (MAMPs). In recent years, several pattern-recognition receptors, including receptor-like kinases and receptor-like proteins, and their contribution to disease resistance have been described. MAMP signaling must be carefully controlled and seems to involve receptor endocytosis. As a further surveillance layer, plants are able to specifically recognize microbial effector molecules via nucleotide-binding site leucine-rich repeat receptors (NB-LRR). A number of recent studies show that NB-LRR translocate to the nucleus in order to exert their activity. In this review, current knowledge regarding the recognition of MAMPs by surface receptors, receptor activation, signaling, and subcellular redistribution are discussed.
Nodulation Studies in the Model Legume Medicago truncatula: Advantages of Using the Constitutive EF1α Promoter and Limitations in Detecting Fluorescent Reporter Proteins in Nodule Tissues
Authors: Auriac Marie-Christine , Timmers Antonius C. J.
Published: August 2007

The Cauliflower mosaic virus 35S promoter currently is being used in RNAi-based approaches for attenuating host gene expression during legume root nodule development and also for the expression of fluorescent reporters in nodule tissues. In this study, we have evaluated the expression of this promoter in the indeterminate nodules of the model plant Medicago truncatula. Our results clearly show that the 35S promoter is inactive in both the nodule meristem and in bacteroid-containing cells of the nodules. On the other hand, the Arabidopsis thaliana EF1α promoter was found to be strongly expressed both in the nodule meristem and in all nodule-invaded cells. Therefore, we conclude that the constitutive EF1α promoter is far superior for mRNAi or overexpression studies in nodule tissues compared with the commonly used 35S promoter. In addition, our experiments have revealed that the intensity of fluorescent markers such as green fluorescent protein is severely attenuated within invaded cells in the nitrogen-fixation zone of the nodule, most likely by fluorescence quenching. This phenomenon may hinder the use of these tools for live-cell imaging in nodule tissue.
Induction of a Grapevine Germin-Like Protein (VvGLP3) Gene Is Closely Linked to the Site of Erysiphe necator Infection: A Possible Role in Defense?
Authors: Godfrey Dale , Able Amanda J. , Dry Ian B.
Published: August 2007

Germin-like proteins (GLP) have various proposed roles in plant development and defense. Seven novel GLP cDNA clones were isolated from grapevine (Vitis vinifera cv. Chardonnay). Reverse transcriptase-polymerase chain reaction expression analysis revealed that the VvGLP genes exhibit diverse and highly specific patterns of expression in response to a variety of abiotic and biotic treatments, including challenge by Erysiphe necator, Plasmopara viticola, and Botrytis cinerea, suggesting a diversity of roles for each of the GLP family members. Significantly, one of the grapevine GLP genes, VvGLP3, is induced specifically by E. necator infection and expression is closely linked to the site of infection. Subcellular localization of VvGLP3 determined by transient expression of a VvGLP3:GFP fusion construct in onion cells indicated that the recombinant protein was targeted to the cell wall. Recombinant VvGLP3 was successfully expressed in Arabidopsis thaliana and the partially purified recombinant protein was demonstrated to have superoxide dismutase activity. This data has provided an insight into the diverse nature of the GLP family in grapevine and suggests that VvGLP3 may be involved in the defense response against E. necator.