Decomposing productivity and efficiency among Western Australian grain producers

We provide empirical evidence to decompose productivity growth of a group of producers into technical change and efficiency measures at the farm level. Using four years of farm-level data from forty-five grain producers in the low- to medium-rainfall zone of Western Australia, we decompose productivity numbers to analyze total factor productivity. The results show that producers are generally technical, mix, and scale efficient, but the results for input and output mix efficiencies vary. The outcomes for input mix efficiency suggest that producers face some rigidity in their production decisions. In contrast, output mix efficiency suggests that most producers adjust their output mixes to account for different seasonal conditions and enterprise mixes. Copyright 2013 Western Agricultural Economics Association

Measuring the Efficiency of Wheat Production of Western Australian Growers

Using stochastic frontier analysis, efficiency of production of wheat in Western Australia was studied. The production function model used was a relatively simple input model, consisting of wheat yield, effective rainfall, fertilizer application rates and year of study. Inefficiency was captured in a second model that incorporated machinery capital investment, opening equity level, and year of study. Data covered the production years 2004 through to 2007. The results demonstrated that inefficiency was present in wheat production in Western Australia and that inefficiency increased over the period from 18% in 2004 to 29% in 2007. Higher machinery investment per hectare and opening equity levels reduced inefficiency, due to producers having sufficient capacity, mechanical or financial, to adapt to variability within the production season. The results demonstrated the stochastic nature of efficiency and that for some firms improving efficiency may not be possible or feasible due to limitations within the firm. This also holds for firms that are relatively efficient in some years and that the reasons for the inefficiency are not necessarily production related, hence, programs targeted to improve efficiency may not be very successful. On the other hand firms that are consistently inefficient provide an ideal target audience for programs to improve efficiency. However, these programs must be conditioned on adequately identifying the source(s) of inefficiency and the producer having access to resources to increase efficiency. Similar analyses could be undertaken in different crops or different geographic locations, to identify if and why inefficiencies are present in other production systems.Wheat production, efficiency, fertiliser, rainfall., Farm Management,

DAIRY DEREGULATION AND LOW-INPUT DAIRY PRODUCTION: A BIOECONOMIC EVALUATION

Deregulation of the Australian dairy industry could affect the utilization of resources by milk producers and the profitability of dairy production. In this study we examine the feed mix that dairy producers use, both pastures and supplements, under partial and total deregulation. We are particularly interested in the interaction of pasture utilization and farm profitability. The results of this research demonstrate that profitable low-input dairy is constrained by the most limiting resource, feed supplied by pasture, and that the interactions between economic and biological processes are critical to farm profitability.Agricultural and Food Policy, Production Economics,

DYNAMICS OF OPTIMAL INTERACTIONS BETWEEN PASTURE PRODUCTION AND MILK YIELDS OF AUSTRALIAN DAIRY FARMS

Deregulation of the Australian dairy industry could effect the utilization of resources by milk producers. In this study we examine the feed input mix dairy producers use, both pastures and supplements, prior to and after deregulation. We are particularly interested in the interaction of pasture utilization and farm profitability.dairy production, pasture utilization, deregulation, Land Economics/Use, Livestock Production/Industries,

A dynamic conductance model of fluorescent lamp for electronic ballast design simulation

A Spice-compatible dynamic conductance model of a fluorescent lamp for use in electronic ballast simulation is presented. The time-dependent conductance of the fluorescent lamp is derived from a plasma ionization balance equation that uses simplified descriptions of the physical processes within the lamp as its basis. The model has been designed to enable user-defined lamp radius, length, buffer gas pressure and cold-spot temperature as input parameters thus representing a valuable tool for ballast simulations. Simulation results are compared to experimental measurements and satisfactory agreement is achieved

Low multiplication noise thin Al0.6Ga0.4As avalanche photodiodes

Avalanche multiplication and excess noise were measured on a series of Al0.6Ga0.4As p+in+ and n+ip+ diodes, with avalanche region thickness, w ranging from 0.026 μm to 0.85 μm. The results show that the ionization coefficient for electrons is slightly higher than for holes in thick, bulk material. At fixed multiplication values the excess noise factor was found to decrease with decreasing w, irrespective of injected carrier type. Owing to the wide Al0.6Ga0.4As bandgap extremely thin devices can sustain very high electric fields, giving rise to very low excess noise factors, of around F~3.3 at a multiplication factor of M~15.5 in the structure with w=0.026 μm. This is the lowest reported excess noise at this value of multiplication for devices grown on GaAs substrates. Recursion equation modeling, using both a hard threshold dead space model and one which incorporates the detailed history of the ionizing carriers, is used to model the nonlocal nature of impact ionization giving rise to the reduction in excess noise with decreasing w. Although the hard threshold dead space model could reproduce qualitatively the experimental results, better agreement was obtained from the history-dependent mode

Estradiol, progesterone, testosterone profiles in human follicular fluid and cultured granulosa cells from luteinized pre-ovulatory follicles

BACKGROUND: The production of sex steroids by follicular cells is proposed to be influenced by the maturity of the incumbent oocyte. Thus steroid levels may reflect suitability of an oocyte for IVF. We examined follicular fluids and granulosa cell production of steroid from IVF patients in order to test the relationship between steroid levels and fertilization. METHODS: Follicular fluid and granulosa cells were extracted from 206 follicles of 35 women undergoing controlled ovarian stimulation. Follicular fluid was assayed for estradiol, progesterone and testosterone. Granulosa cells were cultured from individual follicles and their culture media assayed for production of these hormones after 24 hrs in vitro. Levels of steroids were correlated with follicular diameter, oocyte recovery and subsequent fertilization. RESULTS: Follicular fluid levels of progesterone were 6100 times higher than that of estradiol, and 16,900 times higher that of testosterone. Despite the size of follicle triggered after controlled luteinization, the levels of progesterone and testosterone were maintained at relatively constant levels (median 98.1 micromoles/L for progesterone, and 5.8 nanomoles/L for testosterone). However, estradiol levels were slightly lower in the larger follicles (follicular diameter 10-15 mm, median 25.3 nanomoles/L; follicles > = 15 mm, median 15.1 nanomoles/L; linear correlation r = -0.47, p < 0.0001). With respect to oocyte recovery, no steroid showed a significant association in follicular fluid levels. Similarly no difference in follicular fluid steroid levels was found for those oocytes that did or did not fertilize. Significant quantities of progesterone were produced by the granulosa cells but production was constant regardless of the size of follicle from which the cells originated. Estradiol levels were only detectable in 10 of 121 cultures examined, and testosterone in none. Interestingly, when an oocyte was present follicular estradiol levels correlated with progesterone levels. However, when absent, follicular estradiol levels correlated with testosterone levels but not with progesterone. CONCLUSIONS: The principle steroid product of luteinized pre-ovulatory granulosa is progesterone, a differentiation triggered by the gonadotropin surge. However, absolute steroid levels are associated with follicular size, not oocyte maturation/ability to fertilize

Modification of the 31P magnetic resonance spectra of a rat tumour using vasodilators and its relationship to hypotension.

The effects of different doses of hydralazine and prostacyclin on the 31P magnetic resonance spectra of the LBDS1 fibrosarcoma were investigated and related to their effects on mean arterial blood pressure (MABP) and heart rate. The effect of reducing MABP by bleeding the animals, via the tail artery, was also investigated. Tumour spectral changes following high dose drug treatment (an increase in inorganic phosphate, a reduction in nucleotide triphosphates and a reduction in pH) were consistent with nutrient deprivation. These changes were dose dependent. Changes in MABP and heart rate were consistent with vasodilatation in normal tissues. However, for the same fall in MABP, hydralazine produced a greater rise in tumour inorganic phosphate (Pi) and a greater fall in tumour pH than did prostacyclin. Controlled bleeding was effective in reducing MABP. It also reduced tumour pH but had no significant effect on tumour Pi. The clinical application of the two drugs for reducing tumour blood flow and pH for therapy is likely to be limited by the large degree of hypotension necessary to produce an effect. The differential effect of the two drugs for the same fall in MABP may be related to different degrees of direct tumour vasodilatation or to a direct effect of hydralazine on tumour energy metabolism. The observation that controlled bleeding does not change tumour Pi is further evidence indicating that the degree of arterial hypotension is not the sole factor in determining tumour energy status

Multiband effects on beta-FeSe single crystals

We present the upper critical fields Hc2(T) and Hall effect in beta-FeSe single crystals. The Hc2(T) increases as the temperature is lowered for field applied parallel and perpendicular to (101), the natural growth facet of the crystal. The Hc2(T) for both field directions and the anisotropy at low temperature increase under pressure. Hole carriers are dominant at high magnetic fields. However, the contribution of electron-type carriers is significant at low fields and low temperature. Our results show that multiband effects dominate Hc2(T) and electronic transport in the normal state

The Fermi surface of CeCoIn5: dHvA

Measurements of the de Haas - van Alphen effect in the normal state of the heavy Fermion superconductor CeCoIn5 have been carried out using a torque cantilever at temperatures ranging from 20 to 500 mK and in fields up to 18 tesla. Angular dependent measurements of the extremal Fermi surface areas reveal a more extreme two dimensional sheet than is found in either CeRhIn5 or CeIrIn5. The effective masses of the measured frequencies range from 9 to 20 m*/m0.Comment: 4 pages, 2 figures, submitted to PRB Rapid