A high-input impedance differential millivolt meter for use with solid ceramic oxygen electrolyte cells

Design factors are given for a high-input impedance differential millivolt meter designed, built, and tested as an inexpensive solid-state electronic system for use in measuring the electromotive force from solid ceramic oxygen electrolyte cells. A schematic diagram is included

Responses of Coccidia-Vaccinated Broilers to Essential Oil Blends Supplementation up to Forty-Nine Days of Age

Coccidiosis control may become a greater problem as the use of growth-promoting antibiotics (GPA) and ionophores declines. Vaccination with live oocysts may turn into a popular alternative to the use of coccidiostats in broilers, although cocci vaccination is frequently linked to temporary lower performance in young flocks. This experiment evaluates the dietary supplementation of 2 specific essential oil (EO) blends (Crina Poultry and Crina Alternate), either as alternatives to GPA and ionophores (BMD + Coban) or as feed additives that help to improve the performance of cocci-vaccinated broilers. Live performance and lesion scores were observed. These 2 specific EO blends differ in their efficacy to promote growth. Chickens that were not cocci vaccinated and were fed Crina Poultry had better feed conversion ratio (FCR) than the unmedicated control treatment in the starter period. The same EO improved FCR in cocci-vaccinated birds in the finisher period in comparison to the negative control group, but those responses were not significantly different from other treatments or significant at 49 d of age. No significant differences were observed in lesion scores at 37 d. Diets supplemented with a GPA-ionophore combination consistently supported the best BW gain and FCR in each period and the entire grow-out period. No significant beneficial or deleterious effects on live performance were observed due to these specific EO blends in cocci-vaccinated broilers

Discovery of Radio/X-ray/Optical Resolved Supernova Remnants in the Center of the Andromeda Galaxy

We have detected a spatially resolved supernova remnant (SNR) in the center of the Andromeda Galaxy, in radio, X-ray, and optical wavelengths. These observations provide the highest spatial resolution imaging of a radio/X-ray/optical SNR in that galaxy to date. The multi-wavelength morphology, radio spectral index, X-ray colors, and narrow-band optical imaging are consistent with a shell-type SNR. A second SNR is also seen resolved in both radio and X-ray. By comparing the morphological sturcture of the SNRs in different wavelengths and with that in our own Galaxy, we can study the shock morphologies of SNRs in the Andromeda Galaxy. The proximity of the SNRs to the core suggests high interstellar medium density in the vicinity of the SNRs in the center of the Andromeda Galaxy.Comment: 5 pages, 3 figures, accepted for publication in ApJ

Hydrology and water quality of a field and riparian buffer adjacent to a mangrove wetland in Jobos Bay watershed, Puerto Rico

Agriculture in coastal areas of Puerto Rico is often adjacent to or near mangrove wetlands. Riparian buffers, while they may also be wetlands, can be used to protect mangrove wetlands from agricultural inputs of sediment, nutrients, and pesticides. We used simulation models and field data to estimate the water, nitrogen, and phosphorus inputs from an agricultural field and riparian buffer to a mangrove wetland in Jobos Bay watershed, Puerto Rico. We used the Agricultural Policy/Environmental eXtender (APEX) and the Riparian Ecosystem Management Model (REMM) models sequentially to simulate the hydrology and water quality of the agricultural fields and an adjacent riparian buffer, respectively. Depth to the water table surface was measured monthly at numerous sites in both field and riparian areas and were used with recording well data from outside the field to estimate daily water table depths in the field and riparian buffer and to calibrate field-scale hydrologic processes. Calibration and validation of the models were successful for the riparian buffer and in three of four field quadrants. In these areas the average simulated depth to water table for the field and the riparian buffer were within ±7% of field estimated water table depths. Over the 3-year study period, the riparian buffer represented by REMM reduced agricultural loadings to the mangrove wetland by 24% for sediment yield, and about 30% for total nitrogen and phosphorus. Simulations indicated that tropical storms and hurricanes played an important role in water and nutrient transport on this site contributing at least 63% of total sediment and nutrient loads

Evidence for high levels of vertical transmission in Toxoplasma gondii

Toxoplasma gondii is a highly ubiquitous and prevalent parasite. Despite the cat being the only definitive host, it is found in almost all geographical areas and warm blooded animals. Three routes of transmission are recognised: ingestion of oocysts shed by the cat, carnivory and congenital transmission. In natural populations, it is difficult to establish the relative importance of these routes. This paper reviews recent work in our laboratory which suggests that congenital transmission may be much more important than previously thought. Using PCR detection of the parasite, studies in sheep show that congenital transmission may occur in as many as 66% of pregnancies. Furthermore, in families of sheep on the same farm, exposed to the same sources of oocysts, significant divergent prevalences of Toxoplasma infection and abortion are found between different families. The data suggest that breeding from infected ewes increases the risk of subsequent abortion and infection in lambs. Congenital transmission rates in a natural population of mice were found to be 75%. Interestingly, congenital transmission rates in humans were measured at 19.8%. The results presented in these studies differ from those of other published studies and suggest that vertical transmission may be much more important than previously thought

Dynamical instability of a condensate induced by a rotating thermal gas

We study surface modes of the condensate in the presence of a rotating thermal cloud in an axisymmetric trap. By considering collisions that transfer atoms between the condensate and noncondensate, we find that modes which rotate in the same sense as the thermal cloud damp less strongly than counter-rotating modes. We show that above a critical angular rotation frequency, equivalent to the Landau stability criterion, the co-rotating mode becomes dynamically unstable, leading to the possibility of vortex nucleation. This kind of mechanism is proposed as a natural explanation for the formation of vortices observed recently in the experiment of Haljan \emph{et al} {[}P. C. Haljan \emph{et al.}, cond-mat/0106362{]}. We also generalize our stability analysis to treat the case where the stationary state of the condensate already possesses a single vortex.Comment: 4 pages, no figure

Finite-temperature simulations of the scissors mode in Bose-Einstein condensed gases

The dynamics of a trapped Bose-condensed gas at finite temperatures is described by a generalized Gross-Pitaevskii equation for the condensate order parameter and a semi-classical kinetic equation for the thermal cloud, solved using $N$-body simulations. The two components are coupled by mean fields as well as collisional processes that transfer atoms between the two. We use this scheme to investigate scissors modes in anisotropic traps as a function of temperature. Frequency shifts and damping rates of the condensate mode are extracted, and are found to be in good agreement with recent experiments.Comment: 4 pages, 3 figure