Multiwavelength Light Curves of Two Remarkable Sagittarius A* Flares.

Sgr A*, the supermassive black hole (SMBH) at the center of our Milky Way Galaxy, is known to be a variable source of X-ray, near-infrared (NIR), and submillimeter radiation and therefore a prime candidate to study the electromagnetic radiation generated by mass accretion flow onto a black hole and/or a related jet. Disentangling the power source and emission mechanisms of this variability is a central challenge to our understanding of accretion flows around SMBHs. Simultaneous multiwavelength observations of the flux variations and their time correlations can play an important role in obtaining a better understanding of possible emission mechanisms and their origin. This paper presents observations of two flares that both apparently violate the previously established patterns in the relative timing of submillimeter/NIR/X-ray flares from Sgr A*. One of these events provides the first evidence of coeval structure between NIR and submillimeter flux increases, while the second event is the first example of the sequence of submillimeter/X-ray/NIR flux increases all occurring within ~1 hr. Each of these two events appears to upend assumptions that have been the basis of some analytic models of flaring in Sgr A*. However, it cannot be ruled out that these events, even though unusual, were just coincidental. These observations demonstrate that we do not fully understand the origin of the multiwavelength variability of Sgr A* and show that there is a continued and important need for long-term, coordinated, and precise multiwavelength observations of Sgr A* to characterize the full range of variability behavior.

Variability Timescale and Spectral Index of Sgr A* in the Near Infrared: Approximate Bayesian Computation Analysis of the Variability of the Closest Supermassive Black Hole.

Sagittarius A* (Sgr A*) is the variable radio, near-infrared (NIR), and X-ray source associated with accretion onto the Galactic center black hole. We present an analysis of the most comprehensive NIR variability data set of Sgr A* to date: eight 24 hr epochs of continuous monitoring of Sgr A* at 4.5 µm with the IRAC instrument on the Spitzer Space Telescope, 93 epochs of 2.18 µm data from Naos Conica at the Very Large Telescope, and 30 epochs of 2.12 µm data from the NIRC2 camera at the Keck Observatory, in total 94,929 measurements. A new approximate Bayesian computation method for fitting the first-order structure function extracts information beyond current fast Fourier transformation (FFT) methods of power spectral density (PSD) estimation. With a combined fit of the data of all three observatories, the characteristic coherence timescale of Sgr A* is τ b = 243 - 57 + 82 minutes (90% credible interval). The PSD has no detectable features on timescales down to 8.5 minutes (95% credible level), which is the ISCO orbital frequency for a dimensionless spin parameter a = 0.92. One light curve measured simultaneously at 2.12 and 4.5 µm during a low flux-density phase gave a spectral index α s = 1.6 ± 0.1 ( F ν ∝ ν - α s ) . This value implies that the Sgr A* NIR color becomes bluer during higher flux-density phases. The probability densities of flux densities of the combined data sets are best fit by log-normal distributions. Based on these distributions, the Sgr A* spectral energy distribution is consistent with synchrotron radiation from a non-thermal electron population from below 20 GHz through the NIR.

Spitzer spectral observations of the deep impact ejecta.

Spitzer Space Telescope imaging spectrometer observations of comet 9P/Tempel 1 during the Deep Impact encounter returned detailed, highly structured, 5- to 35-micrometer spectra of the ejecta. Emission signatures due to amorphous and crystalline silicates, amorphous carbon, carbonates, phyllosilicates, polycyclic aromatic hydrocarbons, water gas and ice, and sulfides were found. Good agreement is seen between the ejecta spectra and the material emitted from comet C/1995 O1 (Hale-Bopp) and the circumstellar material around the young stellar object HD100546. The atomic abundance of the observed material is consistent with solar and C1 chondritic abundances, and the dust-to-gas ratio was determined to be greater than or equal to 1.3. The presence of the observed mix of materials requires efficient methods of annealing amorphous silicates and mixing of high- and low-temperature phases over large distances in the early protosolar nebula.

Production responses by early lactation cows to whole sunflower seed or tallow supplementation of a diet based on barley.

A 2-yr study to evaluate the effectiveness of whole sunflower seed as a source of fat was conducted with 18 primiparous and 31 multiparous Holstein cows. The three diets evaluated were a basal diet based on barley (control), a basal diet supplemented with 2.7% tallow, and a basal diet supplemented with 7.1% whole sunflower seeds. The DMI of lactating cows during the 16-wk test period was not influenced by supplementation with either sunflower seeds or tallow. Milk production was 34.4, 34.6, and 35.5 kg/d for cows fed the control diet or the diets supplemented with sunflower or tallow, respectively, and was not influenced by diet. The production and concentrations of milk protein, fat, and SNF also were not influenced by diet. The concentrations of C6:0 to C14:1 fatty acids were highest in the milk of cows fed the control diet. The concentrations of C10:0 to C16:1 were higher when cows were fed the diet with the tallow supplement than when they were fed the diet with the sunflower supplement. However, the concentrations of C18:0 to C18:2 and C20:0 were higher in the milk of cows that were fed the sunflower supplement than in the milk of cows that were fed the tallow supplement or the control diet. Concentrations of individual VFA and the ratio of acetate to propionate were not influenced by diet. Body weight, body condition score, and reproduction parameters were similar for all diets, suggesting that there were no effects on subsequent production. The performance of cows fed whole sunflower seeds as a source of energy appeared to be similar to the performance of cows fed traditional high energy diets based on barley. The fatty acid profile of the milk of cows fed diets supplemented with sunflower seeds was more favorable than that of the milk of cows fed diets supplemented with tallow.

Influence of moist heat treatment on ruminal and intestinal disappearance of amino acids from canola meal.

Three mature Angus steers fitted with large ruminal cannulas and three Holstein steers each fitted with T-shaped cannulas in the proximal duodenum and reentrant cannulas in the terminal ileum were used to study the effect of moist heat treatment on AA digestion of canola meal in each segment of the digestive tract. Canola meal was treated with moist heat at 127 degrees C for 15 or 45 min. Degradation of AA in the rumen was estimated using small nylon bags incubated for .1, 8, 16, and 24 h in the rumen. Digestion of AA in the small and large intestines and total tract were estimated using separate sets of bags in a sequence of ruminal in situ incubation, in vitro incubation in an acid-pepsin solution, and a mobile bag technique. Heat treatment for 15 or 45 min reduced concentrations of Lys by 15.9 and 29.2% and Arg by 8.0 and 15.2%, respectively. Heat treatment for 15 or 45 min significantly reduced the degradation of AA in the rumen; the availability of AA in the small intestine increased in proportion to the decreased ruminal degradation. Digestion of AA in the large intestine was 5 percentage points higher after heat treatment for 45 min than with no heat treatment. Apparent digestion of AA in the total tract was unaffected by 15 min of heating; however, 45 min of heating reduced digestion.(ABSTRACT TRUNCATED AT 250 WORDS)

The SMS-CESF Medical Outcomes Research Project.

After reviewing the environment of cost, quality data collection and analysis, the State Medical Society of Wisconsin Task Force on Quality Assessment and Implementation of Practice Parameters concluded it is critical for the SMS to take a dynamic role in sponsoring the development and use of medical outcomes research. The initial emphasis will be on chronic diseases and health conditions representative of a large percentage of the Wisconsin patient population and involve physicians from diverse practice settings. The physicians of Wisconsin have a singular opportunity to seize the day by supporting and participating in a non-proprietary, regional study of patient medical outcomes.

Detection of estrus by radiotelemetric monitoring of vaginal and ear skin temperature and pedometer measurements of activity.

Methods to improve detection of estrus in dairy cows have been studied extensively without wide acceptance of any one method. In the present study, the use of body temperatures and pedometer-monitored activity were evaluated as methods of estrus detection. Twice daily activity levels of 13 lactating cows were monitored using pedometers, and vaginal and ear skin temperature measurements were made continuously using radiotelemetry. Activity increased 2.8-fold at estrus for the 8-h daytime period (0630 to 1430 h), during which cows were given a 5-h turnout period, but not for the 16-h overnight period (1430 to 0630 h), during which cows were confined to tie stalls. When increased activity was used to detect estrus on an individual cow basis, 20 of 25 estruses were detected with 4 false positives. Vaginal temperature increased by .6 +/- .3 degree C at estrus and remained elevated by at least .3 degree C for 6.8 +/- 4.6 h. When increased vaginal temperature was used on an individual basis, 17 of 21 estruses were detected with 3 false positives. Rate of detection of estrus by visual observation was 66%.

Lactational response of dairy cows to oral administration of L-tyrosine.

Tyrosine was administered to lactating cows to determine if the lack of response to canola meal treated with formaldehyde could be due to failure to increase uptake of tyrosine. Disappearance of free tyrosine from nylon bags suspended in the rumen of a fistulated steer was 27.4% after 12 h. Oral administration of tyrosine to sheep increased the free tyrosine concentration of duodenal fluid but did not affect tyrosin concentration in blood plasma. Tyrosine (50 g/cow per day) was fed to six lactating Holsteins in a switchback design. Milk yield was increased by 1.0 kg/day. In a second trial with a switchback design, tyrosine was fed to 12 lactating cows that were consuming diets containing formaldehyde-treated canola meal. Supplementing tyrosine to the formaldehyde-treated diet increased milk production by 1.6 kg/day, but adding tyrosine to the untreated diet did not affect milk yield. Results suggest that availability of tyrosine can limit milk production in some circumstances and that the lack of response to canola meal treated with formaldehyde may be partly due to failure to increase the uptake of tyrosine.

Studies on the effects of rapeseed meal on thyroid status of cattle, glucosinolate and iodine content of milk and other parameters.

The effects of feeding rapeseed meals (RSM) containing low (Tower) or high (Target/Turret) levels of glucosinolates on thyroid status, iodine and glucosinolate content of milk and other parameters were studied in dairy cows and young calves. RSM (Tower and Turret) fed to dairy cows at 25% of the grain mixture reduced iodine content of milk. Diets containing Tower and Turret RSM tended to reduce plasma thyroxine (T4) in cows and increase the size of thyroids in rats. Calf diets containing Target and Tower RSM resulted in increased liver and thyroid weights, but only those containing Target tended to reduce plasma T4 levels. Feed intake, weight gain, hemoglobin, blood cell volume and erythrocyte count in calves were not affected by diets containing Tower RSM, but Target RSM reduced all these parameters. In addition, diets containing Target caused more pronounced histological changes of the calves' thyroid than those containing Tower RSM. No measurable amounts of intact glucosinolates were detected in milk of cows fed RSM. Similarly the glucosinolate aglucones, isothiocyanates or vinyl oxazolidinethione, were not transferred to milk although small amounts of unsaturated nitrile (1-cyano-2-hydroxy-3-butene) and inorganic thiocyanate were detected in milk. Rats receiving milk from cows fed Turret RSM developed larger thyroid than those receiving milk from control-fed cows. Supplemental iodine (61.0 microgram/d) in the rat prevented the thyroid enlargement.

Isolation and characterization of lymphocyte associated foamy virus from a red uakari monkey (Cacajao rubicundus).

A syncytium-forming virus was isolated from the lymphocytes of a uakari monkey 70 days after establishing a lymphocyte/owl monkey kidney coculture in the wild. The morphology and morphogenesis of the virus, plus its physicochemical characteristics indicate that the agent is a foamy virus. An unusal cell alteration found in cultures infected with this foamy was the formation of eosinophilic intracytoplasmic inclusion in association with the syncytia. The agent was found to be antigenically distinct to other known simian foamy viruses.

Isolation and in vitro characterization of a herpesvirus from ground squirrels (Citellus sp).

A viral agent was isolated from ground squirrel primary kidney cultures which presented a spontaneous cell layer alteration. The cultural, morphologic, and physico-chemical characteristics of the agent indicated that it belongs in the herpesvirus group. The isolate presented a narrow in vitro cell host range, growing best in marmoset monkey, owl monkey, rabbit, and hamster kidney cultures and poorly in Vero and dog fetal lung cells. The agent is readily released from infected cells, a fact which indicates that it is a cell-free virus. Good plaque formation was observed only in marmoset monkey kidney monolayers. The virus was not neutralized by antisera against other herpesviruses with the exception of a partial 1-way cross-neutralization between ground squirrel agent and Herpesvirus saguinus antisera. All these characteristics indicate that this virus is likely a new member of the herpesvirus family.