Point-of-care (POC) devices that veterinary practitioners can use to easily and rapidly measure blood ionized calcium (iCa) levels in cows immediately after withdrawing a blood sample on the dairy farm are needed. Aims of present studies was to compare the commercially available ion-selective electrode handheld iCa meter (bovine blood iCa checker) with the benchtop blood gas analyzer GEM premier 3500 and handheld analyzer i-STAT 1. Sixty-two paired-point whole blood samples were obtained from three cows with hypocalcemia experimentally induced by Na 2 -EDTA infusion. Whole blood samples were also obtained from the 36 cows kept on a farm in field conditions. The results using the bovine blood iCa checker correlated with those using the GEM premier 3500 and i-STAT 1. Bovine blood iCa checker was “compatible” with the GEM premier 3500 and i-STAT 1 because the frequency of differences between the measurements within ± 20% of the mean were 100% (65/65, >75%) and 90.8% (59/65, >75%), respectively. In the field trial, the blood iCa concentration measured by the bovine blood Ca checker was significantly positively correlated with that measured by the i-STAT 1 portable analyzer. Bovine blood iCa checker was “compatible” with the i-STAT 1 because the frequency of differences between the measurements within ± 20% of the mean was 100% (36/36, >75%). Results from these findings, the bovine blood iCa checker may be applied as a simplified system to measure the iCa concentration in bovine whole blood.

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Abstract. An experiment was carried out to reproduce ball lightning by using microwave radiation and electric discharge without a metal cavity. When the energy of the discharge was high, a plasma fireball was produced. When high-power microwave existed, a plasma fireball was produced even if the power of the discharge was low. We must pay more attention to places where high-power electromagnetic waves exist to see ball lightning. IntroductionBall lightning has been considered a rare phenomenon, and some people think that it is an illusion. However, many scientists have studied ball lightning and believe that it is a real phenomenon in nature [Singer, 1971[Singer, , 1977 In the past our group carried out two types of experiments. One was an electric discharge experiment in flammable hydrocarbon gas, the density of which was under the lower limit for combustion [Ofuruton and Ohtsuki, 1990]. This experiment was based on Barry's [1968] experiments. Another was plasma formation by interference of microwaves in a metal cavity [Ohtsuki and Ofuruton, 1991]. This experiment was based on Kapitza's [1955] theory. Kapitza suggested that the most favorable places for the production of ball lightning were regions where the potential antinodes of the radio waves formed. In the former experiment we got a small fireball which was contained within the chamber. In the latter experiment we got a plasma fireball which went on the wire, went through a ceramic plate, and went against the wind. Especially in the latter experiment, we succeeded in reproducing these three properties of ball lightning. This has led us to believe that most of the ball lightning phenomena are plasma fireballs [Ohtsuki and O•i•ruton, 1994].Recently, we performed a new experiment using both microwaves and electrical discharge. In this experiment, we got plasma fireballs without a cavity [Ofuruton e! al., 1996]. In this paper, we examine the possibility of producing fireballs using microwaves and discharges together. waveguide. In the past experiments we had connected a cylindrical metal cavity with the end of the waveguide, and the cavity had been set in a chamber (110 cm x 71 cm x 100 cm). ExperimentThe frame of the chamber had been made of wood, and the walls had been made of acrylic plates. The outside of the chamber had been covered by metal net, and we had used such a chamber for safety from the microwave radiation.In this experiment all apparatus was as before except the cavity. Therefore the microwave radiated in the chamber, not in a metal cavity. In the chamber the microwave energy radiated in a hemisphere from the end of the waveguide. The energy was absorbed by the wood of the chamber frame and was transmitted through the acrylic plates. Therefore the standing waves did not form in the chamber, and we assume that this arrangement was a good approximation to radiation in free space. Only air, not any other gas, was contained in the chamber. The pressure in the chamber was 1 atm. Copper electrodes (3 mm in diameter) were set up in front of the end o...

The purpose of this study was to clarify the therapeutic effects of oxytetracycline (OTC) as a first-line antibiotic in cattle with acute Escherichia coli mastitis and systemic signs. Drug susceptibility was determined by the minimum inhibitory concentration (MIC) of E. coli isolated from cows with acute E. coli mastitis (n=38). Cattle were divided into OTC-susceptible (S, n=30) and OTC-resistant (R, n=8) groups. They were further subdivided according to susceptibility to the antibiotic used as a second treatment, into susceptible-susceptible (SS, n=30), resistant-susceptible (RS, n=5), and resistant-resistant (RR, n=3) groups. Clinical signs on the day after initial treatment were compared between S and R groups as short-term indicators of treatment effects. The 28-day survival rate of cattle was then compared among SS, RS, and RR groups as a long-term indicator of treatment effects. There were no differences in clinical signs between S and R groups on the day after the first dose, but the 28-day survival rate was significantly greater in the SS group than in the RR group ( P =0.04). The results demonstrated that an effective drug is essential for first-line treatment of acute coliform mastitis. However, anticipating the effectiveness of a first-line antibiotic based on clinical symptoms at the second day of treatment is impossible. It is important to build a picture of drug resistance trends in cattle herds for empirical selection of antibiotics to be administered.

Fibronectin (FN) and type I collagen (Col), which are kinds of extracelluar matrices, were coprecipitated with calcium phosphate to form a composite layer on a hydroxyapatite (HAP) ceramic using a supersaturated calcium phosphate solution (CP solution). The amounts of protein immobilized in the layers were determined to be 20.97±3.04 µg·cm-2 for FN, 5.26±0.19 µg·cm-2 for Col and 21.72±2.30 µg·cm-2 for simultaneously immobilized FN and Col. When osteoblastic MC3T3-E1 cells were cultured on the HAP ceramics with the composite layer containing FN and/or Col, calcified tissue was formed through the activity of the cells. The result showed that the composite layer accelerated the differentiation of MC3T3-E1 to bone-forming cells. It is assumed that osteoblastic cells in alveolar bone migrated and differentiated on the surface of the tooth roots when the artificial tooth roots were covered with the composite layer.