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The extracytoplasmic function sigma factor σVreI of the human pathogen Pseudomonas aeruginosa promotes transcription of potential virulence determinants, including secretion systems and secreted proteins. Its activity is modulated by the VreR anti-σ factor that inhibits the binding of σVreI to the RNA polymerase in the absence of a (still unknown) inducing signal. The vreI-vreR genes are expressed under inorganic phosphate (Pi) starvation, a physiological condition often encountered in the host that increases P. aeruginosa pathogenicity. However, whether or not σVreI is active in vivo during infection and contributes to the Pi starvation-induced virulence of this pathogen has not been analyzed yet. Using zebrafish embryos and a human alveolar basal epithelial cell line as P. aeruginosa hosts, we demonstrate in this work that σVreI is active during infection and that lack of σVreI considerably reduces the Pi starvation-induced virulence of this pathogen. Surprisingly, lack of the σVreI inhibitor, the VreR anti-σ factor, also diminishes the virulence of P. aeruginosa. By transcriptomic analyses we show that VreR modulates gene expression not only in a σVreI-dependent but also in a σVreI-independent manner. This includes potential virulence determinants and transcriptional regulators that could be responsible for the reduced virulence of the ΔvreR mutant., We thank W. Koudstaal for critical review of the manuscript, A. van der Sar and T. Verboom (AUMC, Amsterdam) for facilitating the work on zebrafish embryos, F. Madrazo (Instituto de Investigación Sanitaria Valdecilla) for assistance with the confocal fluorescence imaging, and R. Tobes (Era7 Bioinformatics) for the RNA-seq bioinformatics analysis. This work was funded by FEDER and the Spanish Ministry of Economy with grants SAF2015-68873-P and BIO2017-83763-P. JOA was supported by the Spanish Ministry of Economy through a FPI fellowship (BES-2013-066301).

RhoGTPases regulate cytoskeletal dynamics, migration and cell-cell adhesion in endothelial cells. Besides regulation at the level of guanine nucleotide binding, they also undergo post-translational modifications, for example ubiquitination. RhoGTPases are ubiquitinated by Cullin RING ligases which are in turn regulated by neddylation. Previously we showed that inhibition of Cullin RING ligase activity by the neddylation inhibitor MLN4924 is detrimental for endothelial barrier function, due to accumulation of RhoB and the consequent induction of contractility. Here we analyzed the effect of pharmacological activation of Cullin RING ligases on endothelial barrier integrity in vitro and in vivo. CSN5i-3 induced endothelial barrier disruption and increased macromolecule leakage in vitro and in vivo. Mechanistically, CSN5i-3 strongly induced the expression and activation of RhoB and to lesser extent of RhoA in endothelial cells, which enhanced cell contraction. Elevated expression of RhoGTPases was a consequence of activation of the NF-κB pathway. In line with this notion, CSN5i-3 treatment decreased IκBα expression and increased NF-κB-mediated ICAM-1 expression and consequent adhesion of neutrophils to endothelial cells. This study shows that sustained neddylation of Cullin RING-ligases leads to activation the NF-κB pathway in endothelial cells, elevated expression of RhoGTPases, Rho/ROCK-dependent activation of MLC and disruption of the endothelial barrier.

The widespread use of Optical LANs is dependent on the ability to fabricate low cost transceiver components. These are usually complex, and fabrication involves the integration of optoelectronic and electronic devices, as well as optical components. A number of UK universities are currently involved in a project to demonstrate integrated optical wireless transceiver subsystems that can provide eyesafe line of sight in-building communication at 155Mbit/s and above, using 1550nm eyesafe emitters. The system uses two-dimensional arrays of novel microcavity LED emitters, and arrays of detectors integrated with custom CMOS integrated circuits to implement tracking transceiver components. The project includes design and fabrication of the optoelectronic devices, transimpedance amplifiers and optical systems, as well as flip-chip bonding of the optoelectronic and CMOS integrated circuits to create components scaleable to the large numbers of sources and detectors required. In this paper we report initial results from the first seven channel demonstrator system. Performance of individual components, their limitations and future directions are detailed.

Line-of-sight free-space optical links can provide extremely high bandwidth communications, but this usually requires that transmitter and receiver are precisely aligned. In order to allow terminals to be mobile, links must be able to track users within their field of view so that the link is maintained. There are various means to do this, but all require complex subsystems with a number of different optical, optoelectronic, and electrical components. A solid-state tracking architecture is introduced and a seven-channel tracking system demonstration described. The system is designed to operate at 155 Mb/s and is, to the best of our knowledge, the first that uses an integrated approach. Arrays of novel resonant cavity LED (RCLED) emitters that operate at 980 nm are used as sources. These are flip-chip bonded to arrays of CMOS driver circuits and integrated with the necessary transmitter optics. The receiver uses a back-illuminated detector array flip-chip bonded to arrays of custom CMOS receivers. All these components are custom and have performance substantially better than nonoptimized commercially available components. In the paper, the design and fabrication of the optics, optoelectronics, and electronics required for this is described. Successful operation of all the subsystems is detailed, together with results from an initial link demonstration.

Distillers dried grains with solubles (DDGS) are a coproduct of the ethanol industry and are often used as a replacement for grain in livestock production. Feeding corn DDGS to cattle has been linked to increased fecal shedding of Escherichia coli O157:H7, although in Canada, DDGS are often produced from wheat. This study assessed the effects of including 22.5% wheat or corn DDGS (DM basis) into barley-based diets on performance, carcass characteristics, animal health, and fecal E. coli O157:H7 shedding of commercial feedlot cattle. Cattle (n = 6,817) were randomly allocated to 10 pens per treatment group: WDDGS (diets including 22.5% wheat DDGS), CDDGS (diets including 22.5% corn DDGS), or CTRL (barley substituted for DDGS). Freshly voided fecal pats (n = 588) were collected and pooled monthly for fecal pH measurement and screened for naturally occurring E. coli O157:H7 by immunomagnetic separation (IMS) and direct plating (DP). Hide swabs (n = 367) were collected from randomly selected cattle from each pen before slaughter. Pen-floor fecal samples (n = 18) were collected from treatment groups at entry to the feedlot (

A real-world application is employed to explain three general types of decision situations that can arise under conditions of conflict. In addition, meaningful connections and relationships among these areas of decision making are clearly pointed out. To permit useful decision technologies to be employed by practitioners for better understanding and for resolving a variety of actual decision problems, a range of flexible decision support systems is discussed. Subsequently, interesting research developments contained in the upcoming sequence of 12 articles on decision making under conflict are summarized and compared. The research articles not only present unique approaches to decision making involving multiple participants, each of whom may have multiple objectives, but suggest a variety of challenging research problems to be investigated in the future.

SUMMARY A simple and selective high-performance liquid chromatographic (HPLC) method for the determination of ciprofloxacin in serum has been developed and evaluated. Serum protein was precipitated with acetonitrile. The drug and the internal standard (quinine) were eluated from a 10 μm U-Bondapack C-18 cartridge at ambient temperature with a mobile phase consisting of acetonitrile: 0.1 m sodium dihydrogen phosphate (20:80%, v/v) adjusted to pH 3.9 with phosphoric acid, and at a flow rate of 2.5 ml/min. The effluent was monitored on a fluorescence detector using an excitation and emission wavelength of 280 and 455 nm, respective. Each analysis required no longer than 6 min. Quantification was achieved by the measurement of the peak-height ratio and the limit of quantification for ciprofloxacin in serum is 25 ng/ml. The intraday coefficient of variation (CV) ranged from 0.4 to 5.8%, and interday CV from 4.6 to 8.8% at three different concentrations. Relative recovery ranged from 98 to 100.2% at three different concentrations. Preliminary stability tests show that ciprofloxacin is stable for at least 3 weeks in serum after freezing.

Lactic acid occurs widely in nature and is produced by many life forms from bacteria to human cells. Identified in 1780 as a component of sour milk, it has been used in food, drink, pharmaceutical, cosmetics, chemical and electronic industries in different forms, such as free acid (typically 80–92% in water), salts (e.g., calcium lactate), and esters (e.g., ethyl lactate). If one calculates the amount of its derivatives back to the equivalent amount of original lactic acid, the total global market volume in 2008 is estimated at around 260,000 tons of lactic acid (calculated at 100% concentration) for traditional applications [excluding poly(lactic acid) (PLA)]. PURAC has a market share of over 60%, and other producers share around 30–40% of the global commercial market for lactic acid and its derivates. Whereas lactic acid was historically produced through a chemical process, today more than 95% of the lactic acid produced is derived from biological resources (e.g., sucrose or glucose from starch) by microbial fermentation, which typically produces the l-(+) form of lactic acid. Only one producer still uses petroleum-based chemicals to synthesize racemic mixture of the d-(−) and l-(+) forms of lactic acid.

We conducted a double-blind crossover, placebo-controlled trial to evaluate the effects of guar gum, as a food additive, on glycemic control, plasma lipid concentration, and body weight in 39 Saudi...

155 Mb/s operation of an optical wireless link is achieved by using the spectral characteristics and angular emission spectra of a 7-element tracking array of 980 nm RC-LEDs. Preliminary results show extension to 200 Mb/s/channel.

Optical wireless LANs have the potential to provide bandwidths far in excess of those available with current or planned RF networks. There are several approaches to implementing optical wireless systems, but these usually involve the integration of optical, optoelectronic, and electrical components in order to create transceivers. Such systems are necessarily complex, and the widespread use of optical wireless is likely to be dependent on the ability to fabricate the required transceiver components at low cost. A number of U.K. universities are currently involved in a project to demonstrate integrated optical wireless subsystems that can provide line-of-sight in-building communications at 155 Mb/s and above. The system uses two-dimensional arrays of novel microcavity LED emitters and arrays of detectors integrated with custom CMOS integrated circuits to implement tracking transceiver components. In this article we set out the basic approaches that can be used for in-building optical wireless communication and argue the need for an integrated and scalable approach to the fabrication of transceivers. Our work aimed at implementing these components, including experimental results and potential future directions, is then discussed.

Beef calves from 2 sources entering southern Alberta feedlots in the winters of 1997-98 and 1998-99, were surveyed for the presence of lice. A random sample of multiple source (MS), that is, auction market-derived, calves entering commercial feedlots and single source (SS) calves entering a backgrounding feedlot were examined for the presence of lice at entry to the feedlot. A standardized examination, which involved hair-part examination of 8 louse predilection sites, was conducted on each selected calf to determine prevalence and intensity of infestation. The long-nosed sucking louse, Linognathus vituli, was the most commonly encountered species. This species infested from 57.8% to 95.6% of the calves selected from both MS and SS calves during both winters. Louse index values, indicating intensity of infestation, for L. vituli ranged from 1 to 243 lice per animal. The chewing louse, Bovicola bovis, was present on MS and SS calves only in the winter of 1998-99. The louse index values for B. bovis ranged from 1 to 230 lice per animal. Mixed infestations of the L. vituli and B. bovis were common. The little blue cattle louse, Solenopotes capillatus, was present only on the SS calves in the winter of 1997-98. The short-nosed sucking louse, Haematopinus eurysternus, was present at very low intensities, 1-2 lice per animal, on 2.6% to 4.4% of the MS calves during both winters. Comparison of results from the current study with published literature suggests that efforts to determine the economic impact of louse infestations are confounded by the lack of a uniform method to assess louse population levels.

12 Maintaining high bandwidth indoor optical wireless channels under a wide range of operating conditions usually requires relatively complex transceiver components. Integrating optical, optoelectronic and optical components using techniques that are suitable for mass manufacture is an important step in the development of these systems. This paper describes work to develop low cost integrated tracking transmitter and receiver components for use in a cellular indoor optical wireless network. A seven channel demonstrator operating at 155 Mb/s is under construction, using arrays of Resonant Cavity LEDs, PIN detectors, Silicon CMOS driver circuits and associated optics. Development of components, design methodology and initial results are detailed.

A replicated-pen field trial was performed under commercial feedlot conditions in western Canada to determine the cost-effectiveness of administering ivermectin to yearling beef cattle upon entry to the feedlot after the grazing season, and to establish the level of trichostrongylid gastrointestinal parasite infection in this population, as estimated by fecal egg counts. Six thousand eight hundred and eighty-three, mixed breed, yearling steers were randomly allocated upon arrival at the feedlot to one of 2 experimental groups as follows: Ivermectin, which received topical ivermectin (0.5%) at the rate of 1.0 mL/10 kg body weight; or Fenthion, which received topical fenthion (20%) at the rate of 12 mL/295 kg body weight. There were 15 pens in each experimental group. Final weight, weight gain, average daily gain, and dry matter intake to gain ratio were significantly (P < 0.05) improved in the Ivermectin group as compared with the Fenthion group. There were no significant (P > or = 0.05) differences in initial weight, days on feed, or daily dry matter intake between the experimental groups. The geometric mean fecal egg counts at the time of allocation were 14.7 eggs/5 g and 16.6 eggs/5 g for the Ivermectin and Fenthion groups, respectively (P > or = 0.05). There were no significant (P > or = 0.05) differences in morbidity or mortality between the experimental groups. In the economic analysis, the significant improvements in feedlot performance in the Ivermectin group resulted in a net economic advantage of $4.20 CDN per animal.

Bulk superconducting material has an advantage over superconducting wires in that a significantly higher engineering current density is achievable. There are many different topologies in which bulk materials can be exploited. The most commercially viable application areas will be that where there is an existing cryogenic environment, such as the gas separation industry. To this end two designs of simple liquid nitrogen pumps driven by superconducting motors have been demonstrated. Existing liquid nitrogen pumps suffer from the problems of having the motor separate from the pump. Usually the motor is kept ‘warm’ and is connected to the pump via a long shaft. Often problems arise with the bearings of this assembly. These prototype pumps address the problem in a novel manner, by integrating the pump mechanism and the rotor of the motor, thus alleviating the need of a long shaft and complex bearings. The absence of external mechanical connections to the pump is thought to be of particular advantage for handling liquid hydrogen, where safety considerations are paramount.

The relationships between 4 bacterial and 3 viral antibody titers and morbidity (undifferentiated fever (UF)) and mortality were investigated in recently weaned beef calves. Blood samples from 100 animals that required treatment for UF (Cases) and 100 healthy control animals (Controls) were obtained: upon arrival at the feedlot (Arrival), at the time of selection as a Case or Control (Selection), and at approximately 33 d of the feeding period (Convalescent). Seroconversion to Pasteurella haemolytica antileukotoxin was associated with an increased risk of UF (OR = 2.83); however, seroconversion to bovine herpesvirus-1 G-IV glycoprotein was associated with a decreased risk of UF (OR = 0.43). Higher Arrival bovine viral diarrhea virus antibody titer was associated with a decreased risk of UF (OR = 0.83). Increases in Mycoplasma alkalescens antibody titer after Arrival were associated with an increased risk of UF (OR = 1.10). Higher Arrival Haemophilus somnus antibody titer and increases in Haemophilus somnus antibody titer after Arrival were both associated with a decreased risk of UF (OR = 0.76 and OR = 0.78). The odds of overall mortality (OR = 5.09) and hemophilosis mortality (OR = 11.31) in Cases were significantly (P < 0.05) higher than in the Controls. Higher Arrival bovine herpesvirus-1 antibody titer was associated with an increased risk of mortality (OR = 1.30). Protective immunity to Pasteurella haemolytica antileukotoxin, Haemophilus somnus, bovine herpesvirus-1 G-IV glycoprotein, bovine viral diarrhea virus, and Mycoplasma spp. may be necessary to reduce the occurrence of UF. Animals with UF are at an increased risk of overall and hemophilosis mortality.

A novel, simple processing and wafer level packaging method for a 4/spl times/4 Resonant Cavity LEDs chip with individual array is under development. Palladium/Gold (Pd/Au) alloys are used as p-type contacts and as rewiring metallization for optoelectronic devices to improve the fabrication process. By use of these alloys we have found a reduction of a factor of 10 in the resistance compared to Titanium/Gold (Ti/Au), due to the formation of a conducting oxide at the interface between the metal and semiconductor. On the packaging side, electroplated solder deposition was used to fabricate eutectic solderbump arrays on the chip. For the Under Bump Metallurgies (UBM), a thin layer (100 nm) of Ti and a layer (200 nm) of Cu was sputtered on the wafer. A 10 /spl mu/m thick copper stud is platted on top of the UBM to be used as a stem for the solder.

A patient developed recurrent anti-glomerular basement membrane (GBM) antibody (ab) disease after twelve years of an uneventful posttransplant course, clinically accompanied by rapidly rising creatinine. He additionally exhibited coexisting IgA nephropathy at the time of the reappearing anti-GBM disease. Both linear IgG and mesangial IgA were detected by immunofluorescence, and electron microscopy demonstrated mesangial immune complex deposits. To our knowledge, the association of anti-GBM ab disease and IgA nephropathy has not been reported previously.

A study was conducted in western Canada to evaluate the efficacy of florfenicol for the treatment of undifferentiated fever (UF) in feedlot calves. One hundred and twenty-five recently weaned, auction market derived, crossbred, beef steer calves suffering from UF were allocated to 1 of 2 experimental groups as follows: florfenicol, which was intramuscular florfenicol administered at the rate of 20 mg/kg body weight at the time of allocation (day 0) and again 48 h later; or control, which was intramuscular saline administered at the same volume as florfenicol at the time of allocation and again 48 h later. Eighty-four calves were allocated to the florfenicol group and 41 calves were allocated to the control group. Outcome measures describing animal health, body weight, and rectal temperature parameters were used to determine the efficacy of florfenicol for the treatment of UF. The 1st relapse of UF, 2nd relapse of UF, overall mortality, bovine respiratory disease mortality, and haemophilosis mortality rates were significantly (P < 0.05) lower in the florfenicol group than in the control group. Animals in the florfenicol group were significantly (P < 0.05) heavier at day 15 and day 45 than animals in the control group. The rectal temperature on days 1, 2, 3, and 4 of animals in the florfenicol group was significantly (P < 0.05) lower than in the control group. In addition, the change in rectal temperature from day 0 to day 4 was significantly (P < 0.05) different between the experimental groups. The results of this study demonstrate that florfenicol is an efficacious antimicrobial for the treatment of UF.

Since 1986 there has been much hype about the new high temperature superconductors. However, much work was needed to process these materials into a suitable form. Now that more useful materials are available, it has become clear that properties other than the high current ability of these materials are useful, more specifically it is the hysteretic nature of the magnetisation of these materials which is exploited in the motors described in this work. This paper specifically addresses the measurement and the calculation of the torque speed curve of these hysteretic motors. Three topologies of motor are investigated. Of these the single domain YBCO performs the best, although there is a problem in generating a large applied magnetic field from a conventional stator.

Today's rule mining algorithms all use greedy approaches to generate rules representing the knowledge hidden in vast amounts of data. When using a greedy approach, systems cannot guarantee that optimal rules are found. On the other hand, exhaustive search algorithms find optimal rules. But due to the vast search spaces, exhaustive search algorithms are in most cases impractically slow. This paper presents the A*-like rule mining algorithm DA-2. Similarly to exhaustive search algorithms, DA-2 also finds optimal rules. Its running time, however, is just slightly longer than the running time of greedy algorithms.

A retrospective, epidemiologic field study was performed to determine whether calves that were transported greater distances from the auction market to the feedlot were at significantly higher risk of developing fatal fibrinous pneumonia (shipping fever). The study involved all 45,243 springborn steer calves that were purchased from auction markets and moved into a large commercial feedlot between September 1 and December 31 over a 4-year period (1985-1988). For all 4 years of the study, the distance calves were transported from the market to the feedlot and their shrinkage or subsequent death loss from fibrinous pneumonia were not correlated. The risk of fatal fibrinous pneumonia for calves arriving from nearby markets was just as high as that for calves transported much greater distances. The results suggested that calves can be purchased from more distant markets without having to discount their price for higher expected death losses. Differences between short and long hauls explained little, if any, of the variation among truckloads of calves in the risk of fatal fibrinous pneumonia.

A retrospective, epidemiologic study was performed to quantify the mixing of calves from various sources at auction markets, and to determine whether mixing at the markets and the risk of fatal fibrinous pneumonia (FFP) at the feedlot were associated. In this study, 32,646 spring-born steer calves that entered a single large feedlot during the fall seasons between 1985 and 1988 were traced back to their originating auction market, and sales tickets were used to measure the number of farm sources that contributed to each truckload of calves. Individual cow/calf producers contributed a median of only 2 calves/truckload arriving at the feedlot in this study. An average truckload of 60 steers comprised calves from as many as 20 to 30 farms. The degree of mixing varied little over time and could not, therefore, be used to explain the large variations in FFP risk during different months and different years of the study. However, variation in the degree of mixing of calves from various sources at the markets evidently was responsible for differences in FFP risk among truckloads assembled by different buyers. When truckloads were grouped by buyer, FFP risk and mean number of calves per source were negatively correlated in 1986 (r = -0.67, P = 0.099), and in 1987 (r = -0.90, P = 0.002). These variables also were negatively correlated in 1988 (r = -0.56), although the correlation was not significant. The positive linear relationship between mixing of calves in truckloads supplied by different buyers and subsequent FFP risk suggested that veterinarians and feedlot owners should more aggressively observe and treat calves from truckloads that were highly mixed.(ABSTRACT TRUNCATED AT 250 WORDS)

SUMMARY The effect of intravenous (3.5 mg/kg) and oral (5 mg/kg) famotidine on ciprofloxacin pharmacokinetics after single (i.v.) intravenous (5 mg/kg) and oral (20 mg/kg) doses were examined in the rat. Famotidine co-administration significantly increased the terminal elimination half-life of ciprofloxacin (54% and 29% following i.v. and oral administration, respectively) and tended to reduce the total body clearance by 27% and 34% following i.v. and oral routes, respectively. The area under the plasma concentration-time curve and the mean residence time in the body after i.v. and oral doses were significantly increased following famotidine co-administration. No changes in the steady-state apparent volume of distribution was observed after i.v. administration. The maximum plasma concentration and the time to peak concentration after oral dosing were also unaffected. These results suggest a possible reduction in the total clearance of ciprofloxacin, owing to inhibition of its renal tubular excretion by famotidin. Further studies are warranted to determine whether this interaction occurs in humans.

The authors have characterized the mixing phenomena of one bench top reactor (10 L) and three different size cell culture bioreactors (80 L, 250 L, 1000 L; dimensionally similar) with spin filters (70 micrometer mesh size) using different agitation speeds, aeration rates, impeller types, and configurations. It was shown that the mixing times through the spin filter were much longer than in the bulk of the bioreactor run in batch mode, and this was consistent for all three bioreactor sizes tested. Only slight improvements on mixing time were achieved by using different impeller sizes and types. A perfusion reactor system resulted in lowering the mixing time by about 20% relative to the batch mode. Gas sparging under the impeller (external to the spin filter) did not improve the mixing time significantly. Modifying the spin filter by mounting two baffles angled at 45 degrees fitted on the outer perimeter improved the mixing through the spin filter at least 5–10 fold.

A trial involving 512 beef calves was conducted in a commercial research feedlot to determine the effect of bovine respiratory disease (BRD) on performance parameters and carcass characteristics. Two hundred and fifty-six calves that were deemed to be "sick" (S) from BRD were allocated to 16 pens and 256 calves that were considered to be "well" (W) were allocated to another 16 pens. The outcome variables that were measured included average daily gain (ADG), daily dry matter intake (DDMI), dry matter intake to gain ratio (DM:G), BRD treatment rate, death loss, carcass traits, and net profit per pen.The data were partitioned into several time intervals including processing (P) to day -1, day 0 to day 27, day 28 to day 55, day 56 to day 83, day 84 to day 111, day 112 to day 139, day 140 to slaughter, day 0 to slaughter (0-Slaugh), and processing to slaughter (P-Slaugh). However, the most important interval was from processing to slaughter.For the interval P-Slaugh, there were no significant (p/=0.05) differences between the S and W groups with respect to ADG and DM:G. Also, for the interval 0-Slaugh, the DDMI was similar for both groups. There were no significant (p/=0.05) differences between the S and W groups for carcass weight, average fat, grade fat, rib eye area, marbling score, cutability estimate, or carcass grade distribution.The BRD treatment rates in the S and W groups were 6.6% and 4.7%, respectively. The mortality rates in the S and W groups were 0.78% and 0.39%, respectively. Also, there were no deaths attributable to BRD in either group.In the economic model, there was no significant (p/=0.05) difference between the S and W groups with respect to net profit per pen.We conclude that this trial did not validate the concept that BRD impacts performance parameters, because a sufficient disease challenge was not present. However, this study provides several observations that will enhance the experimental design of future studies that attempt to quantify the total economic impact of BRD.

OBJECTIVE: To determine the physical and chemical compatibilities of ciprofloxacin lactate infusion with other commonly used intravenously administered drugs. DESIGN: Ciprofloxacin lactate injection in a commercially available concentration of 2 mg/mL was mixed with 15 intravenous drugs during simulated Y-site injection. Ciprofloxacin was mixed with usually employed concentrations of other drugs in a 1:1 ratio and examined physically by visual inspection and chemically by HPLC analysis. Adsorption of ciprofloxacin to intravenous administration sets with or without inline filters was also studied. SETTING: The study was carried out at ambient temperature (25 °C) under fluorescent lighting except for vitamin B complex, which was protected from light. All samples were prepared in a laminar airflow hood. MAIN OUTCOME MEASURES: Physical incompatibility was determined by visual inspection against a black-and-white background, and chemical incompatibility was measured by a stability-indicating HPLC assay for ciprofloxacin. Concentrations determined at time zero (before mixing) were defined as 100 percent. Values estimated for each sample at subsequent time points were calculated as percentages of the initial concentration. Recovery below 90 percent of the initial concentration is defined as significant loss. RESULTS: Of the 15 drugs studied, only heparin, furosemide, and teicoplanin were found to be incompatible with ciprofloxacin. Adsorption of ciprofloxacin to administration sets with and without inline filters was minimal. Metronidazole was also found to decrease to 90 percent of its initial concentration immediately upon mixing. CONCLUSIONS: Ciprofloxacin ready-to-infuse solution is compatible with most of the drugs studied except heparin, furosemide, teicoplanin, and, perhaps, metronidazole. Because only the stability and potency of ciprofloxacin were studied, further testing is needed to confirm if any chemical deterioration of the other drugs occurred when combined with ciprofloxacin.

A 90-day finishing trial involving 144 feedlot heifers was conducted to compare the performance parameters and carcass characteristics of open heifers, therapeutically aborted heifers, and pregnant heifers. In the first 28 days of the trial, the aborted heifers had reduced (p0.05) feed intake (FI), average daily gain (ADG), and feed efficiency (FE) compared to pregnant and open heifers. Over the entire trial, on a live weight basis, the aborted group had reduced (p0.05) final weight, ADG, and FE compared to pregnant and open heifers. However, when the data were adjusted for total uterine weight, the aborted and open heifers had improved (p0.05) final weight, ADG, and FE compared to pregnant heifers. The aborted and open group had a higher (p0.05) carcass weight, rib eye area, dressing percentage, and cutability estimate compared to the pregnant heifers. The aborted group had lower (p0.05) carcass weight than the open heifers. Over the entire 90-day feeding period, there were no statistically significant differences among the groups with respect to feed intake (FI), average fat, grade fat, and carcass grades. Also, there were no significant health problems or mortality in any of the groups.In the economic analysis, aborted heifers returned $26.41 per head more than pregnant heifers. Open heifers returned $39.94 per head more than aborted heifers, and $66.35 more than pregnant heifers. Thus, aborting feedlot heifers during the second trimester was determined to be a safe and cost effective management decision.