Comparing Visual and Digital Counting Methods to Estimate Horn Fly (Diptera: Muscidae) Populations on Cattle.

Horn fly, Haematobia irritans (L.), population estimates often serve as a diagnostic tool prior to implementing managerial control options available to researchers and producers. Digital photographs taken of cattle infested with horn flies have been suggested to provide similarly accurate population estimates as compared with traditional visual assessments. The objective of this study was to compare visual and digital techniques used to estimate horn fly populations. Sixteen Angus × Hereford yearling heifers artificially infested with four levels of horn flies (Low = 0 flies; Medium = 250 flies; High = 500 flies; Extreme = 1,000 flies) were evaluated. Population estimates were taken visually by experienced (VE1) and inexperienced (VE2) technicians, as well as digitally, with photographs taken on both lateral sides of the south-facing animal. Horn flies were counted in both photographs and combined (CDC) for full body estimates. In addition, the highest photographed side population times two (DDC) was used for comparison. Estimations were made at 0700, 1200, and 1900 h the day following infestation. A time of observation × infestation level interaction (P < 0.01) was detected. On average, VE1 population estimates were greater (P < 0.01) than any other counting method observed. Morning estimates were greater (P < 0.05) than those taken at noon or in the early evening regardless of counting method. Further research regarding the standardization of these techniques to ensure more accurate population estimates is needed before these methods can be incorporated into integrated pest management programs.

Using an EPID for patient-specific VMAT quality assurance.

PURPOSE: A patient-specific quality assurance (QA) method was developed to verify gantry-specific individual multileaf collimator (MLC) apertures (control points) in volumetric modulated arc therapy (VMAT) plans using an electronic portal imaging device (EPID). METHODS: VMAT treatment plans were generated in an Eclipse treatment planning system (TPS). DICOM images from a Varian EPID (aS1000) acquired in continuous acquisition mode were used for pretreatment QA. Each cine image file contains the grayscale image of the MLC aperture related to its specific control point and the corresponding gantry angle information. The TPS MLC file of this RapidArc plan contains the leaf positions for all 177 control points (gantry angles). In-house software was developed that interpolates the measured images based on the gantry angle and overlays them with the MLC pattern for all control points. The 38% isointensity line was used to define the edge of the MLC leaves on the portal images. The software generates graphs and tables that provide analysis for the number of mismatched leaf positions for a chosen distance to agreement at each control point and the frequency in which each particular leaf mismatches for the entire arc. RESULTS: Seven patients plans were analyzed using this method. The leaves with the highest mismatched rate were found to be treatment plan dependent. CONCLUSIONS: This in-house software can be used to automatically verify the MLC leaf positions for all control points of VMAT plans using cine images acquired by an EPID.

Growth characteristics, reproductive performance, and evaluation of their associative relationships in Brangus cattle managed in a Chihuahuan Desert production system1.

Balancing growth and reproductive performance in beef cattle managed in desert environments is challenging. Our objectives were to 1) evaluate trends in growth and reproductive traits, and 2) assess associative relationships between growth characteristics and reproductive performance in a Brangus herd managed in a Chihuahuan Desert production system from 1972 to 2006. Data were from bull (n = 597) and heifer calves (n = 585; 1988 to 2006) and cows (n = 525; repeated records of cows, n = 2,611; 1972 to 2006). Variables describing the growth curve of each cow were estimated using a nonlinear logistic function (each cow needed 6 yr of data). Mixed-effect models and logistic regression were used to analyze trends across years in growth and reproductive traits (both continuous and categorical). For continuous traits of calves, a slight cubic response (P < 0.01) described the dynamics of birth weight, 205-d BW, and 365-d BW across years. For categorical traits of females, positive linear trends (P < 0.05) across years were observed in percent pregnant as yearlings, calved at 2 yr of age, and first-calf heifer rebreeding (slopes ranged from 0.007 to 0.014%/yr). Autumn cow BW increased gradually until 1997 (509 kg +/- 8.8) and then decreased gradually by 0.6 kg/yr, whereas pregnancy percentage decreased gradually until 1995 (78.4% +/- 1.0) and then increased slightly by 0.2%/yr. A quadratic effect best described the dynamics of these 2 variables across years (P < 0.01) as well as estimates describing the growth curve of each cow. Specifically, asymptotic BW and age increased (P < 0.05) from 1972 to 1983 and 1990, respectively. Asymptotic age then decreased by 27% from 1983 to 1996 (P < 0.05). The maturing rate index was negatively correlated with age at first calving and calving interval (r = -0.42 and -0.18, P < 0.01), which suggested that early-maturing cows had enhanced fertility in this environment and production system. In summary, minimal changes were observed in measures of growth in bulls and heifers in a Brangus herd managed in the Chihuahuan Desert. Opposing relationships were observed among measures of cow size and fertility; as growth curves shifted toward earlier maturity, measures of reproductive performance suggested that fertility improved.

Comparison of low-moisture blocks and salt for manipulating grazing patterns of beef cows.

A study was conducted to compare the effects of strategically placed salt and low-moisture blocks (LMB) and salt on grazing distribution and diurnal behavior patterns of individual cows grazing foothill rangeland in northern Montana during autumn. The study was divided into 2 sets, each containing 2 consecutive 10-d periods. Cows (n = 32) were tracked with global positioning system collars for 1 set. Salt and LMB were available for 1 period, and only salt was available for the other period. During these 2 periods, all supplements were placed in approximately the same location (within a 5-ha area) on ridges away from water and that historically received little use. When LMB was available, cows used higher elevations (1,182 +/- 2 m) and were farther horizontally from water (531 +/- 7 m) than when only salt (1,171 +/- 2 m and 486 +/- 7 m, respectively) was provided (P < 0.001). Cows traveled 4.35 +/- 0.09 km/d when supplemented with LMB and 3.94 +/- 0.09 km/d with salt (P < 0.001). Observed differences between treatments for time spent near supplements were most apparent (P < 0.001) in the higher terrain between 10 to 100 m from placement sites. Cows were more active (not resting) when LMB was available than when only salt was available (P < 0.001), but much of the difference in activity between treatments appeared to be consumption of LMB at night. Over a 24-h period, 47 of the 73 min that cows spent within 10 m of LMB (a visit) occurred at night. Results from this study support previous research suggesting that LMB is an effective attractant that can be used to lure cattle to graze high elevations away from water.

The effects of weaning beef calves in two stages on their behavior and growth rate.

Four trials were conducted to explore possible advantages of weaning beef calves in two stages compared with the traditional method of weaning by abrupt separation. In the two-stage treatment, calves were prevented from nursing their dam for a period (Stage 1) before their separation (Stage 2). Control calves nursed from their dams until they were separated. Calf weights and behavior were recorded before and after the separation of cows and calves. Following separation, calves weaned in two stages vocalized 96.6% less (P = 0.001) and spent 78.9% less time walking (P = 0.001), 23.0% more time eating (P = 0.001), and 24.1% more time resting (P = 0.001) than control calves. Compared with controls, two-stage calves had lower (P < 0.001) ADG when nursing was deprived (Stage 1), but greater (P < 0.001) ADG during the 7 d following separation. In Trial 3, calves weaned by the two-stage method had greater (P = 0.05) growth rates than control calves for 7 wk after separation, but no treatment effects on ADG were detected (P > 0.38) in Trials 1 and 2. Over the entire study period (before and after separation), ADG did not differ (P > 0.10) for both treatments. In Trial 4, calves weaned in two stages walked 1.3 km/d more (P < 0.05) during the 4-d period when nursing was prevented (Stage 1) and 5.8 km/d less (P < 0.05) during the 4-d period after separation than controls. Differences between treatments were the greatest in the 2 d after separation. On the first day after separation, two-stage calves walked 5.2 +/- 0.5 km/ d, whereas control calves walked 16.7 +/- 3.1 km/d. Calves weaned in two stages were less distressed than calves weaned by the traditional method of abrupt separation based on behavioral data, but overall calf ADG did not differ for either method in this study. Nutritional management of two-stage weaned calves during the nursing-deprived period should be evaluated in future research because poor pasture conditions may have decreased gains by calves weaned by the two-stage method in this study.

Management strategies for optimal grazing distribution and use of arid rangelands.

Application of existing and novel management techniques can alter traditional livestock grazing patterns and significantly improve the sustainability of arid rangelands. Livestock often congregate and heavily graze riparian areas and other sensitive rangeland, while abundant forage remains in other areas. Increasing the uniformity of grazing can help protect fisheries, wildlife habitat, and other vegetative and watershed resources. For years, managers have improved grazing distribution in extensive arid pastures by developing new water sources. In addition, strategic supplement placement can be used to lure cattle to graze areas that typically receive little use. Placement of low-moisture molasses blocks in steeper areas that were far from water increased forage use by 14% at distances up to 600 m from supplement in foothill rangeland. Recent research has examined the potential of breed and individual animal selection to improve grazing distribution patterns. Cattle breeds developed in mountainous terrain utilize rugged rangeland more uniformly than breeds developed in more gentle terrain. In pastures that were grazed by cattle identified as "hill climbers" (previously observed on rugged terrain), more residual vegetation was left on gentle slopes and areas closer to water than in pastures grazed by cattle identified as "bottom dwellers" (previously observed on gentle terrain near water). Cattle may use rugged rangeland more uniformly after weaning and during periods when temperatures are more moderate and the forage is more homogeneous (spring, early summer, and autumn). Herding shows great promise for protecting sensitive rangeland. Preliminary data show that residual riparian forage in pastures where livestock were herded was up to two times higher than in a control pasture. The integration of herding and strategic supplement placement seems to be more effective than herding alone. Many concerns associated with the sustainability of grazing on arid rangelands can be resolved by manipulating livestock grazing behavior through management.

Relationship between terrain use and performance of beef cows grazing foothill rangeland.

A study was conducted on foothills rangeland to determine whether grazing patterns differed among cow breeds and to determine whether there was a relationship between individual grazing patterns and performance of beef cows. Hereford (HH), Tarentaise (TT), 3/4 Hereford x 1/4 Tarentaise (3H1T), 1/2 Hereford x 1/2 Tarentaise (HT), and 1/4 Hereford x 3/4 Tarentaise (1H3T) cows were observed during the summers of 1997 (n = 183) and 1998 (n = 159). Locations of individual cows were recorded two to three times per week during 1.5- to 2.5-h periods in the morning by observers on horseback. Statistical models included cow breed, age, and nursing status. Data from each year were analyzed separately. During 1997 and 1998, nonlactating cows were located at greater (P < 0.05) vertical distances from water than lactating cows. In 1998, nonlactating cows used steeper (P < 0.05) slopes than lactating cows. However, nonlactating cows did not travel as far horizontally from water (P < 0.05) as lactating cows in 1997. Younger cows (3 yr) traveled further (P < 0.05) from water both vertically and horizontally than older cows (5+ yr) in 1997, but not during 1998. Tarentaise and 1H3T cows were observed at greater (P < 0.05) vertical distances from water than HH cows during both years of the study. During 1998, TT and 1H3T cows used steeper (P < 0.05) slopes than HH cows. Using residual correlations, there were no consistent relationships between topographic aspects of individual grazing locations and cow weight, height, and body condition score. In 1997, cows with earlier calving dates and correspondingly heavier calf weaning weights used areas that had greater vertical distances to water; however, in 1998 there were no relationships (P > 0.05) of calving date and weaning weight with cow location. During both years, pregnant and nonpregnant cows used terrain similarly (P > 0.05), which suggests that cow reproductive performance was not related to terrain use. Grazing patterns in foothills rangeland varied among cow breeds. Performance of cows that used more rugged topography was similar to cows using gentler terrain.

Just a beta....

Traditional implementation of clinical information systems follows a predictable project management process. The selection, development, implementation, and evaluation of the system and the project management aspects of those phases require considerable time and effort. The purpose of this paper is to describe the beta site implementation of a knowledge-based clinical information system in a specialty area of a southeastern hospital that followed a less than traditional approach to implementation. Highlighted are brief descriptions of the hospital's traditional process, the nontraditional process, and key findings from the experience. Preliminary analysis suggests that selection of an implementation process is contextual. Selection of elements from each of these methods may provide a more useful process. The non-traditional process approached the elements of communication, areas of responsibility, training, follow-up and leadership differently. These elements are common to both processes and provide a focal point for future research.

Thinking about thinking.

BACKGROUND: The nursing leadership at a 900-bed tertiary-care facility in the southeast believed an opportunity existed to improve the critical thinking abilities of the professional nursing staff. METHOD: A team, consisting of a diversified group of nurse educators and managers, had the opportunity to gain understanding of the critical thinking process of the nursing staff as well as to develop a plan designed to improve critical thinking skills. RESULTS: Outputs of the team included development of a critical thinking model and process as well as an action plan that specifically outlined how it would implement the model within the organization using a preceptor-based educational process. CONCLUSION: Nursing leadership within this facility believes that nurturing critical thinking in the staff will have a positive impact on care delivery outcomes. Creating shared visions through the assumptions that the staff and organization hold is important to improving care provided. Assisting staff with using a critical thinking process in order to construct, tear down, and then reconstruct clinical incidents as encouraged by this model is one key to problem-solving.

Calf production by Angus-Hereford and Brahman-Hereford cows on two native rangeland forage systems.

Calf birth weights, weaning weights, and preweaning gain of Simmental-sired calves from Angus-Hereford (AH) and Brahman-Hereford (BH) F1 cows grazing native rangeland (NR) or native rangeland-complementary forage (NRCF) systems in the southern Great Plains mixed prairie were evaluated. Calves from AH dams were heavier (P < .001) at birth than calves from BH dams in both forage systems (40 and 37 kg, respectively). However, birth weights of calves from BH dams were 2 kg heavier (P < .001) in the NRCF fall-calving system. Calves in the NRCF system were 122 d older and heavier (P < .001) than the NR calves at weaning (343 and 256 kg, respectively). During the preweaning period, the NR calves gained faster (P < .001) than the NRCF calves. When calves from both systems were evaluated at 200 d of age, NR calves were heavier (P < .001) than NRCF calves. Calves from BH cows were 8 to 16 kg heavier (P < .001) that calves from AH cows at 200 d of age and at weaning. The increased age at weaning associated with the NRCF did not reduce reproductive efficiency. The NRCF system requires less land than a traditional NR system to support a cow-calf pair and seems to be more economically efficient.

Interferon structural genes do not participate in quantitative regulation of interferon production by If loci as shown in C57BL/6 mice that are congenic with BALB/c mice at the alpha interferon gene cluster.

Previous studies have shown that serum interferon (IFN) production in mice is quantitatively influenced by If loci, whose alleles determine high or low production. Although different loci influence IFN production in response to different inducers, such as Newcastle disease virus, Sendai virus, herpes simplex virus type 1, and polyriboinosinic-polyribocytidylic acid, BALB/c mice are in every instance low producers. It was therefore possible that, in addition to If loci, some feature of the BALB/c structural IFN genes contributed to low production. This was examined in the present work, in which IFN production was measured in two strains of C57BL/6 mice congenic with BALB/c at the murine alpha IFN (IFN-alpha) gene cluster on chromosome 4. One line, HW13 (B6.C-H-15c-H-16c-H-20c-H-21c/By) has a BALB/c fragment on chromosome 4 of at least 35 centimorgans which includes the BALB/c IFN-alpha gene cluster and four loci of the brown histocompatibility complex; the other line, HW13J (B6.C-H-15c/By), has a much shorter fragment (about 15 centimorgans), but it also comprises the BALB/c IFN-alpha gene cluster. We show that these mice, carrying the BALB/c IFN-alpha structural genes on a C57BL/6 background, are high IFN producers when stimulated by Newcastle disease virus, Sendai virus, herpes simplex virus type 1, or polyriboinosinic-polyribocytidylic acid. Thus, the low IFN production of BALB/c mice is not directly due to some feature of the IFN-alpha structural genes but is mainly the result of different alleles at If loci.

Mandibular-morphogenesis gene linked to the H-2 complex in mice.

The shapes of mandibles from mice of a group of H-2 congenic strains are compared to that of their C57BL/6By background strain. One congenic strain carries a passenger gene that evokes an elongation of the dorsal reach of the condylar process as does an H-2 recombinant congenic strain derived from it. Two other independently derived H-2 congenic strains do not carry such a gene. This indicates that the effective gene resides outside of and on the centromeric side of the H-2 complex on chromosome 17. Reiterated tests demonstrate the reproducibility of this type of genetic analysis.

Genetic programming of development: a model.

Genetic programming of the developmental processes in multicellular organisms is proposed to be so intricate and vitally important that a large set of genes is dedicated solely to this end. It is further proposed that this set can be compartmentalized into subsets on the basis of the changes in gene activities that occur during ontogenesis, and that the genes in each subset transiently control the epigenetic activities of a small group of cells. Automatic subset activation is achieved by the product of a gene in each subset that transfers activity specifically to the subset next in the developmental sequence. This device can generate a unidirectional series of activations that cascade hierarchically through development like toppling dominoes. The model provides a basis for developmental phenomena, such as pattern formation, morphogenesis, and regeneration, and it makes testable predictions at the molecular level.

Genes that affect morphogenesis of the murine mandible. Recombinant-inbred strain analysis.

The CXB set of recombinant inbred mouse strains provided an opportunity to observe the effects of reassorted subsets of genes on the shape of the mandible. The distances between 12 landmarks in all paired combinations were calculated to evaluate genetic control in small regions. The genetic relationships between interlandmark distances revealed genes to have most of their effects in localized regions, and the greater heritabilities usually to apply to those distances between adjacent landmarks. Interrelationships between measurements are usually explicable on a developmental basis. It is proposed that genes of this sort bring about the changes seen in organ shape during evolution. A model plan for the organization of gene activation during morphogenesis is described.

Genes that affect the shape of the murine mandible. Congenic strain analysis.

Small specific regions of the adult murine mandible are found to be expanded or contracted by the effects of genes sorted out as passenger genes in a set of congenic strains. The large estimated number of such genes could provide a genetic basis for morphological change during speciation.

Genes on different chromosomes influence the antibody response to bacterial antigens.

B6.C congenic strains of mice, possessing histocompatibility (H) alleles from high responding BALB/cBy (C) mice on the genetic background of low responding C57BL/6By (B6) mice, were assayed for their ability to make an antibody response to Type III pneumococcal polysaccharide (SSS-III) and the alpha(1----3) epitope of bacterial (Leuconostoc) dextran B-1355. The results affirmed that the antibody response to SSS-III is multigenic and that genes making a positive contribution to responsiveness are located on different chromosomes, i.e., chromosomes 1, 3, 4, 5, and 9. At least one other gene also influences responsiveness to SSS-III; it is linked to the H-17 locus, which has not yet been assigned to a specific chromosome. Genes on chromosomes 1, 4, and 5 influence the magnitude of the antibody response to dextran B-1355. Some of these genes may be antigen-specific in their mode of action; however, others may not since they appear to exert a positive influence on the antibody response to both SSS-III and dextran B-1355.