Comparison of results of clinicians' assessments, cytologic examination of fine-needle lymph node aspirates, and flow cytometry for determination of remission status of lymphoma in dogs

OBJECTIVE: To determine interclinician agreement when assessing remission of lymphoma in dogs and the association among results of clinicians' assessments via lymph node palpation, cytologic examination of fine-needle lymph node aspirates, and flow cytometry as determinants of remission. DESIGN: Prospective study. ANIMALS: 23 dogs with untreated lymphoma. PROCEDURE; Two clinicians independently measured large lymph nodes and cytologic examination and flow cytometry of cells from a mandibular or popliteal lymph node were performed 1 week prior to initiating treatment. Lymph node measurements with clinicians' remission assessments and cytologic examination were repeated at weeks 2, 3, and 5; flow cytometry was repeated at week 5. RESULTS: Significant correlation was identified between clinicians' remission assessments. Significant correlation between lymph node palpation and cytologic examination was identified at week 5, but not at weeks 2 and 3. Lymphoma was diagnosed in 16 of 23 (70%) dogs at initial evaluation by use of flow cytometry, although it was of limited use at subsequent evaluations and results were not diagnostic of lymphoma in any dog at week 5, including 1 dog in which lymphoma was diagnosed cytologically. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that physical examination and measurement of lymph node volume may not be sufficient for accurately determining remission, that flow cytometry alone should not be relied on as a means for diagnosis, and that cytologic examination of fine-needle lymph node aspirates should be considered as the most accurate means of determining remission status at times in which treatment modifications are considered.     

Two measures of landscape-graph connectivity: assessment across gradients in area and configuration

Landscape connectivity is critical to species persistence in the face of habitat loss and fragmentation. Graph theory is a well-defined method for quantifying connectivity that has tremendous potential for ecology, but its application has been limited to a small number of conservation scenarios, each with a fixed proportion of habitat. Because it is important to distinguish changes in habitat configuration from changes in habitat area in assessing the potential impacts of fragmentation, we investigated two metrics that measure these different influences on connectivity. The first metric, graph diameter, has been advocated as a useful measure of habitat configuration. We propose a second area-based metric that combines information on the amount of connected habitat and the amount of habitat in the largest patch. We calculated each metric across gradients in habitat area and configuration using multifractal neutral landscapes. The results identify critical connectivity thresholds as a function of the level of fragmentation and a parallel is drawn between the behavior of graph theory metrics and those of percolation theory. The combination of the two metrics provides a means for targeting sites most at risk of suffering low potential connectivity as a result of habitat fragmentation.     

Effects of winter stocker growth rate and finishing system on: I. Animal performance and carcass characteristics

Angus-crossbred steers (n = 216) were used in a 3-yr study to assess the effects of winter stocker growth rate and finishing system on finishing performance and carcass characteristics. During winter months (December to April) steers were randomly allotted to 3 stocker growth rates: low (0.23 kg x d(-1)), medium (0.45 kg x d(-1)), or high (0.68 kg x d(-1)). Upon completion of the winter phase, steers were randomly allotted within each stocker treatment to a corn silage-concentrate or pasture finishing system. All steers regardless of finishing treatment were finished to an equal-time endpoint to eliminate confounding of treatments with animal age or seasonal factors. Upon completion of the finishing period, steers were slaughtered in 2 groups (one-half of pasture and one-half of feedlot cattle each time) and carcass data were collected. Winter data were analyzed as a completely randomized design, with winter treatment, pen replicate, year, and the winter x year interaction in the model. Finishing performance and carcass data were analyzed in a split-plot design with finishing system in the whole plot, and winter growth rate and winter x finish in the split-plot. Winter treatment mean within finishing replication was the experimental unit, and year was considered a random effect. Winter stocker phase treatments resulted in differences (P < 0.001) in final BW, ADG, and ultrasound LM area between all treatments for that phase. Pasture-finished cattle had lower (P < 0.001) final BW, ADG, HCW, LM area, fat thickness, KPH, dressing percent, USDA yield grade, and USDA quality grade. Winter stocker treatment influenced (P < 0.05) final BW and HCW, with low and medium being less than high. Steers with low stocker gain had greater (P < 0.05) finishing ADG. Dressing percent was greater (P < 0.001) for high than low, and USDA quality grade was greater (P < 0.05) for high than low and medium. Carcass LM area, fat thickness, KPH, and USDA yield grade were not influenced (P > 0.05) by winter rate of gain. Cattle on low during winter exhibited compensatory gain during finishing but were unable to catch the high group regarding BW or HCW. The USDA quality grade was greater for high than low or medium. Animal performance during the winter stocker period clearly impacts finishing performance, carcass quality and beef production in both pasture- and feedlot-finishing systems, when cattle were finished to an equal-time endpoint.     

Nitrate and fecal coliform concentration differences at the soil/bedrock interface in Appalachian silvopasture,pasture, and forest

A major limitation to efficient forage-based livestock production in Appalachia is asynchrony of forage availability and quality with nutritional requirements of the grazer. Producers require dependable plant resources and management practices that improve the seasonal distribution and persistence of high quality herbage, sustainability and environmental integrity of the agricultural landscape. It was hypothesized that inorganic N and fecal coliform concentrations delivered in leachate to the soil/bedrock interface would be lowest in deciduous forest (HF) and highest in pasture (CP) with HF converted to silvopasture (SP) between the two. Piezometers were used to monitor water quality at the soil/bedrock interface under conventional pasture, SP, and hardwood forest. The pasture and SP were rotationally grazed by sheep during the spring to fall grazing season (2004–2008). Geometric mean fecal coliform bacteria concentrations (FC) were greatest in SP (18 FC 100 mL⁻¹) with no difference between CP (7.5 FC 100 mL⁻¹) and HF (5.6 FC 100 mL⁻¹). Mean NO₃-N concentration was lowest in SP (2.3 mg L⁻¹) and greatest in CP (4.4 mg L⁻¹) and HF (4.1 mg L⁻¹), which were not significantly different. Mean NH₄-N concentrations showed different trends with the lowest mean concentration in CP (0.5 mg L⁻¹) and the greatest in SP (2.5 mg L⁻¹) and HF (2.6 mg L⁻¹), which were not significantly different. SP was shown to be a management option in the study area that reduces nitrate leaching, but should be considered cautiously in near-stream areas and near wells where fecal bacteria pollution can be problematic. This study makes an important contribution to our knowledge about interactions between landscape management and environmental quality of the Appalachian region. A diversity of land and forage management options are needed to maximize forage and livestock productivity while protecting surface and groundwater quality of the region.     

Learning-style profiles of 150 veterinary medical students

Awareness of student learning-style preferences is important for several reasons. Understanding differences in learning styles permits instructors to design course materials that allow all types of learners to absorb and process information. Students who know their own learning style are better able to help themselves in courses taught in a non-preferred method by developing study strategies in line with their preferred learning method. We used the Felder and Solomon Index of Learning Styles to assess the learning-style profiles of 150 veterinary students in three consecutive years. Students were predominantly active (56.7%), sensing (79.3%), visual (76.7%), and sequential (69.3%). Most were balanced on the active-reflective (59.3%) and global-sequential (50%) dimensions, and 61.3% and 54% were moderately to strongly sensing and visual, respectively. Small but significant numbers of students were moderately to strongly intuitive (8.7%), verbal (13%), and global (12%). The most common patterns were active-sensing-visual-sequential (26%), reflective-sensing-visual-sequential (19.3%), active-sensing-visual-global (8.7%), and active-sensing-verbal-sequential (8.7%). Although most students (65.3%) were balanced on one to two dimensions, 77.3% had one or more strong preferences. Our results show that although people have dominant learning-style preference and patterns, they have significant minor preferences and patterns across all dimensions with moderate to strong preferences on each scale. These results indicate that a balanced approach to teaching is essential to allow all students to learn optimally.     

Hematologic changes after total body irradiation and autologous transplantation of hematopoietic peripheral blood progenitor cells in dogs with lymphoma

Dogs with and without lymphoma have undergone hematopoietic cell transplantation in a research setting for decades. North Carolina State University is currently treating dogs with B- and T-cell lymphoma in a clinical setting with autologous peripheral blood progenitor cell transplants, using peripheral blood CD34+ progenitor cells harvested using an apheresis machine. Complete blood counts were performed daily for 15 to 19 days posttransplantation to monitor peripheral blood cell nadirs and subsequent CD34+ cell engraftment. This study documents the hematologic toxicities of total body irradiation in 10 dogs and the subsequent recovery of the affected cell lines after peripheral blood progenitor cell transplant, indicating successful CD34+ engraftment. All peripheral blood cell lines, excluding red blood cells, experienced grade 4 toxicities. All dogs had ≥ 500 neutrophils/μl by day 12, while thrombocytopenia persisted for many weeks. All dogs were clinically normal at discharge.     

Fertility of Sows Fed ad libitum with a High Fibre Diet During Pregnancy

The effect of ad libitum (ADLIB) feeding strategy on the fertility of the group housed sow was studied in a prospective field trial during 1.5 years. All study animals farrowed under standard farrowing circumstances in crates, and they were provided with an ad libitum feeding throughout the 30‐day lactation. After weaning, animals were randomly allocated to one of the two dry sow feeding strategies (AD LIB or CONT). After oestrus detection in groups, they were artificially inseminated and moved into pregnancy pens with partially slatted floor, in groups of 40 sows each. The ADLIB sows (n = 447) were loose housed and provided with ad libitum access to 7.7 MJ/kg feed high in fibre from two feeders per group. The control sows (n = 479; CONT) were also loose housed and given a standard dry sow feed in feeding stalls once a day (2.5 kg/day. The energy content of the feed was 9.3 MJ/kg NE). The feeding strategy (ADLIB vs CONT) had no effect on pregnancy rate (85.8 vs 90.9, p > 0.05), weaning to oestrus interval (7.7 vs 7.3 days, p > 0.05), piglets born alive (11.5 ± 3.5 vs 11.6 ± 3.3, p > 0.05), stillborn piglets (1.2 ± 1.8 vs 0.9 ± 1.5, p > 0.05) nor on progesterone concentration (p > 0.05). CONT sows weaned more piglets (9.7 ± 2.2 vs 9.4 ± 2.0, p < 0.01), whereas the piglets of AD LIB sows were heavier at weaning (8.8 ± 0.9 vs 8.0 ± 1.3 kg, p < 0.05). In conclusion, ad libitum feeding with a high in fibre diet during pregnancy did not affect the reproductive performance.