A conceptual framework for tree improvement programs

Forest tree improvement programs have become quite complex and program strategies and intensities vary dramatically around the world. It is often necessary to examine the reasons for each activity separately in order to ascertain how all steps fit together in a strategy aimed at achieving genetic gain. This paper establishes a conceptual framework that explains the purposes of the various activities of tree improvement and allows complicated program strategies to be easily conveyed. This conceptual model, called the breeding cycle, stresses why, not how, each activity is conducted. The breeding cycle turns around one time for each generation of breeding and is composed of various types of plant populations. Each plant population serves a role in the tree improvement program and is created form a preceding population in the cycle by an activity of the breeder.Tree improvement concepts are explained and the roles of genetic test plantations are described in the context of the breeding cycle. This conceptual model is useful for foresters responsible for implementing tree improvement programs, for students and breeders trying to understand and compare divergent program strategies and for managers responsible for making investment decisions.     

Clinical and pathological findings in a HERDA-affected foal for 1.5 years of life

A Quarter horse filly bred from two horses affected with HERDA (hereditary equine regional dermal asthenia) was observed clinically and its skin histologically for the 1.5 years of its life. Severe signs of the disease did not manifest until 1.5 years of age, and were not temporally related to saddling. Histological comparison to an age-, breed- and sex-matched control did not show any consistent diagnostic features. Monitoring of the proband substantiated previous reports of (i) the autosomal recessive nature of the disease, (ii) mares affected with HERDA being able to foal without damage to the skin or reproductive tract, (iii) HERDA foals appearing phenotypically normal throughout the first year of life, and (iv) demonstrated that histological interpretation of skin specimens from grossly normal skin may be insufficient to differentiate HERDA-affected horses from controls.     

Influence of Different Protocols of Urethral Catheterization after Pharmacological Induction (Ur.Ca.P.I.) on Semen Quality in the Domestic Cat

The aim of this study was to evaluate the influence that different protocols of urethral catheterization after pharmacological induction (Ur.Ca.P.I.) may have on the semen quality of the domestic cat. The study has been divided into two experiments: one in which different dosages of medetomidine administrated are evaluated and the second one in which the timing of the catheterization after pharmacological induction is tested. In the first experiment, 18 cats were sedated with the recommended dosage of medetomidine (130 μg/kg i.m.) while the other 18 were sedated with a lower dose of the same drug (50 μg/kg i.m.). In the second experiment, three groups were implemented, each containing 25 subjects. In group 1, the semen collection was performed immediately once the pharmacological effect of the drug was reached; in group 2, the semen collection was performed three times every 5 min after the pharmacological effect was reached; finally, in group 3, Ur.Ca.P.I. was performed 20 min after the pharmacological effect was reached. All the different protocols permitted sperm collection, nevertheless the first experiment showed a better quality in terms of volume, concentration, total number of spermatozoa (p < 0.01) and quality of the movement (motility p < 0.05 and forward progressive motility p < 0.01), using a high medetomidine dosage rather than 50 μg/kg i.m. In the second experiment, forward motility was statistically higher (p < 0.01) in the first group and total volume was higher (p < 0.01) in the second and third group, while other parameters were statistically not different. Results suggest that a single catheterization immediately after the onset of the pharmacological effect leads to a good‐quality semen with the lowest possibility of damaging the urethra and that a sedation with 130 μg/kg of medetomidine leads to a better quality sperm collection than 50 μg/kg does.     

Growth factor messenger ribonucleic acid expression during differentiation of porcine embryonic myogenic cells

The growth factors, IGF-I and II, their binding proteins, IGFBP, and members of the transforming growth factor (TGF) superfamily (myostatin and TGFbeta1) are known to regulate proliferation and differentiation of myogenic cells. We hypothesized that changes in the relative expression of members of the IGF and TGFbeta systems play a significant role in regulating myogenesis in porcine embryonic myogenic cell (PEMC) cultures. Therefore, determining the expression patterns of these factors during PEMC myogenesis is important. Consequently, we used real-time PCR to explore the pattern of IGF-I; IGF-II; IGFBP-2, -3, and -5; IGF-type-I receptor; myogenin; myostatin; and TGFbeta1 mRNA expression during PEMC myogenesis. The progression of differentiation was assessed using creatine kinase activity and myogenin mRNA expression. As anticipated, creatine kinase activity was low in PEMC cultures at 48 h and increased 20-fold (P < 0.0001) between 48 h and its peak at 144 h. Similarly, myogenin mRNA was low at 48 h and increased approximately 5-fold (P < 0.0001) as differentiation progressed, peaking at 120 h and decreasing at 144 h. The patterns of IGF-I and IGFBP-2 mRNA expression were similar and were relatively lower in 48-h PEMC cultures, increasing approximately 5-fold (P < 0.0001) to their greatest levels at 120 h. In contrast, IGF-II and IGFBP-5 mRNA levels were relatively high at 48 h, peaking at 72 h, and steadily decreasing by 60 and 80%, respectively (P < 0.001), at 144 h. The level of IGF-type-I receptor mRNA was relatively high until 96 h of culture, after which it decreased 40% (P < 0.01), reaching a low at 144 h. Levels of IGFBP-3 mRNA were relatively high at 48 h, dropped approximately 40% to their lowest level at 72 h (P < 0.001), and then increased approximately 60% (P < 0.001) to their greatest levels at 144 h. Levels of TGFbeta1 mRNA decreased approximately 30% (P < 0.0001) between 48 and 96 h, then quickly rebounded to a peak at 120 h, and by 144 h had dropped to the levels seen at 72 h. Myostatin mRNA was at its greatest level at 48 h and declined rapidly between 72 and 96 h, finally decreasing by approximately 80% at 144 h (P < 0.0001). Our data demonstrate that these factors are differentially regulated during PEMC myogenesis and provide new information about their pattern of mRNA expression in cultured porcine muscle cells.     

Unique educational methods to improve the veterinary employment selection process for rural mixed-animal practices

The rural mixed-animal veterinarian is a critical control point for safe, wholesome, affordable food production and security. The population of students entering food-animal practice is decreasing, and future shortages are likely. Veterinary practice owners will continue to struggle to find associates to fill open positions. Identifying and hiring the correct veterinarian for an open position is a challenging proposition for the rural practitioner. Kansas State University hosted a forum to facilitate the hiring process and provide education regarding the mechanism of an effective selection interview. A unique experiential technique known as "speed interviews" was used to facilitate communication between conference participants and to practice newly acquired skills. A survey of participants revealed similar viewpoints toward most job attributes. Veterinary students and prospective employers expressed realistic expectations of job requirements, salaries, and debt load. Students expressed willingness to work and desire to practice in the types of practices defined by the veterinarians. The symposium provided valuable insight for practitioners and students regarding the recruitment process. Appropriate and accurate representation at the time of job/associate selection is critical for long-term success and employee retention. The goal of the event was to provide a service to both prospective employers and students by offering education regarding the employment selection interview process and placing attendees in an environment rich with people who have complimentary goals.     

Combination vinblastine and palladia for high-grade and metastatic mast cell tumors in dogs

High-grade and metastatic canine mast cell tumors carry a guarded prognosis because of their unpredictable biologic behavior. An ideal chemotherapy regime is yet to be established. The aim of this study was to review the efficacy and toxicity of combination vinblastine and toceranib for high-grade and metastatic mast cell tumors. Twenty-eight dogs were categorized with either high-grade, lymph node metastasis or Stage IV disease. Demographics, disease, and treatment variables were compared between categories (Kruskal-Wallis test for continuous data and Fisher’s Exact test for categorical data). Survival times and progression-free intervals (PFI) were calculated and compared between groups (log rank test). The PFI was 310 d [95% confidence interval (CI): 155 to 1425] and overall survival was 373 d (95% CI: 226 to 1219). There was no difference between disease categories for PFI (P = 0.9) or survival (P = 0.5). The protocol was well-tolerated with increased liver enzyme activity and gastrointestinal toxicity most frequently observed. Progression-free intervals and survival times were similar in dogs with high-grade, metastatic and Stage IV disease.     

Structural Properties of Starch Fractions Isolated from Normal and Mutant Corn Genotypes Using Different Methods

The objectives of this research study were to isolate, evaluate, and compare the fine structures of starch fractions obtained from a wild‐type (normal) corn starch and amylose‐extender25, dull39, sugary2, and sugary1 corn mutants in the same genetic background using three different fractionation procedures based on gel‐permeation chromatography or alcohol‐precipitation methods. Starch fractions obtained from each of the three methods were enzymatically debranched and analyzed using high‐performance anion‐exchange chromatography with a postcolumn amyloglucosidase reactor and a pulsed amperometric detector. The separations were performed by fractionation on a GPC column, by precipitation with 1‐butanol, and by preferential precipitation with 1‐butanol and isoamyl alcohol. Using any of these methods, no apparent differences in the molecular weight distributions of amylopectin or of amylose among the different starches were observed. The proportions of branch chain lengths of the starch components obtained by the various fractionation methods were very similar among methods for each of the starch types analyzed, such as the predominance of long branch chains in ae25 corn and that of the short branch chains in su2 corn. Overall, the effect of the corn mutations was more important to the differences observed among the starch types than was the method of fractionation used.     

Dysidenin from the Marine Sponge Citronia sp. Affects the Motility and Morphology of Haemonchus contortus Larvae In Vitro

High-throughput screening of the NatureBank marine extract library (n = 7616) using a phenotypic assay for the parasitic nematode Haemonchus contortus identified an active extract derived from the Australian marine sponge Citronia sp. Bioassay-guided fractionation of the CH₂Cl₂/MeOH extract from Citronia sp. resulted in the purification of two known hexachlorinated peptides, dysidenin (1) and dysideathiazole (2). Compound 1 inhibited the growth/development of H. contortus larvae and induced multiple phenotypic changes, including a lethal evisceration (Evi) phenotype and/or somatic cell and tissue destruction. This is the first report of anthelmintic activity for these rare and unique polychlorinated peptides.