A high-morbidity outbreak of Johne’s disease in game-ranched elk

Following an outbreak of Johne’s disease on an elk farm in northern Alberta, Canada, fecal culture, fecal polymerase chain reaction (PCR), and serum enzyme-linked immunosorbent assay (ELISA) tests were performed on individual animals. The magnitude of the outbreak is described and the challenges associated with poor test agreement, as well as herd management options, are discussed.     

Agroforestry policy issues and research directions in the US and less developed countries: insights and challenges from recent experience

Efforts to improve the performance of agroforestry systems, and to expand the land area and number of people able to benefit from this integrative approach to agriculture and natural resource management, are constrained throughout the world by non-supportive land use policies. A growing sense of urgency that policy change is needed to enable agroforestry to flourish has contributed during the past two years to an unprecedented level of agroforestry policy assessment and planning activity.In the US, agroforestry has emerged from academia, where it has incubated since the mid-1980s, into the professional resource management arena. A multi-organizational agroforestry evaluation process has driven national policy and program formation to the forefront of the agenda of the agroforestry community, as it seeks to influence the 1995 Farm Bill. Internationally, the Consultative Group on International Agricultural Research and collaborators fostered a sequence of policy issue identification activities as a basis for setting strategic research priorities for forestry and agroforestry.Following a brief review of forces driving agroforestry development in industrialized and less developed countries, the paper highlights recent policy assessment initiatives in each sphere. Observations on the issues driving and the priorities emerging from these processes are offered, to lend perspective to the critical challenges facing the agroforestry policy research community. An explanation for pervasive constraints and inconsistencies in policy effectiveness is then explored, from which a promising approach to research intervention is forwarded.It is argued that social scientists might influence agroforestry policy most favorably at this critical juncture, as perceptions of inter-dependence increase among different stakeholders in the policy system, by employing interventionist, actor-oriented perspectives and participatory methods to facilitate policy innovation and evaluation. The approach is consistent with participatory technology design processes that earlier helped to establish agroforestry as a prototype for sustainable development.     

Identification and characterization of T-DNA inserts by T-DNA fingerprinting

A T-DNA fingerprinting method is presented based on amplified fragmentlength polymorphism with an anchored polymerase chain reaction step. Thismethod allows discrimination between different T-DNA inserts in stablytransformed plants. The technique was evaluated by analyzing 51 transgenicArabidopsis lines that had been characterized in detail by genomicblotting. Comparison of the obtained fingerprints with the availableintegration information demonstrated that fingerprints were correlated tothe predicted patterns, except for the inverted repeat junctions and forthose inserts with large deletions at the left or right border. Ourexperiments show that by using T-DNA fingerprinting multi-copy transgeniclines can be eliminated efficiently so that the technique can be used toenrich a population of transgenic plants for putative single-copytransformants.     

QTL mapping of powdery mildew susceptibility in hop (Humulus lupulus L.)

Hop powdery mildew [Podosphaera macularis (Wallr.) U. Braun & S. Takam.] is best controlled via the production of resistant varieties. Recent evidence supports selection against plant susceptibility genes to fungal pathogens as a more durable resistance mechanism than selection for resistance genes. The objective of this study was to identify molecular-based QTLs, their genetic effects and epistasis among QTLs associated with susceptibility to powdery mildew. Parents and offspring from the cross, ‘Perle’ × ‘USDA 19058M’, were clonally replicated and inoculated in a greenhouse using a CRD experimental design in Corvallis, OR. DNA was extracted, purified and analyzed via three different marker systems. Analysis of the resulting markers was based upon the “two-way pseudo-testcross” procedure. QTL mapping using multiple interval mapping and Bayesian interval mapping analyses were performed using WinQTL Cartographer 2.5_003. Comparison amongst mapping analyses identified three persistent QTLs on three linkage groups without significant epistatic effect upon expression. The persistent QTL on linkage group C7 had both additive and dominant effects controlling phenotype expression. The presence or absence of the two AFLP markers bordering the QTL on C7 defined susceptibility in offspring. This is the first report in hop identifying molecular markers linked to QTLs associated with disease susceptibility.     

Synchrony and flash entrainment in a new Guinea firefly

Fireflies can duplicate both faster and slower rhythms of artificial light. Since the interval between the pacer signal and the firefly's flash of the next cycle approximates the firefly's normal free-run period, it is suggested that the pacer signal resets the flash-timing oscillator in the brain, thus providing a mechanism for synchronization.     

The use of medroxyprogesterone acetate to induce molting in chinstrap penguins (Pygoscelis antarctica).

Molt was successfully induced with a progestational compound, medroxyprogesterone acetate (Depo-Provera), in six of six previously nonmolting chinstrap penguins (Pygoscelis antarctica). The initial treatment consisted of five sequential weekly injections of 30 mg/kg Depo-Provera beginning in early September. Four weeks after completing the injections, the penguins had gained an average of 23% body weight, but none had molted. Beginning early November, five weekly injections were resumed, which initiated molt in all individuals within 34 days following the last injection. Molt was completed by mid-January, nearly 2 wk later. In the following years, nonmolting chinstrap penguins were given a single series of five weekly injections beginning in early November, 2 mo prior to the normal molting period.