A Combination of Phenotypic and Genotypic Characterization Strengthens Pyrenophora tritici-repentis Race Identification

ABSTRACT Pyrenophora tritici-repentis, causal agent of tan spot of wheat, produces multiple host-selective toxins (HSTs), including Ptr ToxA, Ptr ToxB, and Ptr ToxC. The specific complement of HSTs produced by a particular isolate determines its host cultivar specificity. Each unique specificity profile, represented by the differential induction of necrosis or chlorosis on a standard set of wheat differentials, defines a unique race. Eight races of P. tritici-repentis have been formally published, although additional races are under investigation. Although visual assessment of disease phenotype is often used in race designation of P. tritici-repentis, our results suggest that it has the potential to be misleading. Inoculation of the P. tritici-repentis isolates SO3 and PT82 on the current wheat differential set indicated classification as race 2 and race 8, respectively; however, genetic characterization revealed that these isolates do not possess the associated HSTs expected for these race assignments. Despite sharing disease phenotypes similar to known races, SO3 and PT82 were genotypically distinct from these previously characterized races of P. tritici-repentis. To ensure detection of the breadth of physiological variation among the isolates of P. tritici-repentis, our results indicate that race classification, where possible, should include both phenotypic and genotypic analyses and eventual expansion of the differential set.     

An Ex Vivo Biomechanical Study Comparing Strength Characteristics of a New Technique with the Three‐Loop Pulley for Equine Tenorrhaphy

Objective: To test single cycle to failure tensile strength characteristics of 6 suture material–pattern combinations in equine superficial digital flexor (SDF) tenorrhaphy, specifically to compare a 10‐strand modification of the Savage core suture technique with the 3‐loop pulley technique. Study Design: Ex vivo mechanical experiment comparing 3 different suture patterns with 2 different materials. Sample Population: Forelimb and hindlimb SDF tendons (n=48) harvested from adult Thoroughbred and Standardbred horses of mixed age and gender. Methods: Six suture material–pattern combinations were evaluated: (1) 10‐strand Savage, size 2 polydioxanone (PDS); (2) 10‐strand Savage, size 2 polyglactin 910 (PG910); (3) 10‐strand Savage, size 2 PDS with Lin‐locking epitenon suture, size 2–0 PDS; (4) 10‐strand Savage size 2 PG910 with Lin‐locking epitenon suture, size 2–0 PDS; (5) 3‐loop pulley, size 2 PDS; and (6) 3‐loop pulley, size 2 PG910. Maximum load at failure (N), gap at failure (mm), and mode of failure (suture breakage or pull through) were evaluated for each of the 6 suture material–pattern combinations and underwent statistical analysis to determine significance of differences and interactions of the measured data. Results: The 10‐strand Savage technique failed at a mean load of 872 N (804–939, 95% CI). The 10‐strand Savage with Lin‐locking failed at a significantly greater mean load of 998 N (930–1065, 95% CI). The 3‐loop pulley pattern failed with a mean load of 337 N (270–405, 95% CI). There were significant interactions between the technique and suture material used. Conclusion: The 10‐strand Savage technique for repair of transected cadaver SDF tendons has superior strength characteristics with or without the epitenon suture when compared to the 3‐loop pulley. Suture material and pattern interactions were observed with PG 910 conferring higher strength for the 10‐strand Savage whereas PDS did so for the 3‐loop pulley.     

Repair of a scleral defect with an autogenous fascia lata graft in a dog

A case of a traumatic scleral rupture with uveal herniation in a dog was treated with an autogenous fascia lata graft. Placement of the graft resolved the uveal prolapse and resulted in return of strength and a more normal structure. Fascia lata appears to be an effective scaffolding graft for the repair of scleral defects. It is cheap, easily harvested and large grafts may be obtained. Healing was rapid and the end result was a cosmetic, comfortable, fully functional eye.     

Neuronal competition and selection during memory formation

Competition between neurons is necessary for refining neural circuits during development and may be important for selecting the neurons that participate in encoding memories in the adult brain. To examine neuronal competition during memory formation, we conducted experiments with mice in which we manipulated the function of CREB (adenosine 3',5'-monophosphate response element-binding protein) in subsets of neurons. Changes in CREB function influenced the probability that individual lateral amygdala neurons were recruited into a fear memory trace. Our results suggest a competitive model underlying memory formation, in which eligible neurons are selected to participate in amemorytrace as a function of their relative CREB activity at the time of learning.     

Sugar and ethanol production as a rural development strategy in Brazil: Evidence from the state of São Paulo

Sugar and ethanol production are key components of Brazil’s rural development and energy strategies, yet in recent years sugar production has been widely criticized for its environmental and labor practices. This study examines the relationship between rural development and sugarcane, ethanol, and cattle production in the state of São Paulo. Our results suggest that the value added components of sugarcane production, which include sugar refining and ethanol production, may have a strong positive affect on local human development in comparison to primary agricultural production activities and other land uses. These results imply that sugar production, when accompanied by a local processing industry can stimulate rural development. However, this paper also highlights the significant environmental and social harms generated by the sugar industry at large, which may undermine its development benefits if not addressed.     

Assessing women's understandings of health in rural Papua New Guinea: implications for health policy and practice

In Papua New Guinea (PNG), women's health is addressed by applying biomedical solutions which often ignore the complexity of women's histories, cultural contexts and lived experiences. The objective of this study was to examine adult and older women's perceptions of health and well-being to identify priority areas for public service interventions. Rapid ethnographic assessment was conducted in the Wosera district, a rural area of PNG from mid-2005 to early 2006, to examine the health concerns of women. Twenty-seven adult women and 10 older women participated in the study. Health was not limited to one aspect of a woman's life, such as their biology or maternal roles; it was also connected with the social, cultural and spiritual dimensions of women's daily existence. Participants also identified access to money and supportive interpersonal relationships as significant for good health. A disconnect was found to exist between women's understandings of good health and socio-political health policies in PNG, something likely to be repeated in health service delivery to different cultural groups across the Asia Pacific region. Health and development practitioners in PNG must become responsive to the complexity of women's social relationships and to issues relating to the context of women's empowerment in their programmes.     

Relationship between stages of the estrous cycle and bone cell activity in Thoroughbreds

OBJECTIVE: To investigate the relationship between stage of estrous cycle and bone cell activity in Thoroughbreds. SAMPLE POPULATION: Blood samples collected from forty-seven 2-year-old Thoroughbred mares in training for racing. PROCEDURES: Blood samples were collected monthly (in April through September) from the mares. Stage of estrus was determined by assessing serum progesterone concentration. Bone cell activity was determined by measuring concentrations of 2 markers of bone formation (osteocalcin and the carboxy-terminal propeptide of type I collagen [PICP]) and a marker of bone resorption (the cross-linked carboxy-terminal telopeptide of type I collagen [ICTP]) in sera. RESULTS: When the relationship between stage of the estrous cycle and markers of bone cell activity was examined, serum concentrations of both osteocalcin and ICTP were significantly higher in mares that were in the luteal phase, compared with mares that were at other stages of the estrous cycle. Stage of estrus did not affect serum PICP concentration. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that bone cell activity in Thoroughbred mares fluctuates during the estrous cycle; serum concentrations of markers of bone formation and bone resorption are increased during the luteal phase. Further studies are required to determine whether these changes are of clinical importance and increase the risk of injury for mares in training during the breeding season. As in humans, stage of estrus must be considered as a source of uncontrollable variability in serum bone marker concentrations in horses.     

Foraging areas of black‐browed and grey‐headed albatrosses breeding on Macquarie Island in relation to marine protected areas

• 1. Although marine protected areas (MPAs) are often established to protect threatened top‐order predators, there is a paucity of data that can be used to evaluate their efficacy in achieving this purpose.
• 2. We assessed the effectiveness of a network of MPAs around Macquarie Island in the Southern Ocean by examining the foraging areas of breeding black‐browed Thalassarche melanophrys and grey‐headed albatrosses T. chrysostoma.
• 3. During late incubation and brood periods over 90% of time spent foraging by black‐browed albatrosses was contained within MPAs, principally the Economic Exclusion Zone (EEZ) around Macquarie Island. In contrast, grey‐headed albatrosses spent only 34% of their time foraging in MPAs.
• 4. Black‐browed and grey‐headed albatrosses spent 30% and 15% of their respective foraging times in the Marine Park around Macquarie Island.
• 5. Both black‐browed and grey‐headed albatrosses foraged in Antarctic waters under the jurisdiction of the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR), accounting for 5% and 12% of the total foraging times respectively.
• 6. The spatial extent of MPAs around Macquarie Island appear to adequately cover much of the foraging distribution of breeding black‐browed albatrosses from Macquarie Island.
• 7. Breeding grey‐headed albatrosses spend significantly more time in waters outside the spatial extent of the surrounding MPAs and are at higher risk from fisheries activities and other threats.
• 8. Further information on the foraging movements both of albatrosses outside the breeding season and of juvenile albatrosses is required to more fully assess the efficacy of MPAs in protecting foraging habitats of these species.

Copyright © 2005 John Wiley & Sons, Ltd.