Physics festival brightens rainy san jose

A week after floodwaters surged through parts of San Jose's downtown, a flood tide of physicists-almost 6000 of them-appeared for the annual March meeting of the American Physical Society (APS). Gloom and drizzle continued for the first 4 days of the gathering, but there were plenty of bright spots inside the hall.     

Alternative migratory strategies are widespread in subyearling Chinook salmon

Variation in life history traits within and across species is known to reflect adaptations to different environmental drivers through a diversity of mechanisms. Trait variation can also help buffer species and populations against extinction in fluctuating environments and against anthropogenic disturbances. Here, we examine the distribution and drivers of Ocean‐type Chinook salmon (Oncorhynchus tschawytscha) juvenile migratory life histories. We defined alternative migratory strategies according to whether individuals reared in the stream (natal rearing) or left shortly after hatching to rear elsewhere (non‐natal rearing). We then evaluated the frequency of migratory strategies across 16 populations with time series extending up to 25 years and evaluated the environmental variables that influenced variation in migration strategy. We found bimodal migration patterns and abrupt transitions in migrant sizes across all populations, supporting the widespread nature of alternative migratory strategies. Additionally, we found that the amount of freshwater rearing habitat available to juveniles, relative juvenile density and spring flow patterns significantly influenced the overall migration pattern for populations. Smaller streams and higher conspecific densities generally produced more non‐natal rearing migrants and larger streams and lower conspecific densities producing more natal rearing migrants. Our results shed light on previously unexplored patterns of juvenile migratory strategies and encourage broader consideration for how current conservation actions perform at protecting juvenile migratory diversity.     

Health assessment of free-ranging and captive Matschie's tree kangaroos (Dendrolagus matschiei) in Papua New Guinea

Medical evaluations were performed on free-ranging and captive Matschie's tree kangaroos (Dendrolagus matschiei) in Papua New Guinea. The health assessment included physical examination, morphometrics, cloacal swab; and blood, hair, and feces collection. Radio-collars were placed on free-ranging tree kangaroos to determine home range and forest habitat use. The free-ranging tree kangaroos were lightly anesthetized with tiletamine/zolazepam for the data collection. A total of nine free-ranging and seven captive tree kangaroos were evaluated; medical samples were collected from six and five animals, respectively. Results of physical examination, anesthetic monitoring, serum vitamin, mineral, trace nutrient, and electrolytes, whole blood heavy metal analysis, mycobacterial screening, and fecal examinations are presented. Free-ranging tree kangaroos had significantly lower values for beta carotene, copper, selenium, molybdenum, lead, and arsenic and significantly higher values for vitamin E than captive individuals. Cloacal swabs were all negative for Mycobacterium avium via polymerase chain reaction. Some free-ranging and captive individuals had positive coprologic exams revealing Eimeria spp. oocysts and strongyle spp. type ova. These are the first medical and anesthetic data published on Matschie's tree kangaroos from Papua New Guinea.     

Results of single-session bilateral triple pelvic osteotomy with an eight-hole iliac bone plate in dogs: 95 cases (1996-1999)

OBJECTIVE: To evaluate feasibility of single-session bilateral triple pelvic osteotomy with 8-hole iliac bone plates in dogs with bilateral hip dysplasia. DESIGN: Retrospective study. ANIMALS: 95 dogs with bilateral hip dysplasia. PROCEDURE: Medical records were reviewed, and information was obtained on signalment; body weight; angles of subluxation and reduction prior to surgery; durations of surgery and hospitalization; postoperative mobility; severity of lameness, radiographic grade of hip dysplasia, Norberg angle, and femoral head coverage before and after surgery; time required for radiographic evidence of iliac healing; change in pelvic diameter; implant integrity; and complications. RESULTS: Mean age at the time of surgery was 10.8 months, and mean weight was 35.2 kg (77.4 lb). Prior to surgery, mean angles of subluxation were 2.2 degrees on the right and 2.6 degrees on the left; mean angles of reduction were 25.9 degrees on the right and 27.3 degrees on the left. Mean surgical time was 95 minutes. All but 1 dog were able to walk on their own by the fourth day after surgery. Mean hospitalization time was 7.5 days. Clinical signs of lameness and radiographic grade of hip dysplasia were significantly improved during follow-up examinations. Mean time for radiographic iliac healing was 8 weeks. None of the plates and only 7 of the 1,520 (0.5%) screws loosened after surgery. Nineteen dogs had complications, but all complications were minor. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that single-session bilateral triple pelvic osteotomy with 8-hole iliac bone plates is effective for treatment of dogs with bilateral hip dysplasia.     

Effects of a program of human interaction and alterations in diet composition on activity of the hypothalamic-pituitary-adrenal axis in dogs housed in a public animal shelter

OBJECTIVE: To determine whether a program of human interaction or alterations in diet composition would alter activity of the hypothalamic-pituitary-adrenal (HPA) axis in dogs housed in an animal shelter. DESIGN: Prospective study. ANIMALS: 40 dogs. PROCEDURE: Dogs were (n = 20) or were not (20) enrolled in a program of regular supplemental human interaction (20 min/d, 5 d/wk, for 8 weeks) involving stroking, massaging, and behavioral training. In addition, half the dogs in each group were fed a typical maintenance-type diet, and the other half were fed a premium diet. Plasma cortisol and ACTH concentrations were measured during weeks 0, 2, 4, and 8 and before and after exposure to a battery of novel situations during weeks 0 and 8. RESULTS: Plasma cortisol concentration was significantly decreased by week 2, but plasma ACTH concentration was not significantly decreased until week 8 and then only in dogs fed the premium diet. Following exposure to novel situations, plasma cortisol and ACTH concentrations were significantly increased. However, during week 8, dogs enrolled in the program of human interaction had significantly lower increases in cortisol concentration than did dogs not enrolled in the program. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that both a program of human interaction and alterations in diet composition have moderating effects on activity of the HPA axis in dogs housed in an animal shelter and that activity of the HPA axis may be increased for a longer period during shelter housing than measurement of plasma cortisol concentration alone would suggest.