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PubMedDate not supplied

["Crows' feet wrinkles" in high voltage electric accident--a sign of survival?].

A "crowsfoot-like" pattern is considered as being a sign of vitality in fatalities due to the effects of smoke, fire or high voltage (active or reflex contraction of mimic muscles). Introducing the autopsy results of a high voltage accident (66,600 V) it is discussed, whether this phenomenon and the underlying contraction of the facial muscles could also be caused by electrical current in the agony or supravital period. It seems possible that this mechanism of direct muscle contraction anticipates a nerval indirect stimulation of muscle fibres by innervating motoneurones--active or on the basis of a polysynaptic extraneous reflex. If the electrophysiological course discussed should be right, a "crowsfoot-like" pattern in equivalent cases could be interpreted as a vital sign only with great reserve.

Accidents, Occupational↗
PubMed1998

Results of total hip arthroplasty for Crowe Type III developmental hip dysplasia.

From 1969 through 1980, 90 hips in 82 patients had cemented total hip arthroplasty for Type III developmental hip dysplasia. Seventy hips were reviewed at an average of 16.6 years (range, 5-23 years) after operation. Aseptic loosening developed in 53% of acetabular cups and 40% of femoral stems. Despite attempts to place acetabular components in the anatomic center, 18 cups (25.7%) were placed outside that area. Using a measurement method to determine the true acetabular region and approximate femoral head center, final acetabular loosening strongly correlated with initial cup placement. Loosening occurred in 15 of 18 cups (83.3%) initially positioned outside of the true acetabular region compared with loosening in 22 of 52 cups (42.3%) initially positioned within the true acetabular region. Acetabular loosening also correlated with initial lateral displacement or initial superior displacement of the hip center from the approximate femoral head center. Initial cup placement medial to the approximate femoral head center was predictive of successful long term acetabular component fixation. The method of acetabular reconstruction did not affect eventual cup loosening. Placement of the hip arthroplasty center of rotation in or near the true acetabular region is recommended.

Acetabulum↗
PubMed2006

Does the roosting behavior of birds affect transmission dynamics of West Nile virus?

The potential role of many urban passerine birds in the transmission of West Nile virus (WNV) is well-documented by studies on host competency, seroprevalence in wild birds, and identification of vector blood meal source. In contrast, the impact of bird behavior on transmission dynamics is largely unexplored. Bird roosting (perching) behavior may be a critical component regulating WNV transmission because of the crepuscular/nocturnal feeding behavior of Culex mosquitoes, the primary vectors of WNV. We used radio telemetry to determine the roosting behavior of American crows (Corvus brachyrhynchos) and northern cardinals (Cardinalus cardinalus). On average, healthy crows moved slightly shorter distances between roosts than viremic crows, 1,038.3 meters versus 1,255.5 meters, while cardinals only moved 54.7 meters. Given the average movements of crows and cardinals between roosts, crows, which are viremic for five days, could spread the virus throughout a mean +/- SE area of 20.84 +/- 0.79 km(2), while viremic cardinals would, on average, only spread the virus over a mean +/- SE area of 0.03 +/- 0.01 km(2). Because the crow population in Illinois is decreasing at a rate of 11.5% per year and up to 35.6% per year in certain locations, crows are becoming scarce in some areas, thus reducing their role as wild bird sentinels. We suggest that if crows are important in dispersing WNV, large decreases in their abundance will shift transmission cycles to a more focal nature because of the differences in roosting behavior of crows compared with other urban birds, such as cardinals.

Animals↗
PubMed2001

West Nile virus transmission and ecology in birds.

The ecology of the strain of West Nile virus (WNV) introduced into the United States in 1999 has similarities to the native flavivirus, St. Louis encephalitis (SLE) virus, but has unique features not observed with SLE virus or with WNV in the old world. The primary route of transmission for most of the arboviruses in North America is by mosquito, and infected native birds usually do not suffer morbidity or mortality. An exception to this pattern is eastern equine encephalitis virus, which has an alternate direct route of transmission among nonnative birds, and some mortality of native bird species occurs. The strain of WNV circulating in the northeastern United States is unique in that it causes significant mortality in exotic and native bird species, especially in the American crow (Corvus brachyrhynchos). Because of the lack of information on the susceptibility and pathogenesis of WNV for this species, experimental studies were conducted at the USGS National Wildlife Health Center. In two separate studies, crows were inoculated with a 1999 New York strain of WNV, and all experimentally infected crows died. In one of the studies, control crows in regular contact with experimentally inoculated crows in the same room but not inoculated with WNV succumbed to infection. The direct transmission between crows was most likely by the oral route. Inoculated crows were viremic before death, and high titers of virus were isolated from a variety of tissues. The significance of the experimental direct transmission among captive crows is unknown.

Animals↗
PubMed2006

Wild bird mortality and West Nile virus surveillance: biases associated with detection, reporting, and carcass persistence.

Surveillance targeting dead wild birds, in particular American crows (Corvus brachyrhynchos), plays a critical role in West Nile virus (WNV) surveillance in the United States. Using crow decoy surrogates, detection and reporting of crow carcasses within urban and rural environments of DeKalb County, Georgia were assessed for potential biases that might occur in the county's WNV surveillance program. In each of two replicated trials, during July and September 2003, 400 decoys were labeled with reporting instructions and distributed along randomly chosen routes throughout designated urban and rural areas within DeKalb County. Information-theoretic methods were used to compare alternative models incorporating the effects of area and trial on probabilities of detection and reporting. The model with the best empirical support included the effects of area on both detection and reporting of decoys. The proportion of decoys detected in the urban area (0.605, SE=0.024) was approximately twice that of the rural area (0.293, SE=0.023), and the proportion of decoys reported in the urban area (0.273, SE=0.023) was approximately three times that of the rural area (0.103, SE=0.028). These results suggest that human density and associated factors can substantially influence dead crow detection and reporting and, thus, the perceived distribution of WNV. In a second and separate study, the persistence and fate of American crow and house sparrow (Passer domesticus) carcasses were assessed in urban and rural environments in Athens-Clarke, Madison, and Oconee counties, Georgia. Two replicated trials using 96 carcasses of each species were conducted during July and September 2004. For a portion of the carcasses, motion sensitive cameras were used to monitor scavenging species visits. Most carcasses (82%) disappeared or were decayed by the end of the 6-day study. Carcass persistence averaged 1.6 days in rural areas and 2.1 days in urban areas. We analyzed carcass persistence rates using a known-fate model framework in program MARK. Model selection based on Akaike's Information Criteria (AIC) indicated that the best model explaining carcass persistence rates included species and number of days of exposure; however, the model including area and number of days of exposure received approximately equal support. Model-averaged carcass persistence rates were higher for urban areas and for crow carcasses. Six mammalian and one avian species were documented scavenging upon carcasses. Dead wild birds could represent potential sources of oral WNV exposure to these scavenging species. Species composition of the scavenger assemblage was similar in urban and rural areas but "scavenging pressure" was greater in rural areas.

Animals↗
PubMed1989

Contrasting effects of pre- and posthatch exposure to gonadal steroids on the development of vocal, sexual, and aggressive behavior of young domestic fowl.

Prehatch treatment of domestic chicks with 17 beta-estradiol dipropionate (EDP) reduces later testosterone-facilitated sexual behavior, crowing, and suppression of peeping. Prehatch treatment with 5 alpha-dihydrotestosterone propionate (DHTP) reduces later testosterone-facilitated aggressive behavior and produces greatly enhanced avoidance that interferes with sexual behavior in some test situations. It also disturbs crowing by removing trilled call elements and increasing the number of elements/crow but has little effect on crowing posture. The majority of these results can be understood as "demasculinizing" effects of gonadal steroids on the developing male fetus, but the possibility that some result from more extreme pathological changes is also discussed. Posthatch treatment with DHTP facilitates attack and cackling but has no effect on sexual behavior or crowing; the synthetic androgen R1881 has similar effects on cackling and also has no effect on sexual behavior or crowing. Posthatch treatment with EDP enhances sexual behavior but has no effect on attack; the aromatase inhibitor 1,4,6-Androstatrien-3,17-dione (ATD) blocked the suppression of peeping by testosterone but had no effect on testosterone-facilitated sexual behavior. Combined posthatch treatment with EDP and DHTP facilitated crowing although treatment with either steroid alone was ineffective.

Aggression↗