Winter Habitat Use and Survival of Female Ring-necked Pheasants (\u3ci\u3ePhasianus colchicus\u3c/i\u3e) in Southeastern North Dakota

From 1992 to 1995 we used radiotelemetry to monitor winter habitat selection and survival of female ring-necked pheasants (Phasianus colchicus) in southeastern North Dakota. We captured 100 birds at nine sites in six study blocks centered on cattail-dominated (Typha spp.) semi-permanent wetlands. Pheasants showed nonrandom habitat use at two hierarchical scales. At the second-order scale (23-km2 blocks) semi-permanent wetlands were preferred during two winters in which habitat selection could be assessed (1992–1993 and 1994–1995). An additional second-order preference for grass-covered uplands was shown during the mild 1994–1995 winter. At the third-order scale (home-range) pheasants preferred the edges of wetlands in 1992–1993 and 1994–1995. The central portions of wetlands were preferred in 1992–1993 and used proportionately in 1994–1995. Seasonal wetlands were avoided at the third order scale during 1992–1993 and 1994–1995. The average winter survival rate was 0.41, with rates ranging from 0.04–0.86 and differing significantly among winters. Survival was lower during early winter and midwinter periods for birds weighing less than 1090 g and for birds captured in semi-permanent wetlands under private ownership. A 1 C increase in the mean weekly maximum temperature decreased the probability of death by 0.06 and a 2.5 cm increase in new snow raised the probability of death by 0.08

Avian Use of Rural Roadsides with Cattail (Typha spp.)

We surveyed 30 roadsides in North Dakota’s Prairie Pothole Region for birds and active nests between May and July 2001–2002. Each roadside transect was 1608 m and had ≥200 linear meters of standing cattail (Typha spp.). We recorded 45 bird species; four species of Icteridae dominated the avifauna. Red-winged blackbirds (Agelaius phoeniceus) were both the most abundant species and most abundant nester, averaging 53 birds/10 ha (SE = 7.7) and 30 nests/10 ha (SE = 9.7). Among non-icterid species, song sparrow (Melospiza melodia) and common yellowthroat (Geothlypis trichas) ranked first and second consecutively in 2001 and 2002. Canonical correspondence analyses of species compositions indicated that species abundance was related to two roadside variables, length and water depth of cattail stands. Cattails added habitat diversity and acceptable conditions for wetland-dwelling avian species not typically found in rural roadsides outside of the Prairie Pothole Region. We documented use of roadsides by three species of grassland birds of national or regional conservation concern. Roadsides in North Dakota, although dominated mostly by generalist bird species with edge tolerance, may have some management potential for area-dependent grassland birds

Habitat Characteristics of Spring Blackbird Roosts in East-central South Dakota

In the northern Great Plains, blackbirds (Icteridae) roost almost exclusively in emergent-dominated wetlands. The physical characteristics of wetland roosts are not well understood. From March 20 to April 20, 1999, we studied 16 wetlands used as blackbird roosts in east-central South Dakota. Six wetlands had major roosts (range: 102,000-298,000 blackbirds); whereas, 10 wetlands had minor roosts (range: 2,010-34,000 blackbirds). Maximum roost size was correlated directly with emergent vegetation area (P = 0.05) and possibly with wetland basin area (P ≤ 0.10). Water depths were greater at used sites within wetlands of major roosts (median = 44 cm) than at used sites of minor roosts (median = 25 cm). Palustrine wetlands with large expanses of emergents (\u3e 100 ha) and water depths (\u3e 40 cm) had an increased likelihood of developing into major spring roosts in east-central South Dakota

Feeding Habitats of Spring-Migrating Blackbirds in East-central South Dakota

Between March 27 and April 21, 1998, we monitored blackbird (Icteridae) activity and habitat selection at a migratory staging area in east-central South Dakota. We used fixed-area observation points located within 20 l-km2 circular plots centered on four wetland basins that were used as night roosts. Each roost was surveyed four times, with the surveys spread evenly throughout the blackbird migration. We recorded the number of blackbird flocks, flock size and composition, habitat used, and behavior (e.g., loafing and feeding). Fifty percent (n = 242) of the 482 flocks recorded in the quadrats was observed loafing in trees of woodlots and shelterbelts. Feeding flocks preferred habitats classified as Corn (e.g., disked, plowed, and stubble corn fields) over two other foraging habitat categories (Cultivated and Grassland). A comparison of proportional availability of Cultivated habitat (soybean [Lathyrus odoratus] and wheat [Triticum aestivum] stubble, inclusive) against proportional use by feeding flocks indicated that this habitat was avoided. Grassland habitat (hayfields, CRP, and pasture) was used according to its availability. Intensity of Grassland use depended on time of survey (AM and PM), with use greater during the PM survey. A two-factor model (habitat, time, and the interaction term) provided the best parsimonious fit of 15 a priori models tested with Akaike\u27s information criterion (AICc). Selection of foraging habitats by blackbirds might reflect comparable strategies used by other early migrating granivores. This knowledge could help wildlife managers maximize the placement of corn field food plots for optimum benefit to wildlife species

Extensive Investigations on Radial Crack Formation in Labyrinth Seals of Aircraft Engines

Labyrinth seals are due to their non-contact function and their thermal resistance the state of the art in sealing technology for thermal turbomachinery such as jet engines. The purpose of labyrinth seals is to adjust or minimize the leakage between rotor and stator. However, because of transient flight manoeuvres and the resulting mechanical and thermal loads on the components, contact between rotating and stationary parts cannot be ruled out. The aim of this study is to extend the basic understanding of the mechanisms of hot crack formation in the components of a labyrinth seal during the rubbing process. Previous investigations at the Institute of Thermal Turbomachinery have shown that the thermally induced stress caused in connection with the thermal change of the material properties can lead to formation of the cracks in the seal fin. In order to get a deeper understanding of the complex crack initiation mechanisms, it is necessary to carry out fundamental experiments on simplified geometries. For this purpose, the stress conditions of a loaded labyrinth seal are applied to a cylindrical test specimen. It is fixed on both sides and subjected to thermo-cyclic load. To model a rubbing process of a labyrinth seal, the initial temperature of the cycle corresponds to the operating temperature of the rotor in a jet engine and the final temperature corresponds to the contact temperature during the rubbing process. The temperature change causes stress in the specimen due to the rigid mounting. In literature there are analytical considerations regarding the stress-strain curve in the seal fin and a possible pre-damage of the components by remaining tensile stress after the rubbing process. In this paper, these analytical approaches are compared with the test data. Also a residual tensile strength of the seal fin which is still to be tolerated is worked out depending on the temperature load. The stress reduction during heating is very significant and is considered in detail. Due to the high mechanical and thermal loads, the stress reduction is superimposed by relaxation and plastic deformation. For a separate consideration of these basic effects, FE simulations are carried out. The main findings are that stress and strain in the component depends on both the initial and the final temperature of the specimen. The final rubbing temperature mainly influences the remaining tensile stress. With the thus calculated remaining strength of the seal fin a probable crack formation could be determined. The evaluation of this data contributes significantly to the understanding of hot crack formation in labyrinth seal fins and is therefore the basis for the optimization of the sealing system with regard to robustness against rubbing processes

HAS AN INTEGRATED PEST MANAGEMENT APPROACH REDUCED BLACKBIRD DAMAGE TO SUNFLOWER?

Since the mid- 1970s many new and modified damage abatement methods have been used to reduce blackbird damage to ripening sunflower in the northern Great Plains. To assess the overall impact of these techniques, we analyzed the dynamic relationship between breeding blackbird densities and sunflower damage. Breeding density estimates were made at both the regional and county levels, whereas, sunflower damage estimates were made at the county level only. Periodic regional estimates of breeding densities between 1967 and 1998 for red-winged blackbirds (Agelaius phoeniceus), common grackles (Quiscalus quiscula), and yellow-headed blackbirds (Xanthocephalus xanthocephalus) showed no differences among years. To increase our ability to detect changes in breeding density, we started intensive county-level surveys in 1996. These surveys, in four counties in North Dakota and South Dakota, showed that blackbird densities were greater in 1998 and 1999 than during the previous two years. We surveyed sunflower damage in two of these counties from 1994 to 1998 and found no difference in damage (F= 1.8%) among years. In 1997 and 1998, with the two other counties added to the survey, we found that damage was similar between years, averaging 2.2%. Dollar loss per hectare was trending lower in three of the study counties that had a historical database for comparison. This supports the idea that \u27local\u27 breeding densities are not correlated with damage levels. We will continue to use annual estimates of breeding densities and sunflower damage to assess the effects of an evolving Integrated Pest Management program

Emergency percutaneous needle decompression for tension pneumoperitoneum

<p>Abstract</p> <p>Background</p> <p>Tension pneumoperitoneum as a complication of iatrogenic bowel perforation during endoscopy is a dramatic condition in which intraperitoneal air under pressure causes hemodynamic and ventilatory compromise. Like tension pneumothorax, urgent intervention is required. Immediate surgical decompression though is not always possible due to the limitations of the preclinical management and sometimes to capacity constraints of medical staff and equipment in the clinic.</p> <p>Methods</p> <p>This is a retrospective analysis of cases of pneumoperitoneum and tension pneumoperitoneum due to iatrogenic bowel perforation. All patients admitted to our surgical department between January 2005 and October 2010 were included. Tension pneumoperitoneum was diagnosed in those patients presenting signs of hemodynamic and ventilatory compromise in addition to abdominal distension.</p> <p>Results</p> <p>Between January 2005 and October 2010 eleven patients with iatrogenic bowel perforation were admitted to our surgical department. The mean time between perforation and admission was 36 ± 14 hrs (range 30 min - 130 hrs), between ER admission and begin of the operation 3 hrs and 15 min ± 47 min (range 60 min - 9 hrs). Three out of eleven patients had clinical signs of tension pneumoperitoneum. In those patients emergency percutaneous needle decompression was performed with a 16G venous catheter. This improved significantly the patients' condition (stabilization of vital signs, reducing jugular vein congestion), bridging the time to the start of the operation.</p> <p>Conclusions</p> <p>Hemodynamical and respiratory compromise in addition to abdominal distension shortly after endoscopy are strongly suggestive of tension pneumoperitoneum due to iatrogenic bowel perforation. This is a rare but life threatening condition and it can be managed in a preclinical and clinical setting with emergency percutaneous needle decompression like tension pneumothorax. Emergency percutaneous decompression is no definitive treatment, only a method to bridge the time gap to definitive surgical repair.</p

Ungulate browsing shapes climate change impacts on forest biodiversity in Hungary

Climate change can result in a slow disappearance of forests dominated by less drought-tolerant native European beech (Fagus sylvatica) and oak species (Quercus spp.) and further area expansion of more drought-tolerant non-native black locust (Robinia pseudoacacia) against those species in Hungary. We assumed that the shift in plant species composition was modified by selective ungulate browsing. Thus, we investigated which woody species are selected by browsing game. We have collected data on the species composition of the understory and the browsing impact on it in five different Hungarian even-aged forests between 2003 and 2005. Based on these investigations the non-native Robinia pseudoacacialiving under more favourable climatic conditions was generally preferred (Jacobs’ selectivity index: D=0.04±0.77), while the nativeFagus sylvatica and Quercus spp. (Q. petraea, Q. robur), both more vulnerable to increasing aridity, were avoided (D=-0.37±0.11;-0.79±0.56;-0.9±0.16; respectively) among target tree species. However, economically less or not relevant species, e.g. elderberry (Sambucus spp.), blackberry (Rubus spp.) or common dogwood (Cornus sanguinea) were the most preferred species (D=0.01±0.71; -0.12±0.58; -0.2±0.78, respectively). Our results imply that biodiversity conservation, i.e. maintaining or establishing a multi-species understory layer, can be a good solution to reduce the additional negative game impact on native target tree species suffering from drought. Due to preference for Robinia pseudoacaciaselective browsing can decelerate the penetration of this species into native forest habitats. We have to consider the herbivorous pressure of ungulates and their feeding preferences in planning our future multifunctional forests in the light of climate change impacts

Metastatic eccrine porocarcinoma: report of a case and review of the literature

Eccrine porocarcinoma (EPC) is a rare type of skin cancer arising from the intraepidermal portion of eccrine sweat glands or acrosyringium, representing 0.005-0.01% of all cutaneous tumors. About 20% of EPC will recur and about 20% will metastasize to regional lymph nodes. There is a mortality rate of 67% in patients with lymph node metastases. Although rare, the occurrence of distant metastases has been reported