1,173 research outputs found
High Abundance of Nesting Long-Eared Owls in North Dakota
The long-eared owl (Asio otus) is a secretive, poorly understood species in the Great Plains of the United States and Canada. In North Dakota the long-eared owl has been considered a species of special concern (Petersen 1991), due mainly to lack of information on its occurrence and nesting status. We discovered 39 long-eared owl nests while searching for Cooper\u27s hawk (Accipiter cooperii) nests in northwestern and north central North Dakota during April and May 2000. Long-eared owl nests mainly were observed at J. Clark Salyer and Des Lacs National Wildlife Refuges (NWRs) in the Souris River basin (for study area descriptions see Nenneman et al. 2002) and at Lostwood NWR on the Missouri Coteau landform (Murphy 1993). These 39 nests exceed the total of all state breeding records for the long-eared owl through the early 1970\u27s (Stewart 1975: 159). During 1994 to 1999 we annually found 2 to 12 long-eared owl nests while searching for Cooper\u27s hawk nests in approximately the same area of North Dakota
RETHINKING CYBER WAR
The ongoing debate over cybernetic warfare and the threat it poses to modern society has been overly shaped by a traditional paradigm of warfare. This paradigm emphasizes physical destruction, as opposed to network disruption, as the principal means of inflicting damage on an adversary. While the war-as-destruction framework has been the dominant one since time immemorial, it would be highly misleading to view cyber war within this framework. In fact, it is the disruptive potential of cybernetic attacks, as opposed to their destructive potential, that poses the greatest risk to the security of nations. Cybernetic warfare must be reevaluated within this new framework in order to be properly understood. Cybernetic attacks come in two principal forms: those targeting data and those targeting control systems. Data attacks attempt to steal or corrupt information or deny electronic services to legitimate users of the data. The vast majority of cyberneti
Investigation of instability, dynamic forces, and effect of dynamic loading on strength of cages for the bearings in the high pressure oxygen turbopumps for the space shuttle main engine
Experiments were performed to determine the effect of cyclic loading on bearing cage strength. A long term working tensile load of approximately 1300 N (300 lbs) was found to be the likely maximum. Higher loads caused a decrease in cage tensile strength after the 125,000 cycle testing period. Poisson's ratio in compression was found to be highly dependent upon the direction of the fiberglass plies. At room temperature the value was 0.15 with the plies and 0.68 across the plies. At -196 C (-321 F), the value with the plies was 0.20. The results of the analyses conducted have again demonstrated the critical need for improved lubrication in the high pressure oxygen turbopump bearings. Lubricant films with low shear strength and low friction coefficients promote cage stability and decrease ball/cage forces during marginal operating conditions. The analysis of the effect of combined bearing loads on ball/cage loads has identified a radial load of 3600 N (800 lbs) as the maximum for the current clearance of the balls and cage pockets. Liquid oxygen impinging on the cage in the direction of rotation was found to enhance cage stability
Strangeness in Neutron Stars
It is generally agreed on that the tremendous densities reached in the
centers of neutron stars provide a high-pressure environment in which several
intriguing particles processes may compete with each other. These range from
the generation of hyperons to quark deconfinement to the formation of kaon
condensates and H-matter. There are theoretical suggestions of even more exotic
processes inside neutron stars, such as the formation of absolutely stable
strange quark matter. In the latter event, neutron stars would be largely
composed of strange quark matter possibly enveloped in a thin nuclear crust.
This paper gives a brief overview of these striking physical possibilities with
an emphasis on the role played by strangeness in neutron star matter, which
constitutes compressed baryonic matter at ultra-high baryon number density but
low temperature which is no accessible to relativistic heavy ion collision
experiments.Comment: 16 pages, 5 figures, 3 tables; Accepted for publication in the
Proceedings of the International Workshop on Astronomy and Relativistic
Astrophysics (IWARA) 2005, Int. J. Mod. Phys.
TakeCARE, a Video to Promote Bystander Behavior on College Campuses: Replication and Extension
Previous research has demonstrated that college students who view TakeCARE, a video bystander program designed to encourage students to take action to prevent sexual and relationship violence (i.e., bystander behavior), display more bystander behavior relative to students who view a control video. The current study aimed to replicate and extend these findings by testing two different methods of administering TakeCARE and examining moderators of TakeCARE’s effects on bystander behavior. Students at four universities (n = 557) were randomly assigned to one of three conditions: (a) view TakeCARE in a monitored computer lab, (b) view TakeCARE at their own convenience after receiving an email link to the video, or (c) view a video about study skills (control group). Participants completed measures of bystander behavior at baseline and at a 1-month follow-up. Participants in both TakeCARE conditions reported more bystander behavior at follow-up assessments, compared with participants in the control condition. The beneficial effect of TakeCARE did not differ significantly across administration methods. However, the effects of TakeCARE on bystander behavior were moderated by students’ perceptions of campus responsiveness to sexual violence, with more potent effects when students perceived their institution as responsive to reports of sexual violence
Leaf Traits Can Be Used to Predict Rates of Litter Decomposition
Strong relationships exist between litter chemistry traits and rates of litter decomposition. However, leaf traits are more commonly found in online trait databases than litter traits and fewer studies have examined how well leaf traits predict litter decomposition rates. Furthermore, while bulk leaf nitrogen (N) content is known to regulate litter decomposition, few studies have explored the importance of N biochemistry fractions, such as protein and amino acid concentration. Here, we decomposed green leaves and naturally senesced leaf litter of nine species representing a wide range of leaf functional traits. We evaluated the ability of traits associated with leaf and litter physiology, N biochemistry, and carbon quality to predict litter decomposition. The objectives of this study were to determine if 1) N fractions explain variation in decomposition that is not explained by bulk N parameters alone, and 2) green leaf traits, as opposed to litter traits, can accurately determine rates of litter decomposition. We found N biochemistry traits to have similar predictive power to that of bulk N. We also found that leaf N biochemistry traits correlated strongly with each other and aligned on a single axis of variation resembling that of the ‘leaf economic spectrum.’ We noted that green leaf traits associated with this axis, including bulk N, N fractions, leaf mass per area, and lignin, were better predictors of decomposition than litter traits and concluded that leaf trait databases may be used to accurately predict litter decomposition. Future decomposition studies should consider fitting the more flexible Weibull distribution model to litter cohorts, as this model is much less rigid than the classic exponential decay model traditionally used in decomposition studies
A Dramatic Decrease in Carbon Star Formation in M31
We analyze resolved stellar near-infrared photometry of 21 HST fields in M31
to constrain the impact of metallicity on the formation of carbon stars.
Observations of nearby galaxies show that the carbon stars are increasingly
rare at higher metallicity. Models indicate that carbon star formation
efficiency drops due to the decrease in dredge-up efficiency in metal-rich
thermally-pulsing Asymptotic Giant Branch (TP-AGB) stars, coupled to a higher
initial abundance of oxygen. However, while models predict a metallicity
ceiling above which carbon stars cannot form, previous observations have not
yet pinpointed this limit. Our new observations reliably separate carbon stars
from M-type TP-AGB stars across 2.6-13.7 kpc of M31's metal-rich disk using HST
WFC3/IR medium-band filters. We find that the ratio of C to M stars (C/M)
decreases more rapidly than extrapolations of observations in more metal-poor
galaxies, resulting in a C/M that is too low by more than a factor of 10 in the
innermost fields and indicating a dramatic decline in C star formation
efficiency at metallicities higher than [M/H] -0.1 dex. The
metallicity ceiling remains undetected, but must occur at metallicities higher
than what is measured in M31's inner disk ([M/H] +0.06 dex).Comment: 16 pages, 13 Figures; text clarifications in response to the referee.
Results are unchanged; accepted for publication in Ap
Etherscapes: Massless, Elastic, Technology and Control
This thesis is an exploration into the ether of the digital aesthetic. It attempts to capture a segment of the continually morphing space then deconstruct and analyse it through electronic and new media art. Herein you will find a questioning of technology and control within electronic and new media art as an investigation into better understanding the current media image and visual culture that so powerfully influences the modern social construct. By nature this argument has existed for some years but only now with advancements in technology and more affordable realisation of ideas by media artists, the topic of the digital aesethetic, technology and control has become relevant for popular debate. As war lingers in our minds, terrorism hits headlines, and experiements in cloning human DNA take place, the technology that society demands can only necessarily be seen as a major contributing factor to today's strange times. However, strange or not, the questions I wish to discuss; Does technology determine contemporary society or do we determine technology? Where does the control exist
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