444 research outputs found
An Analysis of Flock Organization in Black-Capped Chickadees
An analysis was made of individual behavior and flock organization among 33 color-banded Black-capped Chickadees (Parus atricapillus) on a woodland tract in wester New York State, from December 1967 to June 1970. Also, three of these flocks were confined at various periods for an average aviary tenure of 26 days. From these observations I concluded that the hierarchy and interindividual relationship of a flock remain as observed in the field; testosterone propionate causes an increase in injected subordinate bird\u27s activity; but did not effect a change in its rank.
From the observations in the aviary, it was found that subtle differences in male and female bibs and caps facilitated sexing of the chickadees. All 9 resident flocks of adults usually consisted of 4 birds (9 of 11 flocks) and had a 1:1 sex ratio, whereas first-year and itinerant flocks were more likely to have an uneven sex ratio, indicating that these flocks were not made up entirely of pairs. All flock members observed through the breeding season mated with other members of their flock Nest sites were heavily concentrated in a section of dead trees near the border of the coniferous sector. Six nest boxes placed in the coniferous woods were not used, though fifty percent of the breeding territories on the study area included coniferous woods, and the birds with the longest tenure in the area used the coniferous woods as part of their winter flocking range and breeding territories.
Establishment of feeders affected patterns of flock size and behavior. Also the alpha male\u27s mate took precedence over other flock members at a restricted food source. From other observations of alpha males, it was noted that in one instance in three winters one resident flock disbanded, with its alpha male taking a beta position in its new association, and the beta male becoming the alpha of another flock. Also, it was discovered that the removal of the alpha male from flocks of free-living and confined chickadees for a two day period did not result in disorganization of the flock.
All resident flocks and 2 flocks of first-year birds exhibited a linear hierarchy. Further observation of first-year flocks confirmed that there was no special relationship or pair bond among the male and female members; however, both males and females were present in these flocks and mated with flock members. These flocks of first-year birds also seemed to function as a reservoir for replacing lost members of resident flocks, the formation of which was deferred by the adults until the young dispersed. The independent young formed large bands and ranged widely.
From observations in the aviary it was found that there was no change in hierarchy from that observed for the flock in the wild. Also in the aviary, the subordinate male bird received three injections of testosterone propionate. No apparent elevation in his social posit.ion was observe. However, a statistically significant (P = 0.01) increase in activity among members of one of the flocks was recorded. Finally, caching of surplus food was observed both in the wild and in captivity.
Contrast in social relationships of adult and first-year birds prior to onset of breeding is more pronounced than heretofore recognized. First-year birds apparently are not paired, and tend to travel more widely in flocks that may be larger than those of resident flocks.
Learning appears to be the most important response in the organization of the resident flocks
Down to Earth
By John I. Mosher.Collection of essays intended to convey some basic information about ecology and the view points of the author about environmental issues.https://digitalcommons.brockport.edu/bookshelf/1234/thumbnail.jp
Autonomous Inspections of Utility Networks
Field inspections of utility network assets are a critical aspect of maintaining the quality and integrity of services provided by a utility. Currently, such inspections are performed largely by human inspectors. Such manual inspections are time-consuming, expensive, potentially dangerous to the inspectors and the surrounding public, subject to human error, disruptive to neighboring communities, and lack the speedy response needed in a disaster scenario. This disclosure describes a machine-based inspection mechanism for utility networks, based on, for example, autonomous or remotely-operated drones with the capability to perform intricate inspections at difficult-to-reach regions and heights. The inspection tasks including, for example, navigation routes, assets and parameters to be inspected, etc. are determined, for example, by a machine learner that has access to real-time and historical data from a variety of relevant sources
Measuring HIV risk in the U.S. population aged 15–44: Results from Cycle 6 of the National Survey of Family Growth
Objective—This report presents national estimates of the percentage and number of persons in the U.S. population aged 15–44 who report behaviors that place them at increased risk for acquiring or transmitting human immunodeficiency virus, or HIV. The report also contains data on condom use and HIV testing by persons who report risk behaviors. In addition, estimates of self-reported risk for HIV from the Cycle 6 National Survey of Family Growth (NSFG) are compared with data from other recent national surveys. Methods—Data from the NSFG Cycle 6, conducted by the Centers for Disease Control and Prevention’s (CDC) National Center for Health Statistics (NCHS), are based on interviews with a national sample of the household population of the United States. In-person, face-to-face interviews were conducted in the homes of 12,571 males and females 15–44 years of age in 2002. Most of the data were collected by Computer-Assisted Personal Interviewing (CAPI), in which a laptop computer is used to select and present the questions, which an interviewer reads to the respondent. The more sensitive data, including the risk behavior items on which this report is based, were collected by Audio Computer-Assisted Self-Interviewing (ACASI), in which the respondent listens to recording of each question and enters his or her own answers into the computer without involving an interviewer. Results—Overall, 8.9 percent of persons 15–44 years of age had engaged in sexual behaviors in the past year that put them at increased risk of HIV, and 1.5 percent had engaged in drug use behaviors that put them at risk. In all, an estimated 9.9 percent engaged in either drug use or sexual behavior that placed them at increased risk for HIV. Including those who were treated for a sexually transmitted disease (STD) in the past year, 11.9 percent of persons 15–44 years of age—13.0 percent males and 10.8 percent of females—were at risk of HIV in 2002. The 11.9 percent at risk is equivalent to an estimated 14.4 million persons aged 15–44 at higher risk of HIV through drug use, sexual behavior, or having been treated for an STD in the past year. Persons who were at increased risk reported greater condom use and higher rates of HIV testing, but among those at risk, 33.6 percent had never been tested for HIV and 60.4 percent did not use condoms at last sex
Representative bureaucracy: does female police leadership affect gender-based violence arrests?
Representative bureaucracy theory postulates that passive representation leads to active representation of minority groups. This article investigates the passive representation of female police officers at leadership levels and the active representation of women vis-a-vis gender-based violence arrest rates in the UK. Much of the extant research on representative bureaucracy is located at street level, with evidence showing that discretionary power of minority bureaucrats can lead to active representation. This article is focused on leadership levels of a public bureaucracy. The empirical research is based upon a panel dataset of female police officers as an independent variable and gender-based violence arrest rates as a dependent variable. The analysis reveals that there is little evidence of active representation of women by female police leadership
An ensemble de-noising method for spatio-temporal EEG and MEG data
EEG/MEG are important tools for non-invasive medical diagnosis and basic studies of the brain and its functioning, but often applications are limited due to a very low SNR in the data. Here, we present a discrete wavelet transform (DWT) based de-noising method for spatio-temporal EEG/MEG measurements collected by a sensor array. A robust threshold selection can be achieved by incorporating spatial information and pre-stimulus data to estimate signal and noise energies. Further improvement can be gained by applying a translation-invariant approach to the derived de-noising scheme. In simulations, the performance of the proposed method is evaluated in comparison to standard de-noising and low-rank approximation, which o ers some complementarity to our approach
Orion Suit Loop Variable Pressure Regulator Development
The Orion Multi Purpose Crew Vehicle (MPCV) integrates the cabin and pressure suits with the core life support systems to provide life support during contingency depressurized cabin operations. To provide the multiple suit pressures between nominal pressurized cabin suited operations, suit leak checks, depressurized cabin suited operations, and elevated suit pressure for denitrification, a variable pressure regulator is needed. This paper documents the development of the suit loop regulator for Orion
An F-ratio-Based Method for Estimating the Number of Active Sources in MEG
Magnetoencephalography (MEG) is a powerful technique for studying the human
brain function. However, accurately estimating the number of sources that
contribute to the MEG recordings remains a challenging problem due to the low
signal-to-noise ratio (SNR), the presence of correlated sources, inaccuracies
in head modeling, and variations in individual anatomy. To address these
issues, our study introduces a robust method for accurately estimating the
number of active sources in the brain based on the F-ratio statistical
approach, which allows for a comparison between a full model with a higher
number of sources and a reduced model with fewer sources. Using this approach,
we developed a formal statistical procedure that sequentially increases the
number of sources in the multiple dipole localization problem until all sources
are found. Our results revealed that the selection of thresholds plays a
critical role in determining the method`s overall performance, and appropriate
thresholds needed to be adjusted for the number of sources and SNR levels,
while they remained largely invariant to different inter-source correlations,
modeling inaccuracies, and different cortical anatomies. By identifying optimal
thresholds and validating our F-ratio-based method in simulated, real phantom,
and human MEG data, we demonstrated the superiority of our F-ratio-based method
over existing state-of-the-art statistical approaches, such as the Akaike
Information Criterion (AIC) and Minimum Description Length (MDL). Overall, when
tuned for optimal selection of thresholds, our method offers researchers a
precise tool to estimate the true number of active brain sources and accurately
model brain function
Using a model of family adaptation to examine outcomes of caregivers of individuals with autism spectrum disorder transitioning into adulthood
Background
The study examined the burden of caring for individuals with autism spectrum disorder (ASD) transitioning from high school and factors associated with burden derived from the Double ABCX model of family adaptation (i.e., autism symptom severity, problem behaviors, pile-up life demands, personality traits, social support, cognitive appraisals, and coping strategies). In particular, we were interested in the potential association between the “big 5” personality traits and burden.
Method
Participants (N = 105) were caregivers of individuals with ASD within two years pre- or post-graduation from high school.
Results
Primary caregivers reported moderate levels of burden. As hypothesized, burden was significantly associated with both child (i.e., increased autism symptom severity and problem behaviors) and caregiver characteristics (i.e., greater neuroticism, lower levels of extraversion, conscientiousness, agreeableness, and social support, and increased use of threat appraisals and passive-avoidance coping strategies). Using multiple regression, increased child behavior problems and increased caregiver use of passive-avoidance coping were identified as independent predictors of burden. Passive-avoidance coping mediated the relationship between caregiver burden and individual personality traits (i.e., neuroticism, extraversion, conscientiousness).
Conclusions
The results suggest that proximal variables, such as caregivers’ use of maladaptive coping strategies, explain the associations between burden and personality. Suggestions for interventions to relieve burden are discussed
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