52 research outputs found
Canid vs. Canid: Insights into Coyote-Dog Encounters from Social Media
While the relationship between coyotes (Canis latrans) and house cats (Felis catus) may be characterized as one between predators and their prey, coyote interactions with domestic dogs (C. lupus familiaris) appear to be more varied and may include behaviors associated with canid sociality. While encounters between coyotes and dogs are difficult to observe, we capitalized on publically available video recordings of coyote-dog encounters to observe canid behaviors and examined 35 video clips downloaded from YouTube during fall 2014. We identified coyote-dog interactions that were playful, agonistic, or predatory; those that we could not clearly categorize were labeled as other/undetermined. We found that both species were recorded directing play to the other species, which led to mutual play bouts. We observed a similar number of agonistic encounters, which included dogs biting coyotes and coyotes biting dogs. The main difference in agonistic behavior was that coyotes usually showed defensive aggression while dogs did not show defensive aggression. We also observed coyotes ambushing and bite-shaking small dogs in 3 video clips, from which the dogs escaped, but we did not see predatory behavior of dogs towards coyotes. Dog size may be related to types of interactions. No small dogs were involved in agonistic interactions, and only 1 small dog was observed playing with a coyote. From these videos, we conclude that the relationship between coyotes and dogs cannot be simply described as predator-prey; indeed, much of it appears to be social behavior divided between playful and agonistic. Future work that aims to explain the proximate correlates of play and aggression would provide more information for managers who wish to educate humans to reduce wildlife-human-dog conflicts
DIAmante TESS AutoRegressive Planet Search (DTARPS): I. Analysis of 0.9 Million Light Curves
Nearly one million light curves from the TESS Year 1 southern hemisphere
extracted from Full Frame Images with the DIAmante pipeline are processed
through the AutoRegressive Planet Search statistical procedure. ARIMA models
remove trends and lingering autocorrelated noise, the Transit Comb Filter
identifies the strongest periodic signal in the light curve, and a Random
Forest machine learning classifier is trained and applied to identify the best
potential candidates. Classifier training sets include injections of both
planetary transit signals and contaminating eclipsing binaries. The optimized
classifier has a True Positive Rate of 92.8% and a False Positive Rate of 0.37%
from the labeled training set. The result of this DIAmante TESS autoregressive
planet search (DTARPS) analysis is a list of 7,377 potential exoplanet
candidates. The classifier has a False Positive Rate of 0.3%, a 64% recall rate
for previously confirmed exoplanets, and a 78% negative recall rate for known
False Positives. The completeness map of the injected planetary signals shows
high recall rates for planets with 8 - 30 R(Earth) radii and periods 0.6-13
days and poor completeness for planets with radii < 2 R(Earth) or periods < 1
day. The list has many False Alarms and False Positives that need to be culled
with multifaceted vetting operations (Paper II).Comment: 46 pages, 21 figures, submitted to AAS Journals. A Machine Readable
Table for Table 3 is available at
https://drive.google.com/drive/folders/1DyxNcNlfcHHAoCdsaipxxIbP5A2FPey
DIAmante TESS AutoRegressive Planet Search (DTARPS): II. Hundreds of New TESS Candidate Exoplanets
The DIAmante TESS AutoRegressive Planet Search (DTARPS) project seeks to
identify photometric transiting planets from 976,814 southern hemisphere stars
observed in Year 1 of the TESS mission. This paper follows the methodology
developed by Melton et al. (Paper I) using light curves extracted and
pre-processed by the DIAmante project (Montalto et al. 2020). Paper I emerged
with a list of 7,377 light curves with statistical properties characteristic of
transiting planets but dominated by False Alarms and False Positives. Here a
multistage vetting procedure is applied including: centroid motion and crowding
metrics, False Alarm and False Positive reduction, photometric binary
elimination, and ephemeris match removal. The vetting produces a catalog of 462
DTARPS Candidates across the southern ecliptic hemisphere and 310 objects in a
spatially incomplete Galactic Plane list. Fifty-eight percent were not
previously identified as transiting systems. Candidates are flagged for
possible blending from nearby stars based on Zwicky Transient Facility data and
for possible radial velocity variations based on Gaia satellite data. Orbital
periods and planetary radii are refined using astrophysical modeling; the
resulting parameters closely match published values for Confirmed Planets.
Their properties are discussed in Paper III.Comment: 25 pages, 10 figures, submitted to AAS Journals. Machine Readable
Tables and Figure Sets for Tables 1 and 4 are available at
https://drive.google.com/drive/folders/1DyxNcNlfcHHAoCdsaipxxIbP5A2FPeyi?usp=share_lin
DIAmante TESS AutoRegressive Planet Search (DTARPS): III. Understanding the DTARPS Candidate Transiting Planet Catalogs
The DIAmante TESS AutoRegressive Planet Search (DTARPS) project, using novel
statistical methods, has identified several hundred candidates for transiting
planetary systems obtained from 0.9 million Full Frame Image light curves
obtained in the TESS Year 1 southern hemisphere survey (Melton et al. 2022a and
2022b). Several lines of evidence, including limited reconnaissance
spectroscopy, indicate that at least half are true planets rather than False
Positives. Here various population properties of these objects are examined.
Half of the DTARPS candidates are hot Neptunes, populating the 'Neptune desert'
found in Kepler planet samples. The DTARPS samples also identify dozens of
Ultra Short Period planets with orbital periods down to 5 hours, high priority
systems for atmospheric transimssion spectroscopy, and planets orbiting
low-mass M stars. DTARPS methodology is sufficiently well-characterized at each
step that preliminary planet occurrence rates can be estimated. Except for the
increase in hot Neptunes, DTARPS planet occurrence rates are consistent with
Kepler rates. Overall, DTARPS provides one of the largest and most reliable
catalog of TESS exoplanet candidates that can be tapped to improve our
understanding of various exoplanetary populations and astrophysical processes.Comment: 29 pages, 16 figures, submitted to the AAS Journals February 13, 202
Sustaining Wildlife with Recreation on Public Lands: A Synthesis of Research Findings, Management Practices, and Research Needs
Humans and wildlife interact in multifaceted ways on public lands with both positive and negative outcomes for each group. When managed well, wildlife-based tourism and other forms of recreation can benefit conservation goals. Public lands planners and managers often must decide how to best manage recreational activities and wildlife habitats that overlap spatially and temporally. We conducted an extensive literature review and categorized recreational activity into five types based on the use of motorized equipment, season, and location (terrestrial vs. aquatic), expanding on findings summarized in prior reviews. Our findings provide a reference for public lands planners and managers who need information about how wildlife species respond to recreational activities and to associated changes in their habitats. We also describe management principles gleaned from the literature and outline priority research and administrative study areas to advance our understanding of recreation-wildlife interactions
Audience preferences are predicted by temporal reliability of neural processing
Naturalistic stimuli evoke highly reliable brain activity across viewers. Here we record neural activity from a group of naive individuals while viewing popular, previously-broadcast television content for which the broad audience response is characterized by social media activity and audience ratings. We find that the level of inter-subject correlation in the evoked encephalographic responses predicts the expressions of interest and preference among thousands. Surprisingly, ratings of the larger audience are predicted with greater accuracy than those of the individuals from whom the neural data is obtained. An additional functional magnetic resonance imaging study employing a separate sample of subjects shows that the level of neural reliability evoked by these stimuli covaries with the amount of blood-oxygenation-level-dependent (BOLD) activation in higher-order visual and auditory regions. Our findings suggest that stimuli which we judge favourably may be those to which our brains respond in a stereotypical manner shared by our peers
Catalytic intramolecular hydroamination of aminoallenes using titanium complexes of chiral, tridentate, dianionic imine-diol ligands
Alkylation of D- or L-phenylalanine or valine alkyl esters was carried out using methyl or phenyl Grignard reagents. Subsequent condensation with salicylaldehyde, 3,5-di-tert-butylsalicylaldehyde, or 5-fluorosalicylaldehyde formed tridentate, X_2L type, Schiff base ligands. Chiral shift NMR confirmed retention of stereochemistry during synthesis. X-ray crystal structures of four of the ligands show either inter- or intramolecular hydrogen bonding interactions. The ligands coordinate to the titanium reagents Ti(NMe_2)_4 or TiCl(NMe_2)_3 by protonolysis and displacement of two equivalents of HNMe_2. The crystal structure of one example of Ti(X_2L)Cl(NMe_2) was determined and the complex has a distorted square pyramidal geometry with an axial NMe_2 ligand. The bis-dimethylamide complexes are active catalysts for the ring closing hydroamination of di- and trisubstituted aminoallenes. The reaction of hepta-4,5-dienylamine at 135 °C with 5 mol% catalyst gives a mixture of 6-ethyl-2,3,4,5-tetrahydropyridine (40–72%) and both Z- and E-2-propenyl-pyrrolidine (25–52%). The ring closing reaction of 6-methyl-hepta-4,5-dienylamine at 135 °C with 5 mol% catalyst gives exclusively 2-(2-methyl-propenyl)-pyrrolidine. The pyrrolidine products are obtained with enantiomeric excesses up to 17%
The Effect of Adult Aggression on Habitat Selection by Settlers of Two Coral-Dwelling Damselfishes
Coral-reef fishes experience a major challenge when facing settlement in a multi-threat environment, within which, using settlement cues, they need to select a suitable site. Studies in laboratories and artificial setups have shown that the presence of conspecific adults often serves as a positive settlement cue, whose value is explained by the increased survival of juveniles in an already proven fit environment. However, settlement in already inhabited corals may expose the recruits to adult aggression. Daily observations and manipulation experiments were used in the present study, which was conducted in the natural reef. We revealed differential strategies of settlers, which do not necessarily join conspecific adults. Dascyllus aruanus prefer to settle near (not with) their aggressive adults, and to join them only after gaining in size; whereas Dascyllus marginatus settlers in densely populated reefs settle independently of their adult distribution. Our results present different solutions to the challenges faced by fish recruits while selecting their microhabitat, and emphasize the complexity of habitat selection by the naĂŻve settlers. Although laboratory experiments are important to the understanding of fish habitat selection, further studies in natural habitats are essential in order to elucidate the actual patterns of settlement and habitat selection, which are crucial for the survival of coral-reef fish populations
On the interpretation of removable interactions: A survey of the field 33Â years after Loftus
In a classic 1978 Memory &Cognition article, Geoff Loftus explained why noncrossover interactions are removable. These removable interactions are tied to the scale of measurement for the dependent variable and therefore do not allow unambiguous conclusions about latent psychological processes. In the present article, we present concrete examples of how this insight helps prevent experimental psychologists from drawing incorrect conclusions about the effects of forgetting and aging. In addition, we extend the Loftus classification scheme for interactions to include those on the cusp between removable and nonremovable. Finally, we use various methods (i.e., a study of citation histories, a questionnaire for psychology students and faculty members, an analysis of statistical textbooks, and a review of articles published in the 2008 issue of Psychology andAging) to show that experimental psychologists have remained generally unaware of the concept of removable interactions. We conclude that there is more to interactions in a 2 Ă— 2 design than meets the eye
- …