5,558 research outputs found
Detecting fish aggregations from reef habitats mapped with high resolution side scan sonar imagery
As part of a multibeam and side scan sonar (SSS) benthic survey of the Marine Conservation District (MCD) south of St. Thomas, USVI and the seasonal closed areas in St. Croix—Lang Bank (LB) for red hind (Epinephelus guttatus) and the Mutton Snapper (MS) (Lutjanus analis) area—we extracted signals from water column targets that represent individual
and aggregated fish over various benthic habitats encountered in the SSS imagery. The survey covered a total of 18 km2 throughout the federal jurisdiction fishery management areas. The complementary set of 28 habitat classification digital maps covered a total of 5,462.3 ha;
MCDW (West) accounted for 45% of that area, and MCDE (East) 26%, LB 17%, and MS the remaining 13%. With the exception
of MS, corals and gorgonians on consolidated habitats were significantly more abundant than submerged aquatic vegetation (SAV) on unconsolidated sediments or unconsolidated sediments. Continuous coral habitat was the most abundant consolidated habitat for both MCDW and MCDE (41% and 43% respectively). Consolidated habitats in LB and MS predominantly consisted of gorgonian plain habitat with 95% and 83% respectively. Coral limestone habitat was more abundant than coral patch habitat; it was found near the shelf break in MS, MCDW, and MCDE. Coral limestone and coral patch habitats only covered LB minimally. The high spatial resolution (0.15 m) of the acquired imagery allowed the detection of differing fish aggregation (FA) types. The
largest FA densities were located at MCDW and MCDE over coral communities that occupy up to 70% of the bottom cover.
Counts of unidentified swimming objects (USOs), likely representing individual fish, were similar among locations and occurred primarily over sand and shelf edge areas. Fish aggregation school sizes were significantly smaller at MS than the other three locations (MCDW, MCDE, and LB). This study shows the advantages of utilizing SSS in determining fish distributions and density
Modulation of the DNA damage response during the life cycle of human papillomaviruses
Human papillomavirus (HPV) is the most common sexually transmitted viral infection. Infection with certain types of HPV pose a major public health risk as these types are associated with multiple human cancers, including cervical cancer, other anogenital malignancies and an increasing number of head and neck cancers. The HPV life cycle is closely tied to host cell differentiation with late viral events such as structural gene expression and viral genome amplification taking place in the upper layers of the stratified epithelium. The DNA damage response (DDR) is an elaborate signaling network of proteins that regulate the fidelity of replication by detecting, signaling and repairing DNA lesions. ATM and ATR are two kinases that are major regulators of DNA damage detection and repair. A multitude of studies indicate that activation of the ATM (Ataxia telangiectasia mutated) and ATR (Ataxia telangiectasia and Rad3-related) pathways are critical for HPV to productively replicate. This review outlines how HPV interfaces with the ATM- and ATR-dependent DNA damage responses throughout the viral life cycle to create an environment supportive of viral replication and how activation of these pathways could impact genomic stability
Icosahedral multi-component model sets
A quasiperiodic packing Q of interpenetrating copies of C, most of them only
partially occupied, can be defined in terms of the strip projection method for
any icosahedral cluster C. We show that in the case when the coordinates of the
vectors of C belong to the quadratic field Q[\sqrt{5}] the dimension of the
superspace can be reduced, namely, Q can be re-defined as a multi-component
model set by using a 6-dimensional superspace.Comment: 7 pages, LaTeX2e in IOP styl
Expression of PEG11 and PEG11AS transcripts in normal and callipyge sheep
BACKGROUND: The callipyge mutation is located within an imprinted gene cluster on ovine chromosome 18. The callipyge trait exhibits polar overdominant inheritance due to the fact that only heterozygotes inheriting a mutant paternal allele (paternal heterozygotes) have a phenotype of muscle hypertrophy, reduced fat and a more compact skeleton. The mutation is a single A to G transition in an intergenic region that results in the increased expression of several genes within the imprinted cluster without changing their parent-of-origin allele-specific expression. RESULTS: There was a significant effect of genotype (p < 0.0001) on the transcript abundance of DLK1, PEG11, and MEG8 in the muscles of lambs with the callipyge allele. DLK1 and PEG11 transcript levels were elevated in the hypertrophied muscles of paternal heterozygous animals relative to animals of the other three genotypes. The PEG11 locus produces a single 6.5 kb transcript and two smaller antisense strand transcripts, referred to as PEG11AS, in skeletal muscle. PEG11AS transcripts were detectable over a 5.5 kb region beginning 1.2 kb upstream of the PEG11 start codon and spanning the entire open reading frame. Analysis of PEG11 expression by quantitative PCR shows a 200-fold induction in the hypertrophied muscles of paternal heterozygous animals and a 13-fold induction in homozygous callipyge animals. PEG11 transcripts were 14-fold more abundant than PEG11AS transcripts in the gluteus medius of paternal heterozygous animals. PEG11AS transcripts were expressed at higher levels than PEG11 transcripts in the gluteus medius of animals of the other three genotypes. CONCLUSIONS: The effect of the callipyge mutation has been to alter the expression of DLK1, GTL2, PEG11 and MEG8 in the hypertrophied skeletal muscles. Transcript abundance of DLK1 and PEG11 was highest in paternal heterozygous animals and exhibited polar overdominant gene expression patterns; therefore, both genes are candidates for causing skeletal muscle hypertrophy. There was unique relationship of PEG11 and PEG11AS transcript abundance in the paternal heterozygous animals that suggests a RNA interference mechanism may have a role in PEG11 gene regulation and polar overdominance in callipyge sheep
Perfection of materials technology for producing improved Gunn-effect devices
Chemical vapor deposition system for improved Gunn effect devices using arsenic chloride 3 metho
How model sets can be determined by their two-point and three-point correlations
We show that real model sets with real internal spaces are determined, up to
translation and changes of density zero by their two- and three-point
correlations. We also show that there exist pairs of real (even one
dimensional) aperiodic model sets with internal spaces that are products of
real spaces and finite cyclic groups whose two- and three-point correlations
are identical but which are not related by either translation or inversion of
their windows. All these examples are pure point diffractive.
Placed in the context of ergodic uniformly discrete point processes, the
result is that real point processes of model sets based on real internal
windows are determined by their second and third moments.Comment: 19 page
Escape tactics used by bluegills and fathead minnows to avoid predation by tiger muskellunge
To explain why esocids prefer cylindrical, soft-rayed prey over compressed, spiny-rayed prey, we quantified behavioral interaction between tiger muskellunge (F1 hybrid of male northern pike Esox lucius and female muskellunge E. masquinongy) and fathead minnows (Pimephales promelas) and bluegills (Lepomis macrochirus). Tiger muskellunge required four times as many strikes and longer pursuits to capture bluegills than fathead minnows. Tiger muskellunge attacked each prey species differently; fathead minnows were grasped at midbody and bluegills were attacked in the caudal area. Each prey species exhibited different escape tactics. Fathead minnows remained in open water and consistently schooled; bluegills dispersed throughout the tank and sought cover by moving to corners and edges. Due to their antipredatory behavior (dispersing, cover seeking, and remaining motionless) and morphology (deep body and spines), bluegills were less susceptible to capture by tiger muskellunge than were fathead minnows.Funding for this project was provided by the Federal Aid in Fish Restoration Act under Dingell-Johnson Project F-57-R
Reduction of laser intensity scintillations in turbulent atmospheres using time averaging of a partially coherent beam
We demonstrate experimentally and numerically that the application of a
partially coherent beam (PCB) in combination with time averaging leads to a
significant reduction in the scintillation index. We use a simplified
experimental approach in which the atmospheric turbulence is simulated by a
phase diffuser. The role of the speckle size, the amplitude of the phase
modulation, and the strength of the atmospheric turbulence are examined. We
obtain good agreement between our numerical simulations and our experimental
results. This study provides a useful foundation for future applications of
PCB-based methods of scintillation reduction in physical atmospheres.Comment: 18 pages, 14 figure
Mentoring Youth: A Service-Learning Course Within a College of Nursing
Faculty at the University of Southern Maine College of Nursing and Health Care Professions developed a service-learning course that connected students and faculty with at-risk children in a local community. Nursing students, with faculty supervision and support, developed, implemented, and evaluated interventions to reduce risk factors and increase protective factors to build and strengthen the participants\u27 resiliency.
Students enrolled in the service-learning course worked in the community where they gained an understanding of what it was like for children and adolescents to live in an impoverished community setting with disorganized family units and weak community support. The students learned to collaborate with police, schools, public health nurses, and churches, as well as students in other major programs. The benefits of this course for students and the community were far reaching and even life changing
Random fields on model sets with localized dependency and their diffraction
For a random field on a general discrete set, we introduce a condition that
the range of the correlation from each site is within a predefined compact set
D. For such a random field omega defined on the model set Lambda that satisfies
a natural geometric condition, we develop a method to calculate the diffraction
measure of the random field. The method partitions the random field into a
finite number of random fields, each being independent and admitting the law of
large numbers. The diffraction measure of omega consists almost surely of a
pure-point component and an absolutely continuous component. The former is the
diffraction measure of the expectation E[omega], while the inverse Fourier
transform of the absolutely continuous component of omega turns out to be a
weighted Dirac comb which satisfies a simple formula. Moreover, the pure-point
component will be understood quantitatively in a simple exact formula if the
weights are continuous over the internal space of Lambda Then we provide a
sufficient condition that the diffraction measure of a random field on a model
set is still pure-point.Comment: 21 page
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