2,423 research outputs found
Integrating Factors that Predict Energy Conservation: The Theory of Planned Behavior and Beliefs about Climate Change
A survey of college students was used to examine predictors of four types of energy conservation behavior. Our proposed predictors were derived from Ajzen’s Theory of Planned Behavior (TPB) and from problem awareness variables (environmental concern, and knowledge and beliefs about global warming) thought to have indirect effects on conservation via TPB constructs. TPB constructs were significant direct predictors of target behaviors. Perceived behavioral control (PBC) was the strongest and most consistent predictor, predicting all four behaviors, followed by perceived worth (attitude), predicting three behaviors. TPB variables mediated the effects of either environmental concern or beliefs about the consequences of global warming on three behaviors. Finally, there were also significant mediating relationships among TPB variables themselves. Subjective norm predicted perceived worth and PBC, and perceived worth predicted PBC for all but one behavior. Theoretical implications and implications for intervention are discussed. To our knowledge this is the first study to separately demonstrate, in one sample, the predictive value of TPB with respect to different types of energy conservation, and to integrate TPB variables with climate-change beliefs
Peregrine Falcon Survey, West Greenland, 1972
... The main purpose of the 1972 survey was to study a sample area of West Greenland to supply baseline data about peregrine falcons from which future surveys could determine the status and trends of this bird in Greenland. The main part of the study had as its goals: 1) to determine the density, distribution, and reproductive success of nesting peregrines in a sample area; 2) to band all peregrine nestlings found; 3) to determine prey species of the peregrine; 4) to make interspecific observations of peregrines and gyrfalcons; 5) to make detailed observations from a blind of a sample peregrine falcon eyrie; 6) to conduct a small-bird census in the area of the sample eyrie; 7) to make a photographic record in colour slides and movies of the investigations. ... Eight peregrine falcon eyries and 3 gyrfalcon eyries were found in the survey area. In all, 18 nestlings were found in the 8 peregrine eyries. Of the 8 eyries, 1 had no young, but showed signs of occupancy ... and was defended by an aggressive pair of falcons. Of the other 7 eyries where we found hatched young, 1 had 4 young, 4 had 3 young, and 2 had 1 young bird each. Of the total of 18 nestling peregrines, 13 were banded and 5 were fully-fledged, on the wing, and unable to be caught for banding. Of the peregrine nestlings banded, 9 were males and 4 were females. The number of nestlings (18) in the 8 peregrine eyries gave a production rate of 2.25 per eyrie, or 2.57 if an average is taken of the 7 eyries actually producing young. At 1 eyrie a young falcon was found dead (the eyrie with 4 young). We know that at least 8 of the remaining 17 young fledged successfully, but we are uncertain about the success of the others and cannot therefore make a definite statement on fledging ratio. We estimate, however, that the fledging rate of the peregrines in our survey area was at least 2.00 per producing eyrie. The maximum dimensions of our irregularly-shaped survey area were 39 x 34 miles (63 x 55 km). The estimated area of the survey was about 800 sq. mi. (2,072 sq. km), or about 700 sq. mi. (1,800 sq. km) when the surface area of fiords and lakes is excluded. The nesting density of the active, young-producing peregrine eyries (7) was about 1 pair per 100 sq. mi. (260 sq. km). ... At the 3 gyrfalcon (Falco rusticolus) eyries we found 8 nestlings or fully-fledged young, of which we were able to band 3. Peregrines and gyrfalcons (and a rare white-tailed sea eagle, Haliaetus albicilla) are the only avian predators nesting in southern West Greenland, although ravens (Corvus corax) competed for some nesting cliff sites. We collected remains of prey species and pellets at each falcon eyrie. Addled eggs (2) from 2 peregrine eyries were collected for pesticide analysis. Eggshell fragments for thickness determination were gathered at 5 peregrine eyries. ... Peregrine falcons in West Greenland appear to be in a healthy state as evidenced by a high nesting density (1/100 sq. mi.) and a high production rate (2.25/eyrie), especially in light of the unusually severe conditions in West Greenland during the winter and late spring of 1971-72. We found little interspecific competition for prey species between peregrines and gyrfalcons. The gyrfalcon is already nesting in West Greenland before the peregrines arrive from their winter migration to the south. The gyrfalcons could therefore be expected to be aggressive in defence of their nesting cliffs and thereby occupy optimal cliffs. Despite this, all the peregrines we studied occupied high, sheer, and quite optimal nesting cliffs. Gyrfalcons seemed to prefer a nesting site lower down on a cliff face than peregrines, and both falcons preferred high, sheer cliffs with a southern exposure. Ravens were relegated to lower, less desirable (more accessible) cliffs for nesting. We await pesticide analysis of the peregrine falcon eggs and prey species collected, as well as eggshell thickness determination. Before these facts are determined we can say nothing definite about the status of peregrines in Greenland. Nesting density and production, however, suggest that the status of the peregrine is better in Greenland than in other areas of the north. ..
The first Frontier Fields cluster: 4.5{\mu}m excess in a z~8 galaxy candidate in Abell 2744
We present in this letter the first analysis of a z~8 galaxy candidate found
in the Hubble and Spitzer imaging data of Abell 2744, as part of the Hubble
Frontier Fields legacy program. We applied the most commonly-used methods to
select exceptionally high-z galaxies by combining non-detection and
color-criteria using seven HST bands. We used GALFIT on IRAC images for fitting
and subtracting contamination of bright nearby sources. The physical properties
have been inferred from SED-fitting using templates with and without nebular
emission. This letter is focussed on the brightest candidate we found
(m=26.2) over the 4.9 arcmin field of view covered by the WFC3.
It shows a non-detection in the ACS bands and at 3.6{\mu}m whereas it is
clearly detected at 4.5{\mu}m with rather similar depths. This break in the
IRAC data could be explained by strong [OIII]+H{\beta} lines at z~8 which
contribute to the 4.5{\mu}m photometry. The best photo-z is found at
z~8.0, although solutions at low-redshift (z~1.9) cannot be
completely excluded, but they are strongly disfavoured by the SED-fitting work.
The amplification factor is relatively small at {\mu}=1.490.02. The Star
Formation Rate in this object is ranging from 8 to 60 Mo/yr, the stellar mass
is in the order of M=(2.5-10) x 10Mo and the size is
r~0.350.15 kpc. This object is one of the first z~8 LBG candidates showing
a clear break between 3.6{\mu}m and 4.5{\mu}m which is consistent with the IRAC
properties of the first spectroscopically confirmed galaxy at a similar
redshift. Due to its brightness, the redshift of this object could potentially
be confirmed by near infrared spectroscopy with current 8-10m telescopes. The
nature of this candidate will be revealed in the coming months with the arrival
of new ACS and Spitzer data, increasing the depth at optical and near-IR
wavelengths.Comment: 4 pages, 2 figures, Accepted for publication in Astronomy and
Astrophysics Letter
Probing Bottom-up Processing with Multistable Images
The selection of fixation targets involves a combination of top-down and bottom-up processing. The role of bottom-up processing can be enhanced by using multistable stimuli because their constantly changing appearance seems to depend predominantly on stimulusdriven factors. We used this approach to investigate whether visual processing models based on V1 need to be extended to incorporate specific computations attributed to V4. Eye movements of 8 subjects were recorded during free viewing of the Marroquin pattern in which illusory circles appear and disappear. Fixations were concentrated on features arranged in concentric rings within the pattern. Comparison with simulated fixation data demonstrated that the saliency of these features can be predicted with appropriate weighting of lateral connections in existing V1 models
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RPS19 and TYMS SNPs and Prevalent High Risk Human Papilloma Virus Infection in Nigerian Women
High risk HPV (hrHPV) infection is a necessary cause of cervical cancer but the host genetic determinants of infection are poorly understood. We enrolled 267 women who presented to our cervical cancer screening program in Abuja, Nigeria between April 2012 and August 2012. We collected information on demographic characteristics, risk factors of cervical cancer and obtained samples of blood and cervical exfoliated cells from all participants. We used Roche Linear Array HPV Genotyping Test® to characterize the prevalent HPV according to manufacturer's instruction; Sequenom Mass Array to test 21 SNPs in genes/regions previously associated with hrHPV and regression models to examine independent factors associated with HPV infection. We considered a p<0.05 as significant because this is a replication study. There were 65 women with and 202 women without hrHPV infection. Under the allelic model, we found significant association between two SNPs, rs2305809 on RPS19 and rs2342700 on TYMS, and prevalent hrHPV infection. Multivariate analysis of hrHPV risk adjusted for age, body mass index, smoking, age of menarche, age at sexual debut, lifetime total number of sexual partners and the total number of pregnancies as covariates, yielded a p-value of 0.071 and 0.010 for rs2305809 and rs2342700, respectively. Our findings in this unique population suggest that a number of genetic risk variants for hrHPV are shared with other population groups. Definitive studies with larger sample sizes and using genome wide approaches are needed to understand the genetic architecture of hrHPV risk in multiple populations
Regional Differences Between Perisynovial and Infrapatellar Adipose Tissue Depots and Their Response to Class II and III Obesity in Patients with OA
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Age-specific prevalence of human papilloma virus infection among Nigerian women
Background: Inconsistent trends in HPV prevalence by age have been described in Africa. We examined the age prevalence pattern and distribution of 37 HPV-DNA types among urban Nigerian women. Methods: The study population was a sample of 278 women who presented to cervical cancer screening programs in Abuja, Nigeria, between April and August 2012. Using a nurse administered questionnaire, information on demographic characteristics and risk factors of cervical cancer was collected and samples of cervical exfoliated cells were obtained from all participants. Roche Linear Array HPV Genotyping Test® was used to characterize prevalent HPV and log-binomial regression models were used to examine the association between potential correlates and the prevalence of HPV infection. Results: The mean age (SD) of the women enrolled was 38 (8) years. The overall prevalence of HPV was 37%. HPV 35 was the most prevalent HPV type in the study population. Among women age ≤ 30 years, 52% had HPV infection compared to 23% of those women who were older than 45 years (p = 0.006). We observed a significant linear association between age and the prevalence of HPV infections. The prevalence ratio (PR) and 95% confidence interval (CI) was 2.26 (1.17, 4.34) for any HPV infection, 3.83 (1.23, 11.94) for Group 1 HPV (definite carcinogens), and 2.19 (0.99, 4.84) for Group 2a or 2b HPV (probable or possible carcinogens) types, among women aged 18–30 years, compared to women who were older than 45 years. Conclusion: The prevalence of HPV infection was highest among younger women and decreased steadily with age among this population of urban Nigerian women
PINK1 Is Selectively Stabilized on Impaired Mitochondria to Activate Parkin
Mutations in PINK1 or Parkin lead to familial parkinsonism. The authors suggest that PINK1 and Parkin form a pathway that senses damaged mitochondria and selectively targets them for degradation
Binding Mechanism of Metal⋅NTP Substrates and Stringent-Response Alarmones to Bacterial DnaG-Type Primases
SummaryPrimases are DNA-dependent RNA polymerases found in all cellular organisms. In bacteria, primer synthesis is carried out by DnaG, an essential enzyme that serves as a key component of DNA replication initiation, progression, and restart. How DnaG associates with nucleotide substrates and how certain naturally prevalent nucleotide analogs impair DnaG function are unknown. We have examined one of the earliest stages in primer synthesis and its control by solving crystal structures of the S. aureus DnaG catalytic core bound to metal ion cofactors and either individual nucleoside triphosphates or the nucleotidyl alarmones, pppGpp and ppGpp. These structures, together with both biochemical analyses and comparative studies of enzymes that use the same catalytic fold as DnaG, pinpoint the predominant nucleotide-binding site of DnaG and explain how the induction of the stringent response in bacteria interferes with primer synthesis
Recurrence of cervical intraepithelial lesions after thermo-coagulation in HIV-positive and HIV-negative Nigerian women
Background: The burden of cervical cancer remains huge globally, more so in sub-Saharan Africa. Effectiveness of screening, rates of recurrence following treatment and factors driving these in Africans have not been sufficiently studied. The purpose of this study therefore was to investigate factors associated with recurrence of cervical intraepithelial lesions following thermo-coagulation in HIV-positive and HIV-negative Nigerian women using Visual Inspection with Acetic Acid (VIA) or Lugol’s Iodine (VILI) for diagnosis.
Methods: A retrospective cohort study was conducted, recruiting participants from the cervical cancer “see and treat” program of IHVN. Data from 6 sites collected over a 4-year period was used. Inclusion criteria were: age ≥18 years, baseline HIV status known, VIA or VILI positive and thermo-coagulation done. Logistic regression was performed to examine the proportion of women with recurrence and to examine factors associated with recurrence.
Results: Out of 177 women included in study, 67.8 % (120/177) were HIV-positive and 32.2 % (57/177) were HIV-negative. Recurrence occurred in 16.4 % (29/177) of participants; this was 18.3 % (22/120) in HIV-positive women compared to 12.3 % (7/57) in HIV-negative women but this difference was not statistically significant (p-value 0.31). Women aged ≥30 years were much less likely to develop recurrence, adjusted OR = 0.34 (95 % CI = 0.13, 0.92). Among HIV-positive women, CD4 count <200cells/mm3 was associated with recurrence, adjusted OR = 5.47 (95 % CI = 1.24, 24.18).
Conclusion: Recurrence of VIA or VILI positive lesions after thermo-coagulation occurs in a significant proportion of women. HIV-positive women with low CD4 counts are at increased risk of recurrent lesions and may be related to immunosuppression
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