45 research outputs found
Home Range, Movements, And Habitat Use Of Blanding\u27s Turtle (Emydoidea blandingil) in St. Lawrence County, New York.
I studied the movements, activity centers, and horne ranges of Blanding\u27 s turtles (Emydoidea blandingii) at three sites in St. Lawrence County, New York where it is currently listed as State Threatened. I monitored 24 adult Blanding\u27 s turtles (seven males and 1 7 females) using radiotelemetry from May 2003- August 2004 to provide information on spatial requirements and movements in previously undocumented populations at the easternmost limit of this species\u27 contiguous range, Movement and home range analyses were performed on 1 6 telemetered adult Blanding\u27s turtles (4 males and 1 2 females) with a minimum of 20 locations and assignment of a radio transmitter from at least 1 0 June through 1 5 October in either 2003 or 2004, which covered the majority of the active season. There was no significant difference between male and female home range sizes within and between the study sites, which differed in available wetland area. Additionally, there was no significant difference among the home range sizes of females at each study site. Based on the Minimum Convex Polygon (MCP) home range estimate, the mean home range area for all telemetered females was 1 2.26 (1 . 1 3- 44. 1 4) ha and 7.54 (± 2.63) ha for telemetered males (n = 4). Home range size differed significantly between female and males. The number of activity centers differed among the females (n = 1 2) ranging from one to five. Males (n = 4) had a greater number of activity centers than females, ranging from two to four. In this study, daily movements of males (x = 46.03 ±5 . 1 2 m) were significantly longer and more frequent than females (x = 20.77 ±7. 1 8 m). Four of females that were radio-tagged in 2003 and followed through 2004 showed nest site fidelity across both years. These females traveled up to 1 3 65 m round-trip to nesting areas and back to their home wetlands in consecutive years. A management and conservation concern identified in this study that could have a negative impact on the Blanding\u27s turtle populations in northern New York is the location of nesting areas. Telemetry data revealed that gravid females utilize areas up to 1.5 km away from resident wetlands for nesting. My study suggests that areas in the vicinity of occupied wetlands that are suitable for nesting are very important to the longevity of these populations. Further studies on the distribution, population dynamics, habitat use and requirements, and nesting ecology of Blanding\u27s turtle populations in northern New York should be conducted to assist with the conservation of this species in the eastern periphery of its contiguous Great Lakes range
The PTF Orion Project: a Possible Planet Transiting a T-Tauri Star
We report observations of a possible young transiting planet orbiting a
previously known weak-lined T-Tauri star in the 7-10 Myr old Orion-OB1a/25-Ori
region. The candidate was found as part of the Palomar Transient Factory (PTF)
Orion project. It has a photometric transit period of 0.448413 +- 0.000040
days, and appears in both 2009 and 2010 PTF data. Follow-up low-precision
radial velocity (RV) observations and adaptive optics imaging suggest that the
star is not an eclipsing binary, and that it is unlikely that a background
source is blended with the target and mimicking the observed transit. RV
observations with the Hobby-Eberly and Keck telescopes yield an RV that has the
same period as the photometric event, but is offset in phase from the transit
center by approximately -0.22 periods. The amplitude (half range) of the RV
variations is 2.4 km/s and is comparable with the expected RV amplitude that
stellar spots could induce. The RV curve is likely dominated by stellar spot
modulation and provides an upper limit to the projected companion mass of M_p
sin i_orb < 4.8 +- 1.2 M_Jup; when combined with the orbital inclination, i
orb, of the candidate planet from modeling of the transit light curve, we find
an upper limit on the mass of the planetary candidate of M_p < 5.5 +- 1.4
M_Jup. This limit implies that the planet is orbiting close to, if not inside,
its Roche limiting orbital radius, so that it may be undergoing active mass
loss and evaporation.Comment: Corrected typos, minor clarifications; minor updates/corrections to
affiliations and bibliography. 35 pages, 10 figures, 3 tables. Accepted to
Ap
Smoking-associated risks of conventional adenomas and serrated polyps in the colorectum
PurposePrior studies suggest cigarette smoking is associated with 1.5- to twofold increased risk of colorectal adenomas and possibly a higher risk of serrated polyps. Further clarification of risk differences between adenomas and serrated polyps is needed with regard to co-occurrence and polyp location.Methods We conducted a combined analysis of conventional adenoma and serrated polyp occurrence using individual-level data from 2,915 patients participating in three colonoscopy-based clinical trials. All participants had ≥1 adenomas removed at baseline and were followed for up to 4years. Smoking habits and other lifestyle factors were collected at baseline using questionnaires. We used generalized linear regression to estimate risk ratios and 95% confidence intervals.ResultsSmokers were at slightly increased risk of adenomas compared to never smokers [current: RR 1.29 (95% CI 1.11–1.49) and former: RR 1.18 (1.05–1.32)]. Smoking was associated with greater risk of serrated polyps [current: RR 2.01 (1.66–2.44); former: RR 1.42 (1.20–1.68)], particularly in the left colorectum. Associations between current smoking and occurrence of serrated polyps only [RR 2.33 (1.76–3.07)] and both adenomas and serrated polyps [RR 2.27 (1.68–3.06)] were more pronounced than for adenomas only [RR 1.31 (1.08–1.58)]. Results were similar for other smoking variables and did not differ by gender or for advanced adenomas.ConclusionsCigarette smoking has only a weak association with adenomas, but is associated with a significantly increased risk of serrated polyps, particularly in the left colorectum. Since a minority of left-sided serrated polyps is thought to have malignant potential, the role of smoking in initiation phases of carcinogenesis is uncertain
Smoking-associated risks of conventional adenomas and serrated polyps in the colorectum
PurposePrior studies suggest cigarette smoking is associated with 1.5- to twofold increased risk of colorectal adenomas and possibly a higher risk of serrated polyps. Further clarification of risk differences between adenomas and serrated polyps is needed with regard to co-occurrence and polyp location.Methods We conducted a combined analysis of conventional adenoma and serrated polyp occurrence using individual-level data from 2,915 patients participating in three colonoscopy-based clinical trials. All participants had ≥1 adenomas removed at baseline and were followed for up to 4years. Smoking habits and other lifestyle factors were collected at baseline using questionnaires. We used generalized linear regression to estimate risk ratios and 95% confidence intervals.ResultsSmokers were at slightly increased risk of adenomas compared to never smokers [current: RR 1.29 (95% CI 1.11–1.49) and former: RR 1.18 (1.05–1.32)]. Smoking was associated with greater risk of serrated polyps [current: RR 2.01 (1.66–2.44); former: RR 1.42 (1.20–1.68)], particularly in the left colorectum. Associations between current smoking and occurrence of serrated polyps only [RR 2.33 (1.76–3.07)] and both adenomas and serrated polyps [RR 2.27 (1.68–3.06)] were more pronounced than for adenomas only [RR 1.31 (1.08–1.58)]. Results were similar for other smoking variables and did not differ by gender or for advanced adenomas.ConclusionsCigarette smoking has only a weak association with adenomas, but is associated with a significantly increased risk of serrated polyps, particularly in the left colorectum. Since a minority of left-sided serrated polyps is thought to have malignant potential, the role of smoking in initiation phases of carcinogenesis is uncertain
Social Patterning of Screening Uptake and the Impact of Facilitating Informed Choices: Psychological and Ethical Analyses
Screening for unsuspected disease has both possible benefits and harms for those who participate. Historically the benefits of participation have been emphasized to maximize uptake reflecting a public health approach to policy; currently policy is moving towards an informed choice approach involving giving information about both benefits and harms of participation. However, no research has been conducted to evaluate the impact on health of an informed choice policy. Using psychological models, the first aim of this study was to describe an explanatory framework for variation in screening uptake and to apply this framework to assess the impact of informed choices in screening. The second aim was to evaluate ethically that impact. Data from a general population survey (n = 300) of beliefs and attitudes towards participation in diabetes screening indicated that greater orientation to the present is associated with greater social deprivation and lower expectation of participation in screening. The results inform an explanatory framework of social patterning of screening in which greater orientation to the present focuses attention on the disadvantages of screening, which tend to be immediate, thereby reducing participation. This framework suggests that an informed choice policy, by increasing the salience of possible harms of screening, might reduce uptake of screening more in those who are more deprived and orientated to the present. This possibility gives rise to an apparent dilemma where an ethical decision must be made between greater choice and avoiding health inequality. Philosophical perspectives on choice and inequality are used to point to some of the complexities in assessing whether there really is such a dilemma and if so how it should be resolved. The paper concludes with a discussion of the ethics of paternalism
A high-precision near-infrared survey for radial velocity variable low-mass stars using CSHELL and a methane gas cell
We present the results of a precise near-infrared (NIR) radial velocity (RV) survey of 32 low-mass stars with spectral types K2-M4 using CSHELL at the NASA InfraRed Telescope Facility in the K band with an isotopologue methane gas cell to achieve wavelength calibration and a novel, iterative RV extraction method. We surveyed 14 members of young (≈25-150 Myr) moving groups, the young field star ϵ Eridani, and 18 nearby (<25 pc) low-mass stars and achieved typical single-measurement precisions of 8-15 m s-1with a long-term stability of 15-50 m s-1 over longer baselines. We obtain the best NIR RV constraints to date on 27 targets in our sample, 19 of which were never followed by high-precision RV surveys. Our results indicate that very active stars can display long-term RV variations as low as ∼25-50 m s-1 at ≈2.3125 μm, thus constraining the effect of jitter at these wavelengths. We provide the first multiwavelength confirmation of GJ 876 bc and independently retrieve orbital parameters consistent with previous studies. We recovered RV variabilities for HD 160934 AB and GJ 725 AB that are consistent with their known binary orbits, and nine other targets are candidate RV variables with a statistical significance of 3σ-5σ. Our method, combined with the new iSHELL spectrograph, will yield long-term RV precisions of ≲5 m s-1 in the NIR, which will allow the detection of super-Earths near the habitable zone of mid-M dwarfs
Seasonal pulses of Marburg virus circulation in juvenile Rousettus aegyptiacus bats coincide with periods of increased risk of human infection
Marburg virus (family Filoviridae) causes sporadic outbreaks of severe hemorrhagic disease in sub-Saharan Africa. Bats have been implicated as likely natural reservoir hosts based most recently on an investigation of cases among miners infected in 2007 at the Kitaka mine, Uganda, which contained a large population of Marburg virus-infected Rousettus aegyptiacus fruit bats. Described here is an ecologic investigation of Python Cave, Uganda, where an American and a Dutch tourist acquired Marburg virus infection in December 2007 and July 2008. More than 40,000 R. aegyptiacus were found in the cave and were the sole bat species present. Between August 2008 and November 2009, 1,622 bats were captured and tested for Marburg virus. Q-RT-PCR analysis of bat liver/spleen tissues indicated ,2.5% of the bats were actively infected, seven of which yielded Marburg virus isolates. Moreover, Q-RT-PCR-positive lung, kidney, colon and reproductive tissues were found, consistent with potential for oral, urine, fecal or sexual transmission. The combined data for R. aegyptiacus tested from Python Cave and Kitaka mine indicate low level horizontal transmission throughout the year. However, Q-RT-PCR data show distinct pulses of virus infection in older juvenile bats (,six months of age) that temporarily coincide with the peak twiceyearly birthing seasons. Retrospective analysis of historical human infections suspected to have been the result of discrete spillover events directly from nature found 83% (54/65) events occurred during these seasonal pulses in virus circulation, perhaps demonstrating periods of increased risk of human infection. The discovery of two tags at Python Cave from bats marked at Kitaka mine, together with the close genetic linkages evident between viruses detected in geographically distant locations, are consistent with R. aegyptiacus bats existing as a large meta-population with associated virus circulation over broad geographic ranges. These findings provide a basis for developing Marburg hemorrhagic fever risk reduction strategies.The Department of Health and Human Serviceshttp://www.plospathogens.or