731 research outputs found
Sex allocation theory reveals a hidden cost of neonicotinoid exposure in a parasitoid wasp
P.R.W. was funded by the University of Stirling, C.V.B. and S.M.G. were funded by Nuffield Research Placements and N.C., J.G. and D.M.S. were funded by NERC (NE/J024481/1).Sex allocation theory has proved to be one the most successful theories in evolutionary ecology. However, its role in more applied aspects of ecology has been limited. Here we show how sex allocation theory helps uncover an otherwise hidden cost of neonicotinoid exposure in the parasitoid wasp Nasonia vitripennis. Female N. vitripennis allocate the sex of their offspring in line with Local Mate Competition (LMC) theory. Neonicotinoids are an economically important class of insecticides, but their deployment remains controversial, with evidence linking them to the decline of beneficial species. We demonstrate for the first time to our knowledge, that neonicotinoids disrupt the crucial reproductive behaviour of facultative sex allocation at sub-lethal, field-relevant doses in N. vitripennis. The quantitative predictions we can make from LMC theory show that females exposed to neonicotinoids are less able to allocate sex optimally and that this failure imposes a significant fitness cost. Our work highlights that understanding the ecological consequences of neonicotinoid deployment requires not just measures of mortality or even fecundity reduction among non-target species, but also measures that capture broader fitness costs, in this case offspring sex allocation. Our work also highlights new avenues for exploring how females obtain information when allocating sex under LMC.Publisher PDFPeer reviewe
All-optical reconstruction of atomic ground-state population
The population distribution within the ground-state of an atomic ensemble is
of large significance in a variety of quantum optics processes. We present a
method to reconstruct the detailed population distribution from a set of
absorption measurements with various frequencies and polarizations, by
utilizing the differences between the dipole matrix elements of the probed
transitions. The technique is experimentally implemented on a thermal rubidium
vapor, demonstrating a population-based analysis in two optical pumping
examples. The results are used to verify and calibrate an elaborated numerical
model, and the limitations of the reconstruction scheme which result from the
symmetry properties of the dipole matrix elements are discussed.Comment: 6 pages, 4 figure
The Impact of Pelvic Floor Therapy on Adult Women with Intersticial Cystitis/Painful Bladder Syndrome
Interstitial cystitis/painful bladder syndrome is a major source of chronic pelvic pain and disability affecting women of all ages, predominantly age 18 years and over. Estimates of prevalence among US women range from 2.7% to 6.5% translating to 3.4 and 7.9 million women who have symptoms consistent with this debilitating condition (Kerr, 2009). The bladder epithelium has been the focus for diagnosing and treating symptoms of IC, however taking focus away from the bladder has opened the door for clinicians to explore pelvic floor dysfunction indicating that pelvic floor therapies should be a first line treatment for those women with IC/PBS (Peters & Carrico, 2006). In this evidence based practice change project, the problem of IC/PBS has been identified in a Urology/Gynecology practice in Northeastern Pennsylvania. Based on the clinical problem, a thorough literature review emphasized the solution of pelvic floor therapy as part of usual care to improve symptoms associated with IC/PBS. The evidence based change project was based on the Rosswurm and Larrabee Model. Several meetings were held with the office staff along with a local pelvic floor therapist to discuss details of the EBP change project including the effects this may have on the practice and patient centered care. The project was submitted to Misericordia University’s Internal Review Board and IRB approval was obtained for this project to move forward. Women who were 18 years or older who presented with symptoms of IC/PBS receive a complete history and physical examination, voiding diary, post void residual, full gynecological examination, urinalysis with culture, urine cytology if the patient had a smoking history, and a pain evaluation was performed. These women were invited to participate in the EBP change project. The O’Leary-Sant questionnaire which measures urinary and pain symptoms as well as how problematic these symptoms were to quality of life was performed for a baseline measure. The patient was then educated on usual care in conjunction with pelvic floor therapy. The EBP change project was explained and informed consent was reviewed. If the patient chose to be a part of the project, 8 to 12 sessions of pelvic floor therapy was provided by a trained physical therapist at a local rehabilitation center. The patient then returned to the practice setting at 4 weeks and 8 weeks for follow-up evaluation at which time the O’Leary-Sant questionnaire was readministered. The pre-test and post-test data was compiled to determine if women showed improvement of symptom and problem indices related to IC/PBS. All of the women in the project reported symptom and quality of life improvement
Storing images in warm atomic vapor
Reversible and coherent storage of light in atomic medium is a key-stone of
future quantum information applications. In this work, arbitrary
two-dimensional images are slowed and stored in warm atomic vapor for up to 30
s, utilizing electromagnetically induced transparency. Both the intensity
and the phase patterns of the optical field are maintained. The main limitation
on the storage resolution and duration is found to be the diffusion of atoms. A
techniqueanalogous to phase-shift lithography is employed to diminish the
effect of diffusion on the visibility of the reconstructed image
The definition of sexual selection
The work was supported by Vetenskapsrådet (2020-04992) to C.K.Sexual selection is a key component of evolutionary biology. However, from the very formulation of sexual selection by Darwin, the nature and extent of sexual selection have been controversial. Recently, such controversy has led back to the fundamental question of just what sexual selection is. This has included how we incorporate female-female reproductive competition into sexual or natural selection. In this review, we do four things. First, we examine what we want a definition to do. Second, we define sexual selection: sexual selection is any selection that arises from fitness differences associated with nonrandom success in the competition for access to gametes for fertilization. An important outcome of this is that as mates often also offer access to resources, when those resources are the targets of the competition, rather than their gametes, the process should be considered natural rather than sexual selection. We believe this definition encapsulates both much of Darwin’s original thinking about sexual selection, and much of how contemporary biologists use the concept of sexual selection. Third, we address alternative definitions, focusing in some detail on the role of female reproductive competition. Fourth, we challenge our definition with a number of scenarios, for instance where natural and sexual selection may align (as in some forms of endurance rivalry), or where differential allocation means teasing apart how fecundity and access to gametes influence fitness. In conclusion, we emphasize that whilst the ecological realities of sexual selection are likely to be complex, the definition of sexual selection is rather simple.Publisher PDFPeer reviewe
The definition of sexual selection : a response to comments on Shuker and Kvarnemo
Publisher PDFPeer reviewe
Measurement of Dicke Narrowing in Electromagnetically Induced Transparency
Dicke narrowing is a phenomena that dramatically reduces the Doppler width of
spectral lines, due to frequent velocity-changing collisions. A similar
phenomena occurs for electromagnetically induced transparency (EIT) resonances,
and facilitates ultra-narrow spectral features in room-temperature vapor. We
directly measure the Dicke-like narrowing by studying EIT line-shapes as a
function of the angle between the pump and the probe beams. The measurements
are in good agreement with an analytic theory with no fit parameters. The
results show that Dicke narrowing can increase substantially the tolerance of
hot-vapor EIT to angular deviations. We demonstrate the importance of this
effect for applications such as imaging and spatial solitons using a
single-shot imaging experiment, and discuss the implications on the feasibility
of storing images in atomic vapor.Comment: Introduction revise
- …