Densovirus induces winged morphs in asexual clones of the rosy apple aphid, Dysaphis plantaginea

Winged morphs of aphids are essential for their dispersal and survival. We discovered that the production of the winged morph in asexual clones of the rosy apple aphid, Dysaphis plantaginea, is dependent on their infection with a DNA virus, Dysaphis plantaginea densovirus (DplDNV). Virus-free clones of the rosy apple aphid, or clones infected singly with an RNA virus, rosy apple aphid virus (RAAV), did not produce the winged morph in response to crowding and poor plant quality. DplDNV infection results in a significant reduction in aphid reproduction rate, but such aphids can produce the winged morph, even at low insect density, which can fly and colonize neighboring plants. Aphids infected with DplDNV produce a proportion of virus-free aphids, which enables production of virus-free clonal lines after colonization of a new plant. Our data suggest that a mutualistic relationship exists between the rosy apple aphid and its viruses. Despite the negative impact of DplDNV on rosy apple aphid reproduction, this virus contributes to their survival by inducing wing development and promoting dispersal

Deep observations of the Super-CLASS super-cluster at 325 MHz with the GMRT: the low-frequency source catalogue

We present the results of 325 MHz GMRT observations of a super-cluster field, known to contain five Abell clusters at redshift $z \sim 0.2$. We achieve a nominal sensitivity of $34\,\mu$Jy beam$^{-1}$ toward the phase centre. We compile a catalogue of 3257 sources with flux densities in the range $183\,\mu\rm{Jy}\,-\,1.5\,\rm{Jy}$ within the entire $\sim 6.5$ square degree field of view. Subsequently, we use available survey data at other frequencies to derive the spectral index distribution for a sub-sample of these sources, recovering two distinct populations -- a dominant population which exhibit spectral index trends typical of steep-spectrum synchrotron emission, and a smaller population of sources with typically flat or rising spectra. We identify a number of sources with ultra-steep spectra or rising spectra for further analysis, finding two candidate high-redshift radio galaxies and three gigahertz-peaked-spectrum radio sources. Finally, we derive the Euclidean-normalised differential source counts using the catalogue compiled in this work, for sources with flux densities in excess of $223 \, \mu$Jy. Our differential source counts are consistent with both previous observations at this frequency and models of the low-frequency source population. These represent the deepest source counts yet derived at 325 MHz. Our source counts exhibit the well-known flattening at mJy flux densities, consistent with an emerging population of star-forming galaxies; we also find marginal evidence of a downturn at flux densities below $308 \, \mu$Jy, a feature so far only seen at 1.4 GHz.Comment: 25 pages, 18 figures, 10 tables. Accepted for publication in MNRA

Certification of Bounds of Non-linear Functions: the Templates Method

The aim of this work is to certify lower bounds for real-valued multivariate functions, defined by semialgebraic or transcendental expressions. The certificate must be, eventually, formally provable in a proof system such as Coq. The application range for such a tool is widespread; for instance Hales' proof of Kepler's conjecture yields thousands of inequalities. We introduce an approximation algorithm, which combines ideas of the max-plus basis method (in optimal control) and of the linear templates method developed by Manna et al. (in static analysis). This algorithm consists in bounding some of the constituents of the function by suprema of quadratic forms with a well chosen curvature. This leads to semialgebraic optimization problems, solved by sum-of-squares relaxations. Templates limit the blow up of these relaxations at the price of coarsening the approximation. We illustrate the efficiency of our framework with various examples from the literature and discuss the interfacing with Coq.Comment: 16 pages, 3 figures, 2 table

The Taurus Boundary of Stellar/Substellar (TBOSS) Survey II. Disk Masses from ALMA Continuum Observations

We report 885$\mu$m ALMA continuum flux densities for 24 Taurus members spanning the stellar/substellar boundary, with spectral types from M4 to M7.75. Of the 24 systems, 22 are detected at levels ranging from 1.0-55.6 mJy. The two non-detections are transition disks, though other transition disks in the sample are detected. Converting ALMA continuum measurements to masses using standard scaling laws and radiative transfer modeling yields dust mass estimates ranging from $\sim$0.3-20M$_{\oplus}$. The dust mass shows a declining trend with central object mass when combined with results from submillimeter surveys of more massive Taurus members. The substellar disks appear as part of a continuous sequence and not a distinct population. Compared to older Upper Sco members with similar masses across the substellar limit, the Taurus disks are brighter and more massive. Both Taurus and Upper Sco populations are consistent with an approximately linear relationship in $M_{dust}$ to $M_{star}$, although derived power-law slopes depend strongly upon choices of stellar evolutionary model and dust temperature relation. The median disk around early M-stars in Taurus contains a comparable amount of mass in small solids as the average amount of heavy elements in Kepler planetary systems on short-period orbits around M-dwarf stars, with an order of magnitude spread in disk dust mass about the median value. Assuming a gas:dust ratio of 100:1, only a small number of low-mass stars and brown dwarfs have a total disk mass amenable to giant planet formation, consistent with the low frequency of giant planets orbiting M-dwarfs.Comment: 41 pages and 32 figures, with all tables and appendices presented here in their entirety. Accepted for publication in AJ (November 26, 2017

Radio Frequency Spectra of 388 Bright 74 MHz Sources

As a service to the community, we have compiled radio frequency spectra from the literature for all sources within the VLA Low Frequency Sky Survey (VLSS) that are brighter than 15 Jy at 74 MHz. Over 160 references were used to maximize the amount of spectral data used in the compilation of the spectra, while also taking care to determine the corrections needed to put the flux densities from all reference on the same absolute flux density scale. With the new VLSS data, we are able to vastly improve upon previous efforts to compile spectra of bright radio sources to frequencies below 100 MHz because (1) the VLSS flux densities are more reliable than those from some previous low frequency surveys and (2) the VLSS covers a much larger area of the sky (declination >-30 deg.) than many other low frequency surveys (e.g., the 8C survey). In this paper, we discuss how the spectra were constructed and how parameters quantifying the shapes of the spectra were derived. Both the spectra and the shape parameters are made available here to assist in the calibration of observations made with current and future low frequency radio facilities.Comment: Accepted to ApJ

AMI-LA Observations of the SuperCLASS Super-cluster

We present a deep survey of the SuperCLASS super-cluster - a region of sky known to contain five Abell clusters at redshift $z\sim0.2$ - performed using the Arcminute Microkelvin Imager (AMI) Large Array (LA) at 15.5$~$GHz. Our survey covers an area of approximately 0.9 square degrees. We achieve a nominal sensitivity of $32.0~\mu$Jy beam$^{-1}$ toward the field centre, finding 80 sources above a $5\sigma$ threshold. We derive the radio colour-colour distribution for sources common to three surveys that cover the field and identify three sources with strongly curved spectra - a high-frequency-peaked source and two GHz-peaked-spectrum sources. The differential source count (i) agrees well with previous deep radio source count, (ii) exhibits no evidence of an emerging population of star-forming galaxies, down to a limit of 0.24$~$mJy, and (iii) disagrees with some models of the 15$~$GHz source population. However, our source count is in agreement with recent work that provides an analytical correction to the source count from the SKADS Simulated Sky, supporting the suggestion that this discrepancy is caused by an abundance of flat-spectrum galaxy cores as-yet not included in source population models.Comment: 17 pages, 14 figures, 3 tables. Accepted for publication in MNRA

Our planet, our health, our future. Human health and the Rio conventions: biological diversity, climate change and desertification

Health is our most basic human right and one of the most important indicators of sustainable development. We rely on healthy ecosystems to support healthy communities and societies. Wellfunctioning ecosystems provide goods and services essential for human health. These include nutrition and food security, clean air and fresh water, medicines, cultural and spiritual values, and contributions to local livelihoods and economic development. They can also help to limit disease and stabilize the climate. Health policies need to recognize these essential contributions. The three so-called Rio Conventions arising from the 1992 Earth Summit – the Convention on Biological Diversity, the United Nations Framework Convention on Climate Change and the United Nations Convention to Combat Desertification – together aim to maintain well-functioning ecosystems for the benefit of humanity. There is growing evidence of the impacts of global environmental changes on ecosystems and people, and a renewed consciousness among peoples and nations of the need to act quickly to protect the planet’s ecological and climatic systems. In the last two decades, the Rio Conventions have brought global attention to the impacts of anthropogenic change on the ecosystems of the planet. Increasingly unsustainable practices are placing pressure on natural resources to meet the demands of our economies and the needs of a rapidly growing global population, resulting in soil, water and air pollution, increased emissions of greenhouse gases, deforestation and land use change, expanded urban areas, introduction of non-native species, and inadequately planned development of water and land resources to meet food and energy needs. These changes are having both direct and indirect impacts on our climate, ecosystems and biological diversity. More than ever, the pursuit of public health, at all levels from local to global, now depends on careful attention to the processes of global environmental change. Traditional knowledge and scientific evidence both point to the inexorable role of global environmental changes in terms of their impact on human health and well-being. In many countries, anthropogenic changes to agriculture-related ecosystems have resulted in great benefits for human health and well-being, in particular through increased global food production and improved food security. These positive impacts, however, have not benefited everyone, and unsustainable levels of use of ecosystems have resulted in irreparable loss and degradation, with negative consequences for health and well-being. These range from emerging infectious diseases to malnutrition, and contribute to the rapid rise in noncommunicable diseases. Large-scale human transformation of the environment has contributed to increased disease burdens associated with the expansion of ecological and climatic conditions favourable for disease vectors. For all humans, the provision of adequate nutrition, clean water, and long-term food security depend directly on functioning agro-ecosystems and indirectly on the regulating ecosystem services of the biosphere; these ecosystem services can be eroded if overexploited and poorly managed

The effect of a lumbopelvic compression belt on load transfer during the active straight leg test: A proof of concept study using ultrasound imaging

INTRODUCTION: The active straight leg raise (ASLR) test assesses load transfer through the pelvis. During the ASLR, intraabdominal pressure (IAP) rises, increasing the load on the lumbopelvic region. Several studies have shown a correlation between the magnitude of bladder base displacement (BBD) during the ASLR and lumbopelvic instability. Additionally, greater depression of the bladder and pelvic floor muscles is associated with motor control impairments associated with form and force closure. Pelvic stability belts are a common therapeutic intervention for individuals who report pelvic girdle pain. Their mechanism of action is to improve form closure and assist force closure and motor control. Impaired form and force closure mechanisms through the lumbopelvic area are associated poor load transfer, low back pain, sacroiliac pain, stress urinary incontinence and chronic pelvic pain. OBJECTIVES: This study aimed to observe and determine the impact of the ASLR test with and without a Serola lumbopelvic belt on BBD and participant self-reported level of difficulty score. METHODS: A convenience sample of fifteen physical therapy students (mean age 25 years) who were previously identified as having lumbopelvic instability were recruited for this study. PCOM\u27s institutional review board approved the study, and each participant provided informed consent. All participants completed a bladder filling protocol via natural diuresis to standardize bladder volumes to allow for bladder and pelvic floor delineation on ultrasound imaging. A Clarius C3 curvilinear wireless ultrasound unit was used for image acquisition with images displayed on an IPAD. The ultrasound transducer was placed suprapublically on the lower abdomen, oriented transversely, and manipulated until a clear image of the bladder base was apparent. A standard script was read to each participant to standardize testing. The magnitude of BBD was captured with cine loops across two testing conditions: the ASLR test without a lumbopelvic belt which was repeated with the participant wearing a belt. Participants also self-reported the level of difficulty for each testing condition. Participants were fitted with the lumbopelvic belt according to manufacturer’s recommendation. The belt tension was standardized using a manometer set to 20mmHG placed between the belt\u27s anterior aspect and the participant\u27s lower abdomen. On-screen calipers identified the lateral and medial aspects of the bladder base. All images were saved for post hoc analysis to determine the magnitude and direction of BBD between both testing conditions. RESULTS: Descriptive statistics will be reported, and a repeated measures ANOVA will be completed to determine whether there is a statistically significant difference between the means with the level of significance set at p=.05. CONCLUSION: TB