Geometric reconstruction methods for electron tomography

Electron tomography is becoming an increasingly important tool in materials science for studying the three-dimensional morphologies and chemical compositions of nanostructures. The image quality obtained by many current algorithms is seriously affected by the problems of missing wedge artefacts and nonlinear projection intensities due to diffraction effects. The former refers to the fact that data cannot be acquired over the full $180^\circ$ tilt range; the latter implies that for some orientations, crystalline structures can show strong contrast changes. To overcome these problems we introduce and discuss several algorithms from the mathematical fields of geometric and discrete tomography. The algorithms incorporate geometric prior knowledge (mainly convexity and homogeneity), which also in principle considerably reduces the number of tilt angles required. Results are discussed for the reconstruction of an InAs nanowire

J- and Ks-band Galaxy Counts and Color Distributions in the AKARI North Ecliptic Pole Field

We present the J- and Ks-band galaxy counts and galaxy colors covering 750 square arcminutes in the deep AKARI North Ecliptic Pole (NEP) field, using the FLoridA Multi-object Imaging Near-ir Grism Observational Spectrometer (FLAMINGOS) on the Kitt Peak National Observatory (KPNO) 2.1m telescope. The limiting magnitudes with a signal-to-noise ratio of three in the deepest regions are 21.85 and 20.15 in the J- and Ks-bands respectively in the Vega magnitude system. The J- and Ks-band galaxy counts in the AKARI NEP field are broadly in good agreement with those of other results in the literature, however we find some indication of a change in the galaxy number count slope at J~19.5 and over the magnitude range 18.0 < Ks < 19.5. We interpret this feature as a change in the dominant population at these magnitudes because we also find an associated change in the B - Ks color distribution at these magnitudes where the number of blue samples in the magnitude range 18.5 < Ks < 19.5 is significantly larger than that of Ks < 17.5

Maximizing the potential of multi-parental crop populations.

Most agriculturally significant crop traits are quantitatively inherited which limits the ease and efficiency of trait dissection. Multi-parent populations overcome the limitations of traditional trait mapping and offer new potential to accurately define the genetic basis of complex crop traits. The increasing popularity and use of nested association mapping (NAM) and multi-parent advanced generation intercross (MAGIC) populations raises questions about the optimal design and allocation of resources in their creation. In this paper we review strategies for the creation of multi-parent populations and describe two complementary in silico studies addressing the design and construction of NAM and MAGIC populations. The first simulates the selection of diverse founder parents and the second the influence of multi-parent crossing schemes (and number of founders) on haplotype creation and diversity. We present and apply two open software resources to simulate alternate strategies for the development of multi-parent populations

B4: Bedrock Geology of Mt. Washington, Presidential Range, NH

Guidebook for field trips in Western Maine and Northern New Hampshire: New England Intercollegiate Geological Conference, p. 177-196

A well-conserved Plasmodium falciparum var gene shows an unusual stage-specific transcript pattern

The var multicopy gene family encodes Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) variant antigens, which, through their ability to adhere to a variety of host receptors, are thought to be important virulence factors. The predominant expression of a single cytoadherent PfEMP1 type on an infected red blood cell, and the switching between different PfEMP1 types to evade host protective antibody responses, are processes thought to be controlled at the transcriptional level. Contradictory data have been published on the timing of var gene transcription. Reverse transcription-polymerase chain reaction (RT-PCR) data suggested that transcription of the predominant var gene occurs in the later (pigmented trophozoite) stages, whereas Northern blot data indicated such transcripts only in early (ring) stages. We investigated this discrepancy by Northern blot, with probes covering a diverse var gene repertoire. We confirm that almost all var transcript types were detected only in ring stages. However, one type, the well-conserved varCSA transcript, was present constitutively in different laboratory parasites and does not appear to undergo antigenic variation. Although varCSA has been shown to encode a chondroitin sulphate A (CSA)-binding PfEMP1, we find that the presence of full-length varCSA transcripts does not correlate with the CSA-binding phenotype

Endometrial cancer patients’ preferences for follow-up after treatment: A cross-sectional survey

Purpose Alternatives to hospital follow-up (HFU) following treatment for cancer have been advocated. Telephone follow-up (TFU) and patient-initiated follow-up are being implemented but it is unclear if these approaches will meet the preferences and needs of patients. This study aimed to explore the preferences of endometrial cancer patients and their levels of satisfaction with HFU and nurse-led TFU. Methods A cross-sectional survey design was utilised and a questionnaire was administered to 236 patients who had participated in a randomised controlled trial comparing HFU with TFU for women diagnosed with Stage I endometrial cancer (ENDCAT trial). Results 211 (89.4%) patients returned the questionnaire; 105 in the TFU group and 106 in the HFU group. The TFU group were more likely to indicate that appointments were on time (p < 0.001) and were more likely to report that their appointments were thorough (p = 0.011). Participants tended to prefer what was familiar to them. Those in the HFU group tended to prefer hospital-based appointments while the TFU group tended to prefer appointments with a clinical nurse specialist, regardless of locality. Conclusions To provide patient centred follow-up services we need to ensure that patient preferences are taken into account and understand that patients may come to prefer what they have experienced. Patient initiated approaches may become standard and preferred practice but TFU remains a high-quality alternative to HFU and may provide an effective transition between HFU and patient-initiated approaches

The Los Alamos Supernova Light Curve Project: Computational Methods

We have entered the era of explosive transient astronomy, in which upcoming real-time surveys like the Large Synoptic Survey Telescope (LSST), the Palomar Transient Factory (PTF) and Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) will detect supernovae in unprecedented numbers. Future telescopes such as the James Webb Space Telescope may discover supernovae from the earliest stars in the universe and reveal their masses. The observational signatures of these astrophysical transients are the key to unveiling their central engines, the environments in which they occur, and to what precision they will pinpoint cosmic acceleration and the nature of dark energy. We present a new method for modeling supernova light curves and spectra with the radiation hydrodynamics code RAGE coupled with detailed monochromatic opacities in the SPECTRUM code. We include a suite of tests that demonstrate how the improved physics is indispensable to modeling shock breakout and light curves.Comment: 18 pages, 19 figures, published in ApJ Supplement

The Hubble Deep Field South Flanking Fields

As part of the Hubble Deep Field South program, a set of shorter 2-orbit observations were obtained of the area adjacent to the deep fields. The WFPC2 flanking fields cover a contiguous solid angle of 48 square arcminutes. Parallel observations with the STIS and NICMOS instruments produce a patchwork of additional fields with optical and near-infrared (1.6 micron) response. Deeper parallel exposures with WFPC2 and NICMOS were obtained when STIS observed the NICMOS deep field. These deeper fields are offset from the rest, and an extended low surface brightness object is visible in the deeper WFPC2 flanking field. In this data paper, which serves as an archival record of the project, we discuss the observations and data reduction, and present SExtractor source catalogs and number counts derived from the data. Number counts are broadly consistent with previous surveys from both ground and space. Among other things, these flanking field observations are useful for defining slit masks for spectroscopic follow-up over a wider area around the deep fields, for studying large-scale structure that extends beyond the deep fields, for future supernova searches, and for number counts and morphological studies, but their ultimate utility will be defined by the astronomical community.Comment: 46 pages, 15 figures. Images and full catalogs available via the HDF-S at http://www.stsci.edu/ftp/science/hdfsouth/hdfs.html at present. The paper is accepted for the February 2003 Astronomical Journal. Full versions of the catalogs will also be available on-line from AJ after publicatio

Improving attitudes towards adders (Vipera berus) and nature connectedness in primary‐age group children

Adder ( Vipera berus ) populations are experiencing declines in many countries, including the United Kingdom. Perceptions of adders and other venomous snakes are generally negative, making conservation of these species a challenge, and persecution remains within the top five perceived causes for adder declines in the United Kingdom. Improved understanding and attitudes are needed to support current conservation efforts. However, ensuring these positive attitudes continue into the future relies on addressing children's loss of connection to nature, and intervention at this early attitude‐formation stage can be crucial for traditionally ‘unpopular’ species, such as snakes. An adder‐focussed public engagement project, Adders are Amazing !, was carried out in Pembrokeshire, United Kingdom, in 2018–19 to improve understanding and attitudes towards adders using a blended science‐creative arts approach. The project included half‐day primary school‐based workshops to inform 111 pupils aged 8–11 about adder ecology, alongside creative art experiences. Questionnaires were used to measure the children's attitudes towards adders and their nature connectedness both before and after the workshops and these were compared with equivalent questionnaires carried out at a control school (57 pupils) where no workshops were conducted. The project demonstrated that engagement that blends both art and science can significantly change attitudes towards adders without any direct contact with the animals themselves; specifically, participants' scores for ‘Wonder’, ‘Learning Interest’ and ‘Conservation Concern’ increased. The workshops also significantly increased measures of the children's general connectedness to nature (specifically, ‘Enjoyment of Nature’ and ‘Responsibility for Nature’). We recommend conservation bodies focus on, and not shy away from, so‐called ‘unpopular’ species, to promote understanding and acceptance of these species and support their conservation. Blended arts–science initiatives, which can be easily adapted to suit a wide range of species and the artistic practices of local communities, are an effective way to achieve this. Read the free Plain Language Summary for this article on the Journal blog