Rifts in Spreading Wax Layers

We report experimental results on the rift formation between two freezing wax plates. The plates were pulled apart with constant velocity, while floating on the melt, in a way akin to the tectonic plates of the earth's crust. At slow spreading rates, a rift, initially perpendicular to the spreading direction, was found to be stable, while above a critical spreading rate a "spiky" rift with fracture zones almost parallel to the spreading direction developed. At yet higher spreading rates a second transition from the spiky rift to a zig-zag pattern occurred. In this regime the rift can be characterized by a single angle which was found to be dependent on the spreading rate. We show that the oblique spreading angles agree with a simple geometrical model. The coarsening of the zig-zag pattern over time and the three-dimensional structure of the solidified crust are also discussed.Comment: 4 pages, Postscript fil

Reversible, Opto-Mechanically Induced Spin-Switching in a Nanoribbon-Spiropyran Hybrid Material

It has recently been shown that electronic transport in zigzag graphene nanoribbons becomes spin-polarized upon application of an electric field across the nanoribbon width. However, the electric fields required to experimentally induce this magnetic state are typically large and difficult to apply in practice. Here, using both first-principles density functional theory (DFT) and time-dependent DFT, we show that a new spiropyran-based, mechanochromic polymer noncovalently deposited on a nanoribbon can collectively function as a dual opto-mechanical switch for modulating its own spin-polarization. These calculations demonstrate that upon mechanical stress or photoabsorption, the spiropyran chromophore isomerizes from a closed-configuration ground-state to a zwitterionic excited-state, resulting in a large change in dipole moment that alters the electrostatic environment of the nanoribbon. We show that the electronic spin-distribution in the nanoribbon-spiropyran hybrid material can be reversibly modulated via noninvasive optical and mechanical stimuli without the need for large external electric fields. Our results suggest that the reversible spintronic properties inherent to the nanoribbon-spiropyran material allow the possibility of using this hybrid structure as a resettable, molecular-logic quantum sensor where opto-mechanical stimuli are used as inputs and the spin-polarized current induced in the nanoribbon substrate is the measured output.Comment: Accepted by Nanoscal

New Young Star Candidates in BRC 27 and BRC 34

We used archival Spitzer Space Telescope mid-infrared data to search for young stellar objects (YSOs) in the immediate vicinity of two bright-rimmed clouds, BRC 27 (part of CMa R1) and BRC 34 (part of the IC 1396 complex). These regions both appear to be actively forming young stars, perhaps triggered by the proximate OB stars. In BRC 27, we find clear infrared excesses around 22 of the 26 YSOs or YSO candidates identified in the literature, and identify 16 new YSO candidates that appear to have IR excesses. In BRC 34, the one literature-identified YSO has an IR excess, and we suggest 13 new YSO candidates in this region, including a new Class I object. Considering the entire ensemble, both BRCs are likely of comparable ages, within the uncertainties of small number statistics and without spectroscopy to confirm or refute the YSO candidates. Similarly, no clear conclusions can yet be drawn about any possible age gradients that may be present across the BRCs.Comment: 54 pages, 19 figures, accepted by A

Exome sequencing reveals variants in known and novel candidate genes for severe sperm motility disorders

Publisher Copyright: © The Author(s) 2021. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.STUDY QUESTION: What are the causative genetic variants in patients with male infertility due to severe sperm motility disorders? SUMMARY ANSWER: We identified high confidence disease-causing variants in multiple genes previously associated with severe sperm motility disorders in 10 out of 21 patients (48%) and variants in novel candidate genes in seven additional patients (33%). WHAT IS KNOWN ALREADY: Severe sperm motility disorders are a form of male infertility characterised by immotile sperm often in combination with a spectrum of structural abnormalities of the sperm flagellum that do not affect viability. Currently, depending on the clinical sub-categorisation, up to 50% of causality in patients with severe sperm motility disorders can be explained by pathogenic variants in at least 22 genes. STUDY DESIGN, SIZE, DURATION: We performed exome sequencing in 21 patients with severe sperm motility disorders from two different clinics. PARTICIPANTS/MATERIALS, SETTING, METHOD: Two groups of infertile men, one from Argentina (n = 9) and one from Australia (n = 12), with clinically defined severe sperm motility disorders (motility <5%) and normal morphology values of 0-4%, were included. All patients in the Argentine cohort were diagnosed with DFS-MMAF, based on light and transmission electron microscopy. Sperm ultrastructural information was not available for the Australian cohort. Exome sequencing was performed in all 21 patients and variants with an allele frequency of <1% in the gnomAD population were prioritised and interpreted. MAIN RESULTS AND ROLE OF CHANCE: In 10 of 21 patients (48%), we identified pathogenic variants in known sperm assembly genes: CFAP43 (3 patients); CFAP44 (2 patients), CFAP58 (1 patient), QRICH2 (2 patients), DNAH1 (1 patient) and DNAH6 (1 patient). The diagnostic rate did not differ markedly between the Argentinian and the Australian cohort (55% and 42%, respectively). Furthermore, we identified patients with variants in the novel human candidate sperm motility genes: DNAH12, DRC1, MDC1, PACRG, SSPL2C and TPTE2. One patient presented with variants in four candidate genes and it remains unclear which variants were responsible for the severe sperm motility defect in this patient.N/A. LIMITATIONS, REASONS FOR CAUTION: In this study, we described patients with either a homozygous or two heterozygous candidate pathogenic variants in genes linked to sperm motility disorders. Due to unavailability of parental DNA, we have not assessed the frequency of de novo or maternally inherited dominant variants and could not determine the parental origin of the mutations to establish in all cases that the mutations are present on both alleles. WIDER IMPLICATIONS OF THE FINDINGS: Our results confirm the likely causal role of variants in six known genes for sperm motility and we demonstrate that exome sequencing is an effective method to diagnose patients with severe sperm motility disorders (10/21 diagnosed; 48%). Furthermore, our analysis revealed six novel candidate genes for severe sperm motility disorders. Genome-wide sequencing of additional patient cohorts and re-analysis of exome data of currently unsolved cases may reveal additional variants in these novel candidate genes. STUDY FUNDING/COMPETING INTEREST(S): This project was supported in part by funding from the Australian National Health and Medical Research Council (APP1120356) to M.K.O.B., J.A.V. and R.I.M.L., The Netherlands Organisation for Scientific Research (918-15-667) to J.A.V., the Royal Society and Wolfson Foundation (WM160091) to J.A.V., as well as an Investigator Award in Science from the Wellcome Trust (209451) to J.A.V. and Grants from the National Research Council of Argentina (PIP 0900 and 4584) and ANPCyT (PICT 9591) to H.E.C. and a UUKi Rutherford Fund Fellowship awarded to B.J.H.publishersversionPeer reviewe

Hygienic quality of dehydrated aromatic herbs marketed in Southern Portugal

Dehydrated aromatic herbs are highly valued ingredients, widely used at home level and by food processing industry, frequently added to a great number of recipes in the Mediterranean countries. Despite being considered low-moisture products and classified as GRAS, during pre and post-harvesting stages of production they are susceptible of microbial contamination. In Europe an increasing number of food recalls and disease outbreaks associated with dehydrated herbs have been reported in recent years. In this study the microbial quality of 99 samples of aromatic herbs (bay leaves, basil, coriander, oregano, parsley, Provence herbs, rosemary and thyme) collected from retails shops in the region of Algarve (Southern Portugal) was assessed. All the samples were tested by conventional methods and were assayed for the total count of aerobic mesophilic microorganisms, Salmonella spp., Escherichia coli, coagulase-positive staphylococci and filamentous fungi. Almost 50 % of the herbs did not exceed the aerobic mesophilic level of 104 CFU/g. The fungi count regarded as unacceptable (106 CFU/g) was not found in any of the tested herbs, while 84 % of the samples ranged from ≤102 to 104 CFU/g. No sample was positive for the presence of Salmonella spp., Escherichia coli and staphylococci. The results are in compliance with the European Commission criteria although they point out to the permanent need of surveillance on the good standards of handling/cooking practices as well as the importance of avoiding contamination at production, retailing and distribution. The microbiological hazards associated with the pathogenic and toxigenic microbiota of dried herbs remain as a relevant public health issue, due to the fact that they are added to foods not submitted to any following lethal procedure. Control measures should be adopted in order to ensure that all phases of their supply chain respect the food safety standards.FCT: UID/BIA/04325/2019.info:eu-repo/semantics/publishedVersio

Sex recognition by odour and variation in the uropygial gland secretion in starlings

1. Although a growing body of evidence supports that olfaction based on chemical compounds emitted by birds may play a role in individual recognition, the possible role of chemical cues in sexual selection of birds has been only preliminarily studied.2. We investigated for the first time whether a passerine bird, the spotless starling Sturnus unicolor, was able to discriminate the sex of conspecifics by using olfactory cues and whether the size and secretion composition of the uropygial gland convey information on sex, age and reproductive status in this species.3. We performed a blind choice experiment during mating, and we found that starlings were able to discriminate the sex of conspecifics by using chemical cues alone. Both male and female starlings preferred male scents. Furthermore, the analysis of the chemical composition of the uropygial gland secretion by using gas chromatography–mass spectrometry (GC–MS) revealed differences between sexes, ages and reproductive status.4. In conclusion, our study reveals for first time that a passerine species can discriminate the sex of conspecifics by relying on chemical cues and suggests that the uropygial gland secretion may potentially function as a chemical signal used in mate choice and/or intrasexual competition in this species.This research was funded by the Spanish Ministry of Education and Science ⁄ FEDER (CGL2008-00718) and PIE 200930I029 to J. M. Avilés and D. Parejo.The study was conducted under licence of the Junta de Andalucía GC–MS analyses were performed by Dr. Rafael Núñez at the Scientific Instrumentation Service (EEZ, CSIC) (Granada, Spain).Peer reviewe

Generation of Stable Pluripotent Stem Cells From NOD Mouse Tail-Tip Fibroblasts

OBJECTIVE: The NOD mouse strain has been widely used to investigate the pathology and genetic susceptibility for type 1 diabetes. Induced pluripotent stem cells (iPSCs) derived from this unique mouse strain would enable new strategies for investigating type 1 diabetes pathogenesis and potential therapeutic targets. The objective of this study was to determine whether somatic fibroblasts from NOD mice could be reprogrammed to become iPSCs, providing an alternative source of stem cells for the production of genetically modified NOD cells and mice. RESEARCH DESIGN AND METHODS: Adult tail-tip fibroblasts from male NOD mice were reprogrammed by retroviral transduction of the coding sequences of three transcription factors, OCT4, SOX2, and KLF4, in combination with a histone deacetylase inhibitor, valproic acid. RESULTS: Eighteen NOD iPSC lines were generated, and three of these cell lines were further characterized. All three cell lines exhibited silencing of the three reprogramming transgenes and reactivation of endogenous pluripotent markers (OCT4, SOX2, NANOG, REX1, and SSEA1). These NOD iPSCs readily differentiated in vitro to form embryoid bodies and in vivo by teratoma formation in immunodeficient mice. Moreover, NOD iPSCs were successfully transfected with a reporter transgene and were capable of contributing to the inner cell mass of C57BL/6 blastocysts, leading to the generation of a chimeric mouse. CONCLUSIONS: Adult tail-tip fibroblasts from NOD mice can be reprogrammed, without constitutive ectopic expression of transcription factors, to produce iPSCs that exhibit classic mouse embryonic stem cell (ESC) features. These NOD iPSCs can be maintained and propagated under normal ESC culture conditions to produce genetically altered cell lines, differentiated cells, and chimeric mice

Ornamental plants: a summary of research, 1990

Physical facilities and capital requirements for establishing a three-acre perennial container nursery in Ohio -1989 / Reed D. Taylor, Elton M. Smith, George P. Pealer -- Production costs of operating a three-acre perennial container nursery in Ohio - 1989 / Reed D. Taylor, Elton M. Smith, George P. Pealer -- Comparative costs of producing alternative plants in a three-acre perennial container nursery in Ohio – 1989 / Reed D. Taylor, Elton M. Smith, George P. Pealer -- Marketing and sales strategies practiced by Ohio nurseries / Reed D. Taylor, Elton M. Smith, W. Timothy Rhodus -- Evaluation of flowering crabapple susceptibility to apple scab in Ohio - 1989 / Elton M. Smith and Sharon A. Treaster -- Fertilizing trees in the landscape: an 18-year evaluation / Elton M. Smith and Sharon A. Treaster -- The influence of irrigation water temperature upon leaf abscision in Ficus benjamina and Dracaena marginata / Julia A. O’Bryan and John C. Peterson -- A two-year tolerance study of narcissus cultivars to selected pre-emergence herbicides / Elton M. Smith and Sharon A. Treaster -- Tolerance of clematis and wisteria to Ronstar and Devrinol / Elton M. Smith and Sharon A. Treaster -- Increasing efficiency of slow-release herbicide tablets / Elton M. Smith and Sharon A. Treaster -- Developing biorational pesticides for the landscape industry / David G. Nielsen -- Interactions between subdue and slow-release fertilizers at high temperatures / Y. Inbar, H. A. J. Hoitink, M. E. Watson, K. D. Cochran, E. M. Smith -- Evaluation of powdery mildew severity on deciduous azaleas at the Secrest Arboretum - 1989 / Kenneth D. Cochran and C. Wayne Ellett -- Winter damage, regrowth and vigor of old garden roses / Gary A. Anderso

The Nature of Surround-Induced Depolarizing Responses in Goldfish Cones

Cones in the vertebrate retina project to horizontal and bipolar cells and the horizontal cells feedback negatively to cones. This organization forms the basis for the center/surround organization of the bipolar cells, a fundamental step in the visual signal processing. Although the surround responses of bipolar cells have been recorded on many occasions, surprisingly, the underlying surround-induced responses in cones are not easily detected. In this paper, the nature of the surround-induced responses in cones is studied. Horizontal cells feed back to cones by shifting the activation function of the calcium current in cones to more negative potentials. This shift increases the calcium influx, which increases the neurotransmitter release of the cone. In this paper, we will show that under certain conditions, in addition to this increase of neurotransmitter release, a calcium-dependent chloride current will be activated, which polarizes the cone membrane potential. The question is, whether the modulation of the calcium current or the polarization of the cone membrane potential is the major determinant for feedback-mediated responses in second-order neurons. Depolarizing light responses of biphasic horizontal cells are generated by feedback from monophasic horizontal cells to cones. It was found that niflumic acid blocks the feedback-induced depolarizing responses in cones, while the shift of the calcium current activation function and the depolarizing biphasic horizontal cell responses remain intact. This shows that horizontal cells can feed back to cones, without inducing major changes in the cone membrane potential. This makes the feedback synapse from horizontal cells to cones a unique synapse. Polarization of the presynaptic (horizontal) cell leads to calcium influx in the postsynaptic cell (cone), but due to the combined activity of the calcium current and the calcium-dependent chloride current, the membrane potential of the postsynaptic cell will be hardly modulated, whereas the output of the postsynaptic cell will be strongly modulated. Since no polarization of the postsynaptic cell is needed for these feedback-mediated responses, this mechanism of synaptic transmission can modulate the neurotransmitter release in single synaptic terminals without affecting the membrane potential of the entire cell