102 research outputs found
Infrared chemical imaging through nondegenerate two-photon absorption in silicon-based cameras
Chemical imaging based on mid-infrared (MIR) spectroscopic contrast is an
important technique with a myriad of applications, including biomedical imaging
and environmental monitoring. Current MIR cameras, however, lack in performance
and are much less affordable compared to mature Si-based devices, which operate
in the visible and near-infrared. Here we demonstrate fast MIR chemical imaging
through non-degenerate two-photon absorption (NTA) in a standard Si-based
charge-coupled device (CCD). We show that wide-field MIR images can be obtained
at 100 ms exposure times using picosecond pulse energies of only a few fJ per
pixel through NTA directly on the CCD chip. Because this on-chip approach does
not rely on phase-matching, it is alignment-free and does not necessitate
complex post-processing of the images. We emphasize the utility of this
technique through chemically selective MIR imaging of polymers and biological
samples, including MIR videos of moving targets, physical processes and live
nematodes
High-speed 2D and 3D mid-IR imaging with an InGaAs camera
Recent work on mid-infrared (MIR) detection through the process of
non-degenerate two-photon absorption (NTA) in semiconducting materials has
shown that wide-field MIR imaging can be achieved with standard Si cameras.
While this approach enables MIR imaging at high pixel densities, the low
nonlinear absorption coefficient of Si prevents fast NTA-based imaging at lower
illumination doses. Here we overcome this limitation by using InGaAs as the
photosensor. Taking advantage of the much higher nonlinear absorption
coefficient of this direct bandgap semiconductor, we demonstrate high-speed MIR
imaging up to 500 fps with under 1 ms exposure per frame, enabling 2D or 3D
mapping without pre- or post-processing of the image.Comment: 7 pages, 5 Figure
Landscape perception: linking physical monitoring data to perceived landscape properties
Changes in the landscape affect not only people's well-being but also how people perceive and use the landscape. An increasing number of policies have highlighted the importance of conserving a landscape's recreational and aesthetical values. This study develops and evaluates a model that links people's perceptions of a mountain landscape to physical monitoring data. Using a questionnaire, we revealed how respondents working with the Swedish mountains characterise the Magnificent Mountain landscape (as defined by Swedish policy objectives) and translated these characteristics into data from the National Inventory of Landscapes in Sweden (NILS). We found 14 potential indicators that could be derived from the existing NILS physical monitoring data and which could be used to monitor changes in the landscape values as perceived by people. Based on the results, we suggest how to simultaneously utilise field sampling of physical data and field photos to provide temporal information about landscape perception
The c2d Spitzer Spectroscopic Survey Of Ices Around Low-Mass Young Stellar Objects. I. H2O And The 5-8 Mu M Bands
To study the physical and chemical evolution of ices in solar-mass systems, a spectral survey is conducted of a sample of 41 low-luminosity YSOs (L similar to 0.1-10 L-circle dot) using 3-38 mu m Spitzer and ground-based spectra. The sample is complemented with previously published Spitzer spectra of background stars and with ISO spectra of well-studied massive YSOs (L similar to 10(5) L-circle dot). The long-known 6.0 and 6.85 mu m bands are detected toward all sources, with the Class 0-type YSOs showing the deepest bands ever observed. The 6.0 mu m band is often deeper than expected from the bending mode of pure solid H2O. The additional 5-7 mu m absorption consists of five independent components, which, by comparison to laboratory studies, must be from at least eight different carriers. Much of this absorption is due to simple species likely formed by grain surface chemistry, at abundances of 1%-30% for CH3OH, 3%-8% for NH3, 1%-5% for HCOOH, similar to 6% for H2CO, and similar to 0.3% for HCOO- relative to solid H2O. The 6.85 mu m band has one or two carriers, of which one may be less volatile than H2O. Its carrier(s) formed early in the molecular cloud evolution and do not survive in the diffuse ISM. If an NH4+- containing salt is the carrier, its abundance relative to solid H2O is similar to 7%, demonstrating the efficiency of low-temperature acid-base chemistry or cosmic-ray-induced reactions. Possible origins are discussed for enigmatic, very broad absorption between 5 and 8 mu m. Finally, the same ices are observed toward massive and low-mass YSOs, indicating that processing by internal UV radiation fields is a minor factor in their early chemical evolution.NWO SpinozaNOVAEuropean Research Training Network PLANETS HPRN-CT-2002-00308NASA Origins NAG5-13050NASA Hubble Fellowship 01201.01NASA NAS 5-26555Astronom
A Mechanistic Basis for the Coordinated Regulation of Pharyngeal Morphogenesis in Caenorhabditis elegans by LIN-35/Rb and UBC-18–ARI-1
Genetic redundancy, whereby two genes carry out seemingly overlapping functions, may in large part be attributable to the intricacy and robustness of genetic networks that control many developmental processes. We have previously described a complex set of genetic interactions underlying foregut development in the nematode Caenorhabditis elegans. Specifically, LIN-35/Rb, a tumor suppressor ortholog, in conjunction with UBC-18–ARI-1, a conserved E2/E3 complex, and PHA-1, a novel protein, coordinately regulates an early step of pharyngeal morphogenesis involving cellular re-orientation. Functional redundancy is indicated by the observation that lin-35; ubc-18 double mutants, as well as certain allelic combinations of pha-1 with either lin-35 or ubc-18, display defects in pharyngeal development, whereas single mutants do not. Using a combination of genetic and molecular analyses, we show that sup-35, a strong recessive suppressor of pha-1–associated lethality, also reverts the synthetic lethality of lin-35; ubc-18, lin-35; pha-1, and ubc-18 pha-1 double mutants. SUP-35, which contains C2H2-type Zn-finger domains as well as a conserved RMD-like motif, showed a dynamic pattern of subcellular localization during embryogenesis. We find that mutations in sup-35 specifically suppress hypomorphic alleles of pha-1 and that SUP-35, acting genetically upstream of SUP-36 and SUP-37, negatively regulates pha-1 transcription. We further demonstrate that LIN-35, a transcriptional repressor, and UBC-18–ARI-1, a complex involved in ubiquitin-mediated proteolysis, negatively regulate SUP-35 abundance through distinct mechanisms. We also show that HCF-1, a C. elegans homolog of host cell factor 1, functionally antagonizes LIN-35 in the regulation of sup-35. Our cumulative findings piece together the components of a novel regulatory network that includes LIN-35/Rb, which functions to control organ morphogenesis. Our results also shed light on general mechanisms that may underlie developmental genetic redundancies as well as principles that may govern complex disease traits
Extrinsic Rewards and Intrinsic Motives: Standard and Behavioral Approaches to Agency and Labor Markets
Bisphenol A and its analogues: A comprehensive review to identify and prioritize effect biomarkers for human biomonitoring
Human biomonitoring (HBM) studies have demonstrated widespread and daily exposure to bisphenol A (BPA).
Moreover, BPA structural analogues (e.g. BPS, BPF, BPAF), used as BPA replacements, are being increasingly
detected in human biological matrices. BPA and some of its analogues are classified as endocrine disruptors
suspected of contributing to adverse health outcomes such as altered reproduction and neurodevelopment,
obesity, and metabolic disorders among other developmental and chronic impairments. One of the aims of the
H2020 European Human Biomonitoring Initiative (HBM4EU) is the implementation of effect biomarkers at large
scales in future HBM studies in a systematic and standardized way, in order to complement exposure data with
mechanistically-based biomarkers of early adverse effects. This review aimed to identify and prioritize existing
biomarkers of effect for BPA, as well as to provide relevant mechanistic and adverse outcome pathway (AOP)
information in order to cover knowledge gaps and better interpret effect biomarker data. A comprehensive
literature search was performed in PubMed to identify all the epidemiologic studies published in the last 10 years
addressing the potential relationship between bisphenols exposure and alterations in biological parameters. A
total of 5716 references were screened, out of which, 119 full-text articles were analyzed and tabulated in detail.
This work provides first an overview of all epigenetics, gene transcription, oxidative stress, reproductive, glucocorticoid and thyroid hormones, metabolic and allergy/immune biomarkers previously studied. Then, promising effect biomarkers related to altered neurodevelopmental and reproductive outcomes including brainderived neurotrophic factor (BDNF), kisspeptin (KiSS), and gene expression of nuclear receptors are prioritized,
providing mechanistic insights based on in vitro, animal studies and AOP information. Finally, the potential of
omics technologies for biomarker discovery and its implications for risk assessment are discussed. To the best of
our knowledge, this is the first effort to comprehensively identify bisphenol-related biomarkers of effect for HBM
purposes.European Union Commission H2020-EJP-HBM4EU
733032HBM4EU Initiativ
Role of neoplastic monocyte-derived fibrocytes in primary myelofibrosis
Primary myelofibrosis (PMF) is a fatal neoplastic disease characterized by clonal myeloproliferation and progressive bone marrow (BM) fibrosis thought to be induced by mesenchymal stromal cells stimulated by overproduced growth factors. However, tissue fibrosis in other diseases is associated with monocyte-derived fibrocytes. Therefore, we sought to determine whether fibrocytes play a role in the induction of BM fibrosis in PMF. In this study, we show that BM from patients with PMF harbors an abundance of clonal, neoplastic collagen- and fibronectin-producing fibrocytes. Immunodeficient mice transplanted with myelofibrosis patients’ BM cells developed a lethal myelofibrosis-like phenotype. Treatment of the xenograft mice with the fibrocyte inhibitor serum amyloid P (SAP; pentraxin-2) significantly prolonged survival and slowed the development of BM fibrosis. Collectively, our data suggest that neoplastic fibrocytes contribute to the induction of BM fibrosis in PMF, and inhibiting fibrocyte differentiation with SAP may interfere with this process
A review of the effects of colour and light on non-image function in humans
This paper reviews current knowledge on non-image-forming aspects of vision. Developments in the last 20 years have included the discovery of a fifth class of human visual pigment (melanopsin), in addition to the three classes of photopsin to be found in the cones and rhodopsin in the rods in the human retina. Melanopsin is found in a small number of retinal ganglion cells which then, in addition to receiving input from rods and cones, are intrinsically photosensitive. These retinal ganglion cells send their input primarily to the hypothalamus, where they help to regulate the circadian system (daily rhythms of sleep patterns, body temperature, heart rate, etc.). The discovery of the anatomical basis of non-image-forming vision has led to a great deal of research into the effects of light on sleep, depression and mood, retinal photodamage and well-being, amongst other factors. Given that recent technological innovations in LED lighting now give us greater control over environmental lighting, it is timely to review the non-visual effects of light in humans in order to inform lighting design in the future
Combined heat exchanger of smoke gases by Evrovartrade company
V diplomski nalogi sem predstavil kombinirani prenosnik dimnih plinov, ki je patentni izdelek podjetja Evrovartrade d.o.o. Prenosnik lahko namestimo naknadno na izhodno tuljavo hišnih kotlov. Z dimnimi plini ogrevamo vodo, ki je lahko sanitarna ali za potrebe ogrevanja prostorov. Z razvojnim kondenzatorjem, dimne pline ohladimo pod rosišče in tako povečamo izkoristek kotla do 11%.The aim of my diploma was to introduce a heat exchanger of smoke gases, whitch is a patent by Evrovartrade company. The exchanger can be setted up additionally on the exit side of furnance smoke gases tube. With smoke gases we can heat water, which can be used for industrial or for home heating. With developed exchanger, we can cool smoke gases below saturation temperature, and consecutive enlarge the furnance efficiency up to 11%
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