Modelling of plant circadian clock for characterizing hypocotyl growth under different light quality conditions

To meet the ever-increasing global food demand, the food production rate needs to be increased significantly in the near future. Speed breeding is considered as a promising agricultural technology solution to achieve the zero-hunger vision as specified in the United Nations Sustainable Development Goal 2. In speed breeding, the photoperiod of the artificial light has been manipulated to enhance crop productivity. In particular, regulating the photoperiod of different light qualities rather than solely white light can further improve speed breading. However, identifying the optimal light quality and the associated photoperiod simultaneously remains a challenging open problem due to complex interactions between multiple photoreceptors and proteins controlling plant growth. To tackle this, we develop a first comprehensive model describing the profound effect of multiple light qualities with different photoperiods on plant growth (i.e. hypocotyl growth). The model predicts that hypocotyls elongated more under red light compared to both red and blue light. Drawing similar findings from previous related studies, we propose that this might result from the competitive binding of red and blue light receptors, primarily Phytochrome B (phyB) and Cryptochrome 1 (cry1) for the core photomorphogenic regulator, CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1). This prediction is validated through an experimental study on Arabidopsis thaliana. Our work proposes a potential molecular mechanism underlying plant growth under different light qualities and ultimately suggests an optimal breeding protocol that takes into account light quality

A Butterfly-Shaped Primary Cardiac Lymphoma That Showed Bi-Atrial Involvement

We described here a patient who presented with symptoms of heart failure who was found to have severe bilateral impairment of atrioventricular inflow. Primary cardiac lymphoma (PCL) with extensive involvement of the two atria, pericardium and myocardium is an extremely rare tumor in immunocompetent patients. We report here a case of PCL in an immunocompetent patient with involvement of both atria and the atrial septum. The tumor had a butterfly shape. We could not do surgical excision because of the massive pericardiac invasion. The diagnosis was B-cell lymphoma and this was confirmed by the pericardiac biopsy

Placing the spotted T Tauri star LkCa 4 on an HR diagram

Ages and masses of young stars are often estimated by comparing their luminosities and effective temperatures to pre-main-sequence stellar evolution tracks, but magnetic fields and starspots complicate both the observations and evolution. To understand their influence, we study the heavily spotted weak-lined T-Tauri star LkCa 4 by searching for spectral signatures of radiation originating from the starspot or starspot groups. We introduce a new methodology for constraining both the starspot filling factor and the spot temperature by fitting two-temperature stellar atmosphere models constructed from Phoenix synthetic spectra to a high-resolution near-IR IGRINS spectrum. Clearly discernable spectral features arise from both a hot photospheric component Thot ∼ 4100 K and a cool component Tcool ∼ 2700–3000 K, which covers ∼80% of the visible surface. This mix of hot and cool emission is supported by analyses of the spectral energy distribution, rotational modulation of colors and of TiO band strengths, and features in low-resolution optical/near-IR spectroscopy. Although the revised effective temperature and luminosity make LkCa 4 appear to be much younger and of much lower mass than previous estimates from unspotted stellar evolution models, appropriate estimates will require the production and adoption of spotted evolutionary models. Biases from starspots likely afflict most fully convective young stars and contribute to uncertainties in ages and age spreads of open clusters. In some spectral regions, starspots act as a featureless "veiling" continuum owing to high rotational broadening and heavy line blanketing in cool star spectra. Some evidence is also found for an anticorrelation between the velocities of the warm and cool components.Peer reviewe

Increased Circulating Endothelial Microparticles and Carotid Atherosclerosis in Obstructive Sleep Apnea

Background and Purpose Endothelial impairment is a linking mechanism between obstructive sleep apnea (USA) and cardiovascular diseases Profiles of endothelial micropanicles (EMPs) and endothelial progenitor cells (EPCs) reflect the degree of endothelial impairment The aims of this study were to measure the levels of EMI`s and progenitor cells in USA, determine the correlations between these factors and USA severity and the deuce of atherosclerosis, and document any changes in these factors after therapy Methods Subjects with (n=82) and without (n=22) OSA were recruited prospectively We measured the number of colony-forming units (CM) in cell cultuie as the endothelial progenitor cell index, and the number of EMPs using flow cytometry with CD31 [platelet endothelial cell adhesion molecule (PECAM)], CD42 (platelet glycoprotem), annexm V, and CD62E (E-selectin) antibodies at baseline and Act 4-6 weeks of continuous positive airway pressure (CPA P) therapy Carotid int ima-media thickness (IMT) was regarded as a marker of atherosclerosis Results The levels of PECAM(+)CD42(-) (p<0 001). PECAM(+)annexin V(+) (p<0 001), and E-selectin(+) micropamcles (p=0 001) were higher in USA subjects than in non-USA subjects The number of CRJ did not differ between the two groups OSA severity independently predicted the levels of PECAM(+)CD42(-) (p=0 02) and PECA(+)annexin V(+) (p=0 004) Carotid IMT was correlated with USA severity (p<0 001), PECAM(+)CD42: (p=0 03), and PECAM(+)annexin (p=0 01) Neither USA severity nor carotid IMT was correlated with either the number of CFI) or E-selectin(+) CPAP therapy decreased the occurrence of E-selecte (p<0 001) in 21 of the USA subjects, but had no effect on the other micioparticles of the number CFU Conclusions USA led to the overproduction of EMI`s, which moderately correlated with USA seventy and the degree of atherosclerosis, and partly responded to therapy The endothelial impairment might contribute to future cardiovascular events J Clin Neurol 2010;6`89-98This research was supported by the Stem Cell Research Center of the 21st Century Frontier Research Program funded by the Ministry of Science and Technology, Republic of Korea (#SC4120).de Lima AMJ, 2010, RESPIRATION, V79, P370, DOI 10.1159/000227800Jung KH, 2009, ANN NEUROL, V66, P191, DOI 10.1002/ana.21681Ayers L, 2009, EUR RESPIR J, V33, P574, DOI 10.1183/09031936.00107408Akinnusi ME, 2009, AM J RESP CRIT CARE, V179, P328Christou K, 2009, SLEEP MED, V10, P87, DOI 10.1016/j.sleep.2007.10.011Barcelo A, 2008, THORAX, V63, P946, DOI 10.1136/thx.2007.093740Dorkova Z, 2008, CHEST, V134, P686, DOI 10.1378/chest.08-0556Robinson GV, 2008, THORAX, V63, P855, DOI 10.1136/thx.2007.088096Somers VK, 2008, CIRCULATION, V118, P1080, DOI 10.1161/CIRCULATIONAHA.107.189375Hirschi KK, 2008, ARTERIOSCL THROM VAS, V28, P1584, DOI 10.1161/ATVBAHA.107.155960Daniel L, 2008, NEPHROL DIAL TRANSPL, V23, P2129, DOI 10.1093/ndt/gfn029Martin K, 2008, LUNG, V186, P145, DOI 10.1007/s00408-008-9073-yAmabile N, 2008, AM J RESP CRIT CARE, V177, P1268, DOI 10.1164/rccm.200710-1458OCHeiss C, 2008, J AM COLL CARDIOL, V51, P1760, DOI 10.1016/j.jacc.2008.01.040Chu K, 2008, STROKE, V39, P1441, DOI 10.1161/STROKEAHA.107.499236Jelic S, 2008, CIRCULATION, V117, P2270, DOI 10.1161/CIRCULATIONAHA.107.741512Lee ST, 2008, NEUROLOGY, V70, P1510Bakouboula B, 2008, AM J RESP CRIT CARE, V177, P536, DOI 10.1164/rccm.200706-840OCLopez-Jimenez F, 2008, CHEST, V133, P793, DOI 10.1378/chest.07-0800de la Pena M, 2008, RESPIRATION, V76, P28, DOI 10.1159/000109643WON CHJ, 2008, P AM THORAC SOC, V5, P193Kloner RA, 2007, CIRCULATION, V116, P1306, DOI 10.1161/CIRCULATIONAHA.106.678375El Solh AA, 2007, AM J RESP CRIT CARE, V175, P1186, DOI 10.1164/rccm.200611-1598OCIBER C, 2007, AASM MANUAL SCORINGMONTSERRAT JM, 2007, AM J RESP CRIT CARE, V176, P6Pirro M, 2006, ARTERIOSCL THROM VAS, V26, P2530, DOI 10.1161/01.ATV.0000243941.72375.15Ryan S, 2006, AM J RESP CRIT CARE, V174, P824, DOI 10.1164/rccm.200601-066OCBoulanger CM, 2006, HYPERTENSION, V48, P180, DOI 10.1161/01.HYP.0000231507.00962.b5Arteaga RB, 2006, AM J CARDIOL, V98, P70, DOI 10.1016/j.amjcard.2006.01.054Robinson GV, 2006, EUR RESPIR J, V27, P1229, DOI 10.1183/09031936.06.00062805Werner N, 2005, NEW ENGL J MED, V353, P999Mezentsev A, 2005, AM J PHYSIOL-HEART C, V289, pH1106, DOI 10.1152/ajpheart.00265.2005Minoguchi K, 2005, AM J RESP CRIT CARE, V172, P625, DOI 10.1164/rccm.200412-1652OCMassa M, 2005, BLOOD, V105, P199, DOI 10.1182/blood-2004-05-1831Kim J, 2004, AM J RESP CRIT CARE, V170, P1108, DOI 10.1164/rccm.200404-519OCJy W, 2004, J THROMB HAEMOST, V2, P1842Tramontano AF, 2004, BIOCHEM BIOPH RES CO, V320, P34, DOI 10.1016/j.bbrc.2004.05.127Ip MSM, 2004, AM J RESP CRIT CARE, V169, P348, DOI 10.1164/rccm.200306.767OCBarba C, 2004, LANCET, V363, P157Bernal-Mizrachi L, 2003, AM HEART J, V145, P962, DOI 10.1016/S0002-8703(03)00103-0Jimenez JJ, 2003, THROMB RES, V109, P175, DOI 10.1016/S0049-3848(03)00064-1Hill JM, 2003, NEW ENGL J MED, V348, P593Preston RA, 2003, HYPERTENSION, V41, P211, DOI 10.1161/01.HYP.0000049760.15764.2DSabatier F, 2002, DIABETES, V51, P2840, DOI 10.2337/diabetes.51.9.2840El-Solh AA, 2002, CHEST, V121, P1541Boulanger CM, 2001, CIRCULATION, V104, P2649Barbe F, 2001, ANN INTERN MED, V134, P1015Chin K, 2000, AM J MED, V109, P562Lusis AJ, 2000, NATURE, V407, P233Ohga E, 1999, J APPL PHYSIOL, V87, P10YOUNG T, 1993, NEW ENGL J MED, V328, P1230JOHNS MW, 1991, SLEEP, V14, P540

Structural basis of laminin binding to the LARGE glycans on dystroglycan

Dystroglycan is a highly glycosylated extracellular matrix receptor with essential functions in skeletal muscle and the nervous system. Reduced matrix binding by α-dystroglycan (α-DG) due to perturbed glycosylation is a pathological feature of several forms of muscular dystrophy. Like-acetylglucosaminyltransferase (LARGE) synthesizes the matrix-binding heteropolysaccharide [-glucuronic acid-β1,3-xylose- α1,3-]n. Using a dual exoglycosidase digestion, we confirm that this polysaccharide is present on native α-DG from skeletal muscle. The atomic details of matrix binding were revealed by a high-resolution crystal structure of laminin G-like (LG) domains 4-5 of laminin α2 bound to a LARGE-synthesized oligosaccharide. A single glucuronic acid- β1,3-xylose disaccharide repeat straddles a Ca2+ ion in the LG4 domain, with oxygen atoms from both sugars replacing Ca2+-bound water molecules. The chelating binding mode accounts for the high affinity of this protein-carbohydrate interaction. These results reveal a novel mechanism of carbohydrate recognition and provide a structural framework for elucidating the mechanisms underlying muscular dystrophy

Placing the Spotted T Tauri Star LkCa 4 on an HR Diagram

International audienceAges and masses of young stars are often estimated by comparing their luminosities and effective temperatures to pre-main-sequence stellar evolution tracks, but magnetic fields and starspots complicate both the observations and evolution. To understand their influence, we study the heavily spotted weak-lined T-Tauri star LkCa 4 by searching for spectral signatures of radiation originating from the starspot or starspot groups. We introduce a new methodology for constraining both the starspot filling factor and the spot temperature by fitting two-temperature stellar atmosphere models constructed from Phoenix synthetic spectra to a high-resolution near-IR IGRINS spectrum. Clearly discernable spectral features arise from both a hot photospheric component {T}{hot} ∼ 4100 K and a cool component {T}{cool} ∼ 2700-3000 K, which covers ∼80% of the visible surface. This mix of hot and cool emission is supported by analyses of the spectral energy distribution, rotational modulation of colors and of TiO band strengths, and features in low-resolution optical/near-IR spectroscopy. Although the revised effective temperature and luminosity make LkCa 4 appear to be much younger and of much lower mass than previous estimates from unspotted stellar evolution models, appropriate estimates will require the production and adoption of spotted evolutionary models. Biases from starspots likely afflict most fully convective young stars and contribute to uncertainties in ages and age spreads of open clusters. In some spectral regions, starspots act as a featureless “veiling” continuum owing to high rotational broadening and heavy line blanketing in cool star spectra. Some evidence is also found for an anticorrelation between the velocities of the warm and cool components

Placing the spotted T Tauri star LkCa 4 on an HR diagram

Ages and masses of young stars are often estimated by comparing their luminosities and effective temperatures to pre-main-sequence stellar evolution tracks, but magnetic fields and starspots complicate both the observations and evolution. To understand their influence, we study the heavily spotted weak-lined T-Tauri star LkCa 4 by searching for spectral signatures of radiation originating from the starspot or starspot groups. We introduce a new methodology for constraining both the starspot filling factor and the spot temperature by fitting two-temperature stellar atmosphere models constructed from Phoenix synthetic spectra to a high-resolution near-IR IGRINS spectrum. Clearly discernable spectral features arise from both a hot photospheric component Thot ∼ 4100 K and a cool component Tcool ∼ 2700–3000 K, which covers ∼80% of the visible surface. This mix of hot and cool emission is supported by analyses of the spectral energy distribution, rotational modulation of colors and of TiO band strengths, and features in low-resolution optical/near-IR spectroscopy. Although the revised effective temperature and luminosity make LkCa 4 appear to be much younger and of much lower mass than previous estimates from unspotted stellar evolution models, appropriate estimates will require the production and adoption of spotted evolutionary models. Biases from starspots likely afflict most fully convective young stars and contribute to uncertainties in ages and age spreads of open clusters. In some spectral regions, starspots act as a featureless "veiling" continuum owing to high rotational broadening and heavy line blanketing in cool star spectra. Some evidence is also found for an anticorrelation between the velocities of the warm and cool components