Harmonization of space-borne infra-red sensors measuring sea surface temperature

Sea surface temperature (SST) is observed by a constellation of sensors, and SST retrievals are commonly combined into gridded SST analyses and climate data records (CDRs). Differential biases between SSTs from different sensors cause errors in such products, including feature artefacts. We introduce a new method for reducing differential biases across the SST constellation, by reconciling the brightness temperature (BT) calibration and SST retrieval parameters between sensors. We use the Advanced Along-Track Scanning Radiometer (AATSR) and the Sea and Land Surface Temperature Radiometer (SLSTR) as reference sensors, and the Advanced Very High Resolution Radiometer (AVHRR) of the MetOp-A mission to bridge the gap between these references. Observations across a range of AVHRR zenith angles are matched with dual-view three-channel skin SST retrievals from the AATSR and SLSTR. These skin SSTs act as the harmonization reference for AVHRR retrievals by optimal estimation (OE). Parameters for the harmonized AVHRR OE are iteratively determined, including BT bias corrections and observation error covariance matrices as functions of water-vapor path. The OE SSTs obtained from AVHRR are shown to be closely consistent with the reference sensor SSTs. Independent validation against drifting buoy SSTs shows that the AVHRR OE retrieval is stable across the reference-sensor gap. We discuss that this method is suitable to improve consistency across the whole constellation of SST sensors. The approach will help stabilize and reduce errors in future SST CDRs, as well as having application to other domains of remote sensing

Secondary peritoneal hydatidosis, the challenges of echinococcal disease in South Sudan: A case report

A 28 year old male presented to the Juba Teaching Hospital with progressive shortness of breath. 18 months prior to admission, he presented to a rural hospital with severe abdominal pain. An emergency laparotomy was  performed, and a large hepatic cyst was removed. Examination at the Juba Teaching hospital revealed a grossly distended abdomen with multiple palpable masses per abdomen. An Abdominal Ultrasound revealed multiple loculated cysts throughout the abdomen. A diagnosis of Secondary Peritoneal Hydatidosis resulting from incorrectly performed surgery was made. The patient was conservatively treated and at 14 weeks, the cysts showed a  moderate reduction in size. Cystic Echinococcus(CE) is common in South Sudan and has a considerable disease burden throughout the developing world. Greater governmental and international support is required to develop effective control measures for these diseases

Lattice QCD Evidence that the Lambda(1405) Resonance is an Antikaon-Nucleon Molecule

For almost 50 years the structure of the Lambda(1405) resonance has been a mystery. Even though it contains a heavy strange quark and has odd parity, its mass is lower than any other excited spin-1/2 baryon. Dalitz and co-workers speculated that it might be a molecular state of an antikaon bound to a nucleon. However, a standard quark-model structure is also admissible. Although the intervening years have seen considerable effort, there has been no convincing resolution. Here we present a new lattice QCD simulation showing that the strange magnetic form factor of the Lambda(1405) vanishes, signaling the formation of an antikaon-nucleon molecule. Together with a Hamiltonian effective-field-theory model analysis of the lattice QCD energy levels, this strongly suggests that the structure is dominated by a bound antikaon-nucleon component. This result clarifies that not all states occurring in nature can be described within a simple quark model framework and points to the existence of exotic molecular meson-nucleon bound states.Comment: Manuscript accepted for publication. 4 figures, 5 page

Low-Loss Plasmonic Dielectric Nanoresonators

Material losses in metals are a central bottleneck in plasmonics for many applications. Here we propose and theoretically demonstrate that metal losses can be successfully mitigated with dielectric particles on metallic films, giving rise to hybrid dielectric-metal resonances. In the far field, they yield strong and efficient scattering, beyond even the theoretical limits of all-metal and all-dielectric structures. In the near field, they offer high Purcell factor (>5000), high quantum efficiency (>90%), and highly directional emission at visible and infrared wavelengths. Their quality factors can be readily tailored from plasmonic-like (∼10) to dielectric-like (∼103), with wide control over the individual resonant coupling to photon, plasmon, and dissipative channels. Compared with conventional plasmonic nanostructures, such resonances show robustness against detrimental nonlocal effects and provide higher field enhancement at extreme nanoscopic sizes and spacings. These hybrid resonances equip plasmonics with high efficiency, which has been the predominant goal since the field’s inception. Keywords: light scattering; nanoantennas; Nanoparticles; nonlocality; radiative efficiency; spontaneous emissionUnited States. Army Research Office (Contract W911NF-13-D-0001)National Science Foundation (U.S.) (Grant DMR-1419807)United States. Department of Energy (Grant DE-SC0001299

Targeted subendothelial matrix oxidation by myeloperoxidase triggers myosin II-dependent de-adhesion and alters signaling in endothelial cells

During inflammation, myeloperoxidase (MPO) released by circulating leukocytes accumulates within the subendothelial matrix by binding to and transcytosing the endothelium. Oxidative reactions catalyzed by subendothelial-localized MPO are implicated as a key cause of endothelial dysfunction in inflammatory vascular diseases. Whilst the subendothelial matrix is a reactive target for MPO-derived oxidants in disease, the functional implications of oxidative matrix modification for the endothelium are largely unknown. Here we show that hypochlorous acid (HOCl) produced by endothelial-transcytosed MPO oxidizes the subendothelial matrix, involving covalent crosslinking of the adhesive matrix protein fibronectin. Real-time biosensor and live cell imaging studies showed that HOCl-mediated matrix oxidation triggers rapid membrane retraction from the substratum and adjacent cells (de-adhesion). This de-adhesion was linked with the alteration of Tyr-118 phosphorylation of paxillin, a key focal adhesion-dependent signaling process, as well as Rho kinase-dependent myosin light chain-2 phosphorylation. De-adhesion dynamics were dependent on the contractile state of cells, with myosin II inhibition with blebbistatin markedly attenuating the rate of membrane retraction. Rho kinase inhibition with Y-27632 also conferred protection, but not during the initial phase of membrane retraction, which was driven by pre-existing actomyosin tensile stress. Notably, diversion of MPO from HOCl production by thiocyanate and nitrite attenuated de-adhesion and associated signaling responses, despite the latter substrate supporting MPO-catalyzed fibronectin nitration. This study indicates that HOCl-mediated matrix oxidation by subendothelial MPO deposits may play an important and previously unrecognized role in altering endothelial adhesion, signaling and integrity during inflammatory vascular disorders

Adding to the Family of Copper Complexes Featuring Borohydride Ligands Based on 2-Mercaptopyridyl Units

Borohydride ligands featuring multiple pendant donor functionalities have been prevalent in the chemical literature for many decades now. More recent times has seen their development into new families of so-called soft scorpionates, for example, those featuring sulfur based donors. Despite all of these developments, those ligands containing just one pendant group are rare. This article explores one ligand family based on the 2-mercaptopyridine heterocycle. The coordination chemistry of the monosubstituted ligand, [H3B(mp)]− (mp = 2-mercaptopyridyl), has been explored. Reaction of Na[BH3(mp)] with one equivalent of Cu(I)Cl in the presence of either triphenylphosphine or tricyclohexylphosphine co-ligands leads to the formation of [Cu{H3B(mp)}(PR3)] (R = Ph, 1; Cy, 2), respectively. Structural characterization confirms a κ3-S,H,H coordination mode for the borohydride-based ligand within 1 and 2, involving a dihydroborate bridging interaction (BH2Cu) with the copper centers

Specific inhibition of binding of antistasin and [A103,106,108] antistasin 93–119 to sulfatide (Gal(3-SO4)β1-1Cer) by glycosaminoglycans

AbstractLeech-derived antistasin is a potent anticoagulant and antimetastatic protein that binds sulfatide (Gal(3-SO4)β1-1Cer)and sulfated polysaccharides. In this study, the synthetic fragment [A103,106,108] antistasin 93–119, which corresponds to the carboxyl terminus, showed specific and saturable binding to sulfatide. Binding was competitively blocked by glycosaminoglycans (GAGs) in the order: dextran sulfate 5000 ≅ dextran sulfate 500 0OO > heparin > dermatan sulfate ⪢ chondroitin sulfates A and C. This rank order of inhibitory potency was identical to that observed with whole antistasin. We suggest that residues 93–119 of antistasin represent a critical domain for binding GAGs and sulfated glycolipids

Evaluation of the impact of tillage/cropping systems on soil microflora and week seedbank predation

Soil erosion and pesticide use are critical issues in sustainable agriculture. With a view to decreasing the amount of pesticides used for weed control, researchers assessed the impact of tillage, cropping systems and weed management regimes on seasonal and long-term weed and weed seedbank population dynamics, especially in Conservation Reserve Program land being returned to production

Aneuploidy in oocytes is prevented by sustained CDK1 activity through degron masking in cyclin B1

Successful mitosis requires that cyclin B1:CDK1 kinase activity remains high until chromosomes are correctly aligned on the mitotic spindle. It has therefore been unclear why, in mammalian oocyte meiosis, cyclin B1 destruction begins before chromosome alignment is complete. Here, we resolve this paradox and show that mouse oocytes exploit an imbalance in the ratio of cyclin B1 to CDK1 to control CDK1 activity; early cyclin B1 destruction reflects the loss of an excess of non-CDK1-bound cyclin B1 in late prometaphase, while CDK1-bound cyclin B1 is destroyed only during metaphase. The ordered destruction of the two forms of cyclin B1 is brought about by a previously unidentified motif that is accessible in free cyclin B1 but masked when cyclin B1 is in complex with CDK1. This protects the CDK1-bound fraction from destruction in prometaphase, ensuring a period of prolonged CDK1 activity sufficient to achieve optimal chromosome alignment and prevent aneuploidy

Short-term studies underestimate 30-generation changes in a butterfly metapopulation

Most studies of rare and endangered species are based on work carried out within one generation, or over one to a few generations of the study organism. We report the results of a study that spans 30 generations (years) of the entire natural range of a butterfly race that is endemic to 35 km2 of north Wales, UK. Short-term studies (surveys in single years and dynamics over 4 years) of this system led to the prediction that the regional distribution would be quite stable, and that colonization and extinction dynamics would be relatively unimportant. However, a longer-term study revealed unexpectedly high levels of population turnover (local extinction and colonization), affecting 18 out of the 20 patches that were occupied at any time during the period. Modelling the system (using the 'incidence function model' (IFM) for metapopulations) also showed higher levels of colonization and extinction with increasing duration of the study. The longer-term dynamics observed in this system can be compared, at a metapopulation level, with the increased levels of variation observed with increasing time that have been observed in single populations. Long-term changes may arise from local changes in the environment that make individual patches more or less suitable for the butterfly, or from unusual colonization or extinction events that take metapopulations into alternative states. One implication is that metapopulation and population viability analyses based on studies that cover only a few animal or plant generations may underestimate extinction threats