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Self-organization of cells is central to a variety of biological systems and physical concepts of condensed matter have proven instrumental in deciphering some of their properties. Here we show that microphase separation, long studied in polymeric materials and other inert systems, has a natural counterpart in living cells. When placed below a millimetric film of liquid nutritive medium, a quasi two-dimensional, high-density population of Dictyostelium discoideum cells spontaneously assembles into compact domains. Their typical size of 100 μm is governed by a balance between competing interactions: an adhesion acting as a short-range attraction and promoting aggregation, and an effective long-range repulsion stemming from aerotaxis in near anoxic condition. Experimental data, a simple model and cell-based simulations all support this scenario. Our findings establish a generic mechanism for self-organization of living cells and highlight oxygen regulation as an emergent organizing principle for biological matter. In this work the authors report a quasi two-dimensional population of living cells that can spontaneously self-assemble into finite-sized domains, an analogue of the microphase separation known in inert matter. [ABSTRACT FROM AUTHOR]

The frequencies of interest for redshifted 21 cm observations are heavily affected by terrestrial radio-frequency interference (RFI). We identify the McGill Arctic Research Station (MARS) as a new RFI-quiet site and report its RFI occupancy using 122 h of data taken with a prototype antenna station developed for the Array of Long-Baseline Antennas for Taking Radio Observations from the Sub-Antarctic. Using an RFI flagging process tailored to the MARS data, we find an overall RFI occupancy of 1.8% averaged over 20–125 MHz. In particular, the FM broadcast band (88–108 MHz) is found to have an RFI occupancy of at most 1.6%. The data were taken during the Arctic summer, when degraded ionospheric conditions and an active research base contributed to increased RFI. The results quoted here therefore represent the maximum-level RFI environment at MARS. [ABSTRACT FROM AUTHOR]

Drought stress has a negative impact on crop growth and productivity worldwide. Plant symbionts such as arbuscular mycorrhizal fungi (AMF) can enhance plant growth and improve plant resistance to drought stress. AMF mixture inocula and plant responses to drought still require further study. The objective of this study was to investigate the effects of non-inoculation (NM) or inoculation with three commercial AMF inocula containing a single or mixtures comprising different numbers of AMF species: M1 (Rhizophagus intraradices), M2 (Rhizophagus clarus, R. intraradices, Septoglomus deserticola, Funneliformis mosseae), and M3 (Rhizophagus intraradices, R. aggregatum, Funneliformis mosseae, Olaroideoglomus etunicatum) on growth, nutritional, and physiological responses of soybean (Glycine max L. cv. Hutcheson) grown in a greenhouse under different water stress levels [WW = well watered (90% FC), MS = medium (60% FC) and SS = severe stressed (30% FC)]. The AMF-inoculated plants had significantly higher plant biomass, chlorophyll content, stomatal conductance, leaf water relations, and mineral contents in comparison to NM plants. Applied mycorrhizal inocula differed in their response to water-deficit conditions. M2 inoculant generally supported greater plant biomass, stomatal conductance, leaf water content, and leaf N, P, K, S, Mn, and Cu contents than M1 and M3 inocula, especially under MS and SS treatments. These results indicated that all mycorrhizal inocula supported plant growth both generally and with soil water deficit; however, M2-inoculated plants performed better than M1 and M3 under drought stress. Therefore, mycorrhizal inocula are effective for supporting soybean growth and offsetting the effects of drought and AMF technology that can support sustainable crop cultivation under soil water-deficit conditions. Different types of inocula have different effects, however, and thus require testing for individual crops. [ABSTRACT FROM AUTHOR]

Measurements of redshifted 21 cm emission of neutral hydrogen at ≲ 3 0 MHz have the potential to probe the cosmic "dark ages," a period of the universe's history that remains unobserved to date. Observations at these frequencies are exceptionally challenging because of bright Galactic foregrounds, ionospheric contamination, and terrestrial radio-frequency interference. Very few sky maps exist at ≲ 3 0 MHz, and most have modest resolution. We introduce the Array of Long Baseline Antennas for Taking Radio Observations from the Sub-Antarctic (ALBATROS), a new experiment that aims to image low-frequency Galactic emission with an order-of-magnitude improvement in resolution over existing data. The ALBATROS array will consist of antenna stations that operate autonomously, each recording baseband data that will be interferometrically combined offline. The array will be installed on Marion Island and will ultimately comprise 10 stations, with an operating frequency range of 1.2–125 MHz and maximum baseline lengths of ∼ 2 0 km. We present the ALBATROS instrument design and discuss pathfinder observations that were taken from Marion Island during 2018–2019. [ABSTRACT FROM AUTHOR]

Nanocrystalline metals exhibit a phenomenon called plastic strain recovery whereby plastic strain introduced through a load cycle is gradually recovered under no external loading over a time period of hours and days. In this study, we experimentally explore the diffusive mechanisms and the strain rates for nanocrystalline thin films of copper with an average grain size of about 35 nm during plastic strain recovery and creep. The experiments are performed via the plane strain bulge test and the thin film samples are deposited using thermal evaporation and sputtering. The specimens recover their residual strain in a period of time with two characteristic strain rates, a transient strain recovery rate of the order of 10/ s and a steady-state strain recovery rate of the order of 10/ s and there is a characteristic time at which the transition occurs between the two rates. The results suggest that a diffusive mechanism in conjunction with voids within the nanocrystalline material can explain the two plastic strain recovery rates and the transition between the two. [ABSTRACT FROM AUTHOR]

Besides titanium dioxide (TiO2), zinc oxide (ZnO) nanoparticles (NPs) are commonly used in sunscreen formulations as protective agents against exposure to ultraviolet radiation. Although the majority of prior studies have concluded that NPs do not penetrate healthy skin, compromised skin slightly enhanced metal oxide NP penetration. However, a question arises regarding the possible toxic consequences if consumers who had applied sunscreens containing ZnO-NPs were exposed to environmentally relevant doses of UVB. Considering this, we planned a study where SKH-1 hairless mice were topically exposed to a 5% and/or 10% dose of ZnO-NPs (<50 nm and <100 nm) either alone or along with UVB (50 mJ cm−2). In two additional groups, mice were treated with either bulk ZnO-NPs (<5 μm) or with ZnO-NPs (<5 μm) and subsequently UVB (50 mJ cm−2). Animals of all groups were sacrificed after 6, 24 and 48 h and the Zn ion content in the skin was measured. In addition, estimation of ROS generation, histopathology, myeloperoxidase (MPO) activity, immunohistochemistry for COX-2 and western blot analysis for MAPKs, p-IκBα, p-NF-κB, and COX-2 were also carried out. Significant increases in the Zn ion in exposed skin were seen. Enhanced ROS generation and MPO activity were also found in ZnO-NPs followed by UVB exposed groups at all three time points. Similarly, hyperplasia and over-expression of COX-2 were also greater in ZnO-NPs and UVB exposed groups than in the ZnO-NPs and UVB only groups. The expression of MAPKs, and transcription factors NF-κB along with COX-2 were also enhanced significantly in ZnO-NPs and the UVB treated group. Collectively, our findings suggest that UVB exposure enhanced ZnO-NP penetration in mouse skin and possibly dissolution of these ZnO-NPs takes place during this process, causing significant Zn ion generation leading to oxidative stress by ROS generation which subsequently activates MAPK-NF-κB signaling and increases COX-2 and inflammation. [ABSTRACT FROM AUTHOR]

The radiation damage rates in the Al-303-1-alloy cladding of the Syrian Miniature Neutron Source Reactor reactor has been numerically estimated with the The MCNP-4C and NJOY93 codes and the ENDF/B-VI library. The calculations showed that the Al-cladding alloy had received a maximum radiation damage rate equal to 7.01×10−9 (dpa/s). The total damage and helium production rates in the Al-cladding alloy were 0.13 (dpa) and 1.01×10−2 (appm, He), respectively. The contribution of the fast neutrons in the radiation damage was most effective. [ABSTRACT FROM PUBLISHER]

Date palm (Phoenix dactylifera) is a significant and developing crop especially in the Arabian Peninsula, the Middle East and North Africa regions. The area under cultivation of this tree is increasing annually. Date palms usually grown under harsh and unfavorable growing conditions with low rainfall and high rates of evaporation as well as in soils with low organic matter and nutrient deficiencies. Hence, date palm cultivation becomes dependent on application of high levels of fertilizers as well as on irrigation. This may lead to salinization of soil and leaching of nutrients to deep soils that might affect ground water. Therefore, it is important that date palm plantations are managed in a sustainable way to reduce the impact of date palm cultivation on ecosystems while maximizing dates yield through using such practices as mycorrhizal fungi technology. The application of mycorrhizal fungi technology is an option that can benefit both agronomic plant health and ecosystems. Mycorrhizae confer numerous benefits to host plants including improved plant growth and mineral nutrition, water uptake, tolerance to diseases and stresses such as drought, temperature fluctuation, metal toxicity and salinity. Mycorrhizae may also play a role in the formation of stable soil aggregates, building up a macro porous structure of soil that allows penetration of water and air and prevents erosion. All of these beneficial effects on plant health and soil fitness mean that mycorrhizae have the potential to increase agricultural productivity and are crucial for the sustainable functioning of agricultural ecosystems. This study provides an insight into the application of mycorrhizae in date palm cultivation. [ABSTRACT FROM AUTHOR]

The objectives of this study were to evaluate five forage crops (alfalfa (Medicago sativa), barley (Hordeum vulgare), cowpea (Vigna unguiculata), sorghum (Sorghum bicolor), and wheat (Triticum aestivum)) for green fodder production and water use efficiency under hydroponic conditions. The experiment has been conducted under temperature-controlled conditions (24 ± 1°C) and natural window illumination at growth room of Soilless Culture Laboratory, Arabian Gulf University, Manama, Bahrain. The results showed that green forage can be produced in 8 days from planting to harvest using hydroponic technique. Highest values for green fresh yields were recorded for the crops cowpea, barley, and alfalfa which gave 217, 200, and 194 tons/ha, respectively. However, only cowpea and barley crops gave the highest green dry yield, but not alfalfa. Barely crop used water more efficiently than the other four tested crops when produced about 654 kg fresh matter/m3 water in comparison to 633, 585, 552, and 521 kg fresh matter/m³ water for cowpea, sorghum, wheat, and alfalfa, respectively. No significant differences between barley and cowpea for water use efficiency were noted. It can be concluded from this study that barley crop can be considered the best choice for production of hydroponic green fodder with less water consumption. [ABSTRACT FROM AUTHOR]

A field study was carried out under rainfed conditions during the growing season 2008/2009 in Maru (Northern Jordan) to evaluate the phenological variation using heat-accumulated system and its relation with yield in sixteen durum wheat genotypes. Grain yield was negatively correlated with growing degree days (GDDs) to maturity, while positively correlated with GDD to heading. Increasing GDD to heading resulted in higher grain yield, while increasing grain fill duration had little effect. Rapid grain fill rate was positively correlated with grain weight and negatively correlated with grain fill duration. Waha-1, Omrabi-5, and Massara-1 genotypes had the highest grain yields among genotypes studied. These three genotypes tended to have relatively longer preheading periods with early maturity. The results of this study indicate that Mediterranean-adapted cultivars would have long preheading periods, followed by short periods and high rates of grain fill and mature early to avoid late-season drought and high-temperature stress and to attain high yields. Therefore, it is recommended for the development of high yielding wheat cultivars adapted to semiarid environments to select the genotypes with early maturity and a relatively long time to heading. [ABSTRACT FROM AUTHOR]

PurposeTo assess ranibizumab (Lucentis) penetration into the retina after topical administration in a rabbit model.MethodsRanibizumab was topically applied to the right eye of rabbits according to three regimens: every 2 h (q2hr), four times daily (qid), and twice daily (bid). Intraocular penetration of ranibizumab was assessed at 3, 7, 14, 21, and 28 days following initiation of drops. At each time point, the anterior chambers, vitreous cavities, and blood of one of the rabbits from each subgroup were sampled for ranibizumab detection using enzyme-linked immunosorbent assay (ELISA), and both eyes were then enucleated for ranibizumab detection in the retina by confocal immunohistochemistry (CI). Another group of rabbits received intravitreal ranibizumab and was similarly sampled for comparison.ResultsCI showed ranibizumab staining in the right retina after 7 and 14 days of q2hr topical administration in two out of four experiments. No ranibizumab was detected in the left retina at any of the sampling time points. ELISA was positive in the vitreous of the right eye at 14 and 21 days in the q2hr treated rabbits in one out of four experiments. No ranibizumab was detected in the qid and bid subgroups. CI and ELISA of the aqueous and vitreous were consistently positive in the intravitreal group. Mild ranibizumab levels were detected in the blood in both the topical and intravitreal groups.ConclusionsTopically applied ranibizumab can be detected in the retina following high-frequency administration in a rabbit model. A trans-scleral route of penetration is suggested. [ABSTRACT FROM AUTHOR]

Using alternative water resources such as tertiary treated sewage wastewater is considered very important to produce crops (e.g., green forage) due to irrigation water shortage, especially in arid and semiarid regions like Jordan. Moreover, growing forage hydroponically is now becoming popular in drought prone areas to produce green fodders in large quantities with less water use. The objectives of this study were to investigate the effects of irrigation with tertiary sewage treated wastewater (WW), tap water (TW) or mixed WW with tap water (WW mix) on barley (Hordeum vulgare L.) fodder yield, quality, and water use efficiency (WUE) under hydroponic conditions. A hydroponic system was developed with four shelves and used in this study. The results showed that barley forage can be produced in 9 days from planting to harvest in this system. Using WW in irrigation has effectively increased the yields of green and dry fodder, and the green forage yields obtained were 224, 276 and 320 tons/ha under irrigation with TW, WW mix and WW, respectively. The higher fodder yields obtained with WW than TW or WW mix, probably due to the higher nutritive value of WW especially N content. However, plants irrigated with WW used water more efficiently than those irrigated with other water types, when used 1.26 m3 compared to 1.56 m3 water in TW to produce 1 ton of hydroponic green fodder. Proximate and mineral nutrient contents of dry fodder were significantly higher in plants irrigated with WW than with TW in respect to crude protein, acid and neutral detergent fiber, and N, K, Mg, and Na contents. Heavy metal (Cd, Pb, and Ni) contents in barley fodder were higher in plants irrigated with WW than those irrigated with TW, but their levels did not reached the maximum allowed levels by FAO for edible crops. The results of this study revealed that hydroponic green barley fodder could be irrigated safely with tertiary treated sewage wastewater to produce high yields and less water use. Moreover, use of treated wastewater in irrigation of green forages in hydroponic system considered as useful alternative disposal method of wastewater without the risk of accumulation of heavy metals in the soil. [ABSTRACT FROM AUTHOR]

PurposeTo investigate a viral etiology in certain chalazia.MethodsA prospective study over 7.5 years of all newly presenting chalazia associated with diffuse follicular conjunctivitis but without any other aetiological factors. Patients were investigated for ocular or systemic infections by history, physical exam, slit-lamp exam, and/or histology of conjunctival biopsy (including transmission electron microscopy).ResultsA total of 27 patients developed follicular conjunctivitis without meibomian gland dysfunction, blepharitis, or sexually transmitted diseases. Evidence for a viral aetiology included: recent systemic viral illness (15/27), recent contact with subjects with chalazia or follicular conjunctivitis (5/27), preauricular lymphadenopathy (4/27), viral corneal disease (4/27), or viral particles by ultrastructure (4/4).ConclusionsChalazia may be associated with viral conjunctivitis. Intralesional corticosteroids should be considered with great caution for viral-induced chalazia.Eye (2006) 20, 242–246. doi:10.1038/sj.eye.6701816; published online 4 March 2005 [ABSTRACT FROM AUTHOR]

Dry pea (Pisum sativum L.) growers in the semiarid Mediterranean region require cultivars that are both early maturing and high yielding. However, negative relationships between these two characteristics limit their simultaneous improvement. A better understanding of the relative importance of the developmental stages in determining yield would assist in pea improvement. Sixteen dry pea cultivars were grown for 2 years under semiarid Mediterranean conditions (Maru, north Jordan) in order to see if differences in growing degree days (GDD) to flowering and GDD from planting to physiological maturity exist and to study their relationships with seed yield. Seed yield was negatively correlated with GDD to maturity, but not significantly correlated with GDD to flowering. Increasing GDD to flowering resulted in higher seed yield, while increasing seed fill duration had little effect. Rapid seed fill rate was positively correlated with seed weight and negatively correlated with seed fill duration. These results indicate that Mediterranean-adapted cultivars would have preflowering periods lasting as long as possible, followed by short seedfill periods. Simultaneous selection for early maturity and a relatively long time to flowering is recommended for the development of early-maturing, high-yielding cultivars adapted to semiarid Mediterranean environments. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agronomy & Crop Science is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agronomy & Crop Science is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Arbuscular mycorrhizal fungi (AMF) living symbiotically with host plants enhance plant growth by improving the acquisition of mineral nutrients and water relations. This study determined the effects of AMF inoculation on growth, benefit/cost and water-use efficiency (grams dry matter produced per kilogram water evapotranspired) in two durum wheat genotypes (drought sensitive and drought tolerant) under water-stressed and well-watered conditions. Plants were grown in a low-P silty clay (Typic Xerochrept) soil mix in a greenhouse. Shoot and root dry matter (DM) and root AMF colonization were higher for well-watered than for water-stressed plants. The mycorrhizal plants were more water-use efficient than nonmycorrhizal plants. Shoot DM differences between mycorrhizal and nonmycorrhizal plants represent the benefit derived by plants from AMF-root associations. Shoot DM differences between mycorrhizal and nonmycorrhizal plants under similar conditions of water treatment represent the cost to the plant of AMF-root associations. Values of benefit/cost for AMF-root associations were highest when plants were water-stressed and decreased under well-watered conditions. Genotypic differences in calculated costs and benefits were pronounced. Benefit/cost analysis may be helpful in evaluating host plant genotypes in order to optimize efficiencies of AMF symbiosis under different environmental conditions. [ABSTRACT FROM AUTHOR]

The article presents the case of a five-year-old Hispanic boy with hypertensive retinopathy. He was taken to the University of Virginia Ophthalmology Clinic for the assessment of strabismus. His parents stated that the boy had a one-month history of intermittent crossed eyes. Results of the motility examination revealed the presence of diopters of comitant esodeviation and overaction of the right inferior oblique.