740 research outputs found
A record of communal nesting in the barn owl (Tyto alba)
We report a unique case of two female Barn Owls laying eggs and incubating together in a single nest cup in a communal nest. A trio of two females and one male bred in an abandoned water tower in 2013 in Israel. Both females incubated/brooded together in the communal nest, and all three individuals brought food to the communal family. The two females laid 20 eggs, of which 19 hatched and 16 fledged
Keragaman Produksi Plasma Nutfah Pala (Myristica Fragrans) Di KP Cicurug
Nutmeg known as a major spice in the world. The plant originated from Moluccas island of Indonesia. It is an evergreen tree with 4-10 m height and sometimes up to 20 m. The plant is a dioecious, start bearing fruit at 5 to 8 years after planting, and before reaching generative period it can not be distinguish whether the plant is a male or female plant. Nutmeg has an ovale to rounded fruit shape with 1-10 cm long with thin to thick fleshly fruit and creamy white colour. Nutmeg seed surrounded by arils which is famous known as mace, usually with red colour and the major constituent is myristicin. Collecting of nutmeg at Moluccas, North Sulawesi and Papua obtained 430 seeds from several different locality and the plant were planted with 8 m x 8 m space row at Cicurug garden Sukabumi-West Java, 500 m above sea level, in 1992 and 1993. So far the remaining plant were only 368 trees. Observation of nutmeg yield was carried out in 5 years (2000, 2001, 2002, 2004, and 2005) to those collection to evaluate their yield variation and continuity. T-test were used to estimate the plant with better yield. Result showed that there were high variation in nutmeg fruit yield among and between locality represented value of variation almost 100%. Less than 50 plant have a relative yield continuity, moreover they were only 7 trees which has cumulative yield more than 4000 fruits/tree i.e. Bagea Yan Maliaro 213, Banda 11, Botol 137, Kupal 139, Patani 25, Patani 32, and Patani 33. The cumulative yield per tree ranged from 0-7808 fruits with the average 1195 nut/tree. Harvesting nutmeg fruit at Cicurug garden was done almost all year around, with the peak harvest in Mei to June
Multifunctional sol-gel derived thin film based on nanocrystaline hydroxyapatite powders
The aim of this work was to prepare bioactive hydroxyapatite coatings by sol-gel method and to study the effect of thermal treatment temperature upon the bioactivity and corrosion protection of these coatings on Ti6Al4V alloy. The application of (DTA/TGA) and (XRD) has provided valuable information about the phase transformation, mass loss, identification of the phases developed, crystallite size and degree of crystallinity. (SEM/EDX) has been applied to study the surface morphology of coated samples before and after immersion in simulated body fluid (SBF) to detect the biomimetic precipitation of the bonelike apatite. The obtained results show that all the prepared samples are ceramic nanocrystalline with crystal structure and composition like hydroxyapatite, with little deviations from that present in the human bone. The bioactivity of the studied samples is found to be closely related to the thermal treatments applied. That is, the bioactivity decreases as the temperature of the thermal treatment increase. Coatings from such prepared hydroxyapatite sol have been accomplished by dip-coating technique on non-toxic Ti6Al4V alloy for biomedical applications. The corrosion behaviour of the resulting hydroxyapatite coatings in a (SBF) has been studied by electrochemical impedance spectroscopy (EIS). The hydroxyapatite coated Ti6Al4V alloy displayed excellent bioactivity when soaked in the (SBF) and acceptable corrosion protection behaviour.This work has been supported by the National Program for Materials, Spanish Ministry of Science and Innovation (Project MAT2006-04486). A.A. El hadad acknowledges a pre-doctoral contract JAE financed by CSIC; V. Barranco acknowledges a Ramon y Cajal researcher contract financed by CSIC-MICIN
Trapping cold atoms using surface-grown carbon nanotubes
We present a feasibility study for loading cold atomic clouds into magnetic
traps created by single-wall carbon nanotubes grown directly onto dielectric
surfaces. We show that atoms may be captured for experimentally sustainable
nanotube currents, generating trapped clouds whose densities and lifetimes are
sufficient to enable detection by simple imaging methods. This opens the way
for a novel type of conductor to be used in atomchips, enabling atom trapping
at sub-micron distances, with implications for both fundamental studies and for
technological applications
Magnetic-film atom chip with 10 m period lattices of microtraps for quantum information science with Rydberg atoms
We describe the fabrication and construction of a setup for creating lattices
of magnetic microtraps for ultracold atoms on an atom chip. The lattice is
defined by lithographic patterning of a permanent magnetic film. Patterned
magnetic-film atom chips enable a large variety of trapping geometries over a
wide range of length scales. We demonstrate an atom chip with a lattice
constant of 10 m, suitable for experiments in quantum information science
employing the interaction between atoms in highly-excited Rydberg energy
levels. The active trapping region contains lattice regions with square and
hexagonal symmetry, with the two regions joined at an interface. A structure of
macroscopic wires, cut out of a silver foil, was mounted under the atom chip in
order to load ultracold Rb atoms into the microtraps. We demonstrate
loading of atoms into the square and hexagonal lattice sections simultaneously
and show resolved imaging of individual lattice sites. Magnetic-film lattices
on atom chips provide a versatile platform for experiments with ultracold
atoms, in particular for quantum information science and quantum simulation.Comment: 7 pages, 7 figure
Properties of electrons scattered on a strong plane electromagnetic wave with a linear polarization: classical treatment
The relations among the components of the exit momenta of ultrarelativistic
electrons scattered on a strong electromagnetic wave of a low (optical)
frequency and linear polarization are established using the exact solutions to
the equations of motion with radiation reaction included (the Landau-Lifshitz
equation). It is found that the momentum components of the electrons traversed
the electromagnetic wave depend weakly on the initial values of the momenta.
These electrons are mostly scattered at the small angles to the direction of
propagation of the electromagnetic wave. The maximum Lorentz factor of the
electrons crossed the electromagnetic wave is proportional to the work done by
the electromagnetic field and is independent of the initial momenta. The
momentum component parallel to the electric field strength vector of the
electromagnetic wave is determined only by the diameter of the laser beam
measured in the units of the classical electron radius. As for the reflected
electrons, they for the most part lose the energy, but remain relativistic.
There is a reflection law for these electrons that relates the incident and the
reflection angles and is independent of any parameters.Comment: 12 pp, 3 fig
Particle production in string cosmology models
We compute spectra of particles produced during a dilaton-driven kinetic
inflation phase within string cosmology models. The resulting spectra depend on
the parameters of the model and on the type of particle and are quite varied,
some increasing and some decreasing with frequency. We use an approximation
scheme in which all spectra can be expressed in a nice symmetric form, perhaps
hinting at a deeper symmetry of the underlying physics. Our results may serve
as a starting point for detailed studies of relic abundances, dark matter
candidates, and possible sources of large scale anisotropy.Comment: 20 pages, no figures, latex, RevTe
Solar-wind ventilation to enhance the cabinet dryer performance for medicinal herbs and horticultural products
This paper presents the design, construction and performance evaluation of a mixed-mode solar cabinet dryer (SCD) for medicinal herbs and horticultural products. Solar- wind ventilation system is used to enhance the cabinet dryer performance. The solar cabinet is equipped with a vertical blackened solar chimney and a flat plate solar collector to enhance buoyancy force. The chimney is provided with suction axial fan that can rotate smoothly by wind power. The performance of SCD was evaluated without load (empty) and with load (potato chips and peppermint). After performing various standardized pretreatments, products were dried separately under open sun, SCD and electric oven. Results of parametric studies indicated that, highest drying air temperature was achieved at 60° collector tilt angle followed by 30°, when the dehydration system tracked the sun. The developed SCD exhibited sufficient ability to dry the chips and peppermint reasonably to a safe moisture level within 9-10 and 5-6 hrs (≈1 clear sunny day), respectively. The best chips colour was achieved at 15 s frying time. All the fried chips and dried peppermint were well accepted by the panelists. The SCD ensures a superior quality of the dried products. In terms of electricity requirement, frying time, health conscious and utilization of solar energy, the enhanced SCD is considered a suitable method for drying potato chips as well as peppermint. Keywords: solar cabinet, solar collector, windmill, drying, chips, peppermint
MAGE-A cancer/testis antigens inhibit MDM2 ubiquitylation function and promote increased levels of MDM4
Melanoma antigen A (MAGE-A) proteins comprise a structurally and biochemically similar sub-family of Cancer/Testis antigens that are expressed in many cancer types and are thought to contribute actively to malignancy. MAGE-A proteins are established regulators of certain cancer-associated transcription factors, including p53, and are activators of several RING finger-dependent ubiquitin E3 ligases. Here, we show that MAGE-A2 associates with MDM2, a ubiquitin E3 ligase that mediates ubiquitylation of more than 20 substrates including mainly p53, MDM2 itself, and MDM4, a potent p53 inhibitor and MDM2 partner that is structurally related to MDM2. We find that MAGE-A2 interacts with MDM2 via the N-terminal p53-binding pocket and the RING finger domain of MDM2 that is required for homo/hetero-dimerization and for E2 ligase interaction. Consistent with these data, we show that MAGE-A2 is a potent inhibitor of the E3 ubiquitin ligase activity of MDM2, yet it does not have any significant effect on p53 turnover mediated by MDM2. Strikingly, however, increased MAGE-A2 expression leads to reduced ubiquitylation and increased levels of MDM4. Similarly, silencing of endogenous MAGE-A expression diminishes MDM4 levels in a manner that can be rescued by the proteasomal inhibitor, bortezomid, and permits increased MDM2/MDM4 association. These data suggest that MAGE-A proteins can: (i) uncouple the ubiquitin ligase and degradation functions of MDM2; (ii) act as potent inhibitors of E3 ligase function; and (iii) regulate the turnover of MDM4. We also find an association between the presence of MAGE-A and increased MDM4 levels in primary breast cancer, suggesting that MAGE-A-dependent control of MDM4 levels has relevance to cancer clinically
Environmental, maternal, and reproductive risk factors for childhood acute lymphoblastic leukemia in Egypt : a case-control study
BACKGROUND\ud
Acute lymphocytic leukemia (ALL) is the most common pediatric cancer. The exact cause is not known in most cases, but past epidemiological research has suggested a number of potential risk factors. This study evaluated associations between environmental and parental factors and the risk for ALL in Egyptian children to gain insight into risk factors in this developing country.\ud
METHODS\ud
We conducted a case-control design from May 2009 to February 2012. Cases were recruited from Children's Cancer Hospital, Egypt (CCHE). Healthy controls were randomly selected from the general population to frequency-match the cumulative group of cases by sex, age groups (<1; 1 - 5; >5 - 10; >10 years) and region of residence (Cairo metropolitan region, Nile Delta region (North), and Upper Egypt (South)). Mothers provided answers to an administered questionnaire about their environmental exposures and health history including those of the father. Odds ratios (ORs) and 95 % confidence intervals (CI) were calculated using logistic regression with adjustment for covariates.\ud
RESULTS\ud
Two hundred ninety-nine ALL cases and 351 population-based controls frequency-matched for age group, gender and location were recruited. The risk of ALL was increased with the mother's use of medications for ovulation induction (ORadj = 2.5, 95 % CI =1.2 -5.1) and to a lesser extend with her age (ORadj = 1.8, 95 % CI = 1.1 - 2.8, for mothers ≥ 30 years old). Delivering the child by Cesarean section, was also associated with increased risk (ORadj = 2.01, 95 % CI =1.24-2.81).\ud
CONCLUSIONS\ud
In Egypt, the risk for childhood ALL appears to be associated with older maternal age, and certain maternal reproductive factors
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