InAs-AlSb quantum wells in tilted magnetic fields

InAs-AlSb quantum wells are investigated by transport experiments in magnetic fields tilted with respect to the sample normal. Using the coincidence method we find for magnetic fields up to 28 T that the spin splitting can be as large as 5 times the Landau splitting. We find a value of the g-factor of about 13. For small even-integer filling factors the corresponding minima in the Shubnikov-de Haas oscillations cannot be tuned into maxima for arbitrary tilt angles. This indicates the anti-crossing of neighboring Landau and spin levels. Furthermore we find for particular tilt angles a crossover from even-integer dominated Shubnikov-de Haas minima to odd-integer minima as a function of magnetic field

Impact of paddy straw mulch on germination and growth of celery (Apium graveolens L.) seedlings and associated weeds in nursery

A study was undertaken during three consecutive rabi seasons of 2014–15 to 2016–17 at the Research Farm, Department of Agronomy, Punjab Agricultural University, Ludhiana (Punjab) to determine the effect of paddy straw mulch load and retention time on the germination and growth of celery and associated weeds. The experiment was conducted in randomized complete block design (RCBD) with nine treatments viz., paddy straw mulch @ 4 and 6 t ha-1 with retention time of 15, 20, 25 days after sowing (DAS), full time retention (60 DAS), and control (without mulch). The results indicated that application of paddy straw mulch @ 4 or 6 t ha-1 significantly improved the germination of celery in nursery as compared to no mulch treatment but retention of paddy straw mulch beyond 20 days after sowing suppressed the celery seedlings adversely resulting in lowering seedling population as well as fresh and dry weight of celery seedlings. Application of paddy straw mulch @ 4 or 6 t ha-1 resulted in significantly lower density and dry weight of weeds as compared to control. Further, each successive increase in retention time of paddy straw mulch from 15 DAS to full time retention (60 DAS) through 20 and 25 DAS significantly reduced the weed population in celery nursery

An Ethanol-Based Proliposome Technology for Enhanced Delivery and Improved Respirability of Antiasthma Aerosols Generated Using a Micropump Vibrating-Mesh Nebulizer

Salbutamol sulphate liposomes were generated using ethanolbased proliposomes followed by nebulization using an Aeroneb Pro vibrating-mesh nebulizer. The droplet size, output and fine particle fraction (FPF) of the drug incorporated in liposome formulation were compared to those of a conventional drug solution. Aerosol output was determined gravimetrically and drug output was analyzed by using high performance liquid chromatography. The potential of aerosol deposition in deep lung was evaluated using inertial impaction and laser diffraction. The effect of formulation surface tension on the aerosol performance was studied. Output and FPF were improved using liposomes compared to the conventional solution, for instance, FPF values were 57.85% and 45.81% respectively. The volume median diameter as measured by laser diffraction was respectively 3.44 μm and 3.22 μm; however, the higher FPF of the liposome formulation is justified by the lower polydispersity of its aerosol. The improved aerosol performance using liposomes was attributed to the reduction of surface tension caused by the presence of phospholipid. This is the first study that demons trates the ability of liposomes to improve the nebulized drug output and FPF

Distinct levels in the nanoscale organization of DNA-histone complex revealed by its mechanical unfolding

Mechanical unfolding of nanoscale DNA-histone complex, using an atomic force microscope, shows a stepwise disassembly of histones from the nucleosome. A quantitative analysis of the rupture jump statistics and the length released per jump reveals insights into the possible histone contacts within the octamer complex. The measured ruptures correlate with the breakage of multiple contacts that stabilize the histone octamer. These results provide a mechanistic basis by which stepwise disassembly of histone proteins may result from an external force exerted by the adenosinetriphosphate (ATP) dependent chromatin remodeling machines to access regulatory sites on DNA

Characterization of tissue inhibitor metalloproteinases in semen and their relationship with vital sperm function tests vis-à-vis fertility of breeding buffalo bulls

The present study was undertaken to separate and compare the tissue inhibitor metalloproteinases (TIMP) of seminal plasma and frozen-thawed sperm extracts from 30 buffalo bulls by immunoblotting and determine a relationship between various TIMP with post-thaw sperm function tests vis-à-vis bull fertility. Seven immunoreactive bands in seminal plasma (65, 55, 48, 33, 31, 24 and 11 kDa) and 5 in frozen-thawed spermatozoa (75, 65, 55, 24 and 16 kDa) were detected in Western blots following incubation (TIMP–140) and subsequent washing in vitro, indicating that TIMP is bound to sperm membranes. The frozen-thawed semen was evaluated for first service conception rate (FSCR), per cent HOST, acrosome reaction, viability, DNA integrity and total motility and linked to TIMP. In seminal plasma, the bulls positive for 48, 33 and 24 kDa TIMP had significantly higher FSCR (57.0 ± 2.6 vs 27.0 ± 2.4%, 55.7 ± 3.0 vs 31.3 ± 3.2% and 45.0 ± 3.8 vs 32.8 ± 4.7%, respectively) as compared to their negative counterparts. Except per cent viability, almost all seminal parameters (acrosome reaction, per cent HOST, DNA integrity and total motility) were significantly higher in bulls positive for TIMP of 48, 33, 31 and 24 kDa than in their negative contemporary mates. In frozen-thawed sperm extracts, the bulls positive for TIMP–24 had significantly higher FSCR (51.7 ± 3.7 vs 27.2 ± 3.0%), higher percentage of acrosome-reacted (55.9 ± 2.8 vs 48.9 ± 2.2%) and HOS-positive (69.2 ± 1.5 vs 65.3 ± 1.9%) spermatozoa in comparison to their negative herd mates. These results suggested that TIMP influences semen quality and subsequent fertility of buffalo bulls through inhibition of metalloprotease activity in semen

Local density of states and scanning tunneling currents in graphene

We present exact analytical calculations of scanning tunneling currents in locally disordered graphene using a multimode description of the microscope tip. Analytical expressions for the local density of states (LDOS) are given for energies beyond the Dirac cone approximation. We show that the LDOS at the $A$ and $B$ sublattices of graphene are out of phase by $\pi$ implying that the averaged LDOS, as one moves away from the impurity, shows no trace of the $2q_F$ (with $q_F$ the Fermi momentum) Friedel modulation. This means that a STM experiment lacking atomic resolution at the sublattice level will not be able of detecting the presence of the Friedel oscillations [this seems to be the case in the experiments reported in Phys. Rev. Lett. {\bf 101}, 206802 (2008)]. The momentum maps of the LDOS for different types of impurities are given. In the case of the vacancy, $2q_F$ features are seen in these maps. In all momentum space maps, $K$ and $K+K^\prime$ features are seen. The $K+K^\prime$ features are different from what is seen around zero momentum. An interpretation for these features is given. The calculations reported here are valid for chemical substitution impurities, such as boron and nitrogen atoms, as well as for vacancies. It is shown that the density of states close to the impurity is very sensitive to type of disorder: diagonal, non-diagonal, or vacancies. In the case of weakly coupled (to the carbon atoms) impurities, the local density of states presents strong resonances at finite energies, which leads to steps in the scanning tunneling currents and to suppression of the Fano factor.Comment: 21 pages. Figures 6 and 7 are correctly displayed in this new versio