Scattering and Bound State Solutions of the Yukawa Potential within the Dirac Equation

In the presence of spin symmetry case, we obtain bound and scattering states solutions of the Dirac equation for the equal scalar and vector Yukawa potentials for any spin-orbit quantum number κ. The approximate analytical solutions are presented for the bound and scattering states and scattering phase shifts

Assessing hygienic behavior and attraction to Varroa mite (Acari: Varroidae) in Iranian honey bee (Apis. mellifera meda)

In the current study, the hygienic behaviors of 5th instar larva of Iranian honeybees (Apis mellifera. meda) were investigated. The results of hygienic evaluation demonstrated that 35% of Iranian honeybees are hygienic. For more research, different levels of hygienic behaviors were used as a treatment and then the selected 5th instar larva were transferred to fundamental colonies with 10 to 12 % infestation. Three days later, the number of female Varroa in the capped cells were counted as attraction criteria for each treatment separately. The result  demonstrated that hygienic colonies were fantastic because of their great interest for the least attraction. Moreover, the apparent correlation between resistant traits and performance traits exhibited that there are no significant relationship amongst resistance traits and performance traits. The relationship between uncapping and removing (which measured in the same recording day) was relatively high (>0.90). Furthermore, the correlation between hygienic behavior and attraction traits was negative so that the correlation between attraction and removing within 48 h after pouring liquid nitrogen was -0.86. The negative correlation between 2 major resistance traits (hygienic behavior and attraction traits) in the breeding stock deems that selection for resistance against Varroa mite and improved performance traits may be possible in the Iranian honeybees. Despite, it is believed that in the breeding stock for determining the best selection strategy, other resistant mechanisms must be evaluated.Key words: Varroa mite, hygienic behavior (uncapping and removing), attraction, performance traits, Iranian honeybee

Prey-preference of Orius albidipennis (Het.: Anthocoridae) on onion thrips and two-spotted spider mite under laboratory conditions

Prey-preference of the predatory bug, Orius albidipennis Reuter, with predation rate and prey-preference tests on the basis of completely randomized design (CRD) and without the replacement of consumed prey was examined under laboratory conditions (25 ± 1°C, 65 ± 5% RH and L16: D8 photoperiod). Results of the predation rate test indicated that the predation of the female predatory bug on the 2nd larvae of onion thrips and the female two-spotted spider mite was 14.8 ± 1.46 and 20 ± 0.7 respectively, showing a significant difference (P < 0.05) between them. In the prey-preference test, the preying of the female predatory bug on the 2nd larvae of onion thrips and the female two-spotted spider mite was 8.4 ± 0.84 and 4.4 ± 0.22 respectively. The Manly preferance index (α) of the 2nd larvae of onion thrips (prey I) and the female two-spotted spider mite (prey II) was 0.8 ± 0.09 and 0.2 ± 0.03 respectively, which demonstrated that the predatory bug more preferred the 2nd larvae of onion thrips than the two-spotted spider mite. Both tests were repeated for the male predatory bug in similar conditions. In the predation rate test, the results from the preying of the male predatory bug on the 2nd larvae of onion thrips and the female two-spotted spider mite was 11 ± 1.58 and 12 ± 1.22 respectively, showing no significant difference. In the prey-preference test, consumption of the male predatory bug from the 2nd larvae of onion thrips was 3.3 ± 0.13 and from the female two-spotted spider mite was 3.2 ± 0.17. In this experiment, the Manly preference index (α) of the 2nd larvae of onion thrips (prey I) and the female two-spotted spider mite (prey II) was 0.52 ± 0.03 and 0.48 ± 0.05 respectively. According to these data, the male predatory bug showed no preference for either prey species

The effect of lovastatin on cognition impairment induced by bilateral electrical lesion of nucleus basalis magnocellularis in the Alzheimerâs disease model in adult male rats

Background: Statins, inhibitors of 3-hydroxy-3-methyl glutaryl coenzyme A reductase, are widely used as medication to lower cholesterol levels in human patients. Much evidence indicates that statins can also exert neuroprotective actions. So, this study aimed at examining the effect of lovastatin on cognition deficit induced by bilateral electrical lesion of nucleus basalis magnocellularis (NBM) in the Alzheimer&rsquo;s disease model in adult male rats. Materials and Methods: In this experimental study, 56 adult male wistar rats were divided into 8 groups (n=7): control (intact), NBM lesion group (which received electrically- induced lesion 0.5 mA in 3s), sham group (the electrode was impaled into the NBM with no lesion(, lovastatin groups (lesion+1, 5, 10, 20 mg/kg) and DMSO 5 group (NBM lesion +DMSO 5). Acquisition and retention testing was done by using an eight-radial arm maze in which the patterns of arm entries were recorded for calculating working memory errors, reference memory error and latency in each group. Results: The bilateral NBM lesion resulted in significant reduction of spatial memory in acquisition and retention tests in the form of increased working and reference memory errors compared to the control group (P&lt;0.05). Post-lesion treatment with lovastatin improved the parameters of spatial memory errors in the acquisition and retention tasks compared to the lesion group. Conclusion: The electrical NBM lesion can reduce spatial memory function and the lovastatin therapy after brain injury improved cognitive disorders. It seems that lovastatin by reducing the activity of the acetylcholinesterase enzyme and increasing acetylcholine transferase enzyme activity can cause improvement in learning and memory capability

Pressure sensitive adhesives produced by in-situ emulsion polymerization of cellulose nanocrystal-poly(nBA-VAc)

Pressure sensitive adhesives (PSAs) are conventionally produced using a variety of polymerization methods such as emulsion, solution, or radiation curing. Environmental concerns favor the development of emulsion polymerization based PSAs.[1] However, maintaining and controlling the PSA properties achievable from solution polymerization in PSAs produced by emulsion polymerization remains challenging. Depending on the particular adhesive application, PSA properties are largely guided by the polymer glass transition temperature and the polymer microstructure. The latter is controlled in a variety of ways but typically via the addition of chain transfer agents and crosslinkers.[2] During the last decades, efforts in PSA property manipulation have included the preparation of nanocomposite latexes by introducing nanomaterials such as titanium dioxide, silica, and carbon nanotubes into the formulations.[3] On the other hand, utilizing cellulose nanocrystals (CNCs) as a sustainable source of reinforcement in polymers is emerging rapidly.[4] CNCs are the product of controlled hydrolysis of plant based tissues, through which crystalline domains of cellulose are isolated from the disordered parts of the raw material. High aspect ratio, surface activity and modulus, as well as non-toxic nature of CNCs make them ideal candidates for use in nanocomposite formulations. More recently, our group have prepared CNC nanocomposite PSAs which were revealed to significantly and simultaneously improve tack, peel strength and shear strength in the PSA films.[5] The ability to improve tack and peel strength without decreasing shear strength overcomes a major challenge in PSA formulation. We will present results from emulsion polymerization of n-butyl acrylate/vinyl acetate/CNC nanocomposite PSAs. We will identify the location of the CNCs relative to the latex particles and show their effect on latex viscosity, gel content, and PSA properties. The goal of these new results is to show how the manipulation of the reaction formulation (e.g., monomer feed ratio, surfactant type) will affect the distribution and relative location of the CNCs in the polymer latex and ultimately the PSA properties. [1] Jovanović, R., Dubé, M. A., J. Macromol. Sci., Part C, 44:1, 1-51, 2004. [2] Qie, L., Dubé, M. A., 46, 1225–1236, 2010. [3] Dastjerdi, Z., Cranston, E. D., Berry, R. Fraschini, C., Dubé, M. A., J. Matls. Sci., submitted January 2018. [4] Lee, K-Y., Aitomäki, Y., Berglund, L. A., Oksman, K., Bismarck, A., Compos. Sci. Technol. 105, 15–27, 2014. [5] Dastjerdi, Z., Cranston, E. D., Dubé, M. A., Macromol. React. Eng., 11, 1700013, 2017. [6] Dastjerdi, Z., Cranston, E. D., Dubé, M. A., Int. J. Adh. Adh., 81, 36-42, 201

A group-theoretic approach to the origin of chirality-induced spin selectivity in non-magnetic molecular junctions

Spin-orbit coupling gives rise to a range of spin-charge interconversion phenomena in non-magnetic systems where spatial symmetries are reduced or absent. Chirality-induced spin selectivity (CISS), a term that generically refers to a spin-dependent electron transfer in non-magnetic chiral systems, is one such case, appearing in a variety of seemingly unrelated situations ranging from inorganic materials to molecular devices. In particular, the origin of CISS in molecular junctions is a matter of an intense current debate. Here we contend that the necessary conditions for the CISS effect to appear can be generally and fully understood on the basis of a complete symmetry analysis of the molecular junction, and not only of the molecule. Our approach, which draws on the use of point-group symmetries within the scattering formalism for transport, shows that electrode symmetries are as important as those of the molecule when it comes to the emergence of a spin-polarization and, therefore, a possible appearance of CISS. It turns out that standalone metallic nanocontacts can exhibit spin-polarization when relative rotations are introduced which reduce the symmetry. As a corollary, molecular junctions with $\textbf{achiral}$ molecules can also exhibit spin polarization along the direction of transport, provided that the whole junction is chiral. This formalism also allows to predict the qualitative changes on the spin-polarization upon substitution of a chiral molecule in the junction with its enantiomeric partner. Quantum transport calculations based on density functional theory corroborate all of our predictions and provide further quantitative insight.Comment: 19 pages, 4 figures, 1 tabl

Natural parasitism of Telenomus busseolae (Hym.: Scelionidae) an egg parasitoid of sugarcane stem borers, Sesamia spp. (Lep.: Noctuidae), on sugarcane commercial varieties in Khuzestan

The sugarcane stem borers, Sesamia cretica Led. and S. nonagrioides Lef. are the most important pests of sugarcane in Iran. The egg parasitoid wasp, Telenomus busseolae Gahan is the most important natural enemy of Sesamia spp. in Khuzestan province that play an important role in regulating populations of sugarcane stem borers. A field experiment was conducted to evaluate the performance of T. busseolae on sugarcane commercial varieties in Khuzestan province (southwest of Iran). This study was conducted in a split plot design on 4 sugarcane commercial varieties (i.e. CP69-1062, CP48-103, CP57-614 and SP70-1143) with 5 fields per variety in Khuzestan in 2007. The sampling of egg masses were carried out within the tillering stage of sugarcane (5-15 June) and the final stage of sugarcane growing (10-20 October). Our results indicated that both growth stage and variety of sugarcane had a significant effect on the egg batch density, discovery efficiency and percent parasitism. The interaction between growth stage and variety on percent parasitism and discovery efficiency were statistically different (