Alien Registration- Tozer, Catherine A. (Lincoln, Penobscot County)

https://digitalmaine.com/alien_docs/7371/thumbnail.jp

Methods for Estimating Seed Production of Two Summer-Active Grass Weeds, \u3cem\u3eSetaria pumila\u3c/em\u3e and \u3cem\u3eDigitaria sanguinalis\u3c/em\u3e, in New Zealand Dairy Pastures

Undesirable C4 annual grasses such as summer grass (Digitaria sanguinalis, (L.) Scop., SG) and yellow bristle grass (Setaria pumila (Poir.) Roem. et Schult., YBG) are prevalent in dairying regions in the North Island of New Zealand. Field surveys of 39 dairy pastures in the central North Island demonstrated that their percentage ground cover has tripled over the last four years (Tozer et al. 2012). The prolific seed production of these species is thought be facilitating this increase in ground cover. However, little information is available on their fecundity in dairy pastures. Counting the number of seeds in a panicle is slow and laborious, therefore a rapid and robust method to assess fecundity is required. In USA crops, Forcella et al. (2000) found a significant curvilinear relationship between YBG seeds per panicle and panicle length, regardless of crop identity, year and weed density. A study was therefore established to determine if panicle length or weight could be used to estimate YBG and SG fecundity in intensively managed dairy pastures in New Zealand

Quantum transport of two-dimensional Dirac fermions in SrMnBi2

We report two-dimensional quantum transport in SrMnBi$_2$ single crystals. The linear energy dispersion leads to the unusual nonsaturated linear magnetoresistance since all Dirac fermions occupy the lowest Landau level in the quantum limit. The transverse magnetoresistance exhibits a crossover at a critical field $B^*$ from semiclassical weak-field $B^2$ dependence to the high-field linear-field dependence. With increase in the temperature, the critical field $B^*$ increases and the temperature dependence of $B^*$ satisfies quadratic behavior which is attributed to the Landau level splitting of the linear energy dispersion. The effective magnetoresistant mobility $\mu_{MR}\sim 3400$ cm$^2$/Vs is derived. Angular dependent magnetoresistance and quantum oscillations suggest dominant two-dimensional (2D) Fermi surfaces. Our results illustrate the dominant 2D Dirac fermion states in SrMnBi$_2$ and imply that bulk crystals with Bi square nets can be used to study low dimensional electronic transport commonly found in 2D materials like graphene.Comment: 5 papges, 4 figure

Persistence to high temperatures of interlayer coherence in an organic superconductor

The interlayer magnetoresistance $\rho_{zz}$ of the organic metal \cuscn is studied in fields of up to 45 T and at temperatures $T$ from 0.5 K to 30 K. The peak in $\rho_{zz}$ seen in in-plane fields, a definitive signature of interlayer coherence, remains to $T$s exceeding the Anderson criterion for incoherent transport by a factor $\sim 30$. Angle-dependent magnetoresistance oscillations are modeled using an approach based on field-induced quasiparticle paths on a 3D Fermi surface, to yield the $T$ dependence of the scattering rate $\tau^{-1}$. The results suggest that $\tau^{-1}$ does not vary strongly over the Fermi surface, and that it has a $T^2$ dependence due to electron-electron scattering

PyMT-Maclow: A novel, inducible, murine model for determining the role of CD68 positive cells in breast tumor development

CD68+ tumor-associated macrophages (TAMs) are pro-tumorigenic, pro-angiogenic and are associated with decreased survival rates in patients with cancer, including breast cancer. Non-specific models of macrophage ablation reduce the number of TAMs and limit the development of mammary tumors. However, the lack of specificity and side effects associated with these models compromise their reliability. We hypothesized that specific and controlled macrophage depletion would provide precise data on the effects of reducing TAM numbers on tumor development. In this study, the MacLow mouse model of doxycycline-inducible and selective CD68+ macrophage depletion was crossed with the murine mammary tumor virus (MMTV)-Polyoma virus middle T antigen (PyMT) mouse model of spontaneous ductal breast adenocarcinoma to generate the PyMT-MacLow line. In doxycycline-treated PyMT-MacLow mice, macrophage numbers were decreased in areas surrounding tumors by 43%. Reducing the number of macrophages by this level delayed tumor progression, generated less proliferative tumors, decreased the vascularization of carcinomas and down-regulated the expression of many pro-angiogenic genes. These results demonstrate that depleting CD68+ macrophages in an inducible and selective manner delays the development of mammary tumors and that the PyMT-MacLow model is a useful and unique tool for studying the role of TAMs in breast cancer

The relationship between regional variations in blood flow and histology in a transplanted rat fibrosarcoma

The regional distribution of blood flow to the LBDS1 fibrosarcoma, transplanted into the subcutaneous site in rats, was investigated using the readily diffusible compound 14C-iodo-antipyrine (14C-IAP). Quantitative autoradiography was used to establish absolute values of specific blood flow F for 100 X 100 X 20 microns adjacent tissue volumes of the unperturbed tumour. Mean blood flow to whole tumours was found to decrease with increase in tumour size. This relationship was abolished if blood flow was only measured in sections cut from the periphery of the tumours. Detailed analysis of a sub-group of tumours showed that blood flow to individual tumours was heterogeneous. The range of blood flow was large, indicating that mean blood flow to a whole tumour is a poor reflection of the blood perfusion pattern of that tumour. Necrotic tumour regions were usually very poorly perfused. With the exception of the smallest tumours studied, blood flow was lower in the centre of tumours than in the periphery. Necrosis also tended to develop centrally. However, the peripheral to central gradient of blood flow was apparent even when densely cellular, viable tumour regions and necrotic regions were analysed separately. The decrease in blood flow with tumour size was also apparent in densely cellular, viable tumour regions when analysed separately. Qualitative comparison of tumour histology and regional blood flow showed that there were areas of very low blood flow associated with viable tumour regions. Less common were areas of rather high blood flow associated with necrotic tumour regions. A complicated relationship exists between tumour histology and blood flow. The quantitative autoradiography technique is suitable for investigating the most poorly perfused and the most well perfused viable fractions of animal tumours which may limit the efficacy of different types of therapy

Estradiol, progesterone, testosterone profiles in human follicular fluid and cultured granulosa cells from luteinized pre-ovulatory follicles

BACKGROUND: The production of sex steroids by follicular cells is proposed to be influenced by the maturity of the incumbent oocyte. Thus steroid levels may reflect suitability of an oocyte for IVF. We examined follicular fluids and granulosa cell production of steroid from IVF patients in order to test the relationship between steroid levels and fertilization. METHODS: Follicular fluid and granulosa cells were extracted from 206 follicles of 35 women undergoing controlled ovarian stimulation. Follicular fluid was assayed for estradiol, progesterone and testosterone. Granulosa cells were cultured from individual follicles and their culture media assayed for production of these hormones after 24 hrs in vitro. Levels of steroids were correlated with follicular diameter, oocyte recovery and subsequent fertilization. RESULTS: Follicular fluid levels of progesterone were 6100 times higher than that of estradiol, and 16,900 times higher that of testosterone. Despite the size of follicle triggered after controlled luteinization, the levels of progesterone and testosterone were maintained at relatively constant levels (median 98.1 micromoles/L for progesterone, and 5.8 nanomoles/L for testosterone). However, estradiol levels were slightly lower in the larger follicles (follicular diameter 10-15 mm, median 25.3 nanomoles/L; follicles > = 15 mm, median 15.1 nanomoles/L; linear correlation r = -0.47, p < 0.0001). With respect to oocyte recovery, no steroid showed a significant association in follicular fluid levels. Similarly no difference in follicular fluid steroid levels was found for those oocytes that did or did not fertilize. Significant quantities of progesterone were produced by the granulosa cells but production was constant regardless of the size of follicle from which the cells originated. Estradiol levels were only detectable in 10 of 121 cultures examined, and testosterone in none. Interestingly, when an oocyte was present follicular estradiol levels correlated with progesterone levels. However, when absent, follicular estradiol levels correlated with testosterone levels but not with progesterone. CONCLUSIONS: The principle steroid product of luteinized pre-ovulatory granulosa is progesterone, a differentiation triggered by the gonadotropin surge. However, absolute steroid levels are associated with follicular size, not oocyte maturation/ability to fertilize

High-magnetic field lattice length changes in URu2Si2

We report high magnetic field (up to 45 T) c-axis thermal expansion and magnetostriction experiments on URu2Si2 single crystals. The sample length change associated with the transition to the hidden order phase becomes increasingly discontinous as the magnetic field is raised above 25 T. The re-entrant ordered phase III is clearly observed in both the thermal expansion and magnetostriction above 36 T, in good agreement with previous results. The sample length is also discontinuous at the boundaries of this phase, mainly at the upper boundary. A change in the sign of the coefficient of thermal-expansion is observed at the metamagnetic transition (B_M = 38 T) which is likely related to the existence of a quantum critical end point.Comment: 5 pages, 4 figures, to be published in PR