1,601 research outputs found
A comparison of methodologies for the staining and quantification of intracellular components of Arbuscular Mychorrizal (AM) fungi in the root cortex of two varieties of winter wheat
© 2019 The Authors. The definitive peer reviewed, edited version of this article is published in Access Microbiology, https://doi.org/10.1099/acmi.0.000083. This is an open-access article distributed under the terms of the Creative Commons Attribution License.Arbuscular Mychorrizal (AM) fungi are one of the most common fungal organisms to exist in symbiosis with terrestrial plants facilitating the growth and maintenance of arable crops. Wheat has been studied extensively for AM fungal symbiosis using the carcinogen trypan blue as the identifying stain for fungal components, namely arbuscles, vesicles and hyphal structures. The present study uses Sheaffer® blue ink with a lower risk as an alternative to this carcinogenic stain. Justification for this is determined by stained wheat root sections (n = 120), with statistically significant increases in the observed abundance of intracellular root cortical fungal structures stained with Sheaffer® blue ink compared to trypan blue for both Zulu (P = 0.003) and Siskin (P = 0.0003) varieties of winter wheat. This new alternative combines an improved quantification of intracellular fungal components with a lower hazard risk at a lower cost.Peer reviewe
HLA class II antibodies at the time of kidney transplantation and cardiovascular outcome : a retrospective cohort study
Background.
The negative role of HLA class II donor-specific antibody on graft outcome is well recognized. However, the potentially negative cardiovascular effects of preformed HLA class II antibodies and donor HLA in kidney transplant recipients (KTRs) remain unestablished.
Methods.
We conducted a single-center, retrospective cohort study including 1115 KTRs (2003–2016) with up to 4449 person-years of follow-up after transplantation and a median follow-up time of 5.1 years (interquartile range, 2.7–7.6). We evaluated the unadjusted and multivariable-adjusted association between pretransplant HLA class I and II antibodies, as well as HLA-DR1 donor/recipient genotype and the primary (major adverse cardiac and cerebrovascular event [MACCE] or all-cause mortality) and secondary (MACCE or cardiovascular mortality) outcome.
Results.
In a multivariate Cox proportional hazard model, HLA class II antibodies before transplantation were associated with increased adjusted hazard ratio (aHR) for MACCE or all-cause mortality (aHR, 1.71 [1.13–2.60]; P = 0.012) even after adjustment for time-varying covariate graft loss (aHR, 1.68 [1.08–2.62]; P = 0.022) and biopsy-proven acute rejection (aHR, 1.71 [1.13–2.60]; P = 0.012). HLA class II antibodies were also associated with increased aHR for the secondary outcome, MACCE, or cardiovascular mortality (aHR, 1.92 [1.12–3.30]; P = 0.018). We investigated the effect of donor and recipient HLA-DR1 on these outcome parameters and demonstrated that KTRs with HLA-DR1 positive donors had an increased aHR for MACCE with all-cause (aHR, 1.45 [1.09–1.94]; P = 0.012) and cardiovascular mortality (aHR, 1.49 [1.00–2.22]; P = 0.05).
Conclusions.
Prior sensitization against HLA class II antigens is associated with unfavorable long-term cardiovascular outcome in KTRs independent of graft loss or rejection. Recipients of an HLA-DR1 donor also have an impaired cardiovascular outcome
SU(3) Clebsch-Gordan Coefficients for Baryon-Meson Coupling at Arbitrary N_c
We present explicit formulae for the SU(3) Clebsch-Gordan coefficients that
are relevant for the couplings of large N_c baryons to mesons. In particular,
we compute the Clebsch-Gordan series for the coupling of the octet (associated
with mesons, and remains the correct representation at large N_c) to the large
N_c analogs of the baryon octet and decuplet representations.Comment: 8 pages, no figures, ReVTe
Surface quotients of hyperbolic buildings
Let I(p,v) be Bourdon's building, the unique simply-connected 2-complex such
that all 2-cells are regular right-angled hyperbolic p-gons and the link at
each vertex is the complete bipartite graph K(v,v). We investigate and mostly
determine the set of triples (p,v,g) for which there exists a uniform lattice
{\Gamma} in Aut(I(p,v)) such that {\Gamma}\I(p,v) is a compact orientable
surface of genus g. Surprisingly, the existence of {\Gamma} depends upon the
value of v. The remaining cases lead to open questions in tessellations of
surfaces and in number theory. Our construction of {\Gamma}, together with a
theorem of Haglund, implies that for p>=6, every uniform lattice in Aut(I)
contains a surface subgroup. We use elementary group theory, combinatorics,
algebraic topology, and number theory.Comment: 23 pages, 4 figures. Version 2 incorporates referee's suggestions
including new Section 7 discussing relationships between our constructions,
previous examples, and surface subgroups. To appear in Int. Math. Res. No
Cryptococcosis of the upper genital tract.
Upper genital tract infection by Cryptococcus neoformans has not previously been reported. We describe such a case, in order to alert clinicians to the existence of this rare infection. A 34-year-old woman with AIDS presented with chronic menorrhagia, fever, anemia, and thrombocytopenia. Despite blood transfusions and hormonal therapy, her vaginal bleeding could not be controlled and she became hemodynamically unstable. Total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed, at which time granulomatous peritonitis and prominent myometrial blood vessels were found. Histologic examination revealed cryptococcal infection of all upper genital organs. This case demonstrates that disseminated cryptococcosis may involve the upper genital tract in women, and may be associated with profuse vaginal bleeding
Pion Photoproduction Amplitude Relations in the 1/N_c Expansion
We derive expressions for pion photoproduction amplitudes in the 1/N_c
expansion of QCD, and obtain linear relations directly from this expansion that
relate electromagnetic multipole amplitudes at all energies. The leading-order
relations in 1/N_c compare favorably with available data, while the
next-to-leading order relations seem to provide only a small improvement.
However, when resonance parameters are compared directly, the agreement at
O(1/N_c) or O(1/N_c^2) is impressive.Comment: 19 pages, ReVTeX, 50 eps files combine into 5 compound figure
Pion-Nucleon Scattering Relations at Next-to-Leading Order in 1/N_c
We obtain relations between partial-wave amplitudes for pi-N-->pi-N and
pi-N-->pi-Delta directly from large N_c QCD. While linear relations among
certain amplitudes holding at leading order (LO) in 1/N_c were derived in the
context of chiral soliton models two decades ago, the present work employs a
fully model-independent framework based on consistency with the large N_c
expansion. At LO we reproduce the soliton model results; however, this method
allows for systematic corrections. At next-to-leading order (NLO), most
relations require additional unknown functions beyond those appearing at
leading order (LO) and thus have little additional predictive power. However,
three NLO relations for the pi-N-->pi-Delta reaction are independent of unknown
functions and make predictions accurate at this order. The amplitudes relevant
to two of these relations were previously extracted from experiment. These
relations describe experiment dramatically better than their LO counterparts.Comment: 8 pages, 2 figures; references adde
Law School Intentions Of Undergraduate Business Students
The purpose of this paper is to examine factors that influence business students’ intentions to enroll in law school. Scant research has focused on factors that influence business students’ decisions to enroll in law school. This paper attempts to fill that gap. Hypotheses about student intentions are based on Ajzen & Fishbein’s (1977) Theory of Planned Behavior. A sample of students enrolled in a business law class at a large Midwestern university is used to examine the hypotheses. Results indicate that law school intentions are driven by whether students feel they would enjoy the work of a lawyer, whether they feel having a law degree would provide them with job opportunities, and whether they feel they have the skills and abilities to get a law degree. Surprisingly, perceptions about future wealth are not associated with law school intentions. The sample may generalize to business student populations at other large state universities; however, it is important for future researchers to similarly investigate student law school intentions at other types of universities and colleges. The paper encourages undergraduate teachers of business law, as well as administrators of law schools, to consider the determinants of student intentions to study law. We particularly encourage law schools to work with undergraduate law faculty and periodically survey their target undergraduate populations to better understand student perceptions about attending law school
The diet of woodland caribou populations in west-central Alberta
The diet of woodland caribou (Rangifer tarandus caribou) populations in the foothills and Rocky Mountains of west-central Alberta was estimated by microhistological analyses of feces collected in winter and summer. In winter, terrestrial lichens averaged 60-83% of fecal fragment densities in both areas. In the mountains, decreasing proportions of terrestrial lichens and increasing proportions of conifer needles and moss indicated decreasing accessibility of forage because of deeper/harder snow. Apparent diets in summer were dominated by Salix spp., sedges, and lichens. However, forb inflorescences and stems were largely undetected by the microhistological technique and results for summer samples must be interpreted accordingly. We conclude that the conservation and management of forest ecotypes of caribou must include options of lichen-rich habitats as a major component of management plans
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