1,906 research outputs found
Genetic variation and possible origins of weedy rice found in California.
Control of weeds in cultivated crops is a pivotal component in successful crop production allowing higher yield and higher quality. In rice-growing regions worldwide, weedy rice (Oryza sativa f. spontanea Rosh.) is a weed related to cultivated rice which infests rice fields. With populations across the globe evolving a suite of phenotypic traits characteristic of weeds and of cultivated rice, varying hypotheses exist on the origin of weedy rice. Here, we investigated the genetic diversity and possible origin of weedy rice in California using 98 simple sequence repeat (SSR) markers and an Rc gene-specific marker. By employing phylogenetic clustering analysis, we show that four to five genetically distinct biotypes of weedy rice exist in California. Analysis of population structure and genetic distance among individuals reveals diverse evolutionary origins of California weedy rice biotypes, with ancestry derived from indica, aus, and japonica cultivated rice as well as possible contributions from weedy rice from the southern United States and wild rice. Because this diverse parentage primarily consists of weedy, wild, and cultivated rice not found in California, most existing weedy rice biotypes likely originated outside California
Diagnostic value of transvaginal 'tenderness-guided' ultrasonography for the prediction of location of deep endometriosis
BACKGROUND: The aim was to evaluate the diagnostic accuracy of transvaginal tenderness-guided ultrasonography in the identification of location of deep endometriosis. METHODS: Consecutive women scheduled for surgery in our Department for clinically suspected endometriosis were included in this prospective study. All women underwent modified transvaginal ultrasonography using a stand-off in the week before surgery, which also evaluated the painful sites evocated by a gentle pressure of the probe. Five locations of deep endometriosis were considered: vaginal walls, rectovaginal septum, rectosigmoid involvement, uterosacral ligaments and anterior compartment (anterior pouch and/or bladder). Sensitivity, specificity and likelihood ratios (LR1/2) were calculated with 95% confidence intervals (CIs). RESULTS: We included 88 women; surgery associated with histopathological evaluation revealed deep endometriosis in different pelvic locations in 72 patients. With respect to the vaginal walls, transvaginal ultrasonography had a sensitivity of 91% (95% CI, 79 –97%), specificity of 89% (95% CI, 81–93%), an LR1 of 8.2 and an LR2 of 0.09. For endometriosis of rectovaginal septum, transvaginal ultrasonography had a sensitivity of 74% (95% CI, 64–80%), specificity of 88% (95% CI, 4–8%), an LR1 of 6.2 and an LR2 of 0.3. For other locations, the sensitivity was lower (ranging from 67% to 33%) with a comparable specificity. CONCLUSIONS: This technique shows a high specificity and sensitivity in the detection of vaginal and rectovaginal endometriosis. Good specificity associated with a lower sensitivity was obtained in the diagnosis of deep endometriosis of uterosacral ligaments, rectosigmoid involvement or anterior deep endometriosis
Fc receptor-mediated phagocytosis occurs in macrophages at exceedingly low cytosolic Ca2+ levels.
Cytosolic free Ca2+ ([Ca2+]i) homeostasis was investigated in mouse peritoneal macrophages and in the macrophage-like cell line J774. [Ca2+]i measurements were performed in both cells in suspension and cells in monolayers loaded with either quin2 or fura-2. Resting [Ca2+]i was 110-140 and 85-120 nM for cell suspensions and monolayers, respectively. There were no significant differences in [Ca2+]i between the two macrophage populations whether quin2 or fura-2 were used as Ca2+ indicators. Addition of heat-aggregated IgG, IgG-coated erythrocyte ghosts, or a rat monoclonal antibody (2.4G2) directed against mouse Fc receptor II induced a rise in [Ca2+]i. This [Ca2+]i increase was consistently observed in J774 and peritoneal macrophage suspensions and in J774 macrophage monolayers; in contrast it was observed inconsistently in peritoneal macrophages in monolayer cultures. The increase in [Ca2+]i induced by ligation of Fc receptors was inhibited totally in macrophages in suspension and by 80% in macrophages in monolayers by a short preincubation of macrophages with PMA; however, phagocytosis itself was unaffected. The effect of reducing cytosolic Ca2+ to very low concentrations on Fc receptor-mediated phagocytosis was also investigated. By incubating macrophages with high concentrations of quin2/AM in the absence of extracellular Ca2+, or by loading EGTA into the cytoplasm, the [Ca2+]i was buffered and clamped to 1-10 nM. Despite this, the phagocytosis of IgG-coated erythrocytes proceeded normally. These observations confirm the report of Young et al. (Young, J. D., S. S. Ko, and Z. A. Cohn. 1984. Proc. Natl. Acad. Sci. USA. 81:5430-5434) that ligation of Fc receptors causes Ca2+ mobilization in macrophages. However, these results confirm and extend the findings of McNeil et al. (McNeil, P. L., J. A. Swanson, S. D. Wright, S. C. Silverstein, and D. L. Taylor. 1986. J. Cell Biol. 102:1586-1592) that a rise in [Ca2+]i is not required for Fc receptor-mediated phagocytosis; and they provide direct evidence that Fc receptor-mediated phagocytosis occurs normally even at exceedingly low [Ca2+]i
Proximal, selective, and dynamic interactions between integrin αIIbβ3 and protein tyrosine kinases in living cells
Stable platelet aggregation, adhesion, and spreading during hemostasis are promoted by outside-in αIIbβ3 signals that feature rapid activation of c-Src and Syk, delayed activation of FAK, and cytoskeletal reorganization. To evaluate these αIIbβ3–tyrosine kinase interactions at nanometer proximity in living cells, we monitored bioluminescence resonance energy transfer between GFP and Renilla luciferase chimeras and bimolecular fluorescence complementation between YFP half-molecule chimeras. These techniques revealed that αIIbβ3 interacts with c-Src at the periphery of nonadherent CHO cells. After plating cells on fibrinogen, complexes of αIIbβ3–c-Src, αIIbβ3–Syk, and c-Src–Syk are observed in membrane ruffles and focal complexes, and the interactions involving Syk require Src activity. In contrast, FAK interacts with αIIbβ3 and c-Src, but not with Syk, in focal complexes and adhesions. All of these interactions require the integrin β3 cytoplasmic tail. Thus, αIIbβ3 interacts proximally, if not directly, with tyrosine kinases in a coordinated, selective, and dynamic manner during sequential phases of αIIbβ3 signaling to the actin cytoskeleton
Estudio Preliminar de las Empresas Comunitarias de la Zona Bananera del Magdalena; Cuatro Casos.
Consistió la presente investigación en el análisis del programa de Empresas Comunitarias que impulsa y desarrollo el Incora en la zona bananera del Magdalena, a través del estudio especÃfico de cuatro casos de empresas especializadas en banano, por haberse considerado como más representativas, basándose esta misma investigación en la creación del programa de Empresas comunitarias por medio de la Ley 4a. de 1.973, el Estatuto jurÃdico de 2.073 y el Acuerdo 11 de 1.975 que son mecanismos en los cuales está enmarcada la polÃtica del Gobierno para impulsar y desarrollar las explotaciones denominadas empresas comunitarias en Colombia. Se hizo una selección al azar de las empresas a estudiar, dándose también orientación teórica y realizando el programa de investigación. Asà mismo se recopiló la información, elaborando un cuestionario para Incora y otro, para las Empresas siendo respondido por los usuarios de las mismas. Se tabularon e interpretaron los cuatro formularios de las empresas menos el de Incora por razón de que no fue respondido. Realizada esta investigación y dada la encrucijada de tipo económico y social que vive el campesino de la zona Bananera, se pone al descubierto la falsa reforma agraria del gobierno cuyo objetivo es la de distraer y frenar la lucha del campesinado por la tierra. De aquà que el campesino el proletariado consecuencia y los autores de este estudio concluimos que debe rechazar este tipo de programa de empresas comunitarias que mantiene al campesinado y al proletariado agrÃcola de la zona bananera y Colombia embaucado en un cÃrculo de miseria y bajo la denominación norteamericana. Los campesinos deberán luchar por la liberación nacional y por una reforma agraria democrática en estrecha alianza con el proletariado y demás sectores explotados
Cost-Effectiveness of Vaccination with the 20-Valent Pneumococcal Conjugate Vaccine in the Italian Adult Population
The availability of a new 20-valent pneumococcal conjugate vaccine (PCV) makes it appropriate to assess its cost-effectiveness. This was evaluated by adopting the Italian National Health Service perspective, using a cost consequences Markovian model. The expected effects of vaccination with 20-valent PCV were compared with the administration of 13-valent PCV and 15-valent PCV. Assuming a 100% vaccination of cohorts aged 65–74 years, in the (lifetime) comparison between 20-valent PCV and 13-valent PCV, the former is dominant (lower cost for a better health outcome). A reduction in disease events was estimated: −1208 deaths; −1171 cases of bacteraemia; −227 of meningitis; −9845 hospitalised all-cause nonbacteremic pneumonia cases (NBP) and −21,058 non-hospitalised. Overall, in the Italian population, a total gain of 6581.6 life years and of 4734.0 QALY was estimated. On the cost side, against an increase in vaccinations costs (EUR +40.568 million), other direct health costs are reduced by EUR 48.032 million, with a net saving of EUR +7.464 million. The comparison between 20-valent PCV and 15-valent PCV results in an Incremental Cost-Effectiveness Ratio (ICER) of EUR 66 per life year gained and EUR 91 per QALY gained. The sensitivity analyses confirm the robustness of the results. We can conclude that the switch to 20-valent PCV is a sustainable and efficient investment
Low disordered, stable, and shallow germanium quantum wells: a playground for spin and hybrid quantum technology
Buried-channel semiconductor heterostructures are an archetype material
platform to fabricate gated semiconductor quantum devices. Sharp confinement
potential is obtained by positioning the channel near the surface, however
nearby surface states degrade the electrical properties of the starting
material. In this paper we demonstrate a two-dimensional hole gas of high
mobility ( cm/Vs) in a very shallow strained germanium
channel, which is located only 22 nm below the surface. This high mobility
leads to mean free paths , setting new benchmarks for holes in
shallow FET devices. Carriers are confined in an undoped Ge/SiGe
heterostructure with reduced background contamination, sharp interfaces, and
high uniformity. The top-gate of a dopant-less field effect transistor controls
the carrier density in the channel. The high mobility, along with a percolation
density of , light effective mass (0.09
m), and high g-factor (up to ) highlight the potential of undoped
Ge/SiGe as a low-disorder material platform for hybrid quantum technologies
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