2,942 research outputs found
Faculty and Staff Perceptions of Their Roles in Preparing Students for College and Career Readiness: A Qualitative Exploration of High Schools, Community Colleges, and Universities
In 2020, nearly half of Texas’s 385,000 public high school graduates were unprepared for college-level reading or math. Limited research reveals K-12 faculty perceive limited roles and responsibilities in the college process, relying heavily on guidance counselors and college admissions counselors for preparing students for college and careers. The purpose of this study was to help fill this gap by answering the central research question: How do high school and college-level faculty and staff prepare high school students for college and careers? I chose a qualitative, interpretive design to explore educators’ individual and shared social meanings and interpretations. I used purposeful sampling to identify 10 subjects in South Central Texas who taught math, English language arts, social studies, or science in a high school, community college, university, and regional education agency participating in an alignment partnership in 2019. My data collection included semi-structured interviews, observations, e-mails, and supplemental documents. To study this phenomenon, I incorporated tools from grounded theory informed by Glaser and Strauss, and Charmaz. My data analysis methods involved using Hahn’s coding technique to organize and format large quantities of data for coding. Finally, I also used member checking and triangulation of data to ensure accuracy of my data analysis and to increase validity. The College and Career Readiness Collaborative Theory emerged and illustrates how interaction and dialogue in an alignment partnership led a team of faculty and staff to (a) co-construct meaning, (b) align curriculum, (c) clarify expectations, (d) improve perceptions, and (e) reevaluate teaching decisions to better prepare students for college and careers. This study reinforces the need for faculty and staff collaboration and dialogue to clarify skills gaps in entry level college courses, college level expectations, instruction, meanings, and perceptions of college and career readiness. Finally, the study addresses the pandemic’s impact on college and career readiness and the achievement gap
Cardiovascular responses during IgE-mediated peanut allergic reactions
INTRODUCTION:
The pathophysiology of IgE-mediated food allergy is poorly described and this impairs our ability to develop new treatments or predict reaction phenotype. Data from case series and animal models suggest there may be significant cardiovascular changes during severe reactions. The aims of this thesis were to describe the local and systemic cardiovascular (CVS) changes during IgE-mediated reactions to peanut, and evaluate whether local vascular responses to skin prick test can predict threshold or severity of reaction.
METHODS:
Fifty-seven peanut-allergic adults underwent continuous, non-invasive cardiac monitoring during double-blind placebo-controlled food challenges. CVS parameters during a 10-minute epoch at time of objective symptoms were compared to a 10-minute epoch at baseline. Comparisons were also made to equivalent data at the placebo reaction, and a further repeat open challenge in the same participants. Skin blood flow and titrated skin prick testing (SPT) were performed at each challenge.
RESULTS:
A significant increase in peripheral blood flow (median 20%, IQR [-2.2 to 46.7%]), decrease in stroke volume (mean -2.3ml/beat/m2, 95% CI [-0.3 to -4.2]) and increase in heart rate (mean 7.7bpm, 95% CI [5.6 to 9.8]) were observed during reactions irrespective of reaction severity, which were reproduced at open challenge. Changes in heart rate variability were also noted, consistent with increased sympathetic activity, however these were not observed at repeat challenge. Titrated SPT (as a measure of local cutaneous vascular response) was found to predict reaction threshold at challenge. Time to resolution of peanut SPT wheal was associated with several measures of reaction severity at challenge.
CONCLUSION:
There is a significant reduction in stroke volume during IgE-mediated reactions to peanut. This is likely to be caused by peripheral vasodilatation leading to reduced venous return, and was seen in both mild and severe reactions. This finding highlights the importance of adequate fluid resuscitation in the management of IgE-mediated allergic reactions to food.Open Acces
Effect of harvesting time on seed quality of two bell pepper cultivars (Capsicum annuum)
The maturation status of seeds is fundamental at the harvest time to get high rates of germination and vigor. The aim of this study was to determine the effect of harvest time on the quality of pepper seeds. The trial was conducted in two bell type cultivars: Fyuco INTA and Lungo INTA. Fruits were harvested at 4, 5, 6, 7, 8 and 9 weeks after anthesis. Starting from the eighth week the average seed weight stabilized, coincidently with the change in the fruit colour to red. Germination percentage increased linearly as it increased the age of the seed. The electrical conductivity of the leachate was also stabilized in seeds got from fruit harvested from 8 weeks after anthesis, showing that they had reached physiological maturity. The results demonstrate to harvest the fruits of pepper cv Fyuco INTA and Lungo INTA with over 8 weeks of age after anthesis to reach high quality seeds.El nivel de maduración de la semilla es fundamental al momento de cosecha para obtener elevadas tasas de germinación y buen vigor. El objetivo de este trabajo fue determinar el efecto del momento de cosecha sobre la calidad de semillas de pimiento. El ensayo se realizó en dos cultivares tipo cuatro cascos: Fyuco INTA y Lungo INTA. Se cosecharon frutos a las 4, 5, 6, 7, 8 y 9 semanas después de la antesis. A partir de la octava semana el peso promedio de las semillas se estabilizó, coincidiendo con el cambio de coloración del fruto a rojo. La germinación se incrementó linealmente conforme aumentó la edad de la semilla. La conductividad eléctrica del sobrenadante se estabilizó también, en las semillas obtenidas de los frutos cosechados a partir de las 8 semanas después de la antesis, indicando que estas habían alcanzado la madurez fisiológica. Los resultados demuestran la importancia de cosechar los frutos de pimiento de estas cultivares con más de 8 semanas de edad para lograr semillas de calidad.EEA San JuanFil: Ruiz, Monica Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Departamento de Ingeniería Agronómica. Cátedra de Fisiología Vegetal; ArgentinaFil: Parera, Carlos Alberto. Universidad Nacional de San Juan. Facultad de Ingeniería. Departamento de Ingeniería Agronómica. Cátedra de Fisiología Vegetal; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro Regional Mendoza-San Juan; Argentin
The fine line between total and partial tidal disruption events
Flares from tidal disruption events are unique tracers of quiescent black
holes at the centre of galaxies. The appearance of these flares is very
sensitive to whether the star is totally or partially disrupted, and in this
paper we seek to identify the critical distance of the star from the black hole
(r_d) that enables us to distinguish between these two outcomes. We perform
here Mesh-free Finite Mass, traditional, and modern Smoothed Particle
Hydrodynamical simulations of star-black hole close encounters, with the aim of
checking if the value of r_d depends on the simulation technique. We find that
the critical distance (or the so-called critical disruption parameter beta_d)
depends only weakly on the adopted simulation method, being beta_d=0.92\pm 0.02
for a gamma=5/3 polytrope and beta_d=2.01\pm 0.01 for a gamma=4/3 polytrope.Comment: 8 pages, 8 figures, 2 tables; accepted to A&
Quantifying Syringe Exchange Program Operational Space in the District of Columbia.
Syringe exchange programs (SEPs) are effective structural interventions for HIV prevention among persons who inject drugs. In 2000, a buffer zone policy (the 1000 Foot Rule) was implemented in Washington, DC, that prohibited SEP operations within 1000 feet of schools. We examined changes in the amount of legal SEP operational space over time. We used data pertaining to school operations and their approximate physical property boundaries to quantify the impact of the 1000 Foot Rule on legal SEP operational space from its implementation in 2000-2013. Adherence to the 1000 Foot Rule reduced SEP operational space by more than 50 % annually since its implementation. These findings demonstrate the significant restrictions on the amount of legal SEP operational space in Washington, DC, that are imposed by the 1000 Foot Rule. Changing this policy could have a significant impact on SEP service delivery among injectors
Inhibition of hepatitis B virus replication using synthetic antiviral RNA interference activators
A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand in
fulfilment of the requirements for the degree of Doctor of Philosophy.
Johannesburg 2016Chronic liver infection by hepatitis B virus (HBV) may lead to devastating clinical
conditions that include hepatocellular carcinoma and cirrhosis. Approved antiHBV drugs
do not completely eradicate the infection, leading to continued viral persistence in infected
individuals. Inhibition of HBV replication using synthetic activators of RNA interference
(RNAi) may provide a feasible strategy of developing superior antiviral drugs. The aim of
this study was to evaluate the therapeutic utility of novel 2’-O-guanidinopropyl (GP)
modified synthetic small interfering RNAs (siRNAs) to counter HBV replication in
cultured mammalian cells and mice. Initially, single GP moieties were placed at different
nucleotide positions of the guide strand of a potent antiHBV siRNA. Some GP-modified
siRNAs enhanced antiHBV activity in vitro following transient transfection of Human
hepatoma 7 (Huh7) cells with siRNAs and pCH-9/3091, a replication competent HBV
target plasmid. These siRNAs inhibited the secretion of Hepatitis B surface antigen
(HBsAg) by up to 95% in Huh7 cells. The level of knockdown exhibited by some modified
siRNAs was statistically significant relative to that displayed by unmodified siRNA3
which achieved HBsAg silencing of 73%. Additionally, modified siRNAs were also
capable of reducing RNA containing the X sequence in vitro by 88-93%. Impressively,
some of these knockdown levels were statistically significant when compared to
unmodified siRNA3, which achieved HBx knockdown of 83%. Quantitation of interferon
(IFN) response genes by reverse transcription quantitative polymerase chain reaction (RTqPCR)
and evaluation of cell viability by 3-(4,5-Dimethylthiazol-2-yl)-2,5-
diphenyltetrazolium bromide (MTT) assay revealed no evidence of innate immune
stimulation or cytotoxicity in cultured cells, respectively.
Modified siRNAs also displayed moderate stability in 80% foetal calf serum (FCS). Target
specificity was markedly improved by GP-modified siRNAs, especially those with seed
modifications (comprising nucleotide position 2 to 8 from the 5’ end of the guide strand).
The siRNA-mediated mRNA cleavage product was detected from transfected cells using 5’
Rapid Amplification of cDNA ends (5’ RACE).
In the hydrodynamic mouse model, co-injection of GP-modified siRNAs and HBV
plasmid vector led to HBsAg suppression of approximately 80-92% at day 3 and 77-96%
at day 5 post-administration. The HBV knockdown levels observed at day 3 were
statistically significant when compared to those displayed by unmodified siRNA3 which
achieved HBsAg silencing of 58% during the same time frame. Furthermore, both sets of
siRNAs also suppressed the number of circulating viral particle equivalents (VPEs) by 88-
90% at day 3 post-injection. HBV silencing efficacy of 70-75% and 65% was achieved by
modified and unmodified siRNAs, respectively at day 5 post-administration.
Finally, antiHBV efficacy of GP-modified siRNAs was tested in HBV transgenic mice
following delivery of these RNAi effectors using cationic polyglutamate (PG) adjuvant
liposomes. Both groups of antiHBV siRNAs effected HBsAg knockdown that ranged from
70-86% at day 3 to 7 post-administration as siRNA lipoplexes in HBV transgenic mice. In
contrast to the unmodified siRNA3, GP-containing siRNAs achieved durable HBsAg
silencing of 70% at day 14 post-administration, while the unmodified siRNA3 displayed a
shorter duration of activity. As with HBsAg data, the GP-modified siRNAs also displayed
silencing efficacy that was similar to the unmodified siRNA, reducing the number of
circulating VPEs by 95% from day 3 to 7 post-injection. However, the unmodified siRNA3
lost efficacy by day 14 post-administration, while the GP-modified siRNAs displayed
prolonged suppression by reducing the number of circulating VPEs by 75% during the
same time interval. Intrahepatic RNA levels were also assessed in transgenic mice, in
which GP3 siRNA3 significantly suppressed surface and core RNA levels by 40 and 42%,
respectively at day 18 post-injection. The unmodified siRNA3 suppressed surface RNA
levels by 20% and core RNA levels by 25% at day 21 post-administration. Furthermore,
GP4 siRNA3 silenced both surface and core RNA levels by 42% during the same time
period. Additionally, intrahepatic RNA quantitation revealed no induction of IFN response
genes by either unmodified or GP-modified siRNAs. In contrast to mice that had received
GP-modified siRNAs, significant induction of proinflammatory cytokine release was
observed in mice treated with unmodified siRNAs. The siRNA-mediated mRNA cleavage
product was also detected from liver samples following 5’ RACE analysis. Neither GPmodified
nor unmodified siRNAs significantly induced toxicity in injected mice.
Collectively, our data provide evidence that utilisation of GP-modified siRNAs and an
efficient hepatotropic non-viral delivery system may be used as a strategy to counter
chronic HBV infection.MT201
Manual de pràctiques de protecció de cultius
Grau en Enginyeria Agroalimentària i del Medi rural. Codi assignatura: AG101
Efecto del manejo de la cubierta vegetal en el control biológico de Tetranychus Urticae (Acari: Prostigmata) en Clementino
Tetranychus urticae ocasiona manchas en fruto que son especialmente
temidas en mandarinas. Puesto que esta fruta se destina mayoritariamente
al consumo en fresco, su valor comercial puede verse seriamente afectado.
Como consecuencia de la naturaleza polífaga de este ácaro, nuestra hipótesis
de trabajo fue que el manejo de la cubierta vegetal podía afectar a la
dinámica poblacional tanto de T. urticae como de sus principales enemigos
naturales, los ácaros depredadores de la familia de los Phytoseiidae. En
estudios previos, en los que se caracterizó la acarofauna asociada a especies
vegetales adventicias presentes en los huertos de cítricos, se observó
que las gramíneas (Poaceae) presentaban una proporción Phytoseiidae :
T. urticae más favorable que otras especies estudiadas. Consecuentemente,
hemos comparado el efecto de una cubierta sembrada de Festuca arundinacea
(Poaceae) frente a las alternativas tradicionales de suelo desnudo y
cubierta vegetal espontánea. Desde 2006, se ha realizado el seguimiento de
las poblaciones de ácaros en cuatro parcelas comerciales de clementino en
las que se ha delimitado tres áreas de estudio de 1 ha en las que se ha llevado
a cabo una diferente gestión de la cubierta vegetal: (a) Cubierta espontánea,
(b) Cubierta sembrada de Festuca arundinacea y (c) Suelo desnudo.
Como esperábamos, la cubierta sembrada de F. arundinacea fue la que presentó
menores poblaciones de T. urticae en el árbol. Los mecanismos que
explican estos resultados pueden estar relacionados tanto con la composición
específica de la de Phytoseiidae asociados a cada cubierta, como con
una posible especialización alimenticia por parte de T. urticae en la cubierta
de F. arundinaceaThe mite pest Tetranychus urticae causes fruit spots that are especially feared in mandarins as these fruits are intended mainly for fresh consumption, and commercial value can be severely affected. Because of the polyphagous nature of this mite, the working hypothesis of this study was that the management of vegetation cover could affect both the population dynamics of T. urticae and of its main natural enemies, which are predatory mites of the Phytoseiidae family. In previous studies that characterized the mites associated with adventitious plant species present in citrus orchards, it was observed that the grasses (Poaceae) harboured a proportion of Phytoseiidae, with a greater amount of T. urticae than of other species. In this experiment, the effect was compared of planted cover of Festuca arundinacea versus the traditional alternatives of bare soil and spontaneous vegetation cover. Since 2006, the mite population (Phytoseiidae in general and T. urticae in particular) has been monitored in four commercial plots of clementines (cv. Clementina de Nules grafted onto citrange Carizo), each in different municipalities in the province of Valencia, Spain; in each of these there were 3 study areas with different vegetation management: (a) spontaneous cover, (b) sown F. arundinacea and (c) bare soil. The results are presented for 2006 and 2007, and show, as expected, that where cover of F. arundinacea was planted, there were lower tree populations of T. urticae. The mechanisms that underlie these results may be related to both the specific composition of the Phytoseiidae associated with each type of cover, and as a possible food specialization by T. urticae on the F. arundinacea cover
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