To Work or Not to Work: Student Employment, Resiliency, and Institutional Engagement of Low-Income, First-Generation College Students

This exploratory study examines the difference between two college persistence factors—resiliency and institutional engagement—for lowincome, working, first-generation college students. Participants in the study consisted of 52 respondents to the Family History Knowledge and College Persistence Survey. Among respondents, 50 students reported participating in some form of employment, with 9 students in workstudy, 22 students in off-campus employment, and 19 students in both work-study and off-campus employment. Data analysis shows a significant relationship between resiliency and employment type, but no significant relationship between institutional engagement and employment type. Our findings indicate students who balance academics and employment exhibit a higher resiliency toward attaining graduation

Novel thin and compact H-plane SIW horn antenna

The substrate integrated waveguide (SIW) technology allows to construct several types of commonly used antennas in a planar way. However, some practical constraints limit their performances when frequencies below 20 GHz are considered. In the case of SIW horn antennas, the available substrates are much thinner than the wavelength yielding to poor matching and undesired back radiation. In this paper, an innovative structure to overcome these limitations is presented. It consists of a transition printed on the same SIW substrate, which improves both the radiation and the matching performances of conventional SIW horns. The horn shape is also further optimized by reducing its dimensions required for a given directivity. This is obtained by modifying the horn profile in order to effectively combine different TE modes. Guidelines are provided to design this type of thin and compact SIW horn antenna. They were applied to manufacture a prototype in the Ku-band with a substrate thinner than lambda(0)/10. Measurement results validate the proposed concepts showing excellent performances

Influencia de la densidad de la masa adulta y el tratamiento del suelo sobre la regeneración del pino laricio (Pinus nigra Arn. ssp. Salzmannii) en España

Satisfactory results relating to the natural regeneration of the Spanish black pine (Pinus nigra Arn ssp. salzmannii) is generally difficult to achieve. The natural regeneration of this pine was studied comparing two types of soil treatment and various overstory densities in six experimental forests. These studies were conducted from 1999 to 2002 and seed rain and germination, as well as seedling survival were observed in a number of specific plots: Brushing, scalping and control plots. In addition various overstory densities were used (measured as base area (square m/ha). Soil and air temperature together with soil moisture were continuously recorded throughout this summer period. The results showed that seed germination was higher in plots using the scalping technique, as opposed to the brushed or controlled plots. The best seedling survival percentage was found in scalped plots together with a larger basal area. It was also found that seedling survival was lower during the first year than during the second one. The results have practical implications for management of Spanish black pine forests as well as valuable information which could improve the conditions for regeneration.Generalmente es difícil conseguir una regeneración natural satisfactoria del pino laricio (Pinus nigra Arn ssp. salzmannii). Esta ha sido estudiada en dos tipos de tratamiento del suelo y bajo diferentes rangos de densidad de masa en seis montes de la Provincia de Cuenca. Entre 1999 y 2000 se ha seguido la lluvia de semillas, germinación y supervivencia de plántulas en las parcelas en las que se realizaron los tratamientos de suelo y bajo diferentes rangos de densidad de masa adulta, medida como área basimétrica (m cuadrados/ha). La temperatura del suelo y aire y la humedad del suelo han sido registradas durante el verano y para las dos primeras épocas de crecimiento de las plántulas. En las zonas decapadas la germinación fue superior a la encontrada en las zonas desbrozadas o testigo. El mejor porcentaje de supervivencia se calculó para las zonas decapadas en combinación con el mayor nivel de área basimétrica medido. La mortalidad de plántulas fue superior durante el primer periodo de crecimiento. Los resultados tienen implicaciones prácticas especialmente en lo relativo a una gestión forestal que mejore las condiciones para la regeneración natural de los bosques de pino laricio

A printed transition for matching improvement of SIW horn antennas

The substrate integrated waveguide (SIW) technology allows to construct several types of commonly used antennas in a planar way. However, frequency limitations associated to commercial substrates appear in the implementation of certain types of antennas, e.g., SIW horn antennas are not well matched when the substrate thickness is much smaller than the wavelength. A printed transition is proposed to overcome this problem. Differently from current solutions, no bulky elements are required allowing to maintain the most important features of this technology namely its compactness and ease of manufacturing. In order to quickly analyze and design the transition, both a coupled resonator and a transmission line models are developed, together with design guidelines. The proposed transition is designed to match a H-plane SIW horn antenna built in a thin substrate (thickness < lambda(0)/10) at different frequency bands at the Ku-band. Experimental results for 3 different transitions show that the matching characteristics are efficiently improved compared with the conventional SIW horn antenna and validates the proposed models

Crucial Role for Ecto-5′-Nucleotidase (CD73) in Vascular Leakage during Hypoxia

Extracellular adenosine has been widely implicated in adaptive responses to hypoxia. The generation of extracellular adenosine involves phosphohydrolysis of adenine nucleotide intermediates, and is regulated by the terminal enzymatic step catalyzed by ecto-5′-nucleotidase (CD73). Guided by previous work indicating that hypoxia-induced vascular leakage is, at least in part, controlled by adenosine, we generated mice with a targeted disruption of the third coding exon of Cd73 to test the hypothesis that CD73-generated extracellular adenosine functions in an innate protective pathway for hypoxia-induced vascular leakage. Cd73 (−/−) mice bred and gained weight normally, and appeared to have an intact immune system. However, vascular leakage was significantly increased in multiple organs, and after subjection to normobaric hypoxia (8% O(2)), Cd73 (−/−) mice manifested fulminant vascular leakage, particularly prevalent in the lung. Histological examination of lungs from hypoxic Cd73 (−/−) mice revealed perivascular interstitial edema associated with inflammatory infiltrates surrounding larger pulmonary vessels. Vascular leakage secondary to hypoxia was reversed in part by adenosine receptor agonists or reconstitution with soluble 5′-nucleotidase. Together, our studies identify CD73 as a critical mediator of vascular leakage in vivo

Artificial intelligence-based software (AID-FOREST) for tree detection: A new framework for fast and accurate forest inventorying using LiDAR point clouds

Forest inventories are essential to accurately estimate different dendrometric and forest stand parameters. However, classical forest inventories are time consuming, slow to conduct, sometimes inaccurate and costly. To address this problem, an efficient alternative approach has been sought and designed that will make this type of field work cheaper, faster, more accurate, and easier to complete. The implementation of this concept has required the development of a specifically designed software called "Artificial Intelligence for Digital Forest (AID-FOREST)", which is able to process point clouds obtained via mobile terrestrial laser scanning (MTLS) and then, to provide an array of multiple useful and accurate dendrometric and forest stand parameters. Singular characteristics of this approach are: No data pre-processing is required either pre-treatment of forest stand; fully automatic process once launched; no limitations by the size of the point cloud file and fast computations.To validate AID-FOREST, results provided by this software were compared against the obtained from in-situ classical forest inventories. To guaranty the soundness and generality of the comparison, different tree spe-cies, plot sizes, and tree densities were measured and analysed. A total of 76 plots (10,887 trees) were selected to conduct both a classic forest inventory reference method and a MTLS (ZEB-HORIZON, Geoslam, ltd.) scanning to obtain point clouds for AID-FOREST processing, known as the MTLS-AIDFOREST method. Thus, we compared the data collected by both methods estimating the average number of trees and diameter at breast height (DBH) for each plot. Moreover, 71 additional individual trees were scanned with MTLS and processed by AID-FOREST and were then felled and divided into logs measuring 1 m in length. This allowed us to accurately measure the DBH, total height, and total volume of the stems.When we compared the results obtained with each methodology, the mean detectability was 97% and ranged from 81.3 to 100%, with a bias (underestimation by MTLS-AIDFOREST method) in the number of trees per plot of 2.8% and a relative root-mean-square error (RMSE) of 9.2%. Species, plot size, and tree density did not significantly affect detectability. However, this parameter was significantly affected by the ecosystem visual complexity index (EVCI). The average DBH per plot was underestimated (but was not significantly different from 0) by the MTLS-AIDFOREST, with the average bias for pooled data being 1.8% with a RMSE of 7.5%. Similarly, there was no statistically significant differences between the two distribution functions of the DBH at the 95.0% confidence level.Regarding the individual tree parameters, MTLS-AIDFOREST underestimated DBH by 0.16 % (RMSE = 5.2 %) and overestimated the stem volume (Vt) by 1.37 % (RMSE = 14.3 %, although the BIAS was not statistically significantly different from 0). However, the MTLS-AIDFOREST method overestimated the total height (Ht) of the trees by a mean 1.33 m (5.1 %; relative RMSE = 11.5 %), because of the different height concepts measured by both methodological approaches. Finally, AID-FOREST required 30 to 66 min per ha-1 to fully automatically process the point cloud data from the *.las file corresponding to a given hectare plot. Thus, applying our MTLS-AIDFOREST methodology to make full forest inventories, required a 57.3 % of the time required to perform classical plot forest inventories (excluding the data postprocessing time in the latter case). A free trial of AID -FOREST can be requested at [email protected]

Digestive enzymes indicating nutritional condition in octopus paralarvae Octopus vulgaris Cuvier, 1797

Experiments were conducted to evaluate the effect of different diets in Octopus vulgaris Cuvier, 1797 paralarvae. Diets were composed of different combinations of Artemia salina (L., 1758), Moina salina Daday, 1888 and crab zoea, as well as artificial food. Wet weight of the paralarvae was recorded. Protease and trypsin activity were determined in a number of individuals to assess changes in the digestive use of food. Results show that enzyme secretion was affected both by age and the type of food. It is deduced that protease activity can be used as spawning quality index, and that trypsin activity gives information about whether paralarvae are feeding.El cultivo del pulpo común Octopus vulgaris Cuvier, 1797 no plantea problemas en cuanto a la adaptación de ejemplares a cautividad, engorde de juveniles, maduración sexual y puesta. Sin embargo, la tasa de mortalidad larvaria es muy elevada. La determinación de los cambios en las actividades enzimáticas durante el desarrollo larvario puede ser útil para establecer el momento óptimo del destete y para comprender la dependencia de la larva de fuentes de enzimas exógenas. Con el objetivo de determinar las capacidades digestivas de las paralarvas de pulpo se han llevado a cabo experimentos para evaluar el efecto en ellas de distintas dietas. éstas estaban compuestas por diferentes combinaciones de Artemia salina (L., 1758), Moina salina Daday, 1888 y zoeas de crustáceos, así como microcápsulas de dieta artificial. Determinado el peso húmedo de las paralarvas, se midió la actividad de proteasas y tripsina en ejemplares individuales para valorar la capacidad digestiva sobre los distintos tratamientos. Los resultados mostraron que la secreción enzimática estaba influida por la edad y el tipo de alimentación. Se deduce, pues, que las proteasas pueden ser usadas como índice de calidad de la puesta y la tripsina como indicador de que las paralarvas se están alimentando.Instituto Español de Oceanografí

Reexamining treatment of high-grade T1 bladder cancer according to depth of lamina propria invasion: a prospective trial of 200 patients

BACKGROUND: Management of high-grade T1 (HGT1) bladder cancer represents a major challenge. We studied a treatment strategy according to substaging by depth of lamina propria invasion. METHODS: In this prospective observational cohort study, patients received initial transurethral resection (TUR), mitomycin-C, and BCG. Subjects with shallower lamina propria invasion (HGT1a) were followed without further surgery, whereas subjects with HGT1b received a second TUR. Association of clinical and histological features with outcomes (primary: progression; secondary: recurrence and cancer-specific survival) was assessed using Cox regression. RESULTS: Median age was 71 years; 89.5% were males, with 89 (44.5%) cases T1a and 111 (55.5%) T1b. At median follow-up of 71 months, disease progression was observed in 31 (15.5%) and in univariate analysis, substaging, carcinoma in situ, tumour size, and tumour pattern predicted progression. On multivariate analysis only substaging, associated carcinoma in situ, and tumour size remained significant for progression. CONCLUSIONS: In HGT1 bladder cancer, the strategy of performing a second TUR only in T1b cases results in a global low progression rate of 15.5%. Tumours deeply invading the lamina propria (HGT1b) showed a three-fold increase in risk of progression. Substaging should be routinely evaluated, with HGT1b cases being thoroughly evaluated for cystectomy. Inclusion in the TNM system should also be carefully considered