Effect of voicing and articulation manner on aerosol particle emission during human speech.

Previously, we demonstrated a strong correlation between the amplitude of human speech and the emission rate of micron-scale expiratory aerosol particles, which are believed to play a role in respiratory disease transmission. To further those findings, here we systematically investigate the effect of different 'phones' (the basic sound units of speech) on the emission of particles from the human respiratory tract during speech. We measured the respiratory particle emission rates of 56 healthy human volunteers voicing specific phones, both in isolation and in the context of a standard spoken text. We found that certain phones are associated with significantly higher particle production; for example, the vowel /i/ ("need," "sea") produces more particles than /ɑ/ ("saw," "hot") or /u/ ("blue," "mood"), while disyllabic words including voiced plosive consonants (e.g., /d/, /b/, /g/) yield more particles than words with voiceless fricatives (e.g., /s/, /h/, /f/). These trends for discrete phones and words were corroborated by the time-resolved particle emission rates as volunteers read aloud from a standard text passage that incorporates a broad range of the phones present in spoken English. Our measurements showed that particle emission rates were positively correlated with the vowel content of a phrase; conversely, particle emission decreased during phrases with a high fraction of voiceless fricatives. Our particle emission data is broadly consistent with prior measurements of the egressive airflow rate associated with the vocalization of various phones that differ in voicing and articulation. These results suggest that airborne transmission of respiratory pathogens via speech aerosol particles could be modulated by specific phonetic characteristics of the language spoken by a given human population, along with other, more frequently considered epidemiological variables

Effect of a commercial root growth enhancer on the turfgrass species "Lolium perenne" and the weed "Poa annua"

Se pretende comprobar si la aplicación de un enraizante durante la resiembra otoñal de la cespitosa “Lolium perenne” sobre las calles de los campos de golf conformados por “Cynodon dactylon”, favoreciese la competencia de “L. perenne” frente a Poa annua, mala hierba que germina precisamente en esta época. Se realizaron 2 ensayos iguales en cámara de crecimiento aplicando 10 dosis distintas del enraizante en ambas especies y se determinó al final del ensayo, tanto el crecimiento como el peso seco de la parte aérea y radical de ambas especies. Tan sólo en uno de los 2 ensayos el enraizante parece favorecer a la cespitosa frente a “P. annua” por lo que no puede concluirse categóricamente que el enraizante pueda ser un medio de control efectivo frente a la mala hierba.It is intended to check the performance of a root growth enhancer in order to promote “Lolium perenne” competiveness over “Poa annua”, during the overseeding cultural practice on “Cynodon dactylon” golf course fairway, as “P. annua” naturally germinates at the same time. Two equal laboratory experiments were conducted testing 10 doses of the root enhancer in both species. At the end of the experiments seedling growth and root and leaf dry weight were determined for both species. The tested product only promotes “L. perenne” competiveness in one experiment, therefore it cannot be concluded the root enhancer could be an effective weed control method

Parvalbumin interneurons are differentially connected to principal cells in inhibitory feedback microcircuits along the dorso-ventral axis of the medial entorhinal cortex

The medial entorhinal cortex (mEC) shows a high degree of spatial tuning, predominantly grid cell activity, which is reliant on robust, dynamic inhibition provided by local interneurons (INs). In fact, feedback inhibitory microcircuits involving fast-spiking parvalbumin (PV) basket cells (BCs) are believed to contribute dominantly to the emergence of grid cell firing in principal cells (PrCs). However, the strength of PV BC-mediated inhibition onto PrCs is not uniform in this region, but high in the dorsal and weak in the ventral mEC. This is in good correlation with divergent grid field sizes, but the underlying morphologic and physiological mechanisms remain unknown. In this study, we examined PV BCs in layer (L)2/3 of the mEC characterizing their intrinsic physiology, morphology and synaptic connectivity in the juvenile rat. We show that while intrinsic physiology and morphology are broadly similar over the dorsoventral axis, PV BCs form more connections onto local PrCs in the dorsal mEC, independent of target cell type. In turn, the major PrC subtypes, pyramidal cell (PC) and stellate cell (SC), form connections onto PV BCs with lower, but equal probability. These data thus identify inhibitory connectivity as source of the gradient of inhibition, plausibly explaining divergent grid field formation along this dorsoventral axis of the mEC

Using a simple model for water and nitrogentransport in soil in the practical works ofHorticulture

[EN] Simulation models for the transport of water and nitrogen in the soil are useful tools for evaluating the consequen-ces of di erent crop management practices without waiting until the end of the crop cycle. Particularly, simplecompartmental models for the transport of water and nitrogen are based on the solution of mass balance equationsfor the water and a system of ordinary di erential equations for the nitrogen cycle. In this work, these modelsare used to evaluate di erent possible scenarios of irrigation and nitrogen fertilization in a cauli ower crop, as apractical work for the students of Horticulture course. The results show that di erent irrigation and fertilizationstrategies lead to di erent results for the nitrate leaching, water drainage and nitrogen uptake[ES] Los modelos de simulación del transporte de agua y nitrógeno en el suelo son herramientas útiles para evaluar distintas prácticas de cultivo sin necesidad de tener que esperar a que se complete el ciclo de crecimiento. En concreto, los modelos compartimentales sencillos para el agua y el nitrógeno en el suelo se basan en ecuaciones de balance de masa y en la resolución de un sistema de ecuaciones diferenciales ordinarias. Se plantea la posibilidad de utilizar este tipo de modelos en las prácticas de la asignatura Horticultura, evaluando distintos escenarios posibles de riego y abonado en un cultivo de coliflor. Los resultados muestran que distintas prácticas de cultivo producen diferencias en la lixiviación de nitrato y en la extracción de nitrógeno por el cultivo.Lidón, A.; Ginestar, D.; Gómez De Barreda, D. (2017). Utilizacion de un modelo simple de transporte de agua y nitrógeno en el suelo en las practicas de Horticultura. Modelling in Science Education and Learning. 10(2):21-34. doi:10.4995/msel.2017.6600SWORD2134102Contreras, W. A., Lidón, A. L., Ginestar, D., & Bru, R. (2009). Compartmental model for nitrogen dynamics in citrus orchards. Mathematical and Computer Modelling, 50(5-6), 794-805. doi:10.1016/j.mcm.2009.05.008Lidón, A., Ramos, C., Ginestar, D., & Contreras, W. (2013). Assessment of LEACHN and a simple compartmental model to simulate nitrogen dynamics in citrus orchards. Agricultural Water Management, 121, 42-53. doi:10.1016/j.agwat.2013.01.008Cannavo, P., Recous, S., Parnaudeau, V., & Reau, R. (2008). Modeling N Dynamics to Assess Environmental Impacts of Cropped Soils. Advances in Agronomy Volume 97, 131-174. doi:10.1016/s0065-2113(07)00004-1Lidón, A., Ramos, C., & Rodrigo, A. (1999). Comparison of drainage estimation methods in irrigated citrus orchards. Irrigation Science, 19(1), 25-36. doi:10.1007/s002710050068Porporato, A., D’Odorico, P., Laio, F., & Rodriguez-Iturbe, I. (2003). Hydrologic controls on soil carbon and nitrogen cycles. I. Modeling scheme. Advances in Water Resources, 26(1), 45-58. doi:10.1016/s0309-1708(02)00094-5Wang, L., D’Odorico, P., Manzoni, S., Porporato, A., & Macko, S. (2009). Soil carbon and nitrogen dynamics in southern African savannas: the effect of vegetation-induced patch-scale heterogeneities and large scale rainfall gradients. Climatic Change, 94(1-2), 63-76. doi:10.1007/s10584-009-9548-

Modified Annexin V/Propidium Iodide Apoptosis Assay For Accurate Assessment of Cell Death

Studies of cellular apoptosis have been significantly impacted since the introduction of flow cytometry-based methods. Propidium iodide (PI) is widely used in conjunction with Annexin V to determine if cells are viable, apoptotic, or necrotic through differences in plasma membrane integrity and permeability1,2. The Annexin V/ PI protocol is a commonly used approach for studying apoptotic cells3. PI is used more often than other nuclear stains because it is economical, stable and a good indicator of cell viability, based on its capacity to exclude dye in living cells 4,5. The ability of PI to enter a cell is dependent upon the permeability of the membrane; PI does not stain live or early apoptotic cells due to the presence of an intact plasma membrane 1,2,6. In late apoptotic and necrotic cells, the integrity of the plasma and nuclear membranes decreases7,8, allowing PI to pass through the membranes, intercalate into nucleic acids, and display red fluorescence 1,2,9. Unfortunately, we find that conventional Annexin V/ PI protocols lead to a significant number of false positive events (up to 40%), which are associated with PI staining of RNA within the cytoplasmic compartment10. Primary cells and cell lines in a broad range of animal models are affected, with large cells (nuclear: cytoplasmic ratios <0.5) showing the highest occurrence10. Herein, we demonstrate a modified Annexin V/ PI method that provides a significant improvement for assessment of cell death compared to conventional methods. This protocol takes advantage of changes in cellular permeability during cell fixing to promote entry of RNase A into cells following staining. Both the timing and concentration of RNase A have been optimized for removal of cytoplasmic RNA. The result is a significant improvement over conventional Annexin V/ PI protocols (< 5% events with cytoplasmic PI staining)

Compuestos metal-carbono derivados del petróleo para electrododos de batería ión-litio

III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

Peritoneal protein transport during the baseline peritoneal equilibration test is an accurate predictor of the outcome of peritoneal dialysis patients

[Abstract] Background: Peritoneal protein excretion (PPE) is a potential marker of the outcome in peritoneal dialysis (PD) patients. Method: Observational study of a cohort of 269 patients starting PD in a single unit. Study variables: total PPE during a baseline peritoneal equilibration test (PET; PET-PPE) and 24-hour PPE. Control variables: essential baseline demographic, laboratory and adequacy markers. Main outcomes: mortality, cardiovascular events and risk of peritonitis. We applied univariate and multivariate strategies of survival analysis. Main Results: PET-PPE sustained a significant, yet limited correlation with 24-hour PPE (r = 0.46, p < 0.0005). At baseline, the main study variables showed an independent correlation with peritoneal transport characteristics (D/P240’ creatinine) and cardiovascular comorbidity. PET-PPE (p < 0.0005, model global χ2 59.4) was a more accurate predictor of overall mortality than 24-hour PPE (p = 0.04, χ2 50.5). Moreover, PPE during PET, but not 24-hour PPE, was an independent predictor of the risks of cardiovascular and infectious mortality, and of peritonitis. Conclusions: Baseline PPE represents a strong independent marker of survival of PD patients. Estimation of PPE during PET is more accurate than 24-hour PPE for this purpose, sustains a definite independent association with cardiovascular and infectious mortality, and shows a significant correlation with the risk of peritonitis