Effect of Soil Redox Potential andpH on Nutrient Uptake by Rice With Special Reference to Arsenic Forms and Uptake.

Studies dealing with the availability and speciation of arsenic (As) as affected by soil redox potential and pH were initiated because of the lack of information on As chemistry in flooded soils. The chemistry of native and applied As was studied in a Crowley silt loam soil (Typic Albaqualf). Arsenic uptake and its toxic effect on two rice cultivars as affected by As chemical form and concentration were also studied. Soil redox potential and pH were shown to affect speciation and solubility of both native and applied As. Upon soil reduction, indigenous-As solubility increased, and arsenite (As(III)) comprised most of the soluble As. At the lowest redox potential ($-$200 mV) 7.3, 2.2 and 1.4% of soil As became soluble at pH\u27s 5.5, 6.5 and 7.5 respectively. Under oxidized conditions, As solubility was lower, and arsenate (As(V)) constituted most of the soluble As. When 4 mg kg\sp{-1} monomethylarsenic acid (MMAA) was added, a similar trend occurred. Solubility of applied MMAA increased when the soil was reduced. In the two experiments, the greater availability of As under reduced conditions led to a greater As uptake by rice plants. Studies with plants grown in nutrient solution showed As chemical form to be the most important factor determining As availability and toxicity. Arsenic phytoavailability followed the trend As(III) $\u3e$ MMAA $\u3e$ As(V) $\u3e$ DMAA (dimethylarsenic acid), while As toxicity followed the trend MMAA $\u3e$ As(III) $\u3e$ As(V) $\sim$ DMAA. Arsenic taken up as MMAA, As(III) or As(V) was stored in the root, but As taken up as DMAA was readily translocated to the shoot. Phosphorus uptake decreased with increasing As application. Zinc tissue concentration and uptake was decreased by all chemical forms of As. In both the soil and the nutrient solution experiments, the uptake of As as MMAA interfered with the translocation of Zn and, to a lesser degree, Cu. Root applied DMAA at a concentration of 1.6 mg As L\sp{-1} inhibited photosynthetic activity, photosynthetic capacity and plant growth, leading eventually to death. Photosynthetic activity was inversely related to tissue As concentration

Balancing the arrival times of users in a two-stage location problem

There has been a number of facility location problems dealing with the introduction of the equity issue in the travel distances distribution. In this paper we analyze a new aspect of equity concerning the distribution of the arrival times of customers. Given a depot and a set of demand points generating flow which also represent potential locations, we consider a discrete two-stage location problem whose aim is to locate a given number of facilities and to allocate the demand points to a facility. We assume as objective the maximization of the minimum difference between two consecutive arrival times of flows to the depot through the patronized facility. This particular equity measure is introduced in order to reduce risks of congestion in the dynamic of flow arrivals at the common destination. The problem is described through two Integer Programming formulations. Computational results for solution methods based on both formulations are then shown and analyzed

Fortalecimiento del proceso de manipulación, levantamiento y desplazamiento de cargas muertas en el área de bodega de Cablecol a través de un manual guía que mitigue los accidentes laborales derivados de la mala gestión de las cargas.

No aplicaLa presente investigación tiene como finalidad fortalecer el proceso de manipulación, levantamiento y desplazamiento de cargas muertas en el área de bodega de Cablecol, a través de un manual guía, mitigando los accidentes laborales derivados de la mala gestión de las cargas. Lo anterior desde la consecución de una serie de objetivos específicos, siendo estos: caracterizar el proceso de manipulación, levantamiento y desplazamiento de cargas muertas en el área de bodega de Cablecol; crear un manual para el correcto desarrollo del proceso objeto de estudio en el área de bodega de Cablecol, siguiendo los lineamientos de la ISO 11228; y socializar el manual propuesto con los colaboradores del área de bodega, evaluando el impacto derivado de su proposición. Esto se propone bajo los parámetros de la investigación aplicada, de naturaleza cualitativa,y en función de la aplicación de una serie de entrevistas y encuestas, así como el diligenciamiento de un diario de campo. Entre los resultados obtenidos se destaca la proposición de un manual guía para fortalecer él proceso de manipulación manual de cargas en la organización objeto de estudio.The purpose of this research is to strengthen the process of handling, lifting and moving dead loads in the Cablecol warehouse area, through a guide manual, mitigating labor accidents resulting from poor load management. The foregoing from the achievement of a series of specificobjectives, these being: to characterize the process of handling, lifting and moving dead loads in the Cablecol warehouse area; create a manual for the correct development of the process under study in the Cablecol warehouse area, following the guidelines of ISO 11228; and socialize the proposed manual with collaborators in the warehouse area, evaluating the impact derived from itsproposal. This is proposed under the parameters of applied research, of a qualitative nature, and basedon the application of a series of interviews and surveys, as well as the completion of a field diary. Among the results obtained, the proposal of a manual guide to strengthen the process of manual handling of loads in the organization of objects of study stands out

Perspectives of federal real-estate management in Mexico

Recientemente, ha cobrado una particular relevancia dentro de la agenda pública nacional la importancia de que la administración del patrimonio inmobiliario federal en México cada vez sea más transparente y esté apegada a las mejores prácticas internacionales. Los retos y desafíos que existen para lograr una administración eficaz, moderna y transparente del patrimonio inmobiliario federal será un tema de creciente interés en los próximos años, dado que el inmueble público trasciende en el tiemp

InMyFace: Inertial and Mechanomyography-Based Sensor Fusion for Wearable Facial Activity Recognition

Recognizing facial activity is a well-understood (but non-trivial) computer vision problem. However, reliable solutions require a camera with a good view of the face, which is often unavailable in wearable settings. Furthermore, in wearable applications, where systems accompany users throughout their daily activities, a permanently running camera can be problematic for privacy (and legal) reasons. This work presents an alternative solution based on the fusion of wearable inertial sensors, planar pressure sensors, and acoustic mechanomyography (muscle sounds). The sensors were placed unobtrusively in a sports cap to monitor facial muscle activities related to facial expressions. We present our integrated wearable sensor system, describe data fusion and analysis methods, and evaluate the system in an experiment with thirteen subjects from different cultural backgrounds (eight countries) and both sexes (six women and seven men). In a one-model-per-user scheme and using a late fusion approach, the system yielded an average F1 score of 85.00% for the case where all sensing modalities are combined. With a cross-user validation and a one-model-for-all-user scheme, an F1 score of 79.00% was obtained for thirteen participants (six females and seven males). Moreover, in a hybrid fusion (cross-user) approach and six classes, an average F1 score of 82.00% was obtained for eight users. The results are competitive with state-of-the-art non-camera-based solutions for a cross-user study. In addition, our unique set of participants demonstrates the inclusiveness and generalizability of the approach.Comment: Submitted to Information Fusion, Elsevie

In vitro proizvodnja zametaka bizona u Kolumbiji - rezultati dodavanja faktora rasta i antioksidansa definiranom mediju za uzgoj zametaka

To increase the success rate of the in vitro production (IVP) system of embryos in buffalo, it is necessary to improve parameters. This field requires more research since its results are low compared to cattle. In this study carried out in Colombia, a modification of the methodology to produce buffalo IVP embryos is described, and 24 non-lactating females, aged 4 to 11 years old were included. Follicular wave was synchronised by ablation of the follicles within the ovary, seven days later all follicles were aspirated to obtain oocytes for maturation, fertilisation and embryo production. For all culture media used, animal protein was avoided. Culture media were supplemented with growth factors and other molecules associated with embryonic development. Special care was taken in adding supplements to protect the zygotes against the harmful effect of oxygen free radicals in the culture medium. Two aspiration series were performed 15 days apart. The average number of oocytes obtained by aspiration was 11.33, the number of blastocysts was 3.05, and the obtained blastocyst production rate (36.2%) was higher than literature reports for this species; we hypothesise that this increase is associated with the supplements added. It was possible to observe a female that produced 50 oocytes. Subsequent research is needed to evaluate the effect of the medium on embryo quality and pregnancy rates. A cost analysis of the new proposed medium is required, since all supplements must be imported and handled with a cold chain of up to -80oC, making it more expensive and restricting widespread use. Finally, it is shown that with three embryos per aspiration, at least one pregnancy can be successful after the aspiration, which is one of the objectives of the IVP system.Za povećanje djelotvornosti sustava in vitro proizvodnje (IVP) zametaka u bizona, potrebno je poboljšati parametre. Budući da su rezultati slabi u usporedbi s govedima slavi ovo područje zahtijeva više istraživanja. U ovom radu, provedenom u Kolumbiji, modifikacija metodologije za proizvodnju IVP zametaka bizona opisana je na sljedeći način: korištene su 24 ženke u dobi između 4 i 11 godina, a koje nisu bile u laktaciji. Folikularni val je sinkroniziran ablacijom folikula unutar jajnika, a nakon sedam dana obavljena je aspiracija svih folikula ženki za dobivanje oocista za dozrijevanje, oplodnju i proizvodnju embrija. Za sve rabljene podloge izbjegavan je životinjski protein. Podloge su obogaćene faktorima rasta i drugim molekulama povezanima s razvojem embrija. Posebna pozornost posvećena je pri dodavanju dodataka za zaštitu zigota od štetnih učinaka slobodnih radikala u podlozi. Obavljene su dvije aspiracijske serije u razmaku od 15 dana. Prosječni je broj oocista dobivenih aspiracijom bio 11,33, broj blastocista bio je 3,05, a dobivena je stopa proizvodnje blastocista (36,2 %) bolja je u usporedbi s onom koju su objavili drugi autori u državi, za istu vrstu. Pretpostavljamo da je ovo povećanje povezano s dodanim dodatcima, bilo je moguće promatrati ženku koja je proizvela 50 oocista. Naknadno je istraživanje potrebno za procjenu učinka podloge na kvalitetu zametaka i postotka gravidnosti; potrebna je i analiza troškova novog predloženog medija, jer se svi dodatci moraju uvesti u Kolumbiju i čuvati u hladnim uvjetima do minus 80 oC, što ih čini skupljima, a ograničava i njihovu široku primjenu. Na kraju našeg istraživanja uočeno je da s tri zametka po aspiraciji u ove vrste nije teško postići najmanje jednu gravidnost, a to je i jedan od ciljeva IVP-a

Repercusión de aditivos microbianos en el comportamiento productivo, zoométrico e incidencia diarreica de lechones

Objetivo. Evaluar la repercusión de dos aditivos microbianos en el comportamiento productivo, zoométricos, incidencia de diarreas y mortalidad de lechones post-destete. Materiales y métodos. Se emplearon 120 lechones (Duroc/Yorkshire/Landrace), distribuidos en tres grupos de 40 animales cada uno, control (T1); preparado microbiano A (T2) y preparado microbiano B (T3). El T1 contenía Lactobacillus acidophilus, Lactobacillus bulgaricus y Streptoccus thermophilus. El T2 estuvo compuesto por microorganismos del T1 más Saccharomyces cerevisae y Kluyveromyces fragilis (L-4 UCLV). Se utilizó un diseño completamente aleatorizado donde se evaluó, peso vivo, ganancia media diaria, talla: alzada a la cruz, alzada a la grupa, largo de cuerpo, para ambos sexos e incidencia diarreica y mortalidad. Resultados. Peso vivo en las crías (machos y hembras) que consumieron aditivos microbianos fueron superiores y de estos fueron mayores en el T3. En cuanto a la ganancia media diaria, los mayores incrementos se encontraron en el grupo T3. Alzada a la cruz, alzada a la grupa y largo de cuerpo fue mayor (p<0.05) en el T2 y T3 en el nacimiento; mientras que al final del estudio en el T3 fue superior. La incidencia de diarrea fue mayor (p<0.05) en el grupo control. Los animales de los grupos que consumieron preparado microbiano no presentaron muertes durante el estudio. Conclusiones. El uso de los aditivos microbianos evaluados produjo un efecto positivo en el comportamiento productivo y zoométrico de los lechones. Así mismo, se logró la reducción de la incidencia de diarreas y mortalidad de los animales

In Vitro versus In Vivo Phase Instability of Zirconia-Toughened Alumina Femoral Heads: A Critical Comparative Assessment

A clear discrepancy between predicted in vitro and actual in vivo surface phase stability of BIOLOX (R) delta zirconia-toughened alumina (ZTA) femoral heads has been demonstrated by several independent research groups. Data from retrievals challenge the validity of the standard method currently utilized in evaluating surface stability and raise a series of important questions: (1) Why do in vitro hydrothermal aging treatments conspicuously fail to model actual results from the in vivo environment? (2) What is the preponderant microscopic phenomenon triggering the accelerated transformation in vivo? (3) Ultimately, what revisions of the current in vitro standard are needed in order to obtain consistent predictions of ZTA transformation kinetics in vivo? Reported in this paper is a new in toto method for visualizing the surface stability of femoral heads. It is based on CAD-assisted Raman spectroscopy to quantitatively assess the phase transformation observed in ZTA retrievals. Using a series of independent analytical probes, an evaluation of the microscopic mechanisms responsible for the polymorphic transformation is also provided. An outline is given of the possible ways in which the current hydrothermal simulation standard for artificial joints can be improved in an attempt to reduce the gap between in vitro simulation and reality