Design and fabrication of CuInS2/ZnS-based QLED for automotive lighting systems.

This work reports the design, manufacturing and numerical simulation approach of a 6-pixel (4.5 mm2/pixel) electroluminescent quantum dot light emitting device (QLED) based on CuInS2/ZnS quantum dots as an active layer. The QLED device was fabricated using a conventional multi-layer thin film deposition. In addition, the electrical I-V curves were measured for each pixel independently, observing how the fabrication process and layer thickness have an influence in the shape of the plot. This experimental device, enabled us to create a computational model for the QLED based on the Transfer Hamiltonian approach to calculate the current density J (mA cm-2), the band diagram of the system, and the accumulated charge distribution. Besides, it is worth highlighting that the simulator allows the possibility to study the influence of different parameters of the QLED structure like the junction capacitance between the distinct multilayer set. Specifically, we found that the Anode-HIL interface capacitance has a greater influence in the I-V curve. This junction capacitance plays an important role in the current density increase and the QLED turn-on value when a forward voltage is applied to the device. The simulation enabled that influence could be controlled by the selection of the optimal thickness and transport layers during the experimental fabrication process. This work is remarkable since it achieves to fit simulation and experiment results in an accurate way for electroluminescent QLED devices; particularly the simulation of the device current, which is critical when designing the automotive electronics to control these new nanotechnology lighting devices in the future.

Effect of nitric oxide on boar sperm motility, membrane integrity, and acrosomal status during semen storage.

Nitric oxide (NO) is a major gasotransmitter involved in several physiological processes of male reproduction. There is, nevertheless, little information concerning the role of NO during semen storage. The aim of this study was to evaluate the effect of NO on boar semen stored at 17oC for 72 h. For this purporse, sperm samples were treated with 0.625, 1.25, 2.5, 5, and 10 mM aminoguanidine (AG) or Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME), a selective and non-selective NO synthase (NOS) inhibitor, respectively. Moreover, sodium nitroprusside (SNP), a NO donor, was used at the dose of 18.75, 37.5, 75, and 150 µM. Sperm motility, membrane integrity, and acrosomal status were evaluated at 0, 4, 24, 48, and 72 h of semen storage. A significant increase of the amplitude of lateral sperm head displacement (ALH), and both curvilinear and straight-line velocity (VCL and VSL, respectively) was observed at 72 h of semen storage in samples treated with 0.625 mM AG, probably because of the antioxidant properties of this NOS inhibitor. Contrarily, 0.625 mM L-NAME showed no effect on boar sperm parameters during the entire period of semen storage. Moreover, AG and L-NAME at 10 mM negatively affected sperm kinetics and acrosome integrity, which may provide further support to the notion that low NO levels are necessary for a normal sperm function. The concentrations of SNP used in this study had mostly no or negative effects on boar sperm parameters during semen storage. In conclusion, the results from this study increase the understanding of the role of NO on boar sperm physiology.

Response of thawed epididymal red deer spermatozoa to increasing concentrations of hydrogen peroxide, and importance of individual male variability.

Oxidative stress represents a challenge during sperm manipulation. We have tested the effect of increasing hydrogen peroxide (H(2)O(2)) levels on red deer spermatozoa after cryopreservation, and the role of male-to-male variation in that response. In a first experiment, eight thawed samples were submitted to 0, 25, 50, 100 and 200 µm H(2)O(2) for 2 h at 37 °C. Intracellular reactive oxygen species (H(2)DCFDA-CM) increased with H(2)O(2) concentration, but we only detected a decrease in sperm function (motility by CASA and chromatin damage by sperm chromatin structure assay) with 200 µm. Lipoperoxidation assessed by the thiobarbituric acid reactive substance (TBARS) method increased slightly with 50 µm H(2)O(2) and above. In a second experiment, samples from seven males were submitted to 0 and 200 µm H(2)O(2) for 2 h, triplicating the experiment within each male. Males differed at thawing and regarding their response to incubation and H(2)O(2) presence. We found that the kinematic parameters reflected male-to-male variability, whereas the response of the different males was similar for lipid peroxidation and viability. A multiparametric analysis showed that males grouped differently if samples were assessed after thawing, after incubation without H(2)O(2) or after incubation with H(2)O(2) . Red deer spermatozoa are relatively resilient to H(2)O(2) after thawing, but it seems to be a great male-to-male variability regarding the response to oxidative stress. The acknowledgement of this individual variability might improve the development of optimized sperm work protocols.

Comparison of the TBARS assay and BODIPY C11 probes for assessing lipid peroxidation in red deer spermatozoa.

Several methods are used to measure lipid peroxidation (LPO) in spermatozoa. The objective of this study was comparing the thiobarbituric acid reactive species (TBARS) method and the BODIPY 581/591 C(11) (B581) and BODIPY 665/676 C(11) (B665) fluorescent probes to measure induced peroxidative damage in thawed epididymal spermatozoa from Iberian red deer. Samples from three males were thawed, pooled, diluted in PBS, incubated at room temperature and assessed at 0, 3, 6 and 24 h under different experimental conditions: Control, hydrogen peroxide (H(2)O(2) ) 0.1 mM or 1 mM, or tert-butyl hydroperoxide (TBH) 0.1 mM or 1 mM. LPO was assessed by the TBARS assay [malondialdehyde (MDA) detection] and by the fluorescence probes B581 and B665 (microplate fluorimeter and flow cytometry). Increasing MDA levels were only detectable at 1 mM of TBH or H(2)O(2). Both fluorescence probes, measured with fluorometer, detected significant increases of LPO with time in all treatments, except Control. Flow cytometry allowed for higher sensitivity, with both probes showing a significant linear relationship of increasing LPO with time for all oxidizing treatments (p < 0.001). All methods showed a good agreement, except TBARS, and flow cytometry showed the highest repeatability. Our results show that both B581 and B665 might be used for LPO analysis in Iberian red deer epididymal spermatozoa, together with fluorometry or flow cytometry. Yet, the TBARS method offered comparatively limited sensitivity, and further research must determine the source of that limitation.

Effect of temperature and cell concentration on dolphin (Tursiops truncatus) spermatozoa quality evaluated at different days of refrigeration.

The use of cryopreserved dolphin spermatozoa facilitates the exchange of genetic material between aquatic parks and makes spermatozoa accessible to laboratories for studies to further our understanding of marine mammal reproduction. Sperm cryopreservation in the bottlenose dolphin (Tursiops truncatus) has been developed for the exchange of gametes within the ex situ population. The aim of this study was to develop an effective method for refrigeration of bottlenose dolphin spermatozoa diluted in a commercial extender (BTS). In Experiment 1, the effect of temperature (5 compared with 15 °C) on sperm quality was evaluated during 7 days of storage at 100 × 106 spermatozoa/ml. In Experiment 2, the effect of the storage concentration (100 × 106 compared with 20 × 106 spermatozoa/ml) on sperm quality was assessed during 7 days of storage at 5 °C. In Experiment 1, total motility (including % of rapid sperm) was greater at 5 than 15 °C. When the effect of storage concentration was evaluated (Experiment 2), total motility and ALH were greater at the higher storage concentration (100 × 106 spermatozoa/ml). For both experiments, values for viability, acrosome integrity, and normal morphology variables were consistent throughout the 7 days of refrigeration. In Experiment 3, a microbiological study was performed to evaluate the effect of the refrigeration temperature and days of storage on bacterial growth. The results of microbiological analysis indicated there was Staphylococcus aureus in some samples, however, there was no effect of temperature or days of refrigeration. In conclusion, bottlenose dolphin semen can be refrigerated for a short to medium period of storage and there is maintenance of functionality of sperm when stored at 100 × 106 spermatozoa/ml at 5 °C.

Late watergrass (Echinochloa phyllopogon): mechanisms involved in the resistance to fenoxaprop-p-ethyl.

Fenoxaprop-p-ethyl (FE), 2-[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy] propanoate, ethyl ester (R), is an aryloxyphenoxypropionate herbicide for postemergence control of annual and perennial grasses in paddy fields; its site of action is acetyl-coenzyme A carboxylase (ACCase), an enzyme in fatty acids biosynthesis. The possible mechanism(s) of resistance to FE in a resistant biotype of Echinochloa phyllopogon was examined, namely, absorption, translocation, and metabolism of FE and ACCase susceptibility to fenoxaprop acid (FA). Studies of the in vitro inhibition of ACCase discounted any differential active site sensitivity as the basis of resistance to FE. There were differences in absorption rates between biotypes from 3 to 48 h after application (HAA). Biotypes did not differ in either the amounts or the rates of FE translocated; 98% of applied [14C]FE remaining in the treated leaf. However, there was a good correlation between the rate of herbicide metabolism and the plant resistance. The R biotype produced 5-fold less FA and approximately 2-fold more nontoxic (polar) metabolites 48 HAA than the S biotype. Moreover, the higher rate of GSH conjugation in the resistant biotype as compared to the susceptible one indicates that GSH and cysteine conjugation is the major mechanism of resistance of the R biotype against FE toxicity.

Prevalence of traffic rule infractions in Cali, Colombia, at sites where injury crashes occurred.

This study aim to determine the proportion of traffic rule infractions in Cali, Colombia, in places where a road traffic injury (RTI) occurred. Description of videotaping of sites where a person was injured in an RTI in 2009. Counts of road users and infractions were established for each road user group and were compared using a Z-test. They were found 13,491 users, distributed as follow: 8.9% were pedestrians, 4.6% cyclists, 24.6% motorcyclists, and 61.8% were automobile drivers. The most frequent traffic violation among motorcyclists was transiting on lines designated for other vehicles (55.2%). Among cyclists, the most frequent violations were transiting without a helmet (99.2%) and not wearing the designated vest (100%). Among pedestrians, crossing streets at prohibited places (77.3%), even at sites where a pedestrian bridge was present (72.7%), represented two common violations. Vulnerable road users committed more traffic infractions than automobile drivers (p < 0.001). High rates of traffic rule infractions among vulnerable road users were observed. Studies to better understand the occurrence of these behaviours and the promotion of effective interventions are warranted.

Morphological and molecular characterization of different Echinochloa spp. and Oryza sativa populations.

Echinochloa P. Beauv. is an important genus because many of its species are weeds infesting most paddy fields, which can reduce the rice grain production by up to 80%. A controversy exists about the taxonomy of the genus due to the high level of morphological variations found in these species. Cyhalofop-butyl, an aryloxyphenoxy-propionate herbicide, is used to control Echinochloa spp. in paddy fields, although differences in susceptibility were found between different Echinochloa species. E. colona was highly susceptible [ED50= 34 g of active ingredient (ai) ha(-1)]; very similar results were obtained with the remaining species. By contrast, E. oryzicola (170 g of ai ha(-1)) was less sensitive, with the herbicide symptoms appearing later. Because of this differential susceptibility, morphological and molecular studies were carried out. A morphological study, using 21 characters both quantitative and qualitative of spikelets and seedlings, was capable of clearly distinguishing closely related E. crus-galli plants (two populations), E. muricata and E. crus-pavonis, and E. oryzicola, E. utilis, and E. colona species. The resolution of Echinochloa species at the molecular level, based on RAPD analyses, was fairly consistent with morphological analysis results. Among the 60 primers screened, 21 primers exhibited polymorphic bands and produced a total of 136 RAPD markers. Of all the amplified fragments, 90 were found to be polymorphic. E. oryzicola and E. colona were clearly separated, and the RAPD analyses showed that both E. crus-galli populations were 100% related and 51% related to E. utilis, whereas E. crus-pavonis and E. muricata (73% similarity) appeared as being clearly separated from this group.

Alternative control of two biotypes of Echinochloa phyllopogon susceptible and resistant to fenoxaprop-ethyl.

Rice (Oryza sativa var.), is one of the most important crops worldwide, and is cultivated in the five continents since it adapts itself to all climatic conditions. The most important weeds that reduce the world rice yield are Echinochloa spp., annual gramineae, which, because of the selection pressure imposed on them, have developed resistance to a large series of herbicides. Two Echinochloa phyllopogon biotypes were studied, one of them resistant to molinate, thiobencarb and fenoxaprop-ethyl and the other one susceptible to these herbicides, both originating from California rice fields. In these biotypes, the effects of other herbicides were evaluated, some of them with the same mode of action [profoxydim (Aura) and cyhalofopbutyl (Clincher), both ACCase inhibitors] and others with different modes of action [quinclorac (Facet) belonging to auxinic herbicide families; bispyribac-Na (Nominee) and azimsulfuron (Gulliver), both ALS inhibitors]. The only herbicide that effectively controlled the R biotype was profoxydim (95% control). Cyhalofop-butyl, quinclorac and bispyribac-Na did not control the R biotype by more than 40%. There is no doubt that azimsulfuron hardly had any effect (14%). On the other hand, in the S biotype, three herbicides were quite effective: profoxydim (93%), quinclorac (93%), and cyhalofop-butyl (90%). Bispyribac-Na and azimsulfuron hardly had any effect on the S biotype, with no significant differences in either herbicide (20%).

Botanical identification of several Echinochloa biotypes collected in Spanish rice fields with control failures of cyhalofop-butyl.

There is some disagreement about the species that constitute Echinochloa. Correct identification is agronomically and economically important because Echinochloa spp. are aggressive invaders and difficult to control. The identification of Echinochloa spp. is complicated because of the morphological diversity shown by the genus. This work was initiated because of the differential response to cyhalofop-butyl treatment shown by some populations of Echinochloa spp. Four biotypes were selected for botanical identification: two biotypes collected in the Seville area, one of them susceptible to cyhalofop-butyl (ED50 = 64 g a.i.ha(-1)) and the other one tolerant (ED50 = 560 g a.i.ha(-1)), one tolerant biotype collected in the Badajoz area (ED50 = 420 g a.i.ha(-1)) and one tolerant biotype collected in the Valencia area (ED50 = 860 g a.i.ha(-1)). Botanical identification was carried out following Carretero's Keys (1981) on plants grown at the site of origin. The main distinguishable character of the species was the length of the upper glume. The following results were obtained: the susceptible biotype collected in the Seville area and the tolerant biotype collected in the Valencia area were characterized as Echinochloa oryzoides, the tolerant biotype collected in Badajoz was characterized as E. oryzicola and the tolerant biotype collected in Seville area as E. hispidula.

Evaluation of resistance in Cyperus difformis populations to ALS inhibiting herbicides.

Due to the intensification of rice cultivation in Spain and the repeated use of herbicides as an effective tool to control weeds, one important fact is the appearance of resistant populations of weeds, which are no longer controlled effectively at field doses. Therefore, it is necessary to increase doses to such an extent as to produce phytotoxicity in the rice crop. In paddy fields in Badajoz (Spain), a few years ago, populations of Cyperus difformis resistant to bensulfuron-methyl appeared. In order to characterize this resistance, whole plant assays were carried out in fourteen populations, eight of them originating from treated Spanish paddy fields. The results were expressed as resistance factor (RF) = ED50(R)/ED50(S). Two populations of Cyperus difformis, resistant (R) and tolerant (T) to bensulfuron-methyl, displayed resistance factors greater than 30 and 12.5, respectively. Furthermore, in order to evaluate the existence of a possible cross-resistance, the recommended field doses of 3 other herbicides (imazamox, ethoxysulfuron and bentazone + MCPA) were applied to the plants. All populations were susceptible to both imazamox and bentazone + MCPA and two populations showed cross-resistance to ethoxysulfuron. ALS activity was assayed in vitro in four biotypes, the R/S ratios of the I50 values calculated indicate that resistance involves a reduction in the sensitivity of the ALS mainly in the R population (biotype 4) to bensulfuron-methyl and ethoxysulfuron, displaying R/S ratios of 37500 and 142857, respectively, which may be attributed to inherent differences in the ALS protein itself and/or in the stability of the enzyme.

Is it possible to detect Echinochloa spp. tolerance to ACCase-inhibiting herbicides using a simple quick tolerance test?

The objective of this work was to evaluate the reliability of one quick tolerance test that would enable us, in only six days, to quantify tolerance levels of one biotype to one or more herbicides. For this purpose, we evaluated tolerance levels to cyhalofop-butyl of five Echinochloa spp. biotypes: muricata, crus-galli, crus-pavonis, oryzicola and utilis, with unknown records of herbicide treatment. Moreover, two biotypes of Echinochloa phyllopogon were tested, one of them resistant (R) to fenoxaprop-P-ethyl and the other one susceptible (S). The Oryza sativa Puntal var. and Oryza sativa var. (wild rice) were also checked in order to demonstrate cyhalofop-butyl selectivity profiles. The assays were conducted with petri-dishes where, over the following increasing doses, fifty seeds per biotype and dose, were placed in each one: 0, 3, 6, 12, 18, 24, 48 and 60 ppm of cyhalofop-butyl and codacide oil adjuvant. Six days later, the following parameters were evaluated: plumule length, root length, germination (%) and fresh weight reduction (%). E. muricata germination was reduced by 50% with a 6 ppm dose. A non linear relation dose-germination was observed in the rest of the biotypes. The plumule length permitted the ranking of the biotypes into three groups: (1) resistant (E. phyllopogon R) or very tolerant (Oryza sativa Puntal var. and wild rice), those with a reduction of less than 30%, (2) tolerant, between 30 and 60% (E. oryzicola), and (3) susceptible, with a reduction of over 80% (E. muricata, E. crus-galli, E. crus-pavonis, E. utilis and E. phyllopogon S). Only Oryzo sativa and E. phyllopogon R had a minimal reduction of fresh weight (less than 15%). The assays were repeated with whole plants and we checked the accuracy of this test that indicated the resistance level of one biotype in a quick, reliable and economic way.

Biotypes resistant to herbicides in paddy fields in the Iberian Peninsula.

A consequence of modern agriculture and its dependence on herbicides, is the appearance of resistant weed populations. The first case of resistance on the Iberian Peninsula was found in Portugal and it was in a population of Alisma plantago-aquatica, resistant to bensulfuronmethyl, an ALS-inhibitor. For the same herbicide, control problems with Cyperus difformis were found in some Spanish rice fields. In the same rice field area, tolerance was observed in some Echinochloa spp. when auxinic herbicides (quinclorac) were used and some resistant Echinochloa spp. populations were found due to the long use of PS II inhibitors herbicides (propanil). The association of active ingredients, rotation of crops and adoption of mechanical control methods are the main strategies to combat resistance to herbicides.

Effect of post-mortem time on post-thaw characteristics of Spanish ibex (Capra pyrenaica) spermatozoa.

Viable epididymal sperm can be obtained in the Spanish ibex during 24h after death, but it has been observed a significant effect of the post-mortem time on fertility success, so only goats inseminated with semen recovery during the first 8h became pregnant. The aim of this study was to determine the effect of post-mortem time on epididymal semen samples from of Spanish ibex. For this purpose, sperm samples from 36 males were collected at different post-mortem times, from 2 to 24h, and cryopreserved. Thawed samples were incubated for 2h at 37°C without dilution or after dilution in a modified Tyrode medium, in order to study the sperm resistance to dilution. Moreover, flow cytometry was used to assess the sperm viability (PI), phospolipid disorder of the plasma membrane (M540), mitochondrial membrane potential (Mitotracker Deep Red), indirect apoptosis markers (YOPRO-1) and sperm chromatin stability (SCSA(®)). Sperm motility was evaluated by computer-assisted sperm analysis (CASA). Our results have shown that post-mortem time caused a reduction in mitochondrial membrane potential. In this regard, the loss of energy could be responsible for the loss of maintenance of the membrane with a consequent increase in permeability leading to a decrease in sperm viability and motility, losing linearity and speed. Moreover, the loss of maintenance of the membrane influence the extent to which sperm will survive the cryopreservation process, as it shows the results obtained from the dilution-incubation resistance test. Finally, one important finding of this study is the demonstration of no effect of post-mortem time on post-thaw DNA integrity, giving us the possibility of using sperm samples from valuable males, even if it was not possible to process during the first 8h.

Basis of selectivity of cyhalofop-butyl in Oryza sativa L.

Cyhalofop-butyl (CB), 2-[4-(4-cyano-2-fluorophenoxy)phenoxy]propanoic acid, butyl ester (R), is an aryloxyphenoxypropionate (AOPP) herbicide for postemergence use in rice to control grasses, mainly Echinochloa spp. Similar to other AOPP and cyclohexanedione herbicides, the site of action of CB is acetyl-coenzyme A carboxylase (ACCase), an enzyme in fatty acid biosynthesis. The mechanisms involved in the selectivity of CB in rice (Oryza sativa L.)-absorption, translocation, metabolism, and ACCase susceptibility-were studied. Studies of in vitro inhibition of ACCase in E. oryzoides and O. sativa L. species discounted any differential active site sensitivity as the basis of tolerance to CB. The O. sativa L. cuticle was uniformly covered by waxes, with predominantly unshaped large waxes randomly distributed, obtaining absorption values of under 30%, 24 h after application (HAA). The E. oryzoides cuticle formed a non-uniform covered reticule, with less wax density and areas lacking in waxes reaching maximum values of absorption rising to 73%, 24 HAA. Translocation studies revealed no significant differences, either between species, or between times, remaining in the treated leaf. There was a good correlation between the rate of metabolism and plant tolerance. Plant metabolism studies demonstrated that tolerant rice inactivated the esterases producing a lack of functionality thus reducing the conversion of CB to cyhalofop acid, which is the active form of the herbicide. Moreover, it increased the metabolism of the herbicide forming non toxic metabolites much faster than E. oryzoides. It was concluded that the basis of rice tolerance to CB was a lack of esterase functionality, a reduced absorption through the cuticle and an increase in cyhalofop acid metabolism.

Evaluación sensorial de diferentes presentaciones comerciales de dorada (Sparus aurata L) de acuicultura / Sensory analysis of different aquaculture gilthead sea bream (Sparus aurata L) commercial presentations

El análisis o evaluación sensorial, se puede definir como el análisis de los alimentos a través de los sentidos. Desde la antigüedad se ha utilizado la valoración sensorial para aceptar o rechazar los alimentos, así como para asignarle un determinado valor comercial. El análisis sensorial presenta dos grandes ventajas: la rapidez y la sencillez, sin embargo, las sensaciones que motivan al rechazo o aceptación varían con el tiempo y el momento que se perciben, dependiendo tanto de la persona como del entorno, con lo que es necesario objetivar y normalizar los términos y las condiciones que puedan influir en las determinaciones. En el presente estudio se llevó a cabo el análisis sensorial de cuatro presentaciones diferentes de dorada almacenadas en hielo: enteras, fileteadas, fileteadas y envasadas al vacío, y marinadas con zumo de limón y envasadas al vacío. El estudio se realizó para determinar el momento en el cual los distintos tipos de muestras eran rechazadas organolépticamente. Para ello un panel de catadores semientrenados evaluaron los atributos de apariencia, olor, flavor y textura, en los filetes de dorada cocinados, utilizando una escala puntuada. En las cuatro presentaciones comerciales, las puntuaciones otorgadas por el panel para la frescura decrecen linealmente a medida que pasan los días de permanencia en hielo. Los miembros del panel de catadores consideraron organolépticamente inaceptables las doradas enteras, las fileteadas y las fileteadas al vacío, en el día 22 de almacenamiento en hielo, sin embargo, las doradas marinadas no alcanzaron esta consideración en los 22 días que duró el estudio (AU)

The analysis or sensory test may be defined as an analysis of food by means of the senses. Such sensory evaluations have been used from ancient times to accept or reject food, as well as to designate its commercial value. Sensory analysis provides two important advantages: it is quick and it is simple. However, the senses which give rise to acceptance or rejection do vary over time and at the moment of perception. This depends as much on the person as on the environment. A reliable measure requires objectivity and normative regulation of terms and conditions that can influence specific evaluations. The current study has carried out sensory analysis of four different githhead sea bream presentations (whole, fillets, vacuum packed fillets, and marinated in lemon juice and vacuum packed fillets). The study was done as a quality test in order to determine the moment in which the fish is organoleptically rejected. In the four presentations, the scores given for freshness, decreased linearly according to time spent in ice. The taste panel members found the whole, the filleted and the vacuum filleted sea bream organoleptically unacceptable by the 22nd day on ice. Nevertheless, marinated sea bream were not so considered by the 22nd day (AU)