An experimental demonstration of blind ocean acoustic tomography

Despite the advantages clearly demonstrated by ocean acoustic tomography OAT when compared to other ocean monitoring techniques, it suffers from several technical-related drawbacks. One is the requirement for rather expensive equipment to be maintained and operated at several locations in order to obtain sufficient source–receiver propagation paths to cover a given ocean volume. This paper presents the preliminary feasibility tests of a concept that uses ships of opportunity as sound sources for OAT. The approach adopted in this paper views the tomographic problem as a global inversion that includes determining both the emitted signal and the environmental parameters, which is a similar problem to that seen in blind channel identification and was therefore termed blind ocean acoustic tomography BOAT . BOAT was tested on a data set acquired in October 2000 in a shallow-water area off the west coast of Portugal, including both active and passive ship noise data. Successful results show that BOAT is able to estimate detailed water column temperature profiles coherent with independent measurements in intervals where the uncontrolled source signal ship noise presents a sufficient bandwidth and signal-to-noise ratio, which clearly define the limitations of the presented method.FCT; CN

Algarroba Effects on Behavior and Dairy Production of Grazing Cows II. Rainy Season.

The influence of arborization with algarroba (Prosopis juliflora SW) on behavior and dairy production of grazing cows was evaluated. The trial was made in the rainy season, and six enclosures per arborization treatment were used (low arborization, with 1-7 trees/ha; mid-arborization, with 12-16 trees/ha; and high arborization, with 20-27 trees/ha). Activities were observed every ten minutes during the mornings and afternoons. The number of animals, and each animal´s activity time was recorded. The dairy production data were collected and compared through a randomized design with six repetitions (ANOVA). Significant differences were observed (P < 0.05) to more arborization in grazing (155-173 min), and the monthly values observed were similar. In fields with low arborization, the cows ate less grass, whereas fields with mid and high arborization, the cows grazed longer, and produced more milk (11.2 and 12.59 kg/c/day)

Effect of Algarroba on Grazing Cow Behavior and Milk Production. I. Dry Season.

The effect of algarroba (Prosopis juliflora SW) arborization on grazing cow behavior and milk production was assessed. The trial was made in the rainy season, and six enclosures were used per arborization treatment (low arborization, 1-7 trees/ha; mid arborization, 12-16 trees/ha; high arborization, 20-27 trees/ha). Rational grazing was performed. The grass rested for 21-28 days, and sprinklers were used for irrigation. The animalsʼ activity time and the number of animals were registered. Milk production values were compared using ANOVA, following a randomized design with six replicas. No significant differences were observed in the morning grazing (118-203 min), but there were significant differences (P < 0.05) in the afternoon, in favor of more arborization (103-125 min), whereas in lands with mid and high arborization, cows ruminated longer, with higher water consumption and milk production, and values between 11.85-13.76 kg/v/day

Effects of Milled Maize Stalks on the Productive Response of Grazing Dairy Cows.

The productive response of grazing dairy cows was evaluated, using milled corn stalks in the diet. The study was developed in two different settings, in Ecuador (Costa and Sierra regions). On the coast farm (29.1 ha), cows grazed on Bermuda grass (Cynodon nlemfuensis) and Guinea grass (Panicum maximum) with several types of legumes (Lysicarpus, Centrosema, Desmodium, Galactia), supplemented with corn stalks cv. INIAP 125. The animals received 0.46 kg beginning at 3 kg, and milled maize stalks in 30 and 28-day periods, respectively (M-30 and M-28), and control without stalks for 36 days (M-0). The farm in the other region (14.2 ha) had 23 cows grazing on Kikuyo grass (P. clandestinum) and ryegrass-white clover (L. perenne and whole maize stalks and T. (60-70% ripe grain), at a rate of 18 kg green/cow/day for 48 days; and balanced supplement, at a rate of 0.5 kg/ milk liter, after the fourth kilogram, along with minerals. In both cases the forage had effects (P < 0.05) on cow response. In the Sierra area, the increase was 1.68 kg/cow, and in the coast, it was 1.1 and 2.5 kg/cow). Maize stalks served as a nutritional complement for poorly consumed grass areas in both regions; milk production/animal was increased, and the costs were reduced

Cognitive impairment induced by delta9-tetrahydrocannabinol occurs through heteromers between cannabinoid CB1 and serotonin 5-HT2A receptors

Delta-9-tetrahydrocannabinol (THC), the main psychoactive compound of marijuana, induces numerous undesirable effects, including memory impairments, anxiety, and dependence. Conversely, THC also has potentially therapeutic effects, including analgesia, muscle relaxation, and neuroprotection. However, the mechanisms that dissociate these responses are still not known. Using mice lacking the serotonin receptor 5-HT2A, we revealed that the analgesic and amnesic effects of THC are independent of each other: while amnesia induced by THC disappears in the mutant mice, THC can still promote analgesia in these animals. In subsequent molecular studies, we showed that in specific brain regions involved in memory formation, the receptors for THC and the 5-HT2A receptors work together by physically interacting with each other. Experimentally interfering with this interaction prevented the memory deficits induced by THC, but not its analgesic properties. Our results highlight a novel mechanism by which the beneficial analgesic properties of THC can be dissociated from its cognitive side effects

Influencia del algarrobo en la conducta y producción de leche de vacas en pastoreo. I I . Período l luvioso

Se  evaluó  la  influencia  de  la  arborización  con  algarrobo (Prosopis  juliflora  SW)  en  la  conducta  y  producción  de leche  de  vacas  en  pastoreo.   El  ensayo  se  realizó  en época  de  lluvia  y  se  utilizaron  seis  cuartones  por tratamiento  de arborización  (bajo  grado  de  arborización  con 1-7  árboles/ha;   medio  grado  de  arborización  con  1 2- 1 6  árboles/ha  y  alto  grado  de  arborización  20-27 árboles/ha.   En  la  mañana  y  en  la  tarde  se  observaban  las actividades  cada  1 0  min.   Se registró  el  tiempo  del  animal  en actividad,  el  número  de  animales .  Se  tomó  la  información  de  la  producción  de  leche/tratamiento  y  en  un  diseño  al azar  con  seis  repeticiones  se  comparó  mediante  Anava. Se  registraron  diferencias significativas  (P  <  0, 05)  a  favor  de  mayor  arborización  en  pastoreo  ( 1 55- 1 73  min)  y  los índices  tuvieron  un  comportamiento  muy  similar  por  meses.   En  potreros  con  baja  carga  arbórea  las  vacas consumen  menos  pasto,  mientras  que en  potreros  con medio  y  alto  grado  de  arborización,  las  vacas  pastaron más  tiempo  y  tuvieron  mayor  producción  de leche  con valores  entre  1 1 , 02  y  1 2, 50  kg/v/día. Effect  of  Algarroba  on  Grazing  Cow  Behavior  and  Milk  Production.  II.  Rainy  Season ABSTRACTThe  effect  of  algarroba  (Prosopis juliflora  SW)  arborization on  grazing  cow  behavior  and  milk  production  was assessed.   The  trial  was  made  in  the  rainy  season,  and six  enclosures  were  used  per  arborization  treatment  (low  arborization,  1 -7  trees/ha;  mid  arborization,  1 2- 1 6 trees/ha;  high  arborization,  20-27  trees/ha) .   The  time  of each  animal during  activity,  and  the  number  of  animals, were  registered.   Milk  production  values  were  compared using  ANOVA, following  a  randomized  design  with  six replicas.   The  significant  differences  were  registered  (P  <  0. 05)  positively toward  greater  arborization  grazing  ( 1 55- 1 73  min) ,  and  the  indexes  had  a  very  similar  behavior  for months.   In  poorly arborized  grazing  lands  cows  consumed less  pasture,  whereas  in  highly  arborized  lands,  cows stayed  longer  and  pro-duced  more  milk  ( 1 1 . 02  and  1 2. 50  kg/cow/day).

Pαx6 Expression in Postmitotic Neurons Mediates the Growth of Axons in Response to SFRP1

During development, the mechanisms that specify neuronal subclasses are coupled to those that determine their axonal response to guidance cues. Pax6 is a homedomain transcription factor required for the specification of a variety of neural precursors. After cell cycle exit, Pax6 expression is often shut down in the precursor progeny and most postmitotic neurons no longer express detectable levels of the protein. There are however exceptions and high Pax6 protein levels are found, for example, in postmitotic retinal ganglion cells (RGCs), dopaminergic neurons of the olfactory bulb and the limbic system in the telencephalon. The function of Pax6 in these differentiating neurons remains mostly elusive. Here, we demonstrate that Pax6 mediates the response of growing axons to SFRP1, a secreted molecule expressed in several Pax6-positive forebrain territories. Forced expression of Pax6 in cultured postmitotic cortical neurons, which do not normally express Pax6, was sufficient to increment axonal length. Growth was blocked by the addition of anti-SFRP1 antibodies, whereas exogenously added SFRP1 increased axonal growth of Pax6-transfected neurons but not that of control or untransfected cortical neurons. In the reverse scenario, shRNA-mediated knock-down of Pax6 in mouse retinal explants specifically abolished RGCs axonal growth induced by SFRP1, but had no effect on RGCs differentiation and it did not modify the effect of Shh or Netrin on axon growth. Taken together these results demonstrate that expression of Pax6 is necessary and sufficient to render postmitotic neurons competent to respond to SFRP1. These results reveal a novel and unexpected function of Pax6 in postmitotic neurons and situate Pax6 and SFRP1 as pair regulators of axonal connectivity

Influencia del algarrobo en la conducta y producción de leche de vacas en pastoreo. I. Período de Seca.

Se evaluó la influencia de la arborización con algarrobo (Prosopis juliflora SW) en la conducta y producción deleche de vacas en pastoreo. El ensayo se realizó en época de seca y se utilizaron seis cuartones por tratamiento de arborización (bajo grado de arborización con 1-7 árboles/ha; medio grado de arborización con 12-16 árboles/ha y alto grado de arborización 20-27 árboles/ha). El pastoreo fue racional. El reposo del pasto fue de 21 a 28 días y se utilizó riego por aspersión. En la mañana y en la tarde se observaban las actividades cada 10 min. Se registró el tiempo del animal por actividad, número de animales. Se tomó la información de la producción de leche y en un diseño al azar con seis repeticiones se comparó mediante ANAVA. No hubo diferencias significativas en el pastoreo en la mañana (118 a 203 min), pero sí fueron significativas (P < 0,05) en la tarde a favor de mayor arborización(103 a 125 min), mientras que en potreros con medio y alto grado de arborización, las vacas rumiaron mástiempo, con mayor consumo de agua y producción de leche con valores entre 11,85 y 13,76 kg/v/día.Effect of Algarroba on Grazing Cow Behavior and Milk Production. I. Dry Season ABSTRACTThe effect of algarroba (Prosopis juliflora SW) arborization on grazing cow behavior and milk production was assessed. The trial was made in the rainy season, and six enclosures were used per arborization treatment (low arborization, 1-7 trees/ha; mid arborization, 12-16 trees/ha; high arborization, 20-27 trees/ha). Rational grazing was performed. The grass rested for 21-28 days, and sprinklers were used for irrigation. Each animal´s activity time, and the number of animals, were registered. Milk production values were compared using ANOVA, following a randomized design with six replicas. No significant differences were observed in the morning grazing (118 -203 min),but there were significant differences (P < 0.05) in the afternoon, positively toward more arborization (103 -125 min), whereas in lands with mid and high arborization, cows ruminated longer, with higher water consumption and milk production, and values between11.85 - 13.76 kg/v/day