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Eye-tracking

Submitted by jmalloldiaz on Fri, 11/16/2018 - 15:38

As part of the comparative study of the control of eye movements by secondary eyes, we will have to develop different methods for each species. For example, we have an eye tracker developed particularly for salticids. For other species, we will illuminate the retinas with IR light and then capture the reflection with an IR camera in order to see the movement. We will use eye-masking techniques, already developed in our laboratory, to understand the role of the secondary eyes, if any, in principal eye control.

Pied-wagtails in England

Submitted by jmalloldiaz on Fri, 11/16/2018 - 10:04

Exploit renewable food source on riverbank (tides bring food). Maintain territory size all winter, don’t modify territory size in response to abundance of resources, instead they modify their behavior:

  • If food is low, they get it from other place but return to defend territory.
  • If food is abundant, they allow one subordinate bird (female or juvenile) to stay to help defend the territory because they can be kicked out later.
  • If food is very abundant, defense is abandoned.

Avian gonads

Submitted by jmalloldiaz on Fri, 11/16/2018 - 08:52

Gonad enlargement and ovarian development are driven by proximate factors, which are the external conditions that actually induce reproduction. Temperature is probably the most important modifier of annual gonadal cycles. Other factors such as habitat, vegetation, abundance of resources, or social stimulation help consummate the final stages of gonad enlargement and ovarian development.

New Caledonian Crows

Submitted by jmalloldiaz on Fri, 11/16/2018 - 08:33

New Caledonian Crows craft tools for probing and prying food. They make a variety of hooked tools by first selecting the raw material, then trimming it, and finally sculpting it into a hook. They also craft a second kind of tool from the leaves of a screw pipe by alternating angled cuts with horizontal rips to create a serrated edge. They use the tools for extracting insect prey from crevices.

Zugunruhe

Submitted by jmalloldiaz on Fri, 11/16/2018 - 08:30

Zugunruhe or migratory restlessness is determined by the circadian clock in response to the annual cycle. In a study of the orientation of Zugunruhe in Common Starlings, the birds were placed in cages in a room where they could see the sun, including its change of position as the day progressed. As long as they could see the sun, they focused their attention towards the northeast, the correct direction for spring migration. On overcast days, however, the starlings showed no directional tendency.

Intro

Submitted by jmalloldiaz on Fri, 11/16/2018 - 08:28

Following up on my work on sensory priming during the past semester and this summer, I will continue running arena trials with a new generation of P. princeps in order to study the behavioral responses of jumping spiders towards visual and acoustic stimuli. My experiments consisted of introducing a jumping spider in an arena so that it walked into a viewing chamber were pictures suddenly appeared in an iPod screen. The pictures were of a wasp (a potential predator), a cricket (a preferred prey), and a beetle (a neutral stimulus). Each spider was shown one image per trial and during the sound trials a speaker played a wasp buzzing sound for 5 seconds every 2 minutes.  Since the trials were run between the end of the Spring semester and this summer, it is possible that the effect of age influenced the spider’s response towards the stimuli, because jumping spiders are very visual and still they showed little response towards the pictures.

Statement Draft

Submitted by jmalloldiaz on Thu, 11/15/2018 - 19:59

Following up on my work on sensory priming during the past semester and this summer, I will continue running arena trials with a new generation of P. princeps in order to study the behavioral responses of jumping spiders towards visual and acoustic stimuli. My experiments consisted of introducing a jumping spider in an arena so that it walked into a viewing chamber were pictures suddenly appeared in an iPod screen. The pictures were of a wasp (a potential predator), a cricket (a preferred prey), and a beetle (a neutral stimulus). Each spider was shown one image per trial and during the sound trials a speaker played a wasp buzzing sound for 5 seconds every 2 minutes.  Since the trials were run between the end of the Spring semester and this summer, it is possible that the effect of age influenced the spider’s response towards the stimuli, because jumping spiders are very visual and still they showed little response towards the pictures.

Comparative Power Curves Critique

Submitted by jmalloldiaz on Wed, 11/07/2018 - 11:18

Due to using intermediate flight speeds for calibration purposes, pectoralis power data for cockatiels and doves is overestimated at slow speeds and underestimated at fast speeds. A follow-up study could address this issue by using other calibration parameters that do not interfere with slow and fast speed data for pectoralis power. Apart from the pectoralis muscles, data from other relevant wing muscles was not recorded in this study, and the role of the tail in reducing power requirements at slow speeds was unaddressed. This could be easily solved by employing sonomicrometry and other techniques in the rest of the muscles involved with flight, and by analyzing the bird’s use of its tail when flying at slow speeds. Finally, the model struggled to accurately measure drag at faster speeds due to a gap in the knowledge of the components of total drag. This would require further studies in the aerodynamics of flight, perhaps by employing more advanced biophysics software or using new lab techniques that record the components of total drag.

Organic Chemistry Notes

Submitted by jmalloldiaz on Wed, 11/07/2018 - 11:17

Ethers can only react with HBr and HI.

If they ask for products you have to follow the table, while if they ask for the ingredients to prepare an ether you have to assign the less hindered side to the X. In the second case your alkyl halide can't be vinyl, phenyl, or tertiary.

In Claisen rearrangement you have a phenyl and an allyl on each side of the ether. You have to start numbering form the double bond towards the O, and then shift the double bond to carbons 2-3.

Epoxides:

If a reaction whose product is an epoxide has a reactant with an X you have to use NaOH/H-.

If there is no X, the reaction will happen if there is Ag2O/O3/300C or molecules with CO3.

The base always attacks the less hindered side.

Conclusion Draft

Submitted by jmalloldiaz on Wed, 11/07/2018 - 11:08

Due to using intermediate flight speeds for calibration purposes, pectoralis power data for cockatiels and doves is overestimated at slow speeds and underestimated at fast speeds. A follow-up study could address this issue by using other calibration parameters that do not interfere with slow and fast speed data for pectoralis power. Apart from the pectoralis muscles, data from other relevant wing muscles was not recorded in this study, and the role of the tail in reducing power requirements at slow speeds was unaddressed. This could be easily solved by employing sonomicrometry and other techniques in the rest of the muscles involved with flight, and by analyzing the bird’s use of its tail when flying at slow speeds. Finally, the model struggled to accurately measure drag at faster speeds due to a gap in the knowledge of the components of total drag. This would require further studies in the aerodynamics of flight, perhaps by employing more advanced biophysics software or using new lab techniques that record the components of total drag.

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