Neurons contain two highly specialized compartments: the dendrite, which receives synaptic or sensory inputs, and the axon, which relays these signals to other cells. Different types of neurons often have unique, type-specific dendrite morphologies and proper dendrite patterning is important for normal neuronal function. Underscoring the importance of dendrite morphology to neuronal function, defects in dendrite patterning likely contribute to numerous neurological disease states and the cognitive decline that accompanies normal aging. However, the many genes that contribute to the complex dendrite patterns remain largely uncharacterized. To identify genes involved in this process, we conducted a genetic screen for mutants that alter the patterning of sensory neuron dendrites that innervate the body wall of fruit fly larvae. Briefly, we mutagenized fruit flies with EMS, a chemical mutagen, and screened for late-larval stage lethal mutations that perturb dendrite patterning using a fluorescent protein that allowed us to visualize a single functional class of sensory neurons in living larvae. Here, we report our analysis of a novel mutant, messi. Using live cell imaging and quantitative analysis, we found that messi leads to exuberant dendrite branching and intermingling of dendrites in sensory neurons. This latter defect is of particular interest since “self-avoidance” may represent a general mechanism for organizing sensory dendrites and little is known about the genetic basis for this phenomenon. Using time-lapse microscopy, we found that messi causes progressive dendrite defects: the dendrite patterning of messi mutants is indistinguishable from wild type early in development, but becomes abnormal later in development. Similarly, dendrite defects in many neurological disorders are progressive, therefore further analysis of messi may contribute to our understanding of how dendrite maintenance is deregulated in diseased states. Currently, we are working towards identifying the gene affected in messi mutants and determining whether messi affects dendrite patterning in other functional classes of sensory neurons.

When a photon is absorbed by materials called semiconductor nanocrystals or quantum dots (QDs), the energy from the photon is also absorbed and can be used to excite the semiconductor nanocrystals. If the energy of the photon is at least twice the energy of the bandgap, or the energy between two specific states, at least two charge carriers can be created. Charge carriers are inherent in any material which can absorb energy and undergo a process of excitation to a higher energy state by the photon followed by relaxation to its normal energy state accompanied by a release of energy. Conversely, when the energy of the light does not exceed twice the band gap, only one excitation is observed. If a material exhibits the property of creating multiple charge carriers, often called Multiple Exciton Generation (MEG), it can be stated that this material will likely enhance a solar cell since energy from the light absorbed by the cell will result in multiple charge carriers created followed by multiple relaxations and the releasing of energy. MEG has been shown to exist in a variety of QDs. Here, we attempt to confirm the presence of MEG in germanium QDs. This was done by pumping 400 nm and 800 nm light with a pump-probe laser and collecting the absorbance spectra at different power levels. The spectra can be analyzed to demonstrate if MEG occurs by comparing the absorbance at these different power levels. The results have provided no conclusive evidence of MEG in germanium nanoparticles. This result allows for further research to be performed on what may impact MEG and what materials are ideal for MEG.

Mood disorders affect twice as many women as men. Yet most research done on mouse models is male-focused. For example, social stress induces social withdrawal behavior, which is observed in many mood disorders. However, in many species it is difficult to observe the effects of social stress in females because of low aggression levels. We studied the monogamous California mouse because males and females of this species are aggressive. We focused on the mesolimbic dopamine system because its function is altered in accordance with reduced sensitivity to reward in depression. Female California mice exposed to three episodes of social stress show a decrease in social interaction not seen in males. Preliminary studies suggest that social stress activates kappa opioid receptors (KOR) in the nucleus accumbens (NAc). Activation of KOR induces dysphoria through activation of p38 MAP kinase. We found more phospho-p38 positive cells in the NAc of males and females exposed to three episodes but not in one episode of social stress. We are now examining effects of the KOR agonist U50,488H and antagonist (norbinaltophimine, NorBNI) on conditioned place aversion and social interaction. Human and animal studies suggest that there may be sex differences in sensitivity of KOR. Preliminary data indicate that a conditioned place aversion and social withdrawal are induced by U50,488H, dose dependently. Knowing the effects of KOR can provide better insight into the long-term effects of social stress and effective ways to target this complex network. Targeting kappa opioid receptors to treat depression may provide fewer side effects than dopamine target approaches because the distribution of KOR is more restricted than dopamine receptors.

The immune response of individuals with disrupted sleep such as night-shift workers has been shown to decrease relative to individuals with regular sleep patterns. Cytokines are small molecules secreted as part of the immune response to infection. Certain cytokines have been shown to regulate sleep, and this regulation likely constitutes a critical component of the immune response. A common consequence of exposure to unusual light-dark (LD) cycles, such as those under jetlag or shift-work schedules, is the internal desynchronization of circadian rhythms. This desynchronization is associated with disruptions in the sleep-wake cycle and we hypothesize that this disruption may be linked to abnormal secretion of cytokines. Using an animal model of internal desynchronization, we exposed rats to a 22-hour LD (11L: 11D) cycle which leads to desynchronization of the sleep stages known as Rapid Eye Movement Sleep (REMS) and nonREM sleep (NREMS). In these animals, the temporal sequence of REMS and NREMS changes stably between days of alignment, in which the sequence is normal, and days of misalignment, in which this sequence is disrupted. We will analyze levels of three cytokines, interleukins 1, 6, and tumor necrosis factor (TNF) over a 24-hour period in animals either bled during days of alignment or during days of misalignment. Our hypothesis predicts lower production levels of these cytokines in misaligned rats.The implications of this study may indicate that the alignment of circadian rhythms, particularly of the sleep-wake cycle, are critical to maintaining normal cytokine levels and to sustaining normal immune response.

Contact influences the behavior and associations of delphinids and other cetaceans. However, little is known about the role of contact in beluga (Delphinapterus leucas) social interactions. The purpose of the present study was to investigate the degree of contact in eight belugas at Sea World San Antonio using a focal sampling procedure of 10 minute observations. Frequency and/or duration were recorded for the initiating /receiving beluga, type of contact, body part used to contact, and object receiving contact. Data were collected during two seasons: Summer 2011, which examined contact behaviors between belugas and Fall 2011, which examined contact behaviors between belugas and object contact. During the summer, 27 contact events occurred across 120 observation sessions. Contact occurred at a rate of .02 events per minute, indicating belugas rarely contact each other. Most of the contact events that did occur were initiated by the three non-adult belugas, during affiliative play interactions and were short in duration. A third of the events occurred between a mother-calf pair while the calf was in infant position and lasted longer than most social interactions. During the fall, 17 physical contact events and 909 object contact events occurred across 120 observation sessions. Physical contact occurred at a rate of .01 events per minute. Like the summer session, most of the physical contact events were initiated by the three non-adult belugas, during affiliative play interactions and were short in duration. Again most of the events occurred between the mother-calf pair while the calf was swimming in infant position and were longer than most social interactions. Object contact occurred at a rate of .76 events per minute. Objects were contacted through rubbing 94% of the time, and objects were contacted through touching 6% of the time. Overall, belugas contacted objects more than each other.

Since the phrase Continuous Partial Attention, or CPA, was first coined by former Apple and Microsoft executive Linda Stone in 1998, it has gained considerable press both printed and online. Describing a cognitive tactic employed daily by many who have grown dependent on their digital gadgetry and networking technology, it has been asserted that there are specific consequences associated with prolonged use. These include a heightened level of stress as well as an inability to focus, self-inflect, and an overall feeling of being unfulfilled.
Although discussed and widely accepted as a valid and prevalent condition by many writers in the online blogosphere, there is currently no scholarly research investigating the validity of CPA as an actual condition. This current scientific study proposes preliminary steps towards formulating empirical based research to address a crucial and as of now unexamined question: Is Continuous Partial Attention real?
As there currently is none in existence, the first phase towards answering this question will entail the creation of a scale intent on measuring the purported effects of CPA as detailed by Stone. This will broken down into three separate categories to be measured: the physiological effects, the cognitive effects, and the effects on the individual’s state of mind.
Once a reliable scale is developed, it is hoped that an experimental phase will follow whereby attempts will be made to induce CPA in a controlled laboratory environment so that its effects might be measured and recorded. This will be done in an effort to gather valid evidence to support its existence.
If it is found that the claims surrounding CPA are in fact real and valid, then it is a condition causing scientifically unrecognized cognitive and physiological harm to countless unsuspecting individuals in our current techno-reliant society.