Education and Outreach at NASA's Goddard Space Flight Center

NASA?s Space Communications and Navigation (SCaN) Program Office maintains a year-round educational program for undergraduate and graduate students. Within NASA?s Goddard Space Flight Center, the Exploration and Space Communications Projects Division implements the SCaN intern program with a focus on space operations, including operations of orbiting spacecraft, space communications, ground activities and networking. The intern program enables students to work with various NASA projects in solving real-world problems inside the Exploration and Space Communications division. Goddard interns have been assigned to the NASA?s Near Earth Network facilities in Greenbelt, Maryland, and Wallops, Virginia. They have also been assigned to NASA?s Space Network facilities in Greenbelt, Maryland, and Las Cruces, New Mexico

Latest Changes to NASA's Laser Communication Relay Demonstration Project

Over the last couple of years, NASA has been making changes to the Laser Communications Relay Demonstration Project (LCRD), a joint project between NASA's Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory, California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL). The changes made makes LCRD more like a future Earth relay system that has both high speed optical and radio frequency links. This will allow LCRD to demonstrate a more detailed concept of operations for a future operational mission critical Earth relay. LCRD is expected to launch in June 2019 and is expected to be followed a couple of years later with a prototype user terminal on the International Space Station. LCRD's architecture will allow it to serve as a testbed in space and this paper will provide an update of its planned capabilities and experiments

Role of serotonergic signaling in GABAA receptor phosphorylation and functional expression

γ-aminobutyric acid type-A (GABAA) receptors are heteropentameric ligand-gated chloride channels that mediate the majority of fast synaptic inhibition in the brain. Emerging evidence indicates that their functional expression is subject to dynamic modulation by phosphorylation. However, the cell signaling molecules responsible for regulating GABAA receptor phosphorylation and thus the efficacy of neuronal inhibition remain to be identified. The β subunits are of particular interest in this context as their intracellular domains contain conserved serine residues (S409 in β1, S410 in β2 and S408/9 in β3), known substrates for a number of protein kinases, including PKA and PKC. In vitro binding experiments showed that phosphorylation and/or mutation of these residues confers a reduction in binding of GABAA receptor β subunits to the μ2 adaptin of the clathrin adaptor protein (AP)-2 complex - a critical regulator of GABAA receptor endocytosis and surface number. Consistent with this, coimmunoprecipitation of AP2-μ2 adaptin with endogenous GABAA receptor β3 subunits was significantly reduced in cultured neurons treated with a potent inhibitor of S408/9 dephosphorylation that was accompanied by an increase in the stability of GABAA receptor β3 subunits at the cell surface. Interestingly, recent studies have implicated PKA and PKC in the mediation of serotonergic modulation of GABAA receptor activity in the prefrontal cortex, suggesting that phosphorylation of GABAA receptor β subunits may underlie this regulation. To address this, a phospho-specific antibody directed against β3 at S408/9 was developed. Immunoblotting with anti-pS408/9-β3 demonstrated a PKC-dependent increase in the phosphorylation state of GABAA receptor β3 subunits following enhanced 5-hydroxytryptamine type-2 (5-HT2) receptor activation ex vivo. Moreover, in vivo biochemical and immunohistochemical studies revealed region-specific increases in GABAA receptor β3 subunit phosphorylation in mice dosed with the selective serotonin reuptake inhibitor (SSRI) fluoxetine (Prozac™), a commonly prescribed antidepressant. Together, the results presented herein suggest that the phospho-dependent increase in GABAA receptor functional expression may underlie the therapeutic action of SSRIs

SOCIALQ&A: A NOVEL APPROACH TO NOTIFIYING THE CORRECT USERS IN QUESTION AND ANSWERING SYSTEMS

Question and Answering (Q&A) systems are currently in use by a large number of Internet users. Q&A systems play a vital role in our daily life as an important platform for information and knowledge sharing. Hence, much research has been devoted to improving the performance of Q&A systems, with a focus on improving the quality of answers provided by users, reducing the wait time for users who ask questions, using a knowledge base to provide answers via text mining, and directing questions to appropriate users. Due to the growing popularity of Q&A systems, the number of questions in the system can become very large; thus, it is unlikely for an answer provider to simply stumble upon a question that he/she can answer properly. The primary objective of this research is to improve the quality of answers and to decrease wait times by forwarding questions to users who exhibit an interest or expertise in the area to which the question belongs. To that end, this research studies how to leverage social networks to enhance the performance of Q&A systems. We have proposed SocialQ&A, a social network based Q&A system that identifies and notifies the users who are most likely to answer a question. SocialQ&A incorporates three major components: User Interest Analyzer, Question Categorizer, and Question- User Mapper. The User Interest Analyzer associates each user with a vector of interest categories. The Question Categorizer algorithm associates a vector of interest categories to each question. Then, based on user interest and user social connectedness, the Question-User Mapper identifies a list of potential answer providers for each question. We have also implemented a real-world prototype for SocialQ&A and analyzed the data from questions/answers obtained from the prototype. Results suggest that social networks can be leveraged to improve the quality of answers and reduce the wait time for answers. Thus, this research provides a promising direction to improve the performance of Q&A systems

Systemic exosomal siRNA delivery reduced alpha-synuclein aggregates in brains of transgenic mice.

Alpha-synuclein (α-Syn) aggregates are the main component of Lewy bodies, which are the characteristic pathological feature in Parkinson's disease (PD) brain. Evidence that α-Syn aggregation can be propagated between neurones has led to the suggestion that this mechanism is responsible for the stepwise progression of PD pathology. Decreasing α-Syn expression is predicted to attenuate this process and is thus an attractive approach to delay or halt PD progression. We have used α-Syn small interfering RNA (siRNA) to reduce total and aggregated α-Syn levels in mouse brains. To achieve widespread delivery of siRNAs to the brain we have peripherally injected modified exosomes expressing Ravies virus glycoprotein loaded with siRNA. Normal mice were analyzed 3 or 7 days after injection. To evaluate whether this approach can decrease α-Syn aggregates, we repeated the treatment using transgenic mice expressing the human phosphorylation-mimic S129D α-Syn, which exhibits aggregation. In normal mice we detected significantly reduced α-Syn messenger RNA (mRNA) and protein levels throughout the brain 3 and 7 days after treatment with RVG-exosomes loaded with siRNA to α-Syn. In S129D α-Syn transgenic mice we found a decreased α-Syn mRNA and protein levels throughout the brain 7 days after injection. This resulted in significant reductions in intraneuronal protein aggregates, including in dopaminergic neurones of the substantia nigra. This study highlights the therapeutic potential of RVG-exosome delivery of siRNA to delay and reverse brain α-Syn pathological conditions

Hepatocellular carcinoma in a case of hepatitis C

Hepatocellular carcinoma has incidence of 90% of all liver cancers. HCC is the second most common hepatic malignancy in children after the hepatoblastomas. Patients with hepatocellular carcinoma presents with symptoms like pruritus, splenomegaly, bleeding oesophageal varices etc. Computed Tomography of the liver can look for local spread and thorax can look for metastases. Our case was a 49-year- old hepatitis C positive female came with vague right upper quadrant abdominal discomfort with weight loss of 7 lbs in last 2 months. Mild icterus was present on examination. CT scan revealed a well-defined iso-dense lesion in the segment V of right lobe of the liver, which shows enhancement in the hepatic arterial phase and rapid washout in the portal venous phase. Laboratory investigations showed abnormal liver function test. The HCV RNA levels were 1.45×105 IU/ml by real time PCR. Histopathology examination of biopsy specimen shows characteristic morphological features of steatohepatitic variant of hepatocellular carcinoma. Then the patient was referred to the higher center for the further management

Emotion regulation and executive functioning as predictors of theory of mind competence during early childhood.

The linkage between emotion regulation (ER) skills and executive functioning (EF) abilities as predictors of theory of mind skills (ToM) was examined. 263 3.5-year-old children that participated in an on-going longitudinal study were administered various executive function, emotion regulation, and theory of mind tasks; maternal reports of emotion regulation abilities were also obtained. It was predicted that children who score higher on ER measures will better be able to perform on EF tasks and in turn have a superior ToM ability; superior EF skills would mediate the relation between ER skills and ToM abilities. Results showed no relationship between ER, EF, and ToM after controlling for demographic variables such as maternal education, race, language, gender, and maternal marital status; the mediation hypothesis was not supported. But associations between some EF tasks and ToM tasks were found. Results are discussed in terms of limitations and possible implications for supporting the development of cognitive, regulatory, and social skills in young children

Utility of MRI in diagnosis of empty Sella syndrome in a young female with amenorrhoea and bilateral nipple discharge

Empty sella syndrome is a rare disease in which sella turcica appears empty. It can be asymptomatic or may have symptoms due to hormonal disturbances. Here we report a case of 35-years-old female who presented with amenorrhoea and bilateral nipple discharge.

Presier’s disease: idiopathic avascular necrosis of scaphoid in a case presenting with wrist pain in young male

A 25-years-old male presented with complain of pain in right wrist and difficulty in gripping objects. No history of trauma to the right wrist joint. On local examination, tenderness was present in right anatomical snuff box. Tenderness was elicited by axial compression on right first metacarpal with decreased range of the motion at the right wrist compare to the left side. Routine blood investigation was within normal limits. X-ray of the right wrist joint showed minimal sclerotic in right scaphoid. On MRI right wrist joint, low intensity signal was seen involving the whole right scaphoid bone on T1 weighted, T2 weighted and STIR images with loss of normal marrow signal intensity. So according to the Herbert and Lanzetta it was stage 4 and Kalainov et al, type 1 avascular necrosis.  Diagnosis of idiopathic avascular necrosis of the right scaphoid bone was postulated based on clinical and radiological findings. Patient was treated with vascularised pedicle bone graft from the right distal radius. The patient was gradually improved clinically with subsidence of pain and improvement in the grip strength over 1 year

An Essential Role for the Tetraspanin LHFPL4 in the Cell-Type-Specific Targeting and Clustering of Synaptic GABAReceptors

Inhibitory synaptic transmission requires the targeting and stabilization of GABAA receptors (GABAARs) at synapses. The mechanisms responsible remain poorly understood, and roles for transmembrane accessory proteins have not been established. Using molecular, imaging, and electrophysiological approaches, we identify the tetraspanin LHFPL4 as a critical regulator of postsynaptic GABAAR clustering in hippocampal pyramidal neurons. LHFPL4 interacts tightly with GABAAR subunits and is selectively enriched at inhibitory synapses. In LHFPL4 knockout mice, there is a dramatic cell-type-specific reduction in GABAAR and gephyrin clusters and an accumulation of large intracellular gephyrin aggregates in vivo. While GABAARs are still trafficked to the neuronal surface in pyramidal neurons, they are no longer localized at synapses, resulting in a profound loss of fast inhibitory postsynaptic currents. Hippocampal interneuron currents remain unaffected. Our results establish LHFPL4 as a synapse-specific tetraspanin essential for inhibitory synapse function and provide fresh insights into the molecular make-up of inhibitory synapses