Cryogenic thermal control technology summaries

A summarization and categorization is presented of the pertinent literature associated with cryogenic thermal control technology having potential application to in-orbit fluid transfer systems and/or associated space storage. Initially, a literature search was conducted to obtain pertinent documents for review. Reports determined to be of primary significance were summarized in detail. Each summary, where applicable, consists of; (1) report identification, (2) objective(s) of the work, (3) description of pertinent work performed, (4)major results, and (5) comments of the reviewer (GD/C). Specific areas covered are; (1) multilayer insulation of storage tanks with and without vacuum jacketing, (2) other insulation such as foams, shadow shields, microspheres, honeycomb, vent cooling and composites, (3) vacuum jacketed and composite fluid lines, and (4) low conductive tank supports and insulation penetrations. Reports which were reviewed and not summarized, along with reasons for not summarizing, are also listed

Super Weyl invariance: BPS equations from heterotic worldsheets

It is well-known that the beta functions on a string worldsheet correspond to the target space equations of motion, e.g. the Einstein equations. We show that the BPS equations, i.e. the conditions of vanishing supersymmetry variations of the space-time fermions, can be directly derived from the worldsheet. To this end we consider the RNS-formulation of the heterotic string with (2,0) supersymmetry, which describes a complex torsion target space that supports a holomorphic vector bundle. After a detailed account of its quantization and renormalization, we establish that the cancellation of the Weyl anomaly combined with (2,0) finiteness implies the heterotic BPS conditions: At the one loop level the geometry is required to be conformally balanced and the gauge background has to satisfy the Hermitean Yang-Mills equations.Comment: 1+31 pages LaTeX, 5 figures; final version, discussion relation Weyl invariance and (2,0) finiteness extended, typos correcte

Genome-wide expression profiling and functional characterization of SCA28 lymphoblastoid cell lines reveal impairment in cell growth and activation of apoptotic pathways

BACKGROUND: SCA28 is an autosomal dominant ataxia associated with AFG3L2 gene mutations. We performed a whole genome expression profiling using lymphoblastoid cell lines (LCLs) from four SCA28 patients and six unrelated healthy controls matched for sex and age. METHODS: Gene expression was evaluated with the Affymetrix GeneChip Human Genome U133A 2.0 Arrays and data were validated by real-time PCR. RESULTS: We found 66 genes whose expression was statistically different in SCA28 LCLs, 35 of which were up-regulated and 31 down-regulated. The differentially expressed genes were clustered in five functional categories: (1) regulation of cell proliferation; (2) regulation of programmed cell death; (3) response to oxidative stress; (4) cell adhesion, and (5) chemical homeostasis. To validate these data, we performed functional experiments that proved an impaired SCA28 LCLs growth compared to controls (p\u2009<\u20090.005), an increased number of cells in the G0/G1 phase (p\u2009<\u20090.001), and an increased mortality because of apoptosis (p\u2009<\u20090.05). We also showed that respiratory chain activity and reactive oxygen species levels was not altered, although lipid peroxidation in SCA28 LCLs was increased in basal conditions (p\u2009<\u20090.05). We did not detect mitochondrial DNA large deletions. An increase of TFAM, a crucial protein for mtDNA maintenance, and of DRP1, a key regulator of mitochondrial dynamic mechanism, suggested an alteration of fission/fusion pathways. CONCLUSIONS: Whole genome expression profiling, performed on SCA28 LCLs, allowed us to identify five altered functional categories that characterize the SCA28 LCLs phenotype, the first reported in human cells to our knowledge. \ua9 2013 Mancini et al.; licensee BioMed Central Ltd

Positive Selection within the Schizophrenia-Associated GABA(A) Receptor β(2) Gene

The gamma-aminobutyric acid type-A (GABA(A)) receptor plays a major role in inhibitory neurotransmissions. Intronic SNPs and haplotypes in GABRB2, the gene for GABA(A) receptor β(2) subunit, are associated with schizophrenia and correlated with the expression of two alternatively spliced β(2) isoforms. In the present study, using chimpanzee as an ancestral reference, high frequencies were observed for the derived (D) alleles of the four SNPs rs6556547, rs187269, rs1816071 and rs1816072 in GABRB2, suggesting the occurrence of positive selection for these derived alleles. Coalescence-based simulation showed that the population frequency spectra and the frequencies of H56, the haplotype having all four D alleles, significantly deviated from neutral-evolution expectation in various demographic models. Haplotypes containing the derived allele of rs1816072 displayed significantly less diversity compared to haplotypes containing its ancestral allele, further supporting positive selection. The variations in DD-genotype frequencies in five human populations provided a snapshot of the evolutionary history, which suggested that the positive selections of the D alleles are recent and likely ongoing. The divergence between the DD-genotype profiles of schizophrenic and control samples pointed to the schizophrenia-relevance of positive selections, with the schizophrenic samples showing weakened selections compared to the controls. These DD-genotypes were previously found to increase the expression of β(2), especially its long isoform. Electrophysiological analysis showed that this long β(2) isoform favored by the positive selections is more sensitive than the short isoform to the inhibition of GABA(A) receptor function by energy depletion. These findings represent the first demonstration of positive selection in a schizophrenia-associated gene

The Formin-Homology Protein SmDia Interacts with the Src Kinase SmTK and the GTPase SmRho1 in the Gonads of Schistosoma mansoni

BACKGROUND:Schistosomiasis (bilharzia) is a parasitic disease of worldwide significance affecting human and animals. As schistosome eggs are responsible for pathogenesis, the understanding of processes controlling gonad development might open new perspectives for intervention. The Src-like tyrosine-kinase SmTK3 of Schistosoma mansoni is expressed in the gonads, and its pharmacological inhibition reduces mitogenic activity and egg production in paired females in vitro. Since Src kinases are important signal transduction proteins it is of interest to unravel the signaling cascades SmTK3 is involved in to understand its cellular role in the gonads. METHODOLOGY AND RESULTS:Towards this end we established and screened a yeast two-hybrid (Y2H) cDNA library of adult S. mansoni with a bait construct encoding the SH3 (src homology) domain and unique site of SmTK3. Among the binding partners found was a diaphanous homolog (SmDia), which was characterized further. SmDia is a single-copy gene transcribed throughout development with a bias towards male transcription. Its deduced amino acid sequence reveals all diaphanous-characteristic functional domains. Binding studies with truncated SmDia clones identified SmTK3 interaction sites demonstrating that maximal binding efficiency depends on the N-terminal part of the FH1 (formin homology) domain and the inter-domain region of SmDia located upstream of FH1 in combination with the unique site and the SH3 domain of SmTK3, respectively. SmDia also directly interacted with the GTPase SmRho1 of S. mansoni. In situ hybridization experiments finally demonstrated that SmDia, SmRho1, and SmTK3 are transcribed in the gonads of both genders. CONCLUSION:These data provide first evidence for the existence of two cooperating pathways involving Rho and Src that bridge at SmDia probably organizing cytoskeletal events in the reproductive organs of a parasite, and beyond that in gonads of eukaryotes. Furthermore, the FH1 and inter domain region of SmDia have been discovered as binding sites for the SH3 and unique site domains of SmTK3, respectively

The Executive Branch’s Power in the Drone Program: Why the United States Needs a Drone Court

Senior Project submitted to The Division of Social Studies of Bard College