Using dust shed from asteroids as microsamples to link remote measurements with meteorite classes.

Given the compositional diversity of asteroids, and their distribution in space, it is impossible to consider returning samples from each one to establish their origin. However, the velocity and molecular composition of primary minerals, hydrated silicates, and organic materials can be determined by in situ dust detector instruments. Such instruments could sample the cloud of micrometer-scale particles shed by asteroids to provide direct links to known meteorite groups without returning the samples to terrestrial laboratories. We extend models of the measured lunar dust cloud from LADEE to show that the abundance of detectable impact-generated microsamples around asteroids is a function of the parent body radius, heliocentric distance, flyby distance, and speed. We use Monte Carlo modeling to show that several tens to hundreds of particles, if randomly ejected and detected during a flyby, would be a sufficient number to classify the parent body as an ordinary chondrite, basaltic achondrite, or other class of meteorite. Encountering and measuring microsamples shed from near-Earth and Main Belt asteroids, coupled with complementary imaging and multispectral measurements, could accomplish a thorough characterization of small, airless bodies.

An age-related reduction of brain TBPH/TDP-43 levels precedes the onset of locomotion defects in a Drosophila ALS model.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. The average age of onset of both sporadic and familial cases is 50-60 years of age. The presence of cytoplasmic inclusions of the RNA-binding protein TAR DNA-binding protein-43 (TDP-43) in the affected neurons is seen in 95% of the ALS cases, which results in TDP-43 nuclear clearance and loss of function. The Drosophila melanogaster ortholog of TDP-43 (TBPH) shares many characteristics with the human protein. Using a TDP-43 aggregation inducer previously developed in human cells, we created a transgenic fly that shows an adult locomotive defect. Phenotype onset correlates with a physiologically age-related drop of TDP-43/TBPH mRNA and protein levels, seen both in mice and flies. Artificial reduction of mRNA levels, in vivo, anticipates the locomotion defect to the larval stage. Our study links, for the first time, aggregation and the age-related, evolutionary conserved reduction of TDP-43/TBPH levels with the onset of an ALS-like locomotion defect in a Drosophila model. A similar process might trigger the human disease.

Character and spatial distribution of OH/H2O on the surface of the Moon seen by M3 on Chandrayaan-1.

The search for water on the surface of the anhydrous Moon had remained an unfulfilled quest for 40 years. However, the Moon Mineralogy Mapper (M3) on Chandrayaan-1 has recently detected absorption features near 2.8 to 3.0 micrometers on the surface of the Moon. For silicate bodies, such features are typically attributed to hydroxyl- and/or water-bearing materials. On the Moon, the feature is seen as a widely distributed absorption that appears strongest at cooler high latitudes and at several fresh feldspathic craters. The general lack of correlation of this feature in sunlit M3 data with neutron spectrometer hydrogen abundance data suggests that the formation and retention of hydroxyl and water are ongoing surficial processes. Hydroxyl/water production processes may feed polar cold traps and make the lunar regolith a candidate source of volatiles for human exploration.

Triplet and ground state potential energy surfaces of 1,4-diphenyl-1,3-butadiene: theory and experiment.

Relative energies of the ground state isomers of 1,4-diphenyl-1,3-butadiene (DPB) are determined from the temperature dependence of equilibrium isomer compositions obtained with the use of diphenyl diselenide as catalyst. Temperature and concentration effects on photostationary states and isomerization quantum yields with biacetyl or fluorenone as triplet sensitizers with or without the presence of O(2), lead to significant modification of the proposed DPB triplet potential energy surface. Quantum yields for ct-DPB formation from tt-DPB increase with [tt-DPB] revealing a quantum chain process in the tt --> ct direction, as had been observed for the ct --> tt direction, and suggesting an energy minimum at the (3)ct* geometry. They confirm the presence of planar and twisted isomeric triplets in equilibrium (K), with energy transfer from planar or quasi-planar geometries (quantum chain events from tt and ct triplets) and unimolecular decay (k(d)) from twisted geometries. Starting from cc-DPB, varphi(cc-->tt) increases with increasing [cc-DPB] whereas varphi(cc-->ct) is relatively insensitive to concentration changes. The concentration and temperature dependencies of the decay rate constants of DPB triplets in cyclohexane are consistent with the mechanism deduced from the photoisomerization quantum yields. The experimental DeltaH between (3)tt-DPB* and (3)tp-DPB*, 2.7 kcal mol(-1), is compared with the calculated energy difference [DFT with B3LYP/6-31+G(d,p) basis set]. Use of the calculated DeltaS = 4.04 eu between the two triplets gives k(d) = (2.4-6.4) x 10(7) s(-1), close to 1.70 x 10(7) s(-1), the value for twisted stilbene triplet decay. Experimental and calculated relative energies of DPB isomers on the ground and triplet state surfaces agree and theory is relied upon to deduce structural characteristics of the equilibrated conformers in the DPB triplet state.

Comparison between recombinant baculo- and adenoviral-vectors as transfer system in cardiovascular cells.

The development of effective gene-therapeutic applications for cardiovascular disorders is in part limited by the lack of appropriate delivery systems. In an attempt to overcome this deficiency, we investigated the ability of baculoviral vectors to transduce human cardiovascular cells, for which data are missing in literature. Additionally, baculovirus ability to transduce target cells was compared to that of an adenoviral vector, a well characterized and widely used viral vector. Transduction experiments, performed using baculo/adenoviral vectors expressing the enhanced green fluorescence protein, revealed that, under the experimental condition considered, baculoviruses but not adenoviruses efficiently transduce human coronary smooth muscle cells (hCSMC); an opposite behavior was noticed for human coronary endothelial cells (hCEC). Thus, baculoviral vectors are potentially indicated as transfer system in the treatment of coronary restenosis, where growth inhibitory genes should reach hCSMC but not hCEC. When used to transduce human cardiomyocytes and fibroblasts, both vectors behaved similarly. Finally, studies on cellular DNA replication revealed a more prolonged and pronounced negative effect on cells transduced by adenoviral compared to baculoviral vectors. Our data indicate that baculoviruses represent an attractive alternative to adenoviruses as transfer vectors in cardiovascular cells and that baculovirus have the potential to be used as gene transfer system in cardiovascular diseases such as restenosis.

Start sites of bidirectional DNA synthesis at the human lamin B2 origin.

The initiation sites of bidirectional synthesis at the DNA replication origin located at the 3' end of the human lamin B2 gene were investigated. RNA-primed nascent DNA molecules were subjected to second-strand synthesis with appropriate primers, amplified by ligation-mediated polymerase chain reaction, and size fractionated. Evidence for precise start sites was obtained. Exploration of close to 1 kilobase, coupled to inhibition of Okazaki fragment synthesis, demonstrates that the leading strands initiate at precise nucleotides on either helix, overlapping by three base pairs, within the area bound to a protein complex possibly analogous to the prereplicative complex of yeast.

Purification and properties of an esterase from the yeast Saccharomyces cerevisiae and identification of the encoding gene.

We purified an intracellular esterase that can function as an S-formylglutathione hydrolase from the yeast Saccharomyces cerevisiae. Its molecular mass was 40 kDa, as determined by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoelectric point was 5.0 by isoelectric focusing. The enzyme activity was optimal at 50 degrees C and pH 7.0. The corresponding gene, YJLO68C, was identified by its N-terminal amino acid sequence and is not essential for cell viability. Null mutants have reduced esterase activities and grow slowly in the presence of formaldehyde. This enzyme may be involved in the detoxification of formaldehyde, which can be metabolized to S-formylglutathione by S. cerevisiae.

Mentorship in physical medicine and rehabilitation residencies.

Mentorship is considered by many authorities as being possibly the most important developmental tool for the progression of a professional in training. In recent years, progressively increasing support of mentoring programs has been documented, especially in business, academia, and overall career development. Despite its recognized importance, there is a paucity of literature examining the needs of physicians in residency training programs in regard to mentorship. A 21-item questionnaire was sent to all physical medicine and rehabilitation (PM&R) residents in training in United States residency programs in May of 1993. The objectives of this survey were 3-fold: to assess interest in mentorship among PM&R residents, to determine the effect of preresidency mentorship on candidates choosing PM&R as a specialty, and to identify the factors that establish a successful mentorship in PM&R residency. A response rate of 36.2% (406/1123) was obtained. Analysis of the results indicated that 97.3% (390/401) of the respondents were interested in mentorship programs during PM&R residency; however, only 28.1% (114/406) had a mentor at the time of the survey. Before residency, 35.4% (143/404) of the respondents had a mentor, and of those, 75.9% (107/141) indicated that mentorship had a positive effect on their decision to choose PM&R as a specialty. Regarding the current mentorship, respondents benefited the most in the categories of increased knowledge of PM&R, 72.8% (83/114), and improved clinical skills, 65.8% (75/114). The least satisfaction was with the mentor's assistance with a research project, 46% (52/113), and with the effect of mentorship on the resident's visibility and reputation, 38.6% (44/114). Overall resident satisfaction with mentorship was significantly higher (P < 0.0001) in mentorships formed by free choice compared with those that were formally assigned by the residency program. Success of mentorship significantly correlated (P < 0.0001) with frequency of communication between mentor and protégé, while gender and ethnicity had no effect.

Sequencing of a 40.5 kb fragment located on the left arm of chromosome VII from Saccharomyces cerevisiae.

The nucleotide sequence of a 40.5 kb DNA fragment from the left arm of chromosome VII of Saccharomyces cerevisiae was determined and analysed. Twenty-eight open reading frames (ORFs) longer than 300 nucleotides were identified. Eight of the them correspond to the following known yeast genes: EMP24, GCN1, SPO8, COX13, CDC55, RPS26, COX4 and LSR1, also called GTS1. Twelve ORFs are new, among them eight show homology with other genes while four have no homology with any sequence in the databases. Eight additional ORFs are internal to or partially overlapping with other ORFs.

A putative helicase, the SUA5, PMR1, tRNALys1 genes and four open reading frames have been detected in the DNA sequence of an 8.8 kb fragment of the left arm of chromosome VII of Saccharomyces cerevisiae.

We report the sequence of an 8.8 kb segment of DNA from the left arm of chromosome VII of Saccharomyces cerevisiae. The sequence reveals seven open reading frames (ORFs) G1651, G1654, G1660, G1663, G1666, G1667 and G1669 greater than 100 amino acids in length and the tRNALys1 gene. ORF G1651 shows 100% identity with the ROK1 protein which is a putative RNA helicase of the 'DEAD box' protein family. ORF G1654 exhibits a motif highly conserved in ATP/GTP binding proteins generally referred to as 'P-loop'. From FastA analysis, G1660 and G1666 were found to be previously sequenced genes, respectively SUA5 and PMR1. The three other ORFs identified are partially (G1663) or completely (G1667 and G1669) overlapping with the PMR1 sequence on the complementary strand. This feature, together with their low codon adaptation indexes and the absence of significant homology with known proteins suggest that they do not correspond to real genes.

The sequence of an 11.1 kb fragment on the left arm of Saccharomyces cerevisiae chromosome VII reveals six open reading frames including NSP49, KEM1 and four putative new genes.

We report the sequence of an 11.1 kb fragment located on the left arm of chromosome VII of Saccharomyces cerevisiae. By sequence analysis we have detected six open reading frames (ORFs) longer that 300 bp, which cover 87% of the entire sequence. ORF G1645 is 100% identical to the KEM1 gene, also identified as DST2, XRN1, SEP1 and RAR5, while G1648 is 100% identical to the NSP49 or NUP49 gene. ORF G1642 shares some identity with a hypothetical protein of Caenorhabditis elegans, while the other four ORFs show no significant homology to known proteins.

The DNA sequence of a 7941 bp fragment of the left arm of chromosome VII of Saccharomyces cerevisiae contains four open reading frames including the multicopy suppressor gene of the pop2 mutation and a putative serine/threonine protein kinase gene.

We report the sequence of a 7941 bp DNA fragment from the left arm of chromosome VII of Saccharomyces cerevisiae which contains four open reading frames (ORFs) of greater than 100 amino acid residues. ORF biC834 shows 100% bp identity with the recently identified multicopy suppressor gene of the pop2 mutation (MPT5); its deduced protein product carries an eight-repeat domain region, homologous to that found in the hypothetical regulatory YGL023 protein of S. cerevisiae and the Pumilio protein of Drosophila. ORF biE560 protein exhibits patterns typical of serine/threonine protein kinases, with which it shares high degrees of homology.

Rehabilitation of eosinophilic fasciitis. A case report.

Eosinophilic fasciitis (EF), first described in 1974, is characterized by the sudden onset of painful swelling with induration of the soft tissues and peripheral eosinophilia, often after an episode of intense physical exertion. It rapidly progresses to joint contractures because of inflammation and fibrosis of the fascia. Of the 200 cases reported in the medical literature, most have responded positively to a prolonged course of oral prednisone. Although complete recovery is possible, more frequently signs and symptoms of EF persist. There were no detailed descriptions found in the literature of any rehabilitative interventions in this disease. This case study describes the methods used in a successful, comprehensive rehabilitation treatment of a 21-yr-old man admitted to the Palo Alto VA Medical Center rehabilitation program 8 mo after the onset of symptoms. Previous medication therapy included prednisone and methotrexate. The patient underwent 2 mo of inpatient rehabilitation, which consisted of upper and lower extremity nerve blocks, serial splinting, application of physical modalities, massage, stretching and strengthening exercises and interdisciplinary pain management. Significant improvement was made in the range of motion in all extremities, strength, hand function, level of pain, gait and endurance. Aggressive therapy did not increase eosinophilia. In fact the eosinophil count returned to normal by the time of discharge. A detailed review of the patient's rehabilitation program is presented.

Nerve conduction studies and vibration perception thresholds in diabetic and uremic neuropathy.

Two parameters of nerve conduction studies (nerve conduction velocities and amplitudes of the evoked sensory and motor responses) were compared with quantitative vibration perception thresholds (VPT) in patients with peripheral neuropathy (diabetes mellitus and/or end-stage renal disease). VPT measurements were made using a "two-alternative, forced-choice" method in which the patient is required to identify which of the two rods is vibrating at progressively decreasing vibration intensities. VPTs correlated significantly with nerve conduction velocities in all upper and lower extremity sensory and motor nerves tested, and with the amplitudes of the evoked motor responses in three motor nerves: median and ulnar (motor components) and tibial. For the median and ulnar nerves (motor components) the amplitudes of the evoked motor responses were more sensitive than nerve conduction velocities in correlation with VPTs. Comparison of VPT values, based upon whether or not evoked sensory and motor responses were obtained, indicated that mean VPTs were consistently higher among subjects in whom these evoked responses were not elicited. VPT measurements is thus shown to be a valid and valuable method for evaluation of severity in peripheral neuropathy. It has the advantages of being simple, quick and painless. Patient cooperation and compliance with this form of testing are excellent.

Body image, self-concept, and the orthodontic patient.

Four major criterion groups--orthodontic retention patients, prospective orthodontic patients, a population sample, and mothers of prospective patients--were established. Appropriate relationships between groups and subgroups were studied with regard to body-image and self-concept satisfaction, to body-image and self-concept importance, and other factors. The findings include the following: 1. There was no significant difference in body-image and self-concept satisfaction of importance between prospective orthodontic patients and the population sample. 2. There was no significant difference in body-image and self-concept satisfaction or importance between prospective orthodontic patients and orthodontic patients in retention. 3. There was a significant difference between prospective orthodontic patients' self-concept importance and their mother's perception of self-concept importance. There teen-agers placed more emphasis on their self-concept than did their mothers. 4. There was no significant difference between any of the groups in body-image and self-concept satisfaction or importance with change in age (11 to 16 years). 5. Girls scored significantly lower in both body-image and self-concept satisfaction than did the boys at these ages (11 to 16 years). 6. Patients with Class III malocclusion scored significantly lower than the other malocclusion groups in all categories of body-image and self-concept satisfaction and importance.