If technological intelligent extraterrestrials exist, what biological traits are de rigueur.

If extraterrestrials exist in the depths of cosmic space, and are capable of interstellar communications, even space flight, there is no requirement that they be humanoid in form. However, certain humanoid capabilities would be advantageous for tool fashioning and critical to operating space craft as well as functioning under the disparate extreme conditions under which they may be forced to operate. They would have to be "gas breathing". The reasonable assumption that life based upon the same elements as Earth life requiring water stems from the unique properties of water that no other similar low molecular weight nonmetal hydride offers. Only water offers the diversity of chemical properties and reactivity, including the existence of the three common physical states within a limited temperature range of service to life, avoiding the issues presented by any alternatives. They must, like us, possess a large, abstract-thinking brain, and probably possess at least all the fundamental senses that humankind possess. They would also be carbon-based life, using oxygen as the electron sink of their biochemistry for the reasons considered. They most likely are homeothermic as us, though they may not necessarily be mammalian as we are. Their biochemistry could differ some from ours, perhaps presenting contact hazards for both species as discussed.

The Ionospheric Connection Explorer Mission: Mission Goals and Design.

The Ionospheric Connection Explorer, or ICON, is a new NASA Explorer mission that will explore the boundary between Earth and space to understand the physical connection between our world and our space environment. This connection is made in the ionosphere, which has long been known to exhibit variability associated with the sun and solar wind. However, it has been recognized in the 21st century that equally significant changes in ionospheric conditions are apparently associated with energy and momentum propagating upward from our own atmosphere. ICON's goal is to weigh the competing impacts of these two drivers as they influence our space environment. Here we describe the specific science objectives that address this goal, as well as the means by which they will be achieved. The instruments selected, the overall performance requirements of the science payload and the operational requirements are also described. ICON's development began in 2013 and the mission is on track for launch in 2017. ICON is developed and managed by the Space Sciences Laboratory at the University of California, Berkeley, with key contributions from several partner institutions.

Human papillomavirus 16 L2 inhibits the transcriptional activation function, but not the DNA replication function, of HPV-16 E2.

In this study we analysed the outcome of the interaction between HPV-16 L2 and E2 on the transactivation and DNA replication functions of E2. When E2 was expressed on its own, it transactivated a number of E2-responsive promoters but co-expression of L2 led to the down-regulation of the transcription transactivation activity of the E2 protein. This repression is not mediated by an increased degradation of the E2 protein. In contrast, the expression of L2 had no effect on the ability of E2 to activate DNA replication in association with the viral replication factor E1. Deletion mutagenesis identified L2 domains responsible for binding to E2 (first 50 N-terminus amino acid residues) and down-regulating its transactivation function (residues 301-400). The results demonstrate that L2 selectively inhibits the transcriptional activation property of E2 and that there is a direct interaction between the two proteins, although this is not sufficient to mediate the transcriptional repression. The consequences of the L2-E2 interaction for the viral life cycle are discussed.

Identification of antisense transcripts of the chicken insulin-like growth factor-II gene.

Insulin-like growth factor-II (IGF-II) is a polypeptide mitogen which is believed to play an important role in fetal development. The human and rat IGF-II genes are complex transcription units, which contain multiple promoters and polyadenylation sites and which exhibit alternate splicing of their primary transcripts. In order to study IGF-II gene expression during chick embryonic development, we screened a 10-day chick embryo cDNA library with a human IGF-II cDNA probe. We isolated a clone, designated cigf, that was comprised, in part, of sequences homologous to the second coding exon of the human, mouse and rat IGF-II genes. Comparison of the nucleotide sequence of cigf with that of the corresponding genomic clone indicated that cigf was derived from a spliced antisense transcript of the chicken IGF-II gene, which overlapped the second coding exon. Northern blotting experiments with single-stranded RNA probes synthesized using cigf DNA as a template showed that stage 22 and stage 36 chick embryos contained sense strand IGF-II transcripts of 1.4, 2.2, 4.7 and 7.0 kb and antisense strand transcripts of 0.7, 1.3, 1.8, 2.5, 4.9, 6.0 and 8.0 kb. The pattern of sense strand IGF-II transcripts was similar to that previously found in rat fetal tissues. Whilst there are precedents for the transcription of both strands of a single gene, this is the first evidence for antisense transcription of an IGF gene. The functions of the antisense transcripts remain to be determined. These findings demonstrate a further level of complexity in the IGF-II transcription unit and indicate that studies of IGF-II transcript distribution performed with double-stranded probes should be interpreted with caution. They also suggest explanations for the recent finding that IGF-II peptides are present at much lower levels in embryos than expected from the high levels of IGF-II transcripts present.

Signaling through CD31 protects endothelial cells from apoptosis.

Endothelial damage has been implicated in the pathogenesis of chronic rejection. Conversely, expression of protective genes [including A20, A1, bcl-xl, and hemoxygenase-1 (HO-1)] in the endothelium has been associated with long-term graft survival. Overexpression of protective genes in cultured endothelial cells confers protection from apoptosis and prevents expression of inflammatory molecules through inactivation of NF-kappaB. CD31 (PECAM-1) expressed at endothelial cell junctions is ligated by leukocytes during transendothelial migration. Our laboratory has recently shown that cross-linking CD31 using a monoclonal antibody (LCI-4) triggers signaling events in endothelial cells. In this study, we demonstrate that treatment with LCI-4 protected serum-starved endothelial cells from apoptosis. CD31 cross-linking also led to elevation of A20 and A1 mRNA levels and activation of the transcription factor Sp-1. In summary, signaling through CD31 on endothelial cells leads to protection from apoptosis in association with up-regulation of two protective molecules, A20 and A1.

Aflatoxin B1 and DNA adducts. Proposed model for surface noncovalent and covalent complexes with N(7) of guanine. II.

An alternate model for surface noncovalent and surface covalent binding of aflatoxin B1 to N(7) of guanine in DNA is proposed. This model considers the out-of-plane motions of C(8) of aflatoxin B1 in those interactions. The covalent intercalated fit of aflatoxin B1 into DNA arises from steric adjustments made by DNA at the covalent intercalation site as well as local strain in the bond angles about N(7) of guanine and C(8) of aflatoxin B1. The bond angle about N(7) deviates modestly from the sp2 value toward the sp3 value. This study suggests that the surface covalent aflatoxin B1-DNA complex serves only a minor role in aflatoxin's precarcinogenic interaction with DNA and is a likely correctable error.

The structure of the aflatoxin B1-DNA adduct at N7 of guanine. Theoretical intercalation and covalent adduct models.

Two theoretical models are proposed for the conformational structure of both intercalated and covalent adduct complexes of aflatoxin B1, designated AFB1, with N7 of guanine of DNA. The covalent adduct model requires the DNA to kink a minimum of 39 degrees about the covalent site of the C8 and N7 atoms comprising the bond of the covalent complex. The preference of AFB1 for specific G bases within a sequence of GC content followed that of experimental studies with the added feature that for binding to the third G base of a tetramer sequence from the 3'-end, the AFB1 displayed enhanced binding at the 3' site of the targeted guanosine. Binding of AFB1 to the second G base of a tetramer sequence from the 3'-end leads to preference for a 5' site of the targeted guanosine. Inhibition of AFB1's interaction with the targeted DNA in the presence of intercalated ethidium bromide is explained by these proposed models.

Anti-Syn conformational range of pyrimidines with deoxyribofuranose.

The ability of pyrimidine bases to adopt the syn conformation in DNA has been investigated. The distances between atoms on the sugar and base and the resulting steric energies have been calculated as a function of glycosidic torsion angle for the principal sugar puckers of the deoxyribose of cytosine. The results indicate that pyrimidines can assume both the anti and syn conformations for the 3E, 4E, 1E, 2E, 3E sugar puckers and syn for the 2E sugar pucker. For these sugar puckers the difference between the minimum energies of the anti and syn conformations is in the range of 0.1-2.0 kcal/mole, with the minimum syn energy being lower in the case of the 4E, 1E and 2E sugar puckers. It is particularly significant that cytosine can assume the syn conformation for the 3E sugar pucker commonly observed for the syn nucleotides in Z-DNA with both alternating pyrimidine/purine (APP) and non-APP sequences. The results of this investigation confirm that steric interactions resulting from putting a pyrimidine nucleotide in the syn conformation are not a major factor in the preference for APP base sequences in Z-DNA.

Interactions of molecules with nucleic acids. X. Covalent intercalative binding of the carcinogenic BPDE I(+) to kinked DNA.

A theoretical model is proposed for the covalent binding of (+) 7 beta,8 alpha-dihydroxy-9 alpha,10 alpha-epoxy-7,8,9,10- tetrahydrobenzo[a]pyrene denoted by BPDE I(+), to N2 on guanine. The DNA must kink a minimum of 39 degrees to allow proper hybrid configurations about the C10 and N2 atoms involved in bond formation and to allow stacking of the pyrene moiety with the non-bonded adjacent base pair. Conservative (same sugar puckers and glycosidic angles as in B-DNA) and non-conservative (alternating sugar puckers as in intercalation sites) conformations are found and they are proposed structures in pathways connecting B-DNA, an intercalation site, and a kink site in the formation of a covalently intercalative bound adduct of BPDE I(+) to N2 on guanine. Stereographic projections are presented for (3') and (5') binding in the DNA. Experimental data for bending of DNA by BPDE, orientation of BPDE in DNA and unwinding of superhelical DNA is explained. The structure of a covalent intercalative complex is predicted to result from the reaction. Also, an anti----syn transition of guanine results in a structure which allows the DNA to resume its overall B-form. The only change is that guanine has been rotated by 200 degrees about its glycosidic bond so that the BPDE I(+) is bound in the major groove. The latter step may allow the DNA to be stored with an adduct which may produce an error in the genetic code.

A theoretical model for the binding of cis-Pt(NH3)2(+2) to DNA.

The binding of cis-Pt(NH3)2B1B2 to the bases B1 and B2, i.e., guanine (G), cytosine (C), adenine (A), and thymine (T), of DNA is studied theoretically. The components of the binding are analyzed and a model structure is proposed for the intrastrand binding to the dB1pdB2 sequence of a kinked double helical DNA. Quantum mechanical calculations of the ligand binding energy indicates that cis-Pt(NH3)2(+2) (cis-PDA) binds to N7(G), N3(C), O2(C), O6(G), N3(A), N7(A), O4(T) and O2(T) in order of decreasing binding energy. Conformational analysis provides structures of kinked DNA in which adjacent bases chelate to cis-PDA. Only bending toward the major groove allows the construction of acceptable square planar complexes. Examples are presented for kinks of -70 degrees and -40 degrees at the receptor site to orient the base pairs for ligand binding to B1 and B2 to form a nearly square planar complex. The energies for complex formation of cis-PDA to the various intra-strand base sites in double stranded DNA are estimated. At least 32 kcal/mole separates the energetically favorable dGpdG.cis-PDA chelate from the dCpdG.cis-PDA chelate. All other possible chelate structures are much higher in energy which correlates with their lack of observation in competition with the preferred dGpdG chelate. The second most favorable ligand energy occurs with N3(C). A novel binding site involving dC(N3)pdG(N7) is examined. Denaturation can result in an anti----syn rotation of C about its glycosidic bond to place N3(C) in the major groove for intrastrand binding in duplex DNA. This novel intrastrand dCpdG complex and the most favored dGpdG structure are illustrated with stereographic projections.

Application of theoretical models to exercise behavior among employed women.

PURPOSE: This study examines the utility of three theoretical models--the stages of change model, self-efficacy theory, and the decisional balance model--in understanding exercise behavior among employed women. DESIGN: Data for this cross-sectional study were collected as part of a routine follow-up of a worksite-based smoking and health risk appraisal study. SETTING: The study was conducted in three Rhode Island worksites, including one manufacturing company, one medical center, and one retail outlet. SUBJECTS: Of a sample of 431 women who completed exercise questionnaires, 293 reported participation in a physical activity over the previous week. The average age of the sample was 41.1 years, and mean years of education was 12.8. MEASURES: Previously validated measures to determine stage of exercise behavior, exercise self-efficacy, exercise decisional balance, and physical activity participation were administered. Additional demographic information was also obtained. RESULTS: Frequency counts revealed that 39% of the population was sedentary, 34% were participating in irregular activity, and 27% were active. MANOVAs followed by one way ANOVAs revealed that women in Precontemplation scored the lowest and those in Maintenance scored the highest on the self-efficacy, pro, and decisional-balance indices, with the trend reversed on the con scale. A chi-square test revealed that women with one or more young children in the home were more likely to be in a lower stage of exercise adoption. CONCLUSIONS: Most of the women in this cross-sectional study did not engage in regular activity. Presence of young children in the home was significantly related to decreased activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of motivationally tailored vs. standard self-help physical activity interventions at the workplace.

PURPOSE: This study compares the efficacy of a self-help intervention tailored to the individual's stage of motivational readiness for exercise adoption with a standard self-help exercise promotion intervention. DESIGN: Interventions were delivered at baseline and 1 month; assessments were collected at baseline and 3 months. SETTING: Eleven worksites participating in the Working Healthy Research Trial. SUBJECTS: Participants (n = 1559) were a subsample of employees at participating worksites, individually randomized to one of two treatment conditions. INTERVENTION: Printed self-help exercise promotion materials either (1) matched to the individual's stage of motivational readiness for exercise adoption (motivationally tailored), or (2) standard materials (standard). MEASURES: Measures of stage of motivational readiness for exercise and items from the 7-Day Physical Activity Recall. RESULTS: Among intervention completers (n = 903), chi-square analyses showed that, compared to the standard intervention, those receiving the motivationally tailored intervention were significantly more likely to show increases (37% vs. 27%) and less likely to show either no change (52% vs. 58%) or regression (11% vs. 15%) in stage of motivational readiness. Multivariate analyses of variance showed that changes in stage of motivational readiness were significantly associated with changes in self-reported time spent in exercise. CONCLUSIONS: This is the first prospective, randomized, controlled trial demonstrating the efficacy of a brief motivationally tailored intervention compared to a standard self-help intervention for exercise adoption. These findings appear to support treatment approaches that tailor interventions to the individual's stage of motivational readiness for exercise adoption.

Exercise enhances the maintenance of smoking cessation in women.

We examined the effects of physical exercise on smoking relapse. Twenty previously sedentary female smokers were randomly assigned to smoking cessation plus exercise or smoking cessation with frequency contact control. The smoking cessation program included 12 professionally led sessions over 12 weeks. Exercise treatment included three supervised exercise sessions per week for 15 weeks. Contact control included three women's health/wellness lectures per week for 15 weeks. Smoking abstinence was validated by carbon monoxide and saliva cotinine. Mean exercise attendance for exercise subjects was 88% with an increase in estimated VO2 of 25%. The percentage of subjects who quit for 24 hours was 80% for the exercise and 90% for the contact group. One subject in the contact group remained abstinent at the end of the 12-week treatment and at 1-, 3-, and 12-month follow-ups, whereas three subjects in the exercise group were abstinent at these time points. These results suggest that exercise training improves short-term quit rates and may prove a useful strategy for long-term maintenance of smoking cessation.

Early sexual experiences among pregnant and parenting adolescents.

One hundred sixty-six pregnant or parenting adolescent females completed a survey regarding early sexual experiences (wanted and unwanted), family dysfunction and violence, and health-risky behaviors occurring prior to age 18. Fifty-three percent had at least one unwanted sexual experience. Younger age at first unwanted sexual experience was associated with younger age at first wanted sexual experience. Adolescent females with an unwanted sexual experience, as compared to those without, were more likely to be victims of physical violence, to have run away, to be substance abusers, and to have family members with drug or alcohol problems. Four factors explained 39% of the variance in age at first pregnancy: presence of a family member with a drinking problem, age first got hit with a belt or other object by a family member, age first got drunk, and age at first wanted sexual experience. It was concluded that the prevention of teenage pregnancy entails a multifaceted approach that addresses family life, early sexual experiences, and health-risky behaviors.

Children with special health-care needs in Texas.

A comprehensive system for the delivery of care to children with special healthcare needs and to their families has been developed by the department of pediatrics of The University of Texas Health Science Center at San Antonio. A description of the structure and operations of this system is presented and offered as a model for the state of Texas.

A cereal haemoglobin gene is expressed in seed and root tissues under anaerobic conditions.

Legumes, and a very few non-legume plant species, are known to possess functioning haemoglobin genes. We describe here the characterization of a haemoglobin cDNA isolated from barley. The deduced amino acid sequence shows 71% amino acid identity with a non-legume haemoglobin gene, a further 16% of the residues being conservative replacements. The barley cDNA also hybridizes to genomic sequences in rye, maize and wheat. The demonstration of a gene from a monocotyledon with close sequence homology to the known non-legume plant haemoglobins fills a major gap in the known distribution of haemoglobin genes in the plant kingdom. The expression of the gene is induced in isolated barley aleurone layers exposed to anaerobic conditions, and the roots of flooding-stressed barley plants. The expression of the RNA under anoxic conditions is similar to that of a known anaerobic response gene, alcohol dehydrogenase. Our results suggest that the increased expression of haemoglobin RNA is an integral part of the normal anaerobic response in barley. The findings are discussed in the light of current theories of haemoglobin function and evolution.