Although neurochemical reductions in cholinergic systems have been found to occur during aging, such changes do not necessarily translate to functional deficits. The cognitive deficits of normal aging have been attributed in part to hypocholinergic function, but anticholinergic hypersensitivity in the elderly has not been systematically documented. To test the cholinergic hypothesis of aging, we investigated the effects of scopolamine on memory and attention in healthy young and elderly subjects. Treatments included intramuscular glycopyrrolate (0.0044 mg/kg) and scopolamine (0.002, 0.004, and 0.007 mg/kg) in a randomized double-blind design. The test battery included the Selective Reminding Task (SRT), Digit Span, Paired Associates Learning (PAL), Symbol Digit Modalities Test (SDMT), and the Continuous Performance Task. Elderly controls were more impaired at lower scopolamine doses than were the young on SRT, PAL, and SDMT. These results demonstrate anticholinergic hypersensitivity and are consistent with decremental changes in cholinergic status during normal aging.

The Tol-PAL system of Escherichia coli is a multiprotein system involved in maintaining the cell envelope integrity and is necessary for the import of some colicins and phage DNA into the bacterium. It is organized into two complexes, one near the outer membrane between TolB and PAL and one in the cytoplasmic membrane between TolA, TolQ, and TolR. In the cytoplasmic membrane, all of the Tol proteins have been shown to interact with each other. Cross-linking experiments have shown that the TolA transmembrane domain interacts with TolQ and TolR. Suppressor mutant analyses have localized the TolQ-TolA interaction to the first transmembrane domain of TolQ and have shown that the third transmembrane domain of TolQ interacts with the transmembrane domain of TolR. To get insights on the composition of the cytoplasmic membrane complex and its possible contacts with the outer membrane complex, we focused our attention on TolR. Cross-linking and immunoprecipitation experiments allowed the identification of Tol proteins interacting with TolR. The interactions of TolR with TolA and TolQ were confirmed, TolR was shown to dimerize, and the resulting dimer was shown to interact with TolQ. Deletion mutants of TolR were constructed, and they allowed us to determine the TolR domains involved in each interaction. The TolR transmembrane domain was shown to be involved in the TolA-TolR and TolQ-TolR interactions, while TolR central and C-terminal domains appeared to be involved in TolR dimerization. The role of the TolR C-terminal domain in the TolA-TolR interaction and its association with the membranes was also demonstrated. Furthermore, phenotypic studies clearly showed that the three TolR domains (N terminal, central, and C terminal) and the level of TolR production are important for colicin A import and for the maintenance of cell envelope integrity.

Claudins and occludin are integral membrane proteins at tight junctions (TJs). We examined subcellular localization of claudin-5 and occludin in dermal vascular endothelia. Immunofluorescence staining showed that claudin-5 was expressed at the cell-cell border of dermal vascular endothelia in mouse skin. However, in some dermal vessels, claudin-5 expression was markedly decreased or absent in amount by double-immunofluorescence stainings with PECAM-1 and PAL-E. In contrast, occludin was not detected in dermal vessels. Freeze-fracture and immunoreplica electron microscopy on primary-cultured human dermal endothelial cells showed that claudin-5 was localized at tight junctions. These findings confirmed that TJs in dermal vascular endothelial cells are composed of claudin-5.

The NSF homolog Sec18 initiates fusion of yeast vacuoles by disassembling cis-SNARE complexes during priming. Sec18 is also required for palmitoylation of the fusion factor Vac8, although the acylation machinery has not been identified. Here we show that the SNARE Ykt6 mediates Vac8 palmitoylation and acts during a novel subreaction of vacuole fusion. This subreaction is controlled by a Sec17-independent function of Sec18. Our data indicate that Ykt6 presents Pal-CoA via its N-terminal longin domain to Vac8, while transfer to Vac8's SH4 domain occurs spontaneously and not enzymatically. The conservation of Ykt6 and its localization to several organelles suggest that its acyltransferase activity may also be required in other intracellular fusion events.

To determine whether the increased fatty acid beta-oxidation in the peroxisomes of diabetic rat liver is mediated by a common peroxisome proliferation mechanism, we measured the activation of long-chain (LC) and very long chain (VLC) fatty acids catalyzed by palmitoyl CoA ligase (PAL) and lignoceryl CoA ligase and oxidation of LC (palmitic acid) and VLC (lignoceric acid) fatty acids by isotopic methods. Immunoblot analysis of acyl-CoA oxidase (ACO), and Northern blot analysis of peroxisome proliferator-activated receptor (PPAR-alpha), ACO, and PAL were also performed. The PAL activity increased in peroxisomes and mitochondria from the liver of diabetic rats by 2.6-fold and 2.1 -fold, respectively. The lignoceroyl-CoA ligase activity increased by 2.6-fold in diabetic peroxisomes. Palmitic acid oxidation increased in the diabetic peroxisomes and mitochondria by 2.5-fold and 2.7-fold, respectively, while lignoceric acid oxidation increased by 2.0-fold in the peroxisomes. Immunoreactive ACO protein increased by 2-fold in the diabetic group. The mRNA levels for PPAR-alpha, ACO and PAL increased 2.9-, 2.8- and 1.6-fold, respectively, in the diabetic group. These results suggest that the increased supply of fatty acids to liver in diabetic state stimulates the expression of PPAR-alpha and its target genes responsible for the metabolism of fatty acids.

The TolQRA proteins of Escherichia coli form an inner membrane complex involved in the maintenance of the outer membrane stability and in the late stages of cell division. The TolQR complex uses the proton-motive force to regulate TolA conformation and its interaction with the outer membrane Pal lipoprotein. It has been proposed that an ion channel forms at the TolQR transmembrane helix interface. This complex assembles with a minimal TolQ/TolR ratio of 4:2, therefore involving at least 14 transmembrane helices, which may form the ion pathway. The C-terminal periplasmic domain of TolR protein interacts with TolQ and has been proposed to control the TolQR channel activity. Here, we constructed unique cysteine substitutions in the last 27 residues of TolR. Each of the substitutions results in a functional TolR protein. Disulfide cross-linking demonstrates that the TolQR complex is dynamic, involving conformational modifications of TolR C-terminal domain. We monitored these structural changes by cysteine accessibility experiments and showed that the conformation of this domain is responsive to the proton-motive force and on the presence of critical residues of the ion pathway.

Desensitization of G protein-coupled receptors (GPCRs) involves the binding of members of the family of arrestins to the receptors. In the model system involving the visual GPCR rhodopsin, activation and phosphorylation of rhodopsin is thought to convert arrestin from a low to high affinity binding state. Phosphorylation of the M(2) muscarinic acetylcholine receptor (mAChR) has been shown to be required for binding of arrestins 2 and 3 in vitro and for arrestin-enhanced internalization in intact cells (Pals-Rylaarsdam, R., and Hosey, M. M. (1997) J. Biol. Chem. 272, 14152-14158). For the M(2) mAChR, arrestin binding requires phosphorylation at multiple serine and threonine residues at amino acids 307-311 in the third intracellular (i3) loop. Here, we have investigated the molecular basis for the requirement of receptor phosphorylation for arrestin binding. Constructs of arrestin 2 that can bind to other GPCRs in a phosphorylation-independent manner were unable to interact with a mutant M(2) mAChR in which the Ser/Thr residues at 307-311 were mutated to alanines. However, although phosphorylation-deficient mutants of the M(2) mAChR that lacked 50-157 amino acids from the i3 loop were unable to undergo agonist-dependent internalization when expressed alone in tsA201 cells, co-expression of arrestin 2 or 3 restored agonist-dependent internalization. Furthermore, a deletion of only 15 amino acids (amino acids 304-319) was sufficient to allow for phosphorylation-independent arrestin-receptor interaction. These results indicate that phosphorylation at residues 307-311 does not appear to be required to activate arrestin into a high affinity binding state. Instead, phosphorylation at residues 307-311 appears to facilitate the removal of an inhibitory constraint that precludes receptor-arrestin association in the absence of receptor phosphorylation.

Intermittent hypoxia (IH) associated with sleep apneas leads to cardiorespiratory abnormalities that may involve altered neuropeptide signaling. The effects of IH on neuropeptide synthesis have not been investigated. Peptidylglycine alpha-amidating monooxygenase (PAM; EC 1.14.17.3) catalyzes the alpha-amidation of neuropeptides, which confers biological activity to a large number of neuropeptides. PAM consists of O(2)-sensitive peptidylglycine alpha-hydroxylating monooxygenase (PHM) and peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL) activities. Here, we examined whether IH alters neuropeptide synthesis by affecting PAM activity and, if so, by what mechanisms. Experiments were performed on the brain stem of adult male rats exposed to IH (5% O(2) for 15 s followed by 21% O(2) for 5 min; 8 h/day for up to 10 days) or continuous hypoxia (0.4 atm for 10 days). Analysis of brain stem extracts showed that IH, but not continuous hypoxia, increased PHM, but not PAL, activity of PAM and that the increase of PHM activity was associated with a concomitant elevation in the levels of alpha-amidated forms of substance P and neuropeptide Y. IH increased the relative abundance of 42- and 35-kDa forms of PHM ( approximately 1.6- and 2.7-fold, respectively), suggesting enhanced proteolytic processing of PHM, which appears to be mediated by an IH-induced increase of endoprotease activity. Kinetic analysis showed that IH increases V(max) but has no effect on K(m). IH increased generation of reactive oxygen species in the brain stem, and systemic administration of antioxidant prevented IH-evoked increases of PHM activity, proteolytic processing of PHM, endoprotease activity, and elevations in substance P and neuropeptide Y amide levels. Taken together, these results demonstrate that IH activates PHM in rat brain stem via reactive oxygen species-dependent posttranslational proteolytic processing and further suggest that PAM activation may contribute to IH-mediated peptidergic neurotransmission in rat brain stem.

The purpose of this study was to investigate patterns of physical activity and levels of inactivity in adolescent females in the United Arab Emirates (UAE). A total of 58 adolescent females, age 11-16 years, were recruited from two female-only governmental schools in Abu-Dhabi. Subjects were divided into two groups: 11-13 years (n = 22) and 14-16 years (n = 36). Physical activity patterns were determined from a 3-day activity diary. Total energy expenditure (TEE) was estimated using a factorial approach. The amount of physical activity was expressed as the physical activity level (PAL) and the activity-related energy expenditure (AEE). The number of hours spent watching television was estimated from the activity diaries. There were no significant differences in the energy expenditure parameters between age groups or between schooldays and weekends. PAL was low in both age groups. Television was the predominant leisure time pursuit. The number of hours per day spent watching television (median and interquartile range) was 2.5 (2.3-3.1) in 11-13 years and 2.5 (2.3-2.8) in 14-16 years. Television-watching was significantly higher during the weekend than schooldays: 11-13 years (P = 0.006) and 14-16 years (P < 0.001). In conclusion, the amount of physical activity undertaken by adolescent females in the UAE was very low. Cultural and weather restrictions and social change of the community in the UAE are not conducive to physical activity and play a major role in levels of physical inactivity. This may explain, in part, the rise in the incidence of obesity in this population.

Changes in body composition, in particular the onset of obesity, may result from reductions in total daily energy expenditure (TDEE) as a consequence of relative physical inactivity. Children previously treated for acute lymphoblastic leukemia (ALL) become obese, yet the mechanism remains undefined. TDEE and physical activity levels [PAL = TDEE/basal metabolic rate (BMR)] were measured in 34 long-term survivors of ALL and compared with results from 21 survivors of other malignancies and 32 healthy sibling control subjects using the flex-heart rate technique. Body composition was measured by dual energy x-ray absorptiometry. The median TDEE was reduced in the ALL group (150 kJ x kg d(-1)) compared with other malignancies and controls (207 and 185 kJ x kg d(-1), respectively, p < 0.01). This reduction was accounted for mainly by a relative decrease in the PAL of the ALL group (1.24) compared with both other malignancies and controls (1.58 and 1.47, respectively, p < 0.01). TDEE and PAL were correlated with percentage body fat (r = -0.39, p < 0.001 and r = -0.24, p < 0.05, respectively). Obesity in survivors of ALL may, in part, be explained by a reduction in TDEE as a consequence of reduced PAL. The cause of such reduction is uncertain.

Ambient pH signalling involves a cascade of conserved Rim or Pal products in ascomycetous yeasts or filamentous fungi, respectively. Insertional mutagenesis in the yeast Yarrowia lipolytica identified two components of the endosome-associated ESCRT-I complex involved in multivesicular body (MVB) vesicle formation, YlVps28p and YlVps23p. They were shown to be required at alkaline pH, like Rim factors, for transcriptional activation of alkaline-induced genes and repression of acid-induced genes. The constitutively active YlRIM101-1119 allele, which suppresses the pH-signalling defects of Ylrim mutations, also suppresses Ylvps defects in pH response, but not in endocytosis. The contribution of the ESCRT-III component Snf7p could not be assessed due to the essential nature of this component in Y. lipolytica. Unlike Rim factors, YlVps4p, a component of the MVB pathway acting downstream from ESCRT complexes, seems not to be required for the alkaline response. In Y. lipolytica, all vps mutations including those affecting YlVPS4, affected growth at acidic pH, a feature not exhibited by Ylrim mutations. These results suggest that Rim and Vps pathways cooperate in ambient pH signalling and that this relation is conserved across the full range of hemiascomycetous yeasts.

OBJECTIVE

To investigate whether energy intake or energy expenditure affects 5-7 y weight gain in perimenopausal and early postmenopausal women, and whether hormone replacement therapy (HRT) use or dietary calcium (Ca) intake are contributory factors.

METHODS

Longitudinal, observational study of healthy women around the menopause.

METHODS

A total of 1064 initially premenopausal women, selected from a random population of 5119 women aged 45-54 y at baseline. In all, 907 women (85.2%) returned 6.3+/-0.6 y later for repeat measurements. Of these, 36% were postmenopausal (no HRT) and 45% had taken HRT, and 898 women completed the questionnaires.

METHODS

Weight, height, estimation of energy intake by food frequency questionnaire and physical activity level (PAL) by questionnaire.

RESULTS

Change in PAL influenced weight change explaining 4.4% (P=0.001) of the variation. Alterations in dietary energy intake also had a small but significant effect (0.6% P=0.013). Dietary Ca intake had no effect on weight or weight change.

CONCLUSIONS

Mean weight had increased and was influenced more by reduced energy expenditure rather than increased energy intake. HRT and dietary Ca intake did not influence weight gain.

Human pregnancy is associated with increased requirements for dietary energy and this increase may be partly offset by reductions in physical activity during gestation. Studies in well-nourished women have shown that the physical activity level (PAL), obtained as the total energy expenditure (TEE) divided by the BMR, decreases in late pregnancy. However, it is not known if this decrease is really caused by reductions in physical activity or if it is the result of decreases in energy expenditure/BMR (the so-called metabolic equivalent, MET) for many activities in late pregnancy. In the present study activity pattern, TEE and BMR were assessed in twenty-three healthy Swedish women before pregnancy as well as in gestational weeks 14 and 32. Activity pattern was assessed using a questionnaire and heart rate recording. TEE was assessed using the doubly labelled water method and BMR was measured by means of indirect calorimetry. When compared to the pre-pregnant value, there was little change in the PAL in gestational week 14 but it was significantly reduced in gestational week 32. Results obtained by means of the questionnaire and by heart rate recording showed that the activity pattern was largely unaffected by pregnancy. The findings support the following conclusion: in a population of well-nourished women where the activity pattern is maintained during pregnancy, the increase in BMR represents approximately the main part of the pregnancy-induced increase in TEE, at least until gestational week 32.

Methylphenidate (Ritalin) has been shown to have differential effects on hyperactive children's behavior as a function of dose level. In the present investigation, a triple-blind, placebo-control, within-subject (crossover) experimental design was employed in which 12 hyperactive boys between 6 and 10 years received three different dosages of methylphenidate (5, 10, and 15 mg) in a randomly assigned sequence. Dosage effects were assessed on clinic-(PAL--Paired Associates Learning test) and school-(percent on task, teacher ratings, work completion rates, and accuracy) related behaviors. For 10 of the children, classified as responders to medication by the PAL using the criteria of Swanson, Kinsbourne, and colleagues, a series of ANCOVAs with repeated measures showed significant dosage effects on teacher ratings (p less than .01), percent on task (p less than .01), academic accuracy (p less than .05), and assignment completion rates (p less than .05). PAL performance was also significantly enhanced (p less than .01) after optimal dose levels were considered. Subsequent trend analysis showed a significant positive linear relationship between dose and each of the dependent variables. A comparison of fixed-dose and miligram-per-kilogram plots showed that children's performance across the different dosages were clearly individualistic and task-specific, even when similar body weights were compared. The implications of using clinic-based testing to determine optimal medication responsivity were discussed.

Previous work has shown that the Caenorhabditis elegans gene pal-1, a homolog of Drosophila caudal, is required maternally for blastomere specification in the early embryo and postembryonically for tail development in males. We show here that embryonic (zygotic) transcription of pal-1 is also required for posterior patterning during later embryogenesis. Embryos homozygous for strong loss-of-function mutations arrest as nonviable L1 larvae with gross posterior defects. PAL-1 protein produced from zygotic transcripts is expressed dynamically during gastrulation and morphogenesis in specific cells of all major lineages except the germ line. Most expressing cells are undergoing cell movements or forming midline structures or both. Mutant embryos exhibit defects involving most of the expressing cells. Aberrant early cell positions are observed in posterior hypodermis, both in the C-lineage cells that express pal-1 and in the neighboring hypodermal seam cell precursors, which do not, as well as in posterior muscle derived from the C and D lineages. Defects in late gastrulation, ventral hypodermal enclosure, and formation of the rectum result from failures of cell movements of ABp and MS descendants. Limited mosaic analysis supports the view that most of the required pal-1 functions are cell autonomous.

Previous work in C. elegans has shown that posterior embryonic bodywall muscle lineages are regulated through a genetically defined transcriptional cascade that includes PAL-1/Caudal-mediated activation of muscle-specific transcription factors, including HLH-1/MRF and UNC-120/SRF, which together orchestrate specification and differentiation. Using chromatin immunoprecipitation (ChIP) in embryos, we now demonstrate direct binding of PAL-1 in vivo to an hlh-1 enhancer element. Through mutational analysis of the evolutionarily conserved sequences within this enhancer, we identify two cis-acting elements and their associated transacting factors (PAL-1 and HLH-1) that are crucial for the temporal-spatial expression of hlh-1 and proper myogenesis. Our data demonstrate that hlh-1 is indeed a direct target of PAL-1 in the posterior embryonic C. elegans muscle lineages, defining a novel in vivo binding site for this crucial developmental regulator. We find that the same enhancer element is also a target of HLH-1 positive auto regulation, underlying (at least in part) the sustained high levels of CeMyoD in bodywall muscle throughout development. Together, these results provide a molecular framework for the gene regulatory network activating the muscle module during embryogenesis.

The aim of this review is to describe an in vivo assay of the interactions taking place in the Tol-Pal or TonB-ExbB-ExbD envelope complexes in the periplasm of Escherichia coli and between them and colicins or g3p protein of filamentous bacteriophages. Domains of colicins or periplasmic soluble domains of Tol or TonB proteins can be artificially addressed to the periplasm of bacteria by fusing them to a signal sequence from an exported protein. These domains interact specifically in the periplasm with the Tol or TonB complexes and disturb their function, which can be directly detected by the appearance of specific tol or tonB phenotypes. This technique can be used to detect new interactions, to characterize them biochemically and to map them or to induce tol or tonB phenotypes to study the functions of these two complexes.

BACKGROUND

Pregnancies after perinatal loss are known to be anxiety-filled. Stress in pregnancy and the response to it, often seen as anxiety and depression, have known negative consequences for obstetric outcomes, parenting, and infant behaviors. Women have reported fluctuating emotions in response to events in their subsequent pregnancies, but these pregnancies have not been studied longitudinally.

OBJECTIVE

To test Lazarus' theory of stress, coping, and emotions in this population, and to understand the patterns of threat appraisal, coping, and emotional states of women across pregnancy after perinatal loss.

METHODS

In this predictive correlational study, 82 women pregnant after loss (PAL) were followed, and the study was guided longitudinally by Lazarus' theory of stress, coping, and emotions. Obstetric and loss history, and assigned fetal personhood were gathered at intake (Time 1). Measures completed at 10-week intervals (one time each trimester) included Moneyham Threat Index (threat appraisal), Ways of Coping Checklist-Revised (relative coping), Pregnancy Anxiety Scale (pregnancy anxiety), Multiple Affect Adjective Checklist-Revised (emotional states), and Stress in Life (stress). Time 3 sample size was 70.

RESULTS

Threat appraisal was correlated with assigned fetal personhood and gestational age of past loss. Pregnancy subsequent to loss was perceived as a threat, and threat appraisal strongly predicted pregnancy anxiety. Pregnancy anxiety, reported at moderate levels on average, decreased over time; threat appraisal, coping, and other emotions were stable across pregnancy. Coping did not mediate these effects, but relative coping was correlated with emotional status as theorized, with problem-focused coping used more than emotion-focused coping.

CONCLUSIONS

Women find pregnancy after loss stressful and a threat, and this appraisal remains across pregnancy. Because pregnancy anxiety is common, and highest in early pregnancy, providers should address worries and fears with all women early in PAL. Interventions must be tested in future studies.

BACKGROUND

repeated self-assessment of symptoms and problems of patients is required for quality assurance in palliative care. In Germany, the Minimal Documentation System (MIDOS) has been designed specifically for palliative care patients. To adapt MIDOS as a German version of the Edmonton Symptom Assessment Scale (ESAS) a revised version of MIDOS(2) has now been validated. Two original items on average and highest pain intensity (11-step NRS) were replaced by one item on pain intensity on a 4-step VRS and the assessment of vomitus, lack of appetite and depressive mood were added to the assessment of nausea, dyspnoea, constipation, weakness, tiredness, anxiety, others and well-being which were already part of the original version.

METHODS

all patients admitted to the palliative care unit were asked to participate voluntarily in this study. MIDOS(2), the German versions of the ESAS and the quality of life questionnaire EORTC QLQ-C15-Pal were completed on the same day during their inpatient stay. MIDOS(2) was repeated on the next day.

RESULTS

from August 2009 to March 2010, 60 patients (55% men, 45% women; mean age = 64.3, range = 23.6-92.4 years) treated in the palliative care unit completed the study. Self-assessment with MIDOS(2) was reported to burden the patients only slightly (mean burden = 1.1, range: 0 = no to 10 = maximum burden on a NRS), application of MIDOS(2) took between 1 and 7 min (mean duration = 2.4 min) and 61.7% of the patients preferred MIDOS(2) (with VRS) to ESAS (30%) (with NRS) for routine daily documentation. External criterion validity by inter-item correlations of MIDOS(2) with ESAS varied between r = .533 (anxiety) and .881 (nausea) and between r = .348 (depressive mood) and .717 (constipation) for the corresponding items of the EORTC QLQ-C15-Pal. Test-retest reliability between the sum scores of symptoms and problems reported in MIDOS(2) on the first day and on the second day was .688, and r = .573 for well-being.

CONCLUSIONS

MIDOS(2) can be recommended for routine daily documentation in palliative care because of low burden, little expenditure of time and high participation of patients. Statistical evaluation indicated good external validity and reliability.

Alveolar-pleural fistulas causing persistent air leaks (PALs) are associated with prolonged hospital stays and high morbidity. Prior guidelines recommend surgical repair as the gold standard for treatment, albeit it is a solution with limited success. In patients who have recently undergone thoracic surgery or in whom surgery would be contraindicated based on the severity of illness, there has been a lack of treatment options. This review describes a brief history of treatment guidelines for PALs. In the past 20 years, newer and less invasive treatment options have been developed. Aside from supportive care, the literature includes anecdotal successful reports using fibrin sealants, ethanol injection, metal coils, and Watanabe spigots. More recently, larger studies have demonstrated success with chemical pleurodesis, autologous blood patch pleurodesis, and endobronchial valves. This manuscript describes these treatment options in detail, including postprocedural adverse events. Further research, including randomized controlled trials with comparison of these options, are needed, as is long-term follow-up for these interventions.

The Great Oxidation Event (GOE) is currently viewed as a protracted process during which atmospheric oxygen increased above ∼10(-5) times the present atmospheric level (PAL). This threshold represents an estimated upper limit for sulfur isotope mass-independent fractionation (S-MIF), an Archean signature of atmospheric anoxia that begins to disappear from the rock record at 2.45 Ga. However, an increasing number of papers have suggested that the timing for oxidative continental weathering, and by conventional thinking the onset of atmospheric oxygenation, was hundreds of million years earlier than previously thought despite the presence of S-MIF. We suggest that this apparent discrepancy can be resolved by the earliest oxidative-weathering reactions occurring in benthic and soil environments at profound redox disequilibrium with the atmosphere, such as biological soil crusts and freshwater microbial mats covering riverbed, lacustrine, and estuarine sediments. We calculate that oxygenic photosynthesis in these millimeter-thick ecosystems provides sufficient oxidizing equivalents to mobilize sulfate and redox-sensitive trace metals from land to the oceans while the atmosphere itself remained anoxic with its attendant S-MIF signature. As continental freeboard increased significantly between 3.0 and 2.5 Ga, the chemical and isotopic signatures of benthic oxidative weathering would have become more globally significant from a mass-balance perspective. These observations help reconcile evidence for pre-GOE oxidative weathering with the history of atmospheric chemistry, and support the plausible antiquity of a terrestrial biosphere populated by cyanobacteria well before the GOE.

We report two studies examining the relations among three paired-associate learning (PAL) tasks (visual-visual, verbal-verbal, and visual-verbal), phoneme deletion, and single-word and nonword reading ability. Correlations between the PAL tasks and reading were strongest for the visual-verbal task. Path analyses showed that both phoneme deletion and visual-verbal PAL were unique predictors of a composite measure of single-word reading and of irregular word reading. However, for nonword reading, phoneme deletion was the only unique predictor (and visual-verbal PAL was not a significant predictor). These results are consistent with the view that learning visual (orthography) to phonological mappings is an important skill for developing word recognition skills in reading and that individual differences in this ability can be tapped experimentally by a PAL task.

Acidovorax avenae causes a brown stripe disease in monocot plants. We recently reported that a rice-incompatible strain of A. avenae caused hypersensitive cell death in rice and that the flagellin of the incompatible strain was involved in this response. The incompatible strain induced the rapid generation of H2O2 accompanying hypersensitive cell death and the expression of defense genes such as PAL, Cht-1, PBZ1, and LOX, whereas the compatible strain did not. The purified incompatible flagellin also induced the expression of PAL, Cht-1, and PBZ1, but LOX expression was not induced by the incompatible flagellin. PAL and LOX enzymatic activities were increased by inoculation with the incompatible strain, whereas only PAL activity was increased by the incompatible flagellin. Interestingly, the flagellin-deficient incompatible strain lost the ability to generate H2O2 and induce hypersensitive cell death, but PAL, Cht-1, and PBZ1 expression still were induced by inoculation with the deficient strain, suggesting that induction of these genes is regulated not only by flagellin but also by some other signal. Thus, the incompatible flagellin of A. avenae is a specific elicitor in rice, but it is not the only factor capable of inducing the rice defense system.

Morphogenesis is a complex process operating at several levels of organization--organism, tissues, cells, and molecules. Complex interactions occur between and within these levels. Many of the molecules that mediate these interactions are predictably turning out to be large multidomain proteins. Here we describe one such novel protein associated with remodeling of epithelial monolayers in embryos and developing wings of the moth Manduca sexta. On the basis of its sequence and its expression pattern along lacunae of developing wings, we propose the name lacunin for this extracellular matrix protein that contains nine different types of domains, most of which are present in multiple copies. These include domains of various types: Kunitz proteinase inhibitors, thrombospondin type I, immunoglobulin-like, and several newly defined domains of unknown function (PAL, PLAC, and lagrin domains). This rich patchwork of distinct domains probably exerts multiple effects on a variety of cell behaviors associated with the complex phenomenon of epithelial morphogenesis.