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Recently, a number of authors have used global particle tracking simulations to identify the effect that different surface currents have on marine litter accumulation, including the role of surface waves through the Stokes drift. However, in the upper-ocean boundary layer and in the presence of the Coriolis force, a wave-driven Eulerian flow forms that must be superimposed onto the Stokes drift in order to obtain the correct Lagrangian velocity. Taking into account both the Coriolis-Stokes force and the surface wave stress, Higgins et al. (2020), https://doi.org/10.1029/2020GL089189 derived an expression for this unsteady wave-driven Eulerian-mean flow in the form of a convolution between the Stokes drift and the so-called Ekman-Stokes kernel. In this paper, we apply this Ekman-Stokes kernel to generate a 12-year global hindcast of the wave-driven Eulerian current and show that its inclusion in particle tracking simulations has a significant effect on the distribution of small floating marine litter, such as microplastics. Using Lagrangian simulations, we find that the wave-driven Eulerian current is sensitive to the value of viscosity but generally opposes the dispersive behavior of the Stokes drift, reducing the amount of cross-Equator particle transport and transport to the polar regions, resulting in closer agreement between modeled and observed microplastic distributions. [ABSTRACT FROM AUTHOR]

We examine Stokes drift and wave‐induced transport of floating marine litter on the surface of a rotating ocean with a turbulent mixed layer. Due to Coriolis‐Stokes forcing and surface wave stress, a second‐order Eulerian‐mean flow forms, which must be added to the Stokes drift to obtain the correct wave‐induced Lagrangian velocity. We show that this wave‐driven Eulerian‐mean flow can be expressed as a convolution between the unsteady Stokes drift and an "Ekman‐Stokes kernel." Using this convolution, we calculate the unsteady wave‐driven contribution to particle transport. We report significant differences in both direction and magnitude of transport when the Eulerian‐mean Ekman‐Stokes velocity is included. Plain Language Summary: In transport models for floating marine litter, surface wave effects are often included by simply superimposing their Stokes drift (the small net drift induced by waves) upon wind‐driven flows and currents. However, due to Earth's rotation and turbulent dissipation in the ocean's surface mixed layer, the Stokes drift also drives additional Eulerian‐mean flows. To obtain the correct transport velocity, the wave‐induced Eulerian‐mean flow must be added to the Stokes drift. We develop a model that enables estimation of this wave‐induced Eulerian‐mean flow from measurements or predictions of the wave field and apply our model to buoy data. Accounting for the wave‐induced Eulerian‐mean flow significantly alters predictions of transport of floating marine litter by waves. Key Points: Marine litter studies include surface wave transport by Stokes drift but have neglected wave‐induced Eulerian‐mean flows in the upper oceanWe present a model of the Eulerian‐mean Ekman‐Stokes response to time‐varying Stokes drift for use in marine litter transport modelsUsing buoy data, we show that the unsteady Ekman‐Stokes flow significantly alters both magnitude and direction of near‐surface transport [ABSTRACT FROM AUTHOR]

Results of this study suggest that the differential response of women to part-time work as opposed to a career may be a function of motivational and work-context differences, between career and non-career women. Part-time work was associated with lower work-to-family interference, better time managent ability, and greater life satisfaction for women in both career and earner-type positions. Role overload, family-to-work interference, and family time management, however, were dependent on job type with beneficial effects for earners but not for career women. Job type also played a role: Career women reported higher life satisfaction and lower depressed mood than did women in earner positions. [ABSTRACT FROM AUTHOR]

Background: Irritable bowel syndrome (IBS) and bladder pain syndrome (BPS) are female‐predominant, chronic functional pain disorders that are associated with early life stress (ELS) and therapeutic options for such patients remain limited. Linaclotide, a guanylate cyclase‐C (GC‐C) agonist, relieves abdominal pain and bowel symptoms in adult patients suffering from IBS with constipation. Here, we test the hypothesis that linaclotide will reverse colon and bladder hyperalgesia in a female‐specific rodent model of adverse early life experience. Methods: Neonatal rats were exposed to an odor‐attachment learning paradigm of early life stress (ELS). In adulthood, the effect of linaclotide (3 μg kg−1 d−1, p.o.) on colonic and bladder sensitivity was assessed via quantification of the visceromotor response to colorectal distension and the frequency of withdrawal responses to the application of von Frey hairs to the suprapubic region. In another cohort of rats, the effect of linaclotide on ELS‐induced colonic and bladder permeability was investigated via measurements of transepithelial electrical resistance (TEER). Key Results: Rats exposed to unpredictable ELS exhibited colonic and bladder hypersensitivity that was significantly reduced by linaclotide compared to vehicle‐treated controls. Colonic and bladder tissue isolated from adult rats exposed to unpredictable ELS exhibited a decrease in colonic and bladder TEER that was reversed by linaclotide. Conclusions and Inferences: Our results demonstrate that neonatal rats exposed to unpredictable ELS develop increased sensitivity and permeability of the colon and bladder in adulthood through a mechanism involving activation of peripheral GC‐C signaling. [ABSTRACT FROM AUTHOR]

Aim To determine whether there is evidence of changes in small mammals distributions and emergent metacommunity structure in the Atlantic Forest resulting from extensive habitat loss and fragmentation associated with anthropogenic activities. Location South American Atlantic Forest from northeastern Brazil to eastern Paraguay. Methods Using presence-absence data for non-volant small mammals, we analysed metacommunity structure for communities from 76 fragments distributed throughout Atlantic Forest. We evaluated coherence, range turnover and range boundary clumping for the entire non-volant small mammal assemblage, marsupials, rodents and sigmodontine rodents separately. β-diversity based on the multiplicative model was used to estimate the number of compartments (groups of sites with similar species composition) in Clementsian structures, and cluster analysis identified which sites formed compartments. Canonical correspondence analysis determined which environmental factors were associated with the gradients along which metacommunities were structured. Distance-decay analysis evaluated the spatial structure in small mammal and environmental data, and Mantel tests evaluated correlations between them. Results Rodent metacommunities had Clementsian structure, whereas marsupials had Gleasonian structure. Compartment locations for rodents were consistent with areas of endemism. Temperature seasonality was most associated with the gradients along which metacommunities were structured. Assemblage and environmental dissimilarity among sites had significant positive relationships with geographic distance. Main conclusions Compartment locations in Clementsian structures mirrored historical refugium locations and important vicariance events associated with large rivers. Despite extensive deforestation in Atlantic Forest, small mammal distributions are consistent with expectations based on historical biogeography, suggesting that anthropogenic activities have not yet greatly affected geographic distributions of emergent metacommunity structures. However, extinction debt associated with recent fragmentation and habitat loss may exist. Any effective conservation plan for large and fragmented biomes must consider areas of endemism to maintain regional biodiversity and maintain sufficiently large and connected fragments to facilitate rescue effects and minimize effects of extinction debt. [ABSTRACT FROM AUTHOR]

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Accurate estimates of water losses by evaporation from shallow water tables are important for hydrological, agricultural, and climatic purposes. An experiment was conducted in a weighing lysimeter to characterize the diurnal dynamics of evaporation under natural conditions. Sampling revealed a completely dry surface sand layer after 5 days of evaporation. Its thickness was <1 cm early in the morning, increasing to reach 4-5 cm in the evening. This evidence points out fundamental limitations of the approaches that assume hydraulic connectivity from the water table up to the surface, as well as those that suppose monotonic drying when unsteady conditions prevail. The computed vapor phase diffusion rates from the apparent drying front based on Fick's law failed to reproduce the measured cumulative evaporation during the sampling day. We propose that two processes rule natural evaporation resulting from daily fluctuations of climatic variables: (i) evaporation of water, stored during nighttime due to redistribution and vapor condensation, directly into the atmosphere from the soil surface during the early morning hours, that could be simulated using a mass transfer approach and (ii) subsurface evaporation limited by Fickian diffusion, afterward. For the conditions prevailing during the sampling day, the amount of water stored at the vicinity of the soil surface was 0.3 mm and was depleted before 11:00. Combining evaporation from the surface before 11:00 and subsurface evaporation limited by Fickian diffusion after that time, the agreement between the estimated and measured cumulative evaporation was significantly improved. [ABSTRACT FROM AUTHOR]

In mammalian cells, cytotoxic stress triggers several signaling cascades that converge in the phosphorylation of translation initiation factor 2α, shuttling of nuclear RNA-binding proteins such as TIA-1 to the cytoplasm, and aggregation of most cellular mRNAs into TIA-1-containing stress granules (SGs). As a result, protein synthesis is greatly impaired. Here we describe different dynamics of endogenous transcripts according to their cellular location, in response to stress. While cytosolic mRNAs aggregate into SGs, endoplasmic reticulum (ER) -bound transcripts escape sequestration. This has been specifically demonstrated using the multidrug resistance transporter gene (MDR1)as a model and showing that chimeric RNA constructs can be directed to the cytosol or tethered to the ER depending on the nature of the chimera, in response to stress. In addition, polysome profile analyses indicate that, on stress, ribosomes do not disengage from ER-associated transcripts (puromycin insensitive) and recover their translation status faster than SG-targeted cytosolic mRNAs once the stress is lifted. These findings have important implications for cell survival given that many membrane proteins, which are translated at the ER, have important roles in detoxification. [ABSTRACT FROM AUTHOR]

AIMS: To assess pregnancy outcomes, in particular birthweight, in a large population-based cohort of women in Scotland with pre-gestational insulin-treated diabetes mellitus. METHODS: Data about diabetes from the Diabetes UK cohort were linked to data on births from the Scottish Hospital In-Patient Record System. This identified 1112 eligible singleton deliveries during 1979-95 to 706 insulin-treated women. RESULTS: One thousand and eighty-four (97.5%) deliveries resulted in a live-born infant and 28 (2.5%) in a stillbirth. There were 13 (1.2%) neonatal deaths. The mean birthweight of the live-born infants was 3421 g, 1.06 standard deviations greater than that of infants in the Scottish general population after correcting for sex and gestational age. Forty-three per cent of live-born babies in the study were large (> Scottish 90th percentile) and 4% small (< 10th percentile) for their sex and gestational age. Macrosomia, defined as birthweight > or = 4000 g, occurred in 23% live-born babies and its prevalence was significantly inversely related to duration of maternal diabetes. However, the mean birthweight of infants born to mothers with diabetes for 20 or more years was still 0.90 standard deviations greater than in the general population. Prevalence of macrosomia increased with increasing number of previous pregnancies, but was not associated with maternal height or smoking habits. Stillbirth and neonatal death rates were, respectively, 4.7 (95% confidence interval = 3.3, 6.8) and 2.4 (1.4, 4.1), times higher than those in the general population. CONCLUSIONS: The frequency of adverse pregnancy outcomes in women with pre-existing insulin-treated diabetes was much higher than in the Scottish general population, and changed little during the study period. A detailed quantification of the independent effect of duration of mother's diabetes on birthweight revealed a continuous inverse correlation between these two variables. [ABSTRACT FROM AUTHOR]

Magnetic resonance (MR) flow measurement in the coronary artery can be achieved with either a breath-hold acquisition or a respiration-triggered acquisition. MR measurements of cardiac output are significantly depressed during breath-holding at deep inspiration, but the advantage is that the breath-hold method requires less scan time. Blood flow in the coronary sinus reflects the global myocardial blood flow because it represents approximately 96% of the total myocardial blood flow of the left ventricle (LV). If blood flow in the coronary sinus is measured with phase-contrast cine magnetic resonance imaging (MRI) and LV myocardial mass is measured with cine MRI, both the total myocardial blood flow and the average coronary blood flow per gram of myocardial mass can be quantified. Coronary flow reserve with volumetric MR flow measurement is measured to be within 4.2-5.0-fold. The noninvasive MR measurement of coronary flow reserve has been shown to be useful in identifying the functional significance of stenoses in the left anterior descending artery. The sensitivity and specificity of MR coronary flow velocity reserve for identifying stenosis of 70% or greater in the left main or left anterior descending artery were 100% and 83%, respectively. The MR quantification of total coronary blood flow and coronary blood flow per gram of myocardial mass seems to be an ideal method for evaluating coronary hemodynamics and may be useful in evaluating endothelial dysfunction of the coronary circulation. [ABSTRACT FROM AUTHOR]

Bullous congenital ichthyosiform erythroderma (BCIE) is a dominantly inherited keratinizing disorder characterized by erythroderma and blistering in neonates and generalized epidermolytic hyperkeratosis (EH) in adulthood. Previously, it has been shown that BCIE can be caused by mutations in either of the genes encoding K1 or K10, the keratins predominantly expressed in suprabasal layers of the epidermis. Using direct sequencing of genomic PCR fragments, we have analyzed 4 British families with BCIE, all of whom were found to carry mutations in K10. In 1 family, the affected person was found to have an unusual dinucleotide transversion mutation, 2138CC ??? AA, causing two amino acid substitutions, D155E and R156S, also in the 1A domain of the K10 polypeptide. In 2 further kindreds, the previously reported "hotspot" mutations 2139C ??? T and 2140G ??? A were found. These mutations predict amino acid substitutions in the helix 1A domain of K10, designated R156C and R156H respectively. The proband in the fourth family was found to carry a novel mutation 4724T ??? C, predicting the amino acid change L452P in the helix 2B domain of K10. All mutations were confirmed in the affected persons and were excluded from a population of 50 normal, unrelated individuals by restriction enzyme analysis. The location of these mutations in the highly conserved helix boundary motif sequences of K10 are consistent with previously reported dominant negative mutations in K10 and other keratins. Despite the unusual nature of two of these mutations, in particular the double missense mutation, the phenotypes of the affected individuals in these 4 families were entirely typical of BCIE. [ABSTRACT FROM AUTHOR]

An actuarial program for psychiatric diagnosis is evaluated for agreement with final clinical diagnosis in a series of 288 patients. The actuarial program provides a probability differential diagnosis based on an analysis of history and background data, symptom rating profiles, and MMPI clinical scale profiles. The observed agreement with final clinical diagnosis is approximately 50% higher than previously reported for psychological testing in this same setting. The results emphasize the importance for psychologists of clinical interview and observation skills. [ABSTRACT FROM AUTHOR]

The oligopeptide permease of Salmonella typhimurium is a periplasmic binding protein-dependent transport system. Five gene products, OppABCDF, are required for the functioning of this transporter, two of which (OppB and OppC) are highly hydrophobic, integral membrane proteins and are responsible for mediating passage of peptides across the cytoplasmic membrane. OppB and OppC are each predicted, from their sequences, to span the membrane many times, in this paper we describe experimental evidence confirming these predictions using a combination of biochemical, immunological and genetic procedures. Each of these two proteins is shown to span the membrane six times, with the N- and C-termini both being located at the cytoplasmic face of the membrane. Opp is apparently a typical member of the ABC (ATP-binding cassette) superfamily of transporters. These findings, therefore, have general implications for the organization and function of other ABC transporters, including the human multidrug resistance protein and the product of the cystic fibrosis gene. [ABSTRACT FROM AUTHOR]

The dipeptide permease (Dpp) is one of three genetically distinct peptide-transport systems in enteric bacteria. Dpp also plays a role in chemotaxis towards peptides. We have devised three selections for dpp mutations based on resistance to toxic peptides (bacilysin, valine-containing peptides, and bialaphos). All dpp mutations mapped to a single chromosomal locus between 77 and 78 min in Salmonella typhimurium and at 79.2 min in Escherichia coli. Expression of dpp was constitutive in both species but the absolute level of expression varied widely between strains. At least in part this difference in expression levels is determined by cis-acting sequences. The dpp locus of E. coli was cloned. The first gene in the operon, dppA, encodes a periplasmic dipeptide-binding protein (DBP) required for dipeptide transport and chemotaxis. Downstream of dppA are other genes required for transport but not for chemotaxis. The dipeptide-binding protein was found to share 26.5% sequence identity with the periplasmic oligopeptide-binding protein OppA. [ABSTRACT FROM AUTHOR]

Many promoters are sensitive to DNA supercoiling, and it is becoming apparent that this may play an important rote in gene regulation. The twin super-coiled- domain hypothesis (Liu and Wang, 1987) proposes that transcription can lead to local variation in supercoiling. The mutant leu-500 promoter has presented a long-standing problem to the understanding of the control of promoter function by DNA supercoiling. This promoter is activated by mutations in the gene encoding topoisomerase I, but is apparently unaffected by mutations in the genes encoding DNA gyrase. We propose a model to explain the anomalous regulation of this promoter, based on the twin super-coiled- domain model. This allows us to account for the unusual properties of the leu-500 promoter, and confirms the biological importance of the twin super-coiled- domain model. We suggest that such topological coupling between promoters may be general, leading to co-operativity and anti-co-operativity between divergent promoter pairs. [ABSTRACT FROM AUTHOR]

We describe a family of highly conserved, Enterobacterial Repetitive Intergenic Consensus (ERIC) sequences, 14 of which have been identified in Escherichia coli and Salmonella typhimurium and a further three in other enterobacterial species (Yersinia pseudotuberculosis, Kiebsiella pneumo-niae and Vibrio cholerae). ERIC sequences are 126 bp long and appear to be restricted to transcribed regions of the genome, either in intergenic regions of polycistronic operons or in untranslated regions upstream or downstream of open reading frames. ERIC sequences are highly conserved at the nucleotide sequence level but their chromosomal locations differ between species. Several features of ERIC sequences resemble those of REP sequences (Stern et al., 1984) although the nucleotide sequence is entirely different. The question of whether ERICs have a specific function, or represent a form of 'selfish' DNA, is discussed. [ABSTRACT FROM AUTHOR]

Bacillus subtilis spoOK mutants are blocked at the first step in sporulation. The spoOK strain was found to contain two mutations: one was linked to the trpS locus, and the other was elsewhere on the chromosome. The mutation linked to trpS was responsible for the sporulation defect (spo-). The unlinked mutation enhanced this sporulation deficiency but had no phenotype on its own. The spo- mutation was located in an operon of five genes highly homologous to the oligopeptide transport (Opp) system of Gram-negative species. Studies with toxic peptide analogues showed that this operon does indeed encode a peptide-transport system. However, unlike the Opp system of Salmonella typhimurium, one of the two ATP-binding proteins, OppF, was not required for peptide transport or for sporulation. The OppA peptide-binding protein, which is periplasmically located in Gram-negative species, has a signal sequence characteristic of lipo-proteins with an amino-terminal lipo-amino acid anchor. Cellular location studies revealed that OppA was associated with the cell during exponential growth, but was released into the medium in station-ary phase. A major role of the Opp system in Gram-negative bacteria is the recycling of cell-wall peptides as they are released from the growing peptidogtycan. We postulate that the accumulation of such peptides may play a signaling role in the initiation of sporulation, and that the sporulation defect in opp mutants results from an inability to transport these peptides. [ABSTRACT FROM AUTHOR]

Escherichia coli RNase E is known to process RNA precursors at specific sites. We show that this endoribonuclease has a general role in E. coli mRNA turnover and affects the stability of specific transcripts. The effect of the rne mutation on functional stability of mRNA was much less pronounced than that on chemical stability, although the expression of some genes was affected. The E. coli ams (altered mRNA stability) mutation was found to have phenotypes indistinguishable from those of the rne mutation, affecting both 9S RNA and T4 gene 32 mRNA processing. The rne and ams mutations were both complemented by the same 3.7 kb fragment of E. coli DNA and are probably allelic. RNase E is the first endoribonuclease identified as having a general role in the chemical decay of E. coli mRNA. [ABSTRACT FROM AUTHOR]

There has been a recent revival of interest in one of the most abundant Escherichia coli proteins, H1 (also called H-NS). This protein was first identified many years ago as a major component of the bacterial nucleoid, and has been characterized biochemically by several groups. However, no clear function for the protein emerged from these studies. Our thinking has been transformed by recent findings which complement the biochemistry with genetic data. Several mutations, selected over many years by virtue of their diverse effects on gene expression, have turned out to be allelic and to fall within the structural gene for H1. Bringing together the genetics and the biochemistry has demonstrated that the whole is worth more than the sum of the parts! These findings have far-reaching implications for the mechanisms by which gene expression is regulated and also, perhaps, for the control of bacterial virulence. [ABSTRACT FROM AUTHOR]

Morphological evidence has previously indicated that the periplasmic space of Escherichia coli is compartmentalized at sites corresponding to future sites of cell division. The borders of these morphological compartments are formed by localized zones of adhesion (periseptal annuli). In the present study, the technique of fluorescence recovery after photobleaching was used to determine whether these structures act as barriers to the free movement of proteins within the periplasm. The recovery of fluorescence in the ftsA filaments was found to be uniformly low over at potential sites of cell division and at the cell poles, indicating that these regions are biochemically sequestered from the remainder of the periplasmic space. Our results provide direct evidence for local compartments within the periplasm, primarily located at the sites of past or future cell divisions. The implications of this finding for cell division and other periplasmic processes are discussed. [ABSTRACT FROM AUTHOR]

The OmpC and OmpF porins are major outer membrane proteins of Escherichia coli and Salmonella typhimurium. Their expression is affected by many environmental factors and by mutations in a variety of independent genes. The pair of regulatory proteins, OmpR and EnvZ, are required for normal porin expression. Despite intensive investigation, the mechanisms by which porin expression is regulated remain unclear. Mutations which alter supercoiling, as well as inhibitors of DNA gyrase, show that porin expression is extremely and specifically sensitive to the level of DNA supercoiling. Our data lead us to suggest that environmentally induced changes in DNA supercoiling may play a role in determining the level of porin expression. These findings have implications for current models of porin regulation. [ABSTRACT FROM AUTHOR]

We have constructed a novel promoter probe plasmid pSB40, containing a unique lac-α-tetracycline marker gene tandem, which allows for both positive and negative selection of active promoters. Promoters cloned in pSB40 can be readily mobilized as EcoRI cassettes. Using this vector we have performed a non-invasive analysis of the E. coli chromosome for promoters regulated by osmotic upshift. Only one such promoter, subsequently identified as part of the proU operon, was isolated. A sequence of 253bp, sufficient to mediate osmotic regulation of the proU promoter, was defined. This E. coli promoter was normally regulated in Salmortella typhimurium, Klebsiella and Citrobacter but not in Shigella. A proU-luxAB fusion plasmid was constructed and used to monitor in vivo real-time kinetics of proU induction following osmotic upshock. [ABSTRACT FROM AUTHOR]

The proU loci of Salmonella typhimurium and Escherichia coli encode high-affinity glycine betaine transport systems which play an important role in survival under osmotic stress. Transcription of the proU locus is tightly regulated by osmolarity and this regulation appears to be mediated by osmotically induced changes in DNA supercoiling. In order to study the regulatory mechanisms involved we have cloned and characterized the proU locus of S. typhimurium by an in vivo transductional procedure. The locus is shown to consist of at least three genes, designated proVWX, cotranscribed as a single operon. The first gene in the operon encodes a protein sharing considerable sequence identity with ATP-binding proteins from other periplasmic transport systems. Unexpectedly, the highly expressed periplasmic glycine betaine binding protein was found to be encoded by a distal gene, proX, in the operon. The operon has no significant internal promoters but is expressed from a single osmoregulated promoter whose transcription start site has been mapped. The proU promoter of E. coli has also been sequenced and the transcription start site shown to be similar to that of S. typhimurium. Evidence is presented which suggests that, besides de novo glycine betaine uptake, an important function of ProU may be the recapture and recycling of other osmolytes that leak from the cell. [ABSTRACT FROM AUTHOR]

The regulation of several genes in response to osmotic and anaerobic stress has been examined. We have demonstrated a clear overlap between these two regulatory signals. Thus, the osmotically induced proU and ompC genes require anaerobic growth for optimum induction while the anaerobically induced tppB gene is also regulated by osmolarity. Furthermore, normal expression of tppB and ompC requires the positive regulatory protein OmpR, yet this requirement can be partially, or even fully, overcome by altering the growth conditions. Finally, the pleiotropic, anaerobic regulatory locus, oxrC, is also shown to affect expression of the osmotically regulated proU gene. The oxrC mutation is shown to affect the level of negative supercoiling of plasmid DNA and its effects on gene expression can be explained as secondary consequences of altered DNA topology. We suggest that there is a class of ‘stress-regulated’ genes that are regulated by a common mechanism in response to different environmental signals. Furthermore, our data are consistent with the notion that this regulatory overlap is mediated by changes in DNA supercoiling in response to these environmental stresses. [ABSTRACT FROM AUTHOR]