Observations and analysis of the 10-11 June 1994 coastally trapped disturbance

A coastally trapped disturbance (CTD), characterized by southerly flow at the surface on 10-11 June 1994, was observed from the California Bight to Bodega Bay during a field experiment along the California coast. (North-south approximates the coast-parallel direction.) Data from a special observational network of wind profilers, radio acoustic sounding systems, special surface data, balloon ascents, and a research aircraft were used with satellite and synoptic data to explore both the CTD structure and the regional-scale changes before the event. The disruption of the climatological northerly flow along the central California coast, which preconditioned the area for the development of a CTD, began with the eastward movement of a surface high into Washington and Oregon and the amplification of a thermal low in northern California. As with most CTDs in the region, this occurred over the 2-3 days preceding the CTD's initiation. These large-scale changes caused westward advection of warm continental air across much of the California coast, which increased temperatures by 10°-12°C in the layer from 0.4 to 2.0 km above mean sea level (MSL) during the 48 h before southerly flow appeared offshore at the surface. The warming reversed the alongshore sea level pressure gradients near the coast by creating a region of pressure falls extending along 600-1000 km of the coast. This also modified the cross-shore pressure gradient and thus the geostrophic alongshore flow. The warming along the coast also increased the strength of the temperature inversion capping the marine boundary layer (MBL) by a factor of 2-4 over 48 h. The synoptic-scale changes also moved the axis of the climatological near-surface, northerly jet much farther offshore from central California and strengthened this jet near the headlands of Capes Mendocino and Blanco, The development and decay of southerly flow at the surface along the coast coincided roughly with the evolution of a mesoscale low 200 km offshore, and of a coastal ridge roughly 100 km wide. However, the CTD initiation also followed a 500-m thickening of the MBL inversion in the California Bight region where a Catalina eddy was initially present. At surface sites, the CTD was marked by the passage of a pressure trough, followed by a gradual shift to southerly flow and the appearance of clouds. The area of low cloud was not coincident with the region of southerly flow. The transition to southerly flow propagated northward along shore at 1 1.9 ± 0.3 m s-1 on 10 June, stalled for 11-12 h during the part of the diurnal cycle normally characterized by enhanced northerly flow, and then continued propagating northward along shore at 11.6 m s-1. Both the geostrophic wind and the isallobaric component of the ageostrophic wind were consistent with southerly flow at the surface. Southerly flow was observed up to 5 km MSL in this event and in others, which indicates that the synopticscale environment of many CTDs in this region may include a deep tropospheric cyclonic circulation or trough offshore. Both cross-shore and alongshore flights performed by a research aircraft documented the CTD structure and showed that the southerly flow extended at least 100 km offshore and appeared first within the MBL inversion as the inversion thickened upward. While the top of the inversion rose, the height of the inversion's base remained almost unchanged. The thickening of the inversion decreased with distance offshore, and there was no significant change in the MBL depth (i.e., the inversion base height), until 12-14 h after the surface wind shift. Thus, it is suggested that two-layer, shallow water idealizations may be unable to represent this phenomenon adequately. Nonetheless, the gradual wind shift, the thickening inversion, and the correlation between southerly flow and a mesoscale coastal pressure ridge are consistent with a coastally trapped Kelvin wave, albeit one with a higher-order vertical structure that can exist in a two-layer model. However, the semipermanent nature of the changes in the MBL and its inversion is more characteristic of a shallowly sloped internal bore. The temperature increase and lack of southerly flow exceeding the northward phase speed are inconsistent with gravity current behavior

Вивчення процесу синтезу нанокристалічних плівок двооксиду титану в розряді магнетронного типу за його оптичними та плазмодинамічними характеристиками

Наведено результати експериментального дослiдження плазмодинамiчних i оптичних характеристик цилiндричного газового розряду магнетронного типу в умовах безперервного контролю спектра, випромiнюваного плазмою в дiапазонi 350–820 нм. Визначено умови для синтезу бiнарної сполуки TiО₂, якi забезпечуються пiдтримкою величини iнтенсивностi спектральних лiнiй реагуючих компонентiв i плазмоутворюючого газу. Розглянуто можливiсть контролю умов одержання плiвок TiО₂ як по спектральних характеристиках плазми розряду, так i по змiнi розрядної напруги. Елiпсометричнi дослiдження нанокристалiчних плiвок двооксиду титану показали наявнiсть залежностi показника переломлення вiд товщини плiвки.We present the results of experimental researches of plasmodynamic and optical characteristics of a magnetron-type cylindrical gas discharge. The study was carried out provided a permanent monitoring of the spectrum emitted by plasma in the range 350–820 nm. For the synthesis of binary compound TiO₂, we have determined conditions which can be ensured by a support of the intensity of spectral lines emitted by reacting components and plasma-forming gas. A possibility to control the conditions of the fabrication of a TiO₂ film with the use of both the spectral characteristics of a discharge plasma and a variation of the discharge voltage has been analyzed. Ellipsometric and spectral studies of nanocrystalline titanium dioxide films revealed the dependence of the refractive index of a film on the film thickness.Приведены результаты экспериментального исследования плазмодинамических и оптических характеристик цилиндрического газового разряда магнетронного типа в условиях непрерывного контроля спектра, излучаемого плазмой в диапазоне 350–820 нм. Определены условия для синтеза бинарного соединения TiО₂, которые обеспечиваются поддержанием величины интенсивности спектральных линий реагирующих компонент и плазмообразующего газа. Рассмотрена возможность контроля условий получения пленок TiO₂ как по спектральным характеристикам плазмы разряда, так и по изменению разрядного напряжения. Эллипсометрические и спектральные исследования нанокристаллических пленок диоксида титана показали наличие зависимости показателя преломления от толщины пленки

Genetic plasticity of the Shigella virulence plasmid is mediated by intra- and inter-molecular events between insertion sequences

Acquisition of a single copy, large virulence plasmid, pINV, led to the emergence of Shigella spp. from Escherichia coli. The plasmid encodes a Type III secretion system (T3SS) on a 30kb pathogenicity island (PAI), and is maintained in a bacterial population through a series of toxin:antitoxin (TA) systems which mediate post-segrega tional killing (PSK). The T3SS imposes a significant cost on the bacterium, and strains which have lost the plasmid and/or genes encoding the T3SS grow faster than wild-type strains in the laboratory, and fail to bind the indicator dye Congo Red (CR). Our aim was to define the molecular events in Shigella flexneri that cause loss of Type III secretion (T3S), and to examine whether TA systems exert positional effects on pINV. During growth at 37°C, we found that deletions of regions of the plasmid including the PAI lead to the emergence of CR-negative colonies; deletions occur through intra-molecula r recombination events between insertion sequences (ISs) flanking the PAI. Furthermore, by repositioning MvpAT (which belongs to the VapBC family of TA systems) near the PAI, we demonstrate that the location of this TA system alters the rearrangements that lead to loss of T3S, indicating that MvpAT acts both globally (by reducing loss of pINV through PSK) as well as locally (by preventing loss of adjacent sequences). During growth at environmental temperatures, we show for the first time that pINV spontaneously integrates into different sites in the chromosome, and this is mediated by inter-molecular events involving IS 1294. Integration leads to reduced PAI gene expression and impaired secretion through the T3SS, while excision of pINV from the chromosome restores T3SS function. Therefore, pINV integration provides a reversible mechanism for Shigella to circumvent the metabolic burden imposed by pINV. Intra- and inter-molecular events between ISs, which are abundant in Shigella spp., mediate plasticity of S. flexneri pINV

Energetic particle influence on the Earth's atmosphere

This manuscript gives an up-to-date and comprehensive overview of the effects of energetic particle precipitation (EPP) onto the whole atmosphere, from the lower thermosphere/mesosphere through the stratosphere and troposphere, to the surface. The paper summarizes the different sources and energies of particles, principally galactic cosmic rays (GCRs), solar energetic particles (SEPs) and energetic electron precipitation (EEP). All the proposed mechanisms by which EPP can affect the atmosphere are discussed, including chemical changes in the upper atmosphere and lower thermosphere, chemistry-dynamics feedbacks, the global electric circuit and cloud formation. The role of energetic particles in Earth’s atmosphere is a multi-disciplinary problem that requires expertise from a range of scientific backgrounds. To assist with this synergy, summary tables are provided, which are intended to evaluate the level of current knowledge of the effects of energetic particles on processes in the entire atmosphere

Human health and ocean pollution

Background: Pollution – unwanted waste released to air, water, and land by human activity – is the largest environmental cause of disease in the world today. It is responsible for an estimated nine million premature deaths per year, enormous economic losses, erosion of human capital, and degradation of ecosystems. Ocean pollution is an important, but insufficiently recognized and inadequately controlled component of global pollution. It poses serious threats to human health and well-being. The nature and magnitude of these impacts are only beginning to be understood. Goals: (1) Broadly examine the known and potential impacts of ocean pollution on human health. (2) Inform policy makers, government leaders, international organizations, civil society, and the global public of these threats. (3) Propose priorities for interventions to control and prevent pollution of the seas and safeguard human health. Methods: Topic-focused reviews that examine the effects of ocean pollution on human health, identify gaps in knowledge, project future trends, and offer evidence-based guidance for effective intervention. Environmental Findings: Pollution of the oceans is widespread, worsening, and in most countries poorly controlled. It is a complex mixture of toxic metals, plastics, manufactured chemicals, petroleum, urban and industrial wastes, pesticides, fertilizers, pharmaceutical chemicals, agricultural runoff, and sewage. More than 80% arises from land-based sources. It reaches the oceans through rivers, runoff, atmospheric deposition and direct discharges. It is often heaviest near the coasts and most highly concentrated along the coasts of low- and middle-income countries. Plastic is a rapidly increasing and highly visible component of ocean pollution, and an estimated 10 million metric tons of plastic waste enter the seas each year. Mercury is the metal pollutant of greatest concern in the oceans; it is released from two main sources – coal combustion and small-scale gold mining. Global spread of industrialized agriculture with increasing use of chemical fertilizer leads to extension of Harmful Algal Blooms (HABs) to previously unaffected regions. Chemical pollutants are ubiquitous and contaminate seas and marine organisms from the high Arctic to the abyssal depths. Ecosystem Findings: Ocean pollution has multiple negative impacts on marine ecosystems, and these impacts are exacerbated by global climate change. Petroleum-based pollutants reduce photosynthesis in marine microorganisms that generate oxygen. Increasing absorption of carbon dioxide into the seas causes ocean acidification, which destroys coral reefs, impairs shellfish development, dissolves calcium-containing microorganisms at the base of the marine food web, and increases the toxicity of some pollutants. Plastic pollution threatens marine mammals, fish, and seabirds and accumulates in large mid-ocean gyres. It breaks down into microplastic and nanoplastic particles containing multiple manufactured chemicals that can enter the tissues of marine organisms, including species consumed by humans. Industrial releases, runoff, and sewage increase frequency and severity of HABs, bacterial pollution, and anti-microbial resistance. Pollution and sea surface warming are triggering poleward migration of dangerous pathogens such as the Vibrio species. Industrial discharges, pharmaceutical wastes, pesticides, and sewage contribute to global declines in fish stocks. Human Health Findings: Methylmercury and PCBs are the ocean pollutants whose human health effects are best understood. Exposures of infants in utero to these pollutants through maternal consumption of contaminated seafood can damage developing brains, reduce IQ and increase children’s risks for autism, ADHD and learning disorders. Adult exposures to methylmercury increase risks for cardiovascular disease and dementia. Manufactured chemicals – phthalates, bisphenol A, flame retardants, and perfluorinated chemicals, many of them released into the seas from plastic waste – can disrupt endocrine signaling, reduce male fertility, damage the nervous system, and increase risk of cancer. HABs produce potent toxins that accumulate in fish and shellfish. When ingested, these toxins can cause severe neurological impairment and rapid death. HAB toxins can also become airborne and cause respiratory disease. Pathogenic marine bacteria cause gastrointestinal diseases and deep wound infections. With climate change and increasing pollution, risk is high that Vibrio infections, including cholera, will increase in frequency and extend to new areas. All of the health impacts of ocean pollution fall disproportionately on vulnerable populations in the Global South – environmental injustice on a planetary scale. Conclusions: Ocean pollution is a global problem. It arises from multiple sources and crosses national boundaries. It is the consequence of reckless, shortsighted, and unsustainable exploitation of the earth’s resources. It endangers marine ecosystems. It impedes the production of atmospheric oxygen. Its threats to human health are great and growing, but still incompletely understood. Its economic costs are only beginning to be counted. Ocean pollution can be prevented. Like all forms of pollution, ocean pollution can be controlled by deploying data-driven strategies based on law, policy, technology, and enforcement that target priority pollution sources. Many countries have used these tools to control air and water pollution and are now applying them to ocean pollution. Successes achieved to date demonstrate that broader control is feasible. Heavily polluted harbors have been cleaned, estuaries rejuvenated, and coral reefs restored. Prevention of ocean pollution creates many benefits. It boosts economies, increases tourism, helps restore fisheries, and improves human health and well-being. It advances the Sustainable Development Goals (SDG). These benefits will last for centuries. Recommendations: World leaders who recognize the gravity of ocean pollution, acknowledge its growing dangers, engage civil society and the global public, and take bold, evidence-based action to stop pollution at source will be critical to preventing ocean pollution and safeguarding human health. Prevention of pollution from land-based sources is key. Eliminating coal combustion and banning all uses of mercury will reduce mercury pollution. Bans on single-use plastic and better management of plastic waste reduce plastic pollution. Bans on persistent organic pollutants (POPs) have reduced pollution by PCBs and DDT. Control of industrial discharges, treatment of sewage, and reduced applications of fertilizers have mitigated coastal pollution and are reducing frequency of HABs. National, regional and international marine pollution control programs that are adequately funded and backed by strong enforcement have been shown to be effective. Robust monitoring is essential to track progress. Further interventions that hold great promise include wide-scale transition to renewable fuels; transition to a circular economy that creates little waste and focuses on equity rather than on endless growth; embracing the principles of green chemistry; and building scientific capacity in all countries. Designation of Marine Protected Areas (MPAs) will safeguard critical ecosystems, protect vulnerable fish stocks, and enhance human health and well-being. Creation of MPAs is an important manifestation of national and international commitment to protecting the health of the seas

The association among cytochrome P450 3A, progesterone receptor polymorphisms, plasma 17-alpha hydroxyprogesterone caproate concentrations, and spontaneous preterm birth

Background Infants born <37 weeks’ gestation are of public health concern since complications associated with preterm birth are the leading cause of mortality in children <5 years of age and a major cause of morbidity and lifelong disability. The administration of 17-alpha hydroxyprogesterone caproate reduces preterm birth by 33% in women with history of spontaneous preterm birth. We demonstrated previously that plasma concentrations of 17-alpha hydroxyprogesterone caproate vary widely among pregnant women and that women with 17-alpha hydroxyprogesterone caproate plasma concentrations in the lowest quartile had spontaneous preterm birth rates of 40% vs rates of 25% in those women with higher concentrations. Thus, plasma concentrations are an important factor in determining drug efficacy but the reason 17-alpha hydroxyprogesterone caproate plasma concentrations vary so much is unclear. Predominantly, 17-alpha hydroxyprogesterone caproate is metabolized by CYP3A4 and CYP3A5 enzymes. Objective We sought to: (1) determine the relation between 17-alpha hydroxyprogesterone caproate plasma concentrations and single nucleotide polymorphisms in CYP3A4 and CYP3A5; (2) test the association between progesterone receptor single nucleotide polymorphisms and spontaneous preterm birth; and (3) test whether the association between plasma concentrations of 17-alpha hydroxyprogesterone caproate and spontaneous preterm birth varied by progesterone receptor single nucleotide polymorphisms. Study Design In this secondary analysis, we evaluated genetic polymorphism in 268 pregnant women treated with 17-alpha hydroxyprogesterone caproate, who participated in a placebo-controlled trial to evaluate the benefit of omega-3 supplementation in women with history of spontaneous preterm birth. Trough plasma concentrations of 17-alpha hydroxyprogesterone caproate were measured between 25-28 weeks of gestation after a minimum of 5 injections of 17-alpha hydroxyprogesterone caproate. We extracted DNA from maternal blood samples and genotyped the samples using TaqMan (Applied Biosystems, Foster City, CA) single nucleotide polymorphism genotyping assays for the following single nucleotide polymorphisms: CYP3A4*1B, CYP3A4*1G, CYP3A4*22, and CYP3A5*3; and rs578029, rs471767, rs666553, rs503362, and rs500760 for progesterone receptor. We adjusted for prepregnancy body mass index, race, and treatment group in a multivariable analysis. Differences in the plasma concentrations of 17-alpha hydroxyprogesterone caproate by genotype were evaluated for each CYP single nucleotide polymorphism using general linear models. The association between progesterone receptor single nucleotide polymorphisms and frequency of spontaneous preterm birth was tested using logistic regression. A logistic model also tested interaction between 17-alpha hydroxyprogesterone caproate concentrations with each progesterone receptor single nucleotide polymorphism for the outcome of spontaneous preterm birth. Results The association between CYP single nucleotide polymorphisms *22, *1G, *1B, and *3 and trough plasma concentrations of 17-alpha hydroxyprogesterone caproate was not statistically significant (P =.68,.44,.08, and.44, respectively). In an adjusted logistic regression model, progesterone receptor single nucleotide polymorphisms rs578029, rs471767, rs666553, rs503362, and rs500760 were not associated with the frequency of spontaneous preterm birth (P =.29,.10,.76,.09, and.43, respectively). Low trough plasma concentrations of 17-alpha hydroxyprogesterone caproate were statistically associated with a higher frequency of spontaneous preterm birth (odds ratio, 0.78; 95% confidence ratio, 0.61–0.99; P =.04 for trend across quartiles), however no significant interaction with the progesterone receptor single nucleotide polymorphisms rs578029, rs471767, rs666553, rs503362, and rs500760 was observed (P =.13,.08,.10,.08, and.13, respectively). Conclusion The frequency of recurrent spontaneous preterm birth appears to be associated with trough 17-alpha hydroxyprogesterone caproate plasma concentrations. However, the wide variation in trough 17-alpha hydroxyprogesterone caproate plasma concentrations is not attributable to polymorphisms in CYP3A4 and CYP3A5 genes. Progesterone receptor polymorphisms do not predict efficacy of 17-alpha hydroxyprogesterone caproate. The limitations of this secondary analysis include that we had a relative small sample size (n = 268) and race was self-reported by the patients

Measuring outcome after stroke

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN023015 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Observations and Analysis of the 10-11 June 1994 Coastally Trapped Disturbance

A coastally trapped disturbance (CTD), characterized by southerly flow at the surface on 10â 11 June 1994, was observed from the California Bight to Bodega Bay during a field experiment along the California coast. (Northâ south approximates the coast-parallel direction.) Data from a special observational network of wind profilers, radio acoustic sounding systems, special surface data, balloon ascents, and a research aircraft were used with satellite and synoptic data to explore both the CTD structure and the regional-scale changes before the event.Both the experimental and analysis work on which this paper is based were partially supported by grants from the Office of Naval Research as part of the Coastal Meteorology Accelerated Research Initiative