Prominent Spikes Research Articles

Air quality in different urban hotspots in a metropolitan city in India and the environmental implication.

This research study investigates hourly data on concentrations of five major air pollutants such as particulate matter (PM10, PM2.5) and gaseous pollutants (SO2, NO2, CO) measured during 2022 at four hotspot sites (industrial site, traffic site, commercial site, harbour, and one residential site) in Chennai, India. The analysis encompasses temporal variations spanning annual, seasonal, and diurnal variations in the pollutants. Notably, PM10 and CO emerge as the predominant pollutants, with the highest concentrations at industrial and traffic sites (PM10: 67.64 ± 40.77µg/m3, CO: 1.41 ± 0.84mg/m3; traffic site: PM10: 58.67 ± 20.05µg/m3, CO: 0.99 ± 0.57mg/m3). Seasonal dynamics reveal prominent winter spikes in particulate matter (PM10, PM2.5) and carbon monoxide (CO) concentrations, while nitrogen dioxide (NO2) and sulphur dioxide (SO2) levels peak during the summer season, particularly in the harbour area. The proximity to roadways exerts a discernible influence on diurnal patterns, with traffic sites showcasing broader rush hour peaks compared to sharper spikes observed at other sites. Furthermore, distinct bimodal patterns are evident for PM10 and PM2.5 concentrations in residential and harbour areas. A common lognormal distribution pattern is identified across the studied sites, suggesting consistent air quality trends despite contrasting locations. The conditional probability function (CPF) is used in conjunction with local meteorological conditions for identifying key pollution sources in each location. The implementation of polar plots emphasizes industries as principal local sources of pollution, at industrial sites significantly contributing to PM10, SO2, and NO2 concentrations under specific wind conditions. The main objective of the present study is to facilitate a good understanding of pollutant dynamics, pollution sources, and their intricate interplay with meteorological factors, thereby contributing to the formulation and implementation of effective air pollution control and mitigation strategies.

(527) The Unprecedented Number of Google Searches for Vasectomy Following the Overturning of Roe Versus Wade

Abstract Introduction On June 24, 2022, the United States Supreme Court overturned the landmark 1973 Roe v. Wade decision. This removed constitutional protection for women seeking abortions and introduced uncertainty for couples desiring reproductive autonomy. Currently, each state’s laws determine specific protections or bans for abortion. As a result, many individuals are investigating alternate forms of family planning such as vasectomy. Objective We aimed to characterize the public interest in vasectomy since the overturning of Roe v. Wade and elucidate whether interest varies based on state. Methods We extracted relative search volumes from Google Trends (July 2017 to July 2022) for the keyword “vasectomy”. We compared the relative rates of Google searches for the two weeks preceding and following the Supreme Court decision date of June 24, 2022. The mean rates were compared using a Welch t-test. Lastly, we assessed geographic variations in public interest after the decision by extracting the relative search data separated by state from Google Trends. Results Google searches peaked on June 25, 2022. This was the highest rate of Google searches for vasectomy within the past five years and was about four-fold higher than the average rate over that time (25.9%). There are two other prominent spikes: one on May 4, 2022 to about 60% of the highest rate, and another on May 16, 2019 to about 55% (Figure 1). In the two weeks following the Supreme Court announcement, there was a higher rate of searches for vasectomy (47.3%) compared to searches two weeks prior (17.2%) (P<0.05). Utah was the state with the most Google searches for vasectomy. Idaho, Texas, and North Dakota were the next most common states. The four regions with the lowest search rate were the District of Columbia, Massachusetts, New Jersey, and New York (Figure 2). Conclusions The overturning of Roe v. Wade corresponds with the highest increase in Google searches for vasectomy in the past 5 years with a significant increase in searches the days following. In addition, the two previous spikes in vasectomy searches corresponded to events that threatened access to abortion. The spike in searches in May 2022 happened on the same day the draft of the Supreme Court’s decision on Roe v. Wade was leaked to the public. The spike in May 2019 correlates with the passing of a strict anti-abortion law in Alabama which received national attention. Interestingly, states with the highest rates of searches are also states with laws banning abortion in place. States with the lowest rates appear to be states with laws in place to protect access to abortion. Urologists should be aware of the unprecedented increase in public interest in vasectomy as it relates to a potential flux of patients seeking counseling for this procedure. Disclosure No

Evidence for residual SARS-CoV-2 in corpus cavernosum of patients who recovered from COVID-19 infection.

The COVID-19 is an ongoing health problem with millions of cases and deaths worldwide. Although the virus is transmitted with droplets through the respiratory system, the involvement of different organs has been reported. The pandemic caused urological procedures to be postponed when patient is infected with SARS-CoV-2. However, the reliability of 1 month postpone period and long-term complications of the virus, such as a possible erectile dysfunction (ED) is not clarified. We aimed to compare the corpus cavernosum of patients 1 and 7 months after COVID-19 infection with control patients who had not COVID-19 and search for SARS-CoV-2 in tissues using immunohistochemistry and electron microscopy. Three groups of subjects underwent penile prosthesis implantation and Nesbit procedure for Peyronie's disease 1 and 7 months after COVID-19 infection and control group without previous COVID-19 infection. We searched for SARS-CoV-2 in penile tissue using RT-PCR, electron microscopy and immunohistochemistry. Electron microscopy and immunohistochemical staining showed SARS CoV-2 virus in the penile corpus cavernosum of patients 1 month after COVID-19 recovery. Immunohistochemical staining intensity correlated with the severity of previous infection. Transmission electron microscopy revealed intracellular virtual particles of about 80nm with a typical morphology of prominent spikes and electron-dense dots of nucleocapsid in addition to vesicles filled with virus-like particles. Cells showed increased membrane trafficking. The 1 month after COVID-19 group showed an increased number of fibroblasts. The 7 months after COVID-19 group had similar morphology and immunoreactivity as control group. This is the first study of late post-COVID examination of penis and the second study of early post-COVID examination of corpus cavernosum. For 1 month post-COVID patients, the aetiology of ED could be the viral infection that is also affecting corpora cavernosa. We hypothesize that viral infection affects the endocytic and exocytic pathways, hence the metabolic activity of cells that can be the reason of altered functions in some post-COVID patients. This study is important because it did not detect any virus residue in the tissue samples at the seventh month. In addition, we can say that the penile surgeries should be postponed more than 1 month after the COVID infection according to this study. But, there is a need for new studies with large series and high levels of evidence that can show how long the virus remains in the corpus cavernosum. Patients should be followed in this respect.

Cryo-EM Structure of Gokushovirus ΦEC6098 Reveals a Novel Capsid Architecture for a Single-Scaffolding Protein, Microvirus Assembly System.

Ubiquitous and abundant in ecosystems and microbiomes, gokushoviruses constitute a Microviridae subfamily, distantly related to bacteriophages ΦX174, α3, and G4. A high-resolution cryo-EM structure of gokushovirus ΦEC6098 was determined, and the atomic model was built de novo. Although gokushoviruses lack external scaffolding and spike proteins, which extensively interact with the ΦX174 capsid protein, the core of the ΦEC6098 coat protein (VP1) displayed a similar structure. There are, however, key differences. At each ΦEC6098 icosahedral 3-fold axis, a long insertion loop formed mushroom-like protrusions, which have been noted in lower-resolution gokushovirus structures. Hydrophobic interfaces at the bottom of these protrusions may confer stability to the capsid shell. In ΦX174, the N-terminus of the capsid protein resides directly atop the 3-fold axes of symmetry; however, the ΦEC6098 N-terminus stretched across the inner surface of the capsid shell, reaching nearly to the 5-fold axis of the neighboring pentamer. Thus, this extended N-terminus interconnected pentamers on the inside of the capsid shell, presumably promoting capsid assembly, a function performed by the ΦX174 external scaffolding protein. There were also key differences between the ΦX174-like DNA-binding J proteins and its ΦEC6098 homologue VP8. As seen with the J proteins, C-terminal VP8 residues were bound into a pocket within the major capsid protein; however, its N-terminal residues were disordered, likely due to flexibility. We show that the combined location and interaction of VP8's C-terminus and a portion of VP1's N-terminus are reminiscent of those seen with the ΦX174 and α3 J proteins. IMPORTANCE There is a dramatic structural and morphogenetic divide within the Microviridae. The well-studied ΦX174-like viruses have prominent spikes at their icosahedral vertices, which are absent in gokushoviruses. Instead, gokushovirus major coat proteins form extensive mushroom-like protrusions at the 3-fold axes of symmetry. In addition, gokushoviruses lack an external scaffolding protein, the more critical of the two ΦX174 assembly proteins, but retain an internal scaffolding protein. The ΦEC6098 virion suggests that key external scaffolding functions are likely performed by coat protein domains unique to gokushoviruses. Thus, within one family, different assembly paths have been taken, demonstrating how a two-scaffolding protein system can evolve into a one-scaffolding protein system, or vice versa.

The structures of eleven (4-phen-yl)piperazinium salts containing organic anions.

Eleven (4-phen-yl)piperazinium salts containing organic anions have been prepared and structurally characterized, namely, 4-phenyl-piperazin-1-ium 4-fluoro-benzoate monohydrate, C10H15N2 +·C7H4FO2 -·H2O, 1; 4-phenyl-piperazin-1-ium 4-bromo-benzoate monohydrate, C10H15N2 +·C7H4BrO2 -·H2O, 3; 4-phenyl-piperazin-1-ium 4-iodo-benzoate, C10H15N2 +·C7H4IO2 -, 4; 4-phenyl-piperazin-1-ium 4-nitro-benzoate, C10H15N2 +·C7H4NO4 -, 5; 4-phenyl-piperazin-1-ium 3,5-di-nitro-salicylate, C10H15N2 +·C7H3N2O7 -, 6; 4-phenyl-piperazin-1-ium 3,5-di-nitro-benzoate, C10H15N2 +·C7H3N2O6 -, 7; 4-phenyl-piperazin-1-ium picrate, C10H15N2 +·C6H2N3O7 -, 8; 4-phenyl-piperazin-1-ium benzoate monohydrate, C10H15N2 +·C7H5O2 -·H2O, 9; 4-phenyl-piperazin-1-ium p-toluene-sulfonate, C10H15N2 +·C7H7O3S-, 10; 4-phenyl-piperazin-1-ium tartarate monohydrate, C10H15N2 +·C4H5O6 -·H2O, 11; and 4-phenyl-piperazin-1-ium fumarate, C10H15N2 +·C4H3O4 -, 12. Compounds 1 and 3-12 are all 1:1 salts with the acid proton transferred to the phenyl-piperaizine basic N atom (the secondary amine) with the exception of 3 where there is disorder in the proton position with it being 68% attached to the base and 32% attached to the acid. Of the structures with similar stoichiometries only 3 and 9 are isomorphous. The 4-phenyl substituent in all cases occupies an equatorial position except for 12 where it is in an axial position. The crystal chosen for structure 7 was refined as a non-merohedral twin. There is disorder in 5, 6, 10 and 11. For both 5 and 6, a nitro group is disordered and was modeled with two equivalent orientations with occupancies of 0.62 (3)/0.38 (3) and 0.690 (11)/0.310 (11), respectively. For 6, 10 and 11, this disorder is associated with the phenyl ring of the phenyl-piperazinium cation with occupancies of 0.687 (10)/0.313 (10), 0.51 (7)/0.49 (7) and 0.611 (13)/389 (13), respectively. For all salts, the packing is dominated by the N-H⋯O hydrogen bonds formed by the cation and anion. In addition, several structures contain C-H⋯π (1, 3, 4, 8, 9, 10, and 12) and aromatic π-π stacking inter-actions (6 and 8) and one structure (5) contains a -NO2⋯π inter-action. For all structures, the Hirshfeld surface fingerprint plots show the expected prominent spikes as a result of the N-H⋯O and O-H⋯O hydrogen bonds.

Late-Holocene diatom community response to climate driven chemical changes in a small, subarctic lake, Northwest Territories, Canada

The paleolimnological record of diatoms and climate, spanning the last 2800 years, was investigated in a small subarctic lake (Pocket Lake) that from AD 1948 to 2004 was contaminated by gold smelting waste. An age-depth model was constructed using a combination of 210Pb, 14C, and tephra to determine a 2800 year history of lake ontogeny (natural aging), biological diversity, and regional climate variability. Diatoms form six strong paleoecological assemblages over time in response to changes in local hydrological and sedimentological conditions (including metals). Selected environmental variables explained 28.8% of the variance in the diatom assemblages, with Fe, Ca, and sediment end member distribution being important indicators. The diatom assemblages correlated to the Iron Age Cold Epoch (2800–2300 cal BP), Roman Warm Period (2250–1610 cal BP), Dark Age Cold Period (1500–1050 cal BP), Medieval Climate Anomaly (ca. 1100–800 cal BP), and the Little Ice Age (800–200 cal BP). The disappearance of Staurosira venter highlights the change from the Iron Age Cold Epoch to the Roman Warm Period. After deposition of the White River Ash (833–850 CE; 1117–1100 cal BP), transition to circumneutral conditions was followed in tandem by a transition to planktic influenced communities. Ten discrete peaks of Cu, Pb, and Zn were observed and attributed to soluble mobility from catchment soils through enhanced seepage and spring snowmelt. The prominent metal spikes were aligned with increases in Brachysira neoexilis. Downward mobilization of arsenic and antimony from contaminated surficial sediments highlight the problem of post depositional industrial contamination of paleosediments. Results demonstrate that paleoclimatic changes in the region, modulated by solar radiation, impacted temperature and precipitation in the lake catchment, influencing temporal shifts in diatom ecology. Changes in diatom taxa richness provided valuable information on the relative influence of water quality (planktic taxa) and sediment input (benthic taxa). The diatom assemblage succession also provides evidence that natural aging over time has played a role in the ecological evolution of the lake.

Why does not lithology correlate with gamma-ray spikes in the shaley source rocks of the Upper Jurassic Alge Member (southwestern Barents Sea)?

Prominent high-value gamma-ray spikes in the maximum flooding surfaces of the Middle Oxfordian-Kimmeridgian succession (Alge Member) display stratigraphic and regional variations in the southwestern Barents Sea. These variations suggest heterogeneities in the composition of the Alge Member, thus, challenging the common perception that this interval is a homogenous succession of organic-rich black shale. This study explores the overall variation in; clay mineral composition, source rock quality, minerals and macerals, core logs and seismic facies of the Alge Member. Gamma-log fluctuations were found to be independent of these variations. Uranium precipitates on sea bottom sediments when conditions change from oxic to anoxic. Fluctuations in sea level may result in such changes and, hence, guide gamma-ray responses. Sea level fluctuations also lead to a changing distance to the shoreline, which again influences sediment types, grain sizes, and source rock quality. Thus, indirectly sea level appears to be the common denominator, which sometimes matches source rock richness with spikes on gamma logs. Presence and absence of gamma-ray spikes are, hence, an additional tool to reveal the redox conditions in the SW Barents Sea, which has implications for the understanding of the paleogeography (or paleobathymetry) during deposition.

Prescription Opioids Are Associated With Population Mortality in US Deep South Middle-Age Non-hispanic Whites: An Ecological Time Series Study.

Objective: The US Burden of Disease Collaborators reported that between 1990 and 2016, the top 10 states with increasing probability of death between the ages of 20 and 55 years were all in the South. A recent study of annual surveillance data found that increasing all-cause mortality rates were occurring in middle-age non-Hispanic whites. The vast proportion of all-cause mortality consists of medical causes, not external causes (i.e., overdose, mental illness, suicide, homicide, or motor vehicle crashes). It has been hypothesized by researchers that the ongoing opioid epidemic has an etiologic role in the trend of increasing medical death, but ecological studies looking for an association have not been published. The objective of this study was to test the hypothesis that hydrocodone and oxycodone sales are temporally associated and correlated with annual NHW45-54 medical-cause mortality rates in the Deep South region comprised of Alabama, Arkansas, Louisiana, Mississippi, Oklahoma, and South Carolina.Methods: Mortality and opioid sales data were obtained from the Centers for Disease Control and Prevention Wonder Detailed Mortality and University of Wisconsin State Health Access Data Assistance Center databases, respectively. Annual, state and regional NHW45-54 medical-cause mortality and opioid sales data were analyzed using Spearman rank correlation (rs) testing, after first and second differencing, in order to achieve stationarity and control for trend similarities.Results: Sales of prescription opioids follow very similar temporal patterns across these six states, with simultaneous increases in 2007 and 2013. With few exceptions, annual opioids sales trends were correlated state-to-state. Two prominent spikes are evident in the aggregated opioid sales trends of the six states, with both sales spikes preceding same-directional fluctuations in medical-cause mortality by ~1 year. After a 1 year adjustment of second-differenced data, population hydrocodone exposure was correlated with female NHW45-54 population medical-cause mortality [rs(13) = 0.540; P = 0.038]; and oxycodone exposure correlated with male NHW45-54 population medical-cause mortality [rs(13) = 0.607; P = 0.016].Conclusions: State sales of prescription hydrocodone and oxycodone in the six states studied follow non-random, systematic trajectories. A strong correlation and temporal association exists between prescription opioid sales and medical-cause mortality in this Deep South NHW45-54 population.

Orthobunyavirus spike architecture and recognition by neutralizing antibodies

Orthobunyaviruses (OBVs) form a distinct genus of arthropod-borne bunyaviruses that can cause severe disease upon zoonotic transmission to humans. Antigenic drift or genome segment re-assortment have in the past resulted in new pathogenic OBVs, making them potential candidates for causing emerging zoonoses in the future. Low-resolution electron cryo-tomography studies have shown that OBV particles feature prominent trimeric spikes, but their molecular organization remained unknown. Here we report X-ray crystallography studies of four different OBVs showing that the spikes are formed by an N-terminal extension of the fusion glycoprotein Gc. Using Schmallenberg virus, a recently emerged OBV, we also show that the projecting spike is the major target of the neutralizing antibody response, and provide X-ray structures in complex with two protecting antibodies. We further show that immunization of mice with the spike domains elicits virtually sterilizing immunity, providing fundamental knowledge essential in the preparation for potential newly emerging OBV zoonoses.

Anomalous Upper Devonian mercury enrichments: comparison of Inductively Coupled Plasma – Mass Spectrometry (ICP-MS) and Atomic Absorption Spectrometry (AAS) analytical data

Mercury geochemistry is emerging recently as a hot topic in chemostratigraphical and facies research, owing to the diagnostic character of Hg enrichments as a proxy of volcanic activity (crucial in the context of assumed causal links between volcanic cataclysms and mass extinctions). Thus, as a prerequisite to such far-reaching interpretations, reliable analytical determinations of Hg concentrations are necessary. In conventionally performed analyses in sedimentary geochemistry, Inductively Coupled Plasma – Mass Spectrometry (ICP-MS) is usually applied, as an analytical standard for trace elements, including Hg. However, with a detection limit (DL) of 10 ppb, such measured values have been questioned as a conclusive geochemical indicator of Hg anomalies, and, instead, far more accurate techniques, such as Atomic Absorption Spectrometry (AAS; DL = 0.2 ppb), are requested. As a preliminary test of this view, we present comparative analysis of 91 samples from three sections encompassing the key Frasnian-Famennian and Famennian-Tournaisian boundary intervals in Morocco (Lahmida), Germany (Kahlleite) and Uzbekistan (Novchomok), for which Hg concentrations were determined by both methods in the same samples. Despite some differences, especially at low Hg concentrations, both analytical methods reveal the same 12 extraordinarily enriched samples in excess of 1 ppm (with one exception, the determination error is <20%), as well as similar overall chemostratigraphic patterns characterized by a few prominent Hg spikes, with a top value of 5.8 ppm. The Hg concentrations determined by ICP-MS and AAS are significantly correlated, as high as r = 0.98 (Novchomok), even if the first method reveals a general tendency toward slightly heightened values (by ~15 to 30% for medians). Therefore, ICP-MS results can conclusively be used in mercury chemostratigraphy in order to recognize extraordinary volcanic (or other) signals, at least in the Devonian geological record. False Hg anomalies were not generated by these conventional ICP-MS determinations.

Annual Dynamics of Winery Wastewater Volumes and Quality and the Impact of Disposal on Poorly Drained Duplex Soils

The composition and volume of winery wastewater change throughout the year. Quality is usually at its worst when vintage operations are dominated by the production of red wines. The objective of this study was to investigate the annual dynamics of winery wastewater volumes and quality, as well as the effect of winery wastewater irrigation on the chemical soil properties of a poorly drained duplex soil. The study was conducted over two and half years. The wastewater contained a high concentration of potassium (K+) and low levels of sodium (Na+). The results of the study confirmed that winery wastewater did not comply with South African national legislation for wastewater irrigation with regard to chemical oxygen demand (COD) and pH throughout the study period, while some prominent spikes were observed in sodium adsorption ratio (SAR) and electrical conductivity (EC). Land application of winery wastewater resulted in the accumulation of high levels of K+ in the soil. It is important to note that this study represents the worst-case scenario, i.e. large amounts of wastewater were disposed of on a small surface, particularly during harvest and in winter. Due to the high volumes of wastewater irrigation plus rainfall, the inevitable over-irrigation leached large amounts of K+ beyond 90 cm soil depth. Unfortunately, the leached elements are bound to end up in natural water resources, resulting in the pollution of the environment.

Roles of fluid shear stress and retinoic acid in the differentiation of primary cultured human podocytes

Due to the distinct features that distinguish immortalized podocyte cell lines from their in vivo counterparts, primary cultured human podocytes might be a superior cell model for glomerular disease studies. However, the podocyte de-differentiation that occurs in culture remains an unresolved problem. Here, we present a method to differentiate primary cultured podocytes using retinoic acid (RA) and fluid shear stress (FSS), which mimic the in vivo environment of the glomerulus. RA treatment induced changes in the cell shape of podocytes from a cobblestone-like morphology to an arborized configuration with enhanced mobility. Moreover, the expression of synaptopodin and zonula occludens (ZO)−1 in RA-treated podocytes increased along with Krüppel-like factor 15 (KLF15) expression. Confocal microscopy revealed that RA increased the expression of cytoplasmic synaptopodin, which adopted a filamentous arrangement, and junctional ZO-1 expression, which showed a zipper-like pattern. To elucidate the effect of FSS in addition to RA, the podocytes were cultured in microfluidic devices and assigned to the static, static+RA, FSS, and FSS+RA groups. The FSS+RA group showed increased synaptopodin and ZO-1 expression with prominent spikes on the cell-cell interface. Furthermore, interdigitating processes were only observed in the FSS+RA group. Consistent with these data, the mRNA expression levels of synaptopodin, podocin, WT-1 and ZO-1 were synergistically increased by FSS and RA treatment. Additionally, the heights of the cells were greater in the FSS and FSS+RA groups than in the static groups, suggesting a restoration of the 3D cellular shape. Meanwhile, the expression of KLF15 increased in the RA-treated cells regardless of fluidic condition. Taken together, FSS and RA may contribute through different but additive mechanisms to the differentiation of podocytes. These cells may serve as a useful tool for mechanistic studies and the application of regenerative medicine to the treatment of kidney diseases.

A calibration method for realistic neutron dosimetry in radiobiological experiments assisted by MCNP simulation.

Many studies on biological effects of neutrons involve dose responses of neutrons, which rely on accurately determined absorbed doses in the irradiated cells or living organisms. Absorbed doses are difficult to measure, and are commonly surrogated with doses measured using separate detectors. The present work describes the determination of doses absorbed in the cell layer underneath a medium column (DA) and the doses absorbed in an ionization chamber (DE) from neutrons through computer simulations using the MCNP-5 code, and the subsequent determination of the conversion coefficients R (= DA/DE). It was found that R in general decreased with increase in the medium thickness, which was due to elastic and inelastic scattering. For 2-MeV neutrons, conspicuous bulges in R values were observed at medium thicknesses of about 500, 1500, 2500 and 4000 μm, and these were attributed to carbon, oxygen and nitrogen nuclei, and were reflections of spikes in neutron interaction cross sections with these nuclei. For 0.1-MeV neutrons, no conspicuous bulges in R were observed (except one at ~2000 μm that was due to photon interactions), which was explained by the absence of prominent spikes in the interaction cross-sections with these nuclei for neutron energies <0.1 MeV. The ratio R could be increased by ~50% for small medium thickness if the incident neutron energy was reduced from 2 MeV to 0.1 MeV. As such, the absorbed doses in cells (DA) would vary with the incident neutron energies, even when the absorbed doses shown on the detector were the same.

Whitecap lifetime stages from infrared imagery with implications for microwave radiometric measurements of whitecap fraction

AbstractQuantifying active and residual whitecap fractions separately can improve parameterizations of air‐sea fluxes associated with breaking waves. We use data from a multi‐instrumental field campaign on Floating Instrument Platform (FLIP) to simultaneously capture the signatures of active and residual whitecaps at visible, infrared (IR), and microwave wavelengths using, respectively, video camera, mid‐IR camera, and a radiometer at 10 GHz. We present results from processing and analyzing IR images and correlating this information with radiometric time series of brightness temperature at horizontal and vertical polarizations TBH and TBV. The results provide evidence that breaking crests and decaying foam appear in mid‐IR as bright and dark pixels clearly distinguishing active from residual whitecaps. We quantify the durations of whitecap lifetime stages from the IR images and identify their corresponding signatures in TB time series. Results show that TBH and TBV vary in phase during the active and in antiphase during the residual whitecap stages. A methodology to distinguish active and residual whitecaps in radiometric time series without a priori IR information has been developed and verified with corresponding IR and video images. The method uses the degree of polarization P (the ratio between the sum and difference of TBV and TBH) to capture whitecaps as prominent spikes. The maximum and zero‐crossing of the first derivative of P serve to identify the presence of active whitecaps, while the minimum of dP marks the transition from active to residual whitecap stage. The findings have implications for radiometric measurements of active and total whitecap fractions.

Influence of Cholesterol Microstructures on Fluctuation Spikes in Nystatin Channel Currents in Phospholipid/Cholesterol Bilayers

Nystatin (NYS) is an antifungal agent that preferentially forms ion channels in membranes containing ergosterol (ERG) or cholesterol (CHOL). In phospholipid bilayers ERG or CHOL segregate into ordered (Lo) and disordered (Ld) domains. We prepared POPC bilayers containing CHOL mol fraction 0.18 ≤ χERG ≤ 0.50 separating two chambers containing KCl solutions. The concentration gradient between chambers was 435/150 mM KCl. We allowed the CHOL/POPC bilayer to settle 15 min then added 19 or 38 microM NYS to the reference (Cis) chamber, imposed 50 mV across the bilayer, and stirred the Cis chamber at 4 Hz. The NYS molecules adhered to the bilayer forming channels on the boundaries of the Lo domains. [1] The resultant bilayer current exhibited prominent spikes of very short duration. A plot of the frequency of these spikes against χERG revealed prominent spikes at χERG = 0.19, 0.25 and 0.40. These correspond well to the dips in dehydroergosterol fluorescence observed by Chong [2], which he understood in terms of a superlattice. We conclude that fluctuations in NYS channels on the perimeter of the Lo CHOL domains depend strongly on Lo domain structure.1. Helrich, C. S., J. A. Schmucker, and D. J. Woodbury 2006. Evidence that Nystatin Channels Form at the Boundaries, Not the Interiors of Lipid Domains. Biophys. J. 91: 1116-1127.2. Chong, P.L-G. 1994. Evidence for regular distribution of sterols in liquid crystalline phosphatidylcholine bilayers, Proc. Nati. Acad. Sci. USA 91:10069-10073.

Automatic detection of prominent interictal spikes in intracranial EEG: Validation of an algorithm and relationsip to the seizure onset zone

ObjectiveTo develop an algorithm for the automatic quantitative description and detection of spikes in the intracranial EEG and quantify the relationship between prominent spikes and the seizure onset zone. MethodsAn algorithm was developed for the quantification of time–frequency properties of spikes (upslope, instantaneous energy, downslope) and their statistical representation in a univariate generalized extreme value distribution. Its performance was evaluated in comparison to expert detection of spikes in intracranial EEG recordings from 10 patients. It was subsequently used in 18 patients to detect prominent spikes and quantify their spatial relationship to the seizure onset area. ResultsThe algorithm displayed an average sensitivity of 63.4% with a false detection rate of 3.2 per minute for the detection of individual spikes and an average sensitivity of 88.6% with a false detection rate of 1.4% for the detection of intracranial EEG contacts containing the most prominent spikes. Prominent spikes occurred closer to the seizure onset area than less prominent spikes but they overlapped with it only in a minority of cases (3/18). ConclusionsAutomatic detection and quantification of the morphology of spikes increases their utility to localize the seizure onset area. Prominent spikes tend to originate mostly from contacts located in the close vicinity of the seizure onset area rather than from within it. SignificanceQuantitative analysis of time–frequency characteristics and spatial distribution of intracranial spikes provides complementary information that may be useful for the localization of the seizure-onset zone.

Crises and trends: Mortality in historical perspective

It is well known that mortality in the past was dominated by crises. Prior to the industrial revolution, the contours of mortality of most human populations were punctuated with prominent spikes that could not be missed by any observer scanning a parish register for a sufficient number of pages. Choosing a year at random, the series would show more births than deaths and pretty much the same over the next few years or decades. But sooner or later, suddenly, it was there: the dramatic, unpredictable upswing of mortality, pages after pages, carrying off a tenth, a quarter, or even a third of an entire community in a matter of months, if not weeks. Pestilence, famine, and the devastation of war were the main causes of these dramatic episodes, always ready to surge, lurking against the background of what is called, for lack of a better term, “usual” or “normal” mortality conditions. Crises of mortality were not only startling to the first population historians who browsed the historical archives, but were often taken to have dominated the whole of past demographic trends. Studying Scottish population history, Flinn (1977) went on to suggest that in its early stages, the general decline in mortality of the last centuries was largely due to the attenuation of the severity of crisis mortal-ity. French historical demographer Jacques Dupâquier(1976) devised a measure of “crise de mortalite” that became standard in the historical demography of mortality.Owing to these crises, large numbers of our predecessors died very early in life and their expected lifespan did not surpass 30 to 40 years in most instances. Between 1800 and 2000, however, life expectancy at birth rose to a global average of sixty-seven years (Riley 2001) and to more than 75 years in developed countries like Canada (Bourbeau and Smuga 2003). At the end of what came to be known as the epidemiological transition (Omran 1971)—a gradual shift from epidemic and infectious diseases to those of a degenerative nature—the most common age at death had jumped from infancy to old age. The articles in this special issue of

On the Dependence of Initial Dynamics of Nystatin Channel Formation in Phospholipid/Ergosterol Bilayers on Ergosterol Microstructure

Nystatin (NYS) is an antifungal agent that preferentially forms ion channels in membranes containing ergosterol (ERG) or cholesterol (CHOL). In phospholipid bilayers ERG or CHOL segregate into ordered (Lo) and disordered (Ld) domains. We prepared POPC bilayers containing ERG mol fraction 0.18 ≤ χERG ≤ 0.28 separating two chambers containing 150mM KCl solutions. We imposed a potential of 50mV across the bilayer and introduced NYS molecules into the reference chamber, which was stirred at 4Hz. The NYS molecules adhered to the bilayer and formed channels on the boundaries of the Lo domains, as we have shown previously. The resulting bilayer current increased in a series of log-linear sections. A plot of the rate constant for initial NYS channel formation against χERG revealed prominent spikes at χERG = 0.19 and 0.25. These correspond well to the dips in dehydroergosterol fluorescence observed by P. L-G. Chong, which he understood in terms of a superlattice. We conclude that the initial channel formation rate depends strongly on Lo domain structure and propose a semi-empirical theory for the first two log-linear sections of the bilayer current.

The Dorsal Hippocampal Commissure: When Functionality Matters

The Dorsal Hippocampal Commissure: When Functionality Matters

Road-impacted sediment and water in a Lake Ontario watershed and lagoon, City of Pickering, Ontario, Canada: An example of urban basin analysis

The world is increasingly urban but there are few studies of how contaminated water and sediment move through urban basins with their built landscapes and complexly disturbed geology. The central Canadian city of Pickering, Ontario sprawls across a small (27 km 2) densely urbanized (pop: 53,000) watershed and is underlain by Pleistocene glacial sediments and thick artificial fill deposits. Almost 80% of the area is hardened by impervious cover; road and rail lines cover 40% and include Canada's busiest highway (12-lane Highway 401: 177,000 vehicles per day in 2003). The basin discharges to Lake Ontario through a small (85 ha) shallow (< 3.5 m) lagoon (Frenchman's Bay). A 3-D steady state finite element groundwater numerical model (FEFLOW) was applied to 200 cored and geophysically-logged (gamma and resistivity) boreholes and 3400 digital water wells. It identifies the subsurface stratigraphy and hydrostratigraphic function of deposits and the rates of groundwater flow. Year-round monitoring of groundwater, creek and lagoon water quality shows that transportation infrastructure is the primary source of contaminated water and sediment. Some 7600 tonnes of de-icing salt are applied to watershed roads each year; 52% accumulates in groundwater where it continues to be released as brackish baseflow to creeks in summer. The remainder is rapidly delivered by surface runoff to Frenchman's Bay where chloride contents are more than double the average values in waters across the Great Lakes. Highway 401 is the largest single source of salt contamination to the lagoon; it receives 26% of all road salt applied to the watershed but covers just 1.3% of its area. Prominent spikes in chloride content (> 2000 mg L − 1 ) occur during winter thaws in creeks downstream of the highway. Enhanced stream bank erosion as a consequence of flashy storm runoff from road surfaces moves ∼ 100 tonnes of contaminated sediment to Frenchman's Bay each year. Instantaneous suspended sediment concentrations in storm runoff are as high as 1600 g m − 3 and loadings of sulphate (SO 4 − 2 ) nutrients reach 594 kg h − 1 . Metals and E. coli in road runoff are all elevated well above Canadian water quality standards. These findings underscore findings from other urban areas regardless of regional climate, that transportation corridors are a major global source of contaminated water and sediment.