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Criegee intermediates are reactive intermediates that are implicated in transforming the composition of Earth’s troposphere and in the formation of secondary organic aerosol, impacting Earth’s radiation balance, air quality and human health. Yet, direct identification of their signatures in the field remains elusive. Here, from particulate and gas-phase mass-spectrometric measurements in the Amazon rainforest, we identify sequences of masses consistent with the expected signatures of oligomerization of the CH2OO Criegee intermediate, a process implicated in ozonolysis-driven aerosol formation. We assess the potential contributions of oligomerization through laboratory ozonolysis experiments, direct kinetic studies of Criegee intermediate reactions, and high-level theoretical calculations. Global atmospheric models built on these kinetics results indicate that Criegee intermediate chemistry may play a larger role in altering the composition of Earth’s troposphere than is captured in current atmospheric models, especially in areas of high humidity. However, the models still capture only a relatively small fraction of the observed signatures, suggesting considerable underestimates of Criegee intermediate concentrations and reactivity and/or the dominance of other, presently uncharacterized, oxidation mechanisms. Resolving the remaining uncertainties in emission inventories and the effects of atmospheric water vapour on key chemical reactions will be required to definitively assess the role of Criegee intermediate oligomerization reactions.

The amounts of nitrogen and phosphorus in river water are significantly influenced by anthropogenic inputs associated with land cover, land use, and point sources. We quantified seasonal and spatial patterns in the concentrations of nitrate N and soluble reactive phosphorus (SRP) at 17 sites distributed among tributaries and along the mainstem of the River Raisin, Southeastern Michigan, and also determined land cover, surficial geology, and discharges from waste water treatment plants (WWTPs). Annual flow‐weighted mean concentrations (FWMCs) ranged from nondetectable levels to 18.1 mg L−1for nitrate and to 184 µg L−1for SRP. Nitrate concentrations increased from headwaters to river mouth, and were highest in spring and in association with high runoff episodes. Mean nitrate concentration correlated strongly with the ratio of agricultural to forested land upstream of the sampling location. Concentrations of SRP also increased markedly from headwaters downstream, and exhibited little seasonal variation other than a modest increase during the summer period of low flow. Geology and phosphorus loading from WWTPs best predicted SRP concentrations. The annual yield of nitrate was consistent with expectations based on land use. Point source loading contributed a negligible fraction of the river's discharge of nitrate and at most one‐fourth of its SRP discharge. Compared with findings from headwater sites and other, less altered rivers, nutrient concentrations in this catchment appear strongly influenced by human activity.

Nonfatal penetrating injuries to the brainstem offer a unique opportunity to assess subcortical auditory pathway function. A case study of a patient suffering a severe nailgun accident is presented. Hearing sensitivity and acoustic reflexes were normal bilaterally, but word recognition was reduced for one ear. Auditory brainstem response results indicated waves I–IV were present bilaterally, but wave V was absent bilaterally. Results of vestibular findings indicated central pathology also. Results of audiologic, vestibular, radiologic, neurologic, and physical medicine examinations are discussed.

We determined the distance travelled by drifting nymphs of the mayflies Baetis and Cinygmula to add to existing knowledge of factors influencing drift distance, and to investigate the influence of drift-exiting behavior upon drift magnitude and periodicity. Individuals were released into the water column of a trough at 0.5-m intervals above the exit point, and numbers remaining in suspension over each release distance were fit to a previously developed model which describes return to the substrate according to a negative exponential function. Drift distance increased with increasing current velocity (range studied: 5-55 cm/s) and with decreasing body size (range studied: ca. 0.1-1 mg dry wt) according to log-linear functions. At higher velocities (35 and 55 cm/s), nymphs of both species drifted much shorter distances alive than dead, indicating active exiting from the drift. Drift distances of live nymphs scarcely differed between day and night, which contradicts the suggestion that greater drift abundances at night are caused by disorientation in darkness and consequently greater drift distances. Furthermore, comparisons using nymphs collected from the drift vs. the benthos, and subsequently fed or starved, also revealed no effect of treatment on drift distance, counter to expectations if drifting individuals were intrinsically weaker or less healthy than their benthic counterparts. Thus, although behavioral ability to exit the drift clearly exists in a number of invertebrate taxa, neither the occurrence of drift nor its diel periodicity was explainable on the basis of drift exiting behavior.

The Dan river, a principal source of the Jordan River, Israel, is unusually constant in discharge (~8 m3·s-1) and water temperature (15–16 °C). The Jordan headwaters constitute the southernmost oasis of a palearctic north temperate fauna, and presumably the very constancy of the Dan contributes to its important role as a regional refuge. However, little is known of river ecology from this region. We report a twelve month study of drift, undertaken to assess diel, seasonal, and spatial patterns of the abundance of drifting invertebrates.

Laboratory feeding trials were conducted with the predaceous stonefly Hesperoperla pacifica and a number of mayfly and dipteran prey species to investigate the effects of predator size, and prey size and morphology, on the predator's success. Observations under dim red light permitted estimation of encounter rate (E/min), attack propensity (A/E), capture success (C/A) and handling time (HT). For prey of a particular species and size, HT decreased log-linearly with increasing predator size. Across all prey categories, HT increased log-linearly with increasing values of the ratio prey dry wt/predator dry wt, and differences among species appeared to be small. Overall, capture success was low, but C/A was higher for dipterans than for mayflies, especially with large H. pacifica. Predator size affected C/A when prey fell within a certain size range, but was not a detectable influence with very small or very large prey. Values of A/E of near 10% typified many predatorprey combinations; however, ephemerellid mayflies suffered markedly fewer attacks, and values of A/E up to 30% were obtained with some species-size combinations. We estimated benefit to the predator first as prey wt ingested per unit time (dry wt/HT), and second by mutliplying the former term by capture success. Values increased with increasing size of the predator, and inclusion of the C/A term indicated that predators would obtain greater reward from small relative to large prey, and from dipterans relative to mayflies. Howerver, there was little evidence that attacks were biased toward more profitable prey. We compare the relative contributions of E/min, A/E and C/A to prey choice, and discuss their applicability to predation events in nature.

The in vitro activities of two new cephem antibiotics, ICI 193428 and ICI 194008, were compared with those of cefpirome, cefotaxime, ceftazidime, and piperacillin. Essentially all strains of the family Enterobacteriaceae were inhibited by both study drugs at concentrations of less than or equal to 4 micrograms/ml. Both new cephems were comparable to ceftazidime against Pseudomonas aeruginosa (MIC for 90% of strains, 8 micrograms/ml) and were the most active agents tested against Pseudomonas maltophilia (MIC for 90% of strains, 16 micrograms/ml).

• In the case described, electroencephalography (EEG) proved valuable for determining the nature of spells of loss of consciousness with brief clonic jerks associated with ear and throat pain. A 70-year-old woman had a history of episodic brief attacks of pain below the right ear and deep in the neck that had started three years previously. The spells became more severe and progressed to loss of awareness associated with clonic jerks of the extremities. Because of a concern that the spells represented seizures, an EEG was performed, with electrocardiographic monitoring. Multiple spells were recorded; they began with profound bradycardia followed by generalized slowwave activity and then by suppression of all EEG activity correlating with loss of consciousness and clonic jerking. The spells were thought to represent syncopal attacks associated with glossopharyngeal neuralgia.

• Brainstem auditory evoked potentials (BAEPs) were obtained in 20 patients with palatal myoclonus. The group included 14 men and six women whose ages ranged from 19 to 82 years. Six of the patients had abnormal BAEPs: two with severe head trauma and one each with a brainstem infarct, tumor, demyelination, and an indeterminate inflammatory process. The 14 patients with normal BAEPs had palatal myoclonus secondary to head trauma (five patients), brainstem infarcts (four patients), cerebellar tumors (two patients), degenerative processes (two patients), and an Arnold-Chiari malformation (one patient). Since the auditory pathways are separate from the structures associated with palatal myoclonus, it is possible to have discrete lesions producing palatal myoclonus with sparing of the auditory structures, whereas diffuse or multifocal lesions of the brainstem are more likely to be associated with abnormal BAEPs.

In 29 cases of meningeal carcinomatosis reviewed, the widespread involvement of the cranial and spinal leptomeninges produced a complex neurological picture that made the diagnosis difficult. Examination of cerebrospinal fluid was the most helpful diagnostic procedure; the fluid often had decreased glucose and an increased protein content and contained malignant cells. Diffuse leptomeningeal and craniospinal nerve root infiltration was a consistent postmortem finding. The propensity of adenocarcinoma to metastasize in this fashion is reflected by the high frequency of this histologic type in this series. The two commonest primary sites were the breast and lung. In all patients there was progressive clinical deterioration; the average survival after diagnosis was only six weeks.

The in vitro activities of cefpiramide and apalcillin were compared with those of other third-generation cephalosporins and extended-spectrum penicillins against over 1,000 clinical bacterial isolates. The activity of cefpiramide against Pseudomonas aeruginosa was comparable to those of piperacillin and cefoperazone, inhibiting 90% of strains at concentrations less than or equal to 16.0 micrograms/ml. This drug was also active against a broad range of gram-negative organisms but was generally less active than many of the other cephalosporins tested against members of the family Enterobacteriaceae. The activity of cefpiramide against gram-positive organisms was comparable to that of cefoperazone. Apalcillin, along with ceftazidime, was the most active agent tested against P. aeruginosa and Acinetobacter calcoaceticus subsp. anitratus, inhibiting 90% of these strains at concentrations less than or equal to 8 micrograms/ml. Against other gram-negative and gram-positive organisms, its activity was similar to that of piperacillin. The activities of both cefpiramide and apalcillin were significantly reduced by the presence of several plasmid-mediated beta-lactamases in a series of otherwise isogenic strains of P. aeruginosa in comparison with their activities against a parent strain which lacks these enzymes. Many strains of Enterobacter cloacae were synergistically inhibited by the combination of gentamicin with either cefpiramide (5 of 10 strains) or apalcillin (6 of 10 strains). Most strains of P. aeruginosa were synergistically inhibited by the combination of gentamicin with either cefpiramide (8 of 10 strains) or apalcillin (10 of 10 strains). However, cefoxitin antagonized the activity of both cefpiramide and apalcillin against most of these same strains.

Thorium dioxide (Thorotrast), a radioactive substance with a very long half-life, has been used in the past as a contrast medium for various roentgenologic studies. Some of these have been followed by the delayed appearance of benign and malignant tumors, especially of the liver. Chronic arachnoiditis and myelopathy developed in three patients after myelography with thorium dioxide. Progressive involvement of the cauda equina, spinal cord, and brain stem was observed. One patient died after 26 years of illness.

Small experimental communities of bacteria and Protozoa were designed to test the widely held hypothesis that higher species diversity brings about greater stability. Three species of bacteria, three species of Paramecium and two species of protozoan predators, Didinium and Woodruffia, were used. The communities were maintained by regular additions of the appropriate combinations of species of bacteria. Stability was measured as persistence of all species and as a tendency to maintain evenness of the species abundance distribution. The measures were in essential agreement. Stability at the Paramecium trophic level was increased by increasing diversity at the bacterium level, but three species of Paramecium were less stable than two. An important finding was that one pair of Paramecium species consistently showed greater stability without the third species than with it. This finding indicates that there were significant second—order effects, with two species having an interaction that was detrimental to the third species. We conclude that much more experimental and observational work is necessary before the nature of any functional relationship between diversity and stability can be claimed with confidence.

DIASTEMATOMYELLA is an uncommon developmental abnormality characterized by a split in the spinal cord over several segments, with a dividing spur of bony, fibrous, or cartilaginous material running dorsoventrally between the two halves at one point. Each portion of the spinal cord may represent nearly complete duplication of the cord histologically, with its own central canal surrounded by columns of gray and white matter. The condition might then be better termed "diplomyelia," a truly double spinal cord. However, the internal Structural details of the cord in those cases diagnosed and treated during life are not known, and the descriptive term "diastematomyelia" is most often used. Usually each portion of the divided spinal cord has its own covering of pia mater and arachnoid and less often a separate covering of dura mater. The nerve roots on the lateral aspects are well developed while those on the medial aspect of each portion are

The Yangtze River (YR) region and cities along the river have severe deterioration of air quality due to urbanization and economic development. Black carbon (BC) has significant impacts on air quality and climate, however it is poorly characterized across the region. Here we report the first continuous measurements of BC and gaseous pollutants along the YR in wintertime, with an intensive observation period from November 21 to December 4, 2015, covering ∼7° longitude over the continent in China. The highly polluted periods (HPP) with NOx>80 μg m−3indicated more localized emissions. At the western (longitude <118°E) and eastern (longitude >118°E) ends of the YR valley, the HPP events reduced, mostly since the western end was influenced by terrain height and regional transport, and the eastern end was influenced by easterly oceanic or westerly continental air masses. In these regions, BC core size decreased by 5%–19% during the HPP, and had modes of mass median diameter in the range 120 –180 nm, which was found to be predominately from local sources, contrasting with a more consistent mode ∼200 nm that was due to BC from mixed sources. A comparison of simultaneously measured data from the nearby monitoring stations along the river demonstrated a high consistency of PM2.5over the river, which reflected the important regional impact on the particulate mass. This study evaluates the shipping emission and regional influence over the YR and may guide the policy maker on mitigating air pollution. The first continuous measurements of black carbon (BC) and gaseous pollutants along the Yangtze River were conducted in wintertime covering ∼7° longitude over the continent in ChinaBC core size decreased by 5%–19% during the highly polluted periods, and had modes of mass median diameter in the range 120 –180 nm, which was found to be predominately from local sources, contrasting with a more consistent mode ∼200 nm that was due to BC from mixed sourcesThe evaluation of the shipping emission and regional influence over the Yangtze River can underpin the mitigation strategies of air pollution The first continuous measurements of black carbon (BC) and gaseous pollutants along the Yangtze River were conducted in wintertime covering ∼7° longitude over the continent in China BC core size decreased by 5%–19% during the highly polluted periods, and had modes of mass median diameter in the range 120 –180 nm, which was found to be predominately from local sources, contrasting with a more consistent mode ∼200 nm that was due to BC from mixed sources The evaluation of the shipping emission and regional influence over the Yangtze River can underpin the mitigation strategies of air pollution

CHLOROQUINE PHOSPHATE may induce irreversible retinal pigmentary degeneration in humans who receive the drug in high doses over a long period of time. This report describes ocular changes seen in rabbits after the prolonged oral administration of chloroquine phosphate. MATERIALS AND METHODS Four albino and four pigmented healthy rabbits were fed chloroquine phosphate mixed with their food daily for 11 months. On the basis of a usual human dose of 250 mg/day for a 60-kg human (4.2 mg/k of body weight per day), four animals (two albino and two pigmented) received an approximate daily dosage of 42 mg/day/kg of body weight (ten times the usual human dose), and four animals (two albino and two pigmented) received 21 mg/kg of body weight per day (five times the usual human dose). The dosage for this latter group was later arbitrarily increased fourfold to 84 mg/kg of body weight per day (20 times

Submicron atmospheric aerosol samples were collected during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) 2004 campaign on four platforms: Chebogue Point (Nova Scotia, Canada), Appledore Island (Maine), the CIRPAS Twin Otter over Ohio, and the NOAA R/V Ronald H. Brownin the Gulf of Maine. Saturated aliphatic C‐C‐H, unsaturated aliphatic C=C−H, aromatic C=C−H, organosulfur C‐O‐S, carbonyl C=O, and organic hydroxyl C‐OH functional groups were measured by calibrated Fourier Transform Infrared (FTIR) spectroscopy at all four sampling platforms. The ratio of molar concentrations of carbonyl C=O to saturated aliphatic C‐C‐H groups was nearly constant at each sampling platform, with the Twin Otter samples having the lowest ratio at 0.1 and the three more coastal platforms having ratios of 0.4 and 0.5. Organic mass (OM) to organic carbon (OC) ratios follow similar trends for the four platforms, with the Twin Otter having the lowest ratio of 1.4 and the coastal platforms having slightly higher values typically between 1.5 and 1.6. Organosulfur compounds were occasionally observed. Collocated organic aerosol sampling with two Aerodyne aerosol mass spectrometers for OM, a Sunset Laboratory thermo‐optical analysis instrument for OC, and an ion chromatography‐particle into liquid sampler (IC‐PILS) for speciated carboxylic acids provided comparable results for most of the project, tracking the time series of FTIR OM, OC, and carbonyl groups, respectively, and showing simultaneous peaks of similar magnitude during most of the project. The FTIR/IC‐PILS comparison suggests that about 9% of the carbonyl groups found in submicron organic particles on the Twin Otter are typically associated with low molecular weight carboxylic acids.

We report the detection of a class of related oxygenated compounds by proton‐transfer‐reaction mass‐spectrometry (PTR‐MS) that have rarely or never been observed as a group using in situ instrumentation. Measurements were made as part of the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) 2004 in Chebogue Point, Nova Scotia. The detected class of compounds discussed here includes acetic acid, formaldehyde, acetaldehyde, tentatively identified formic acid and hydroxyacetone, and unidentified compounds detected at mass to charge ratios 85, 87, 99, 101, 113, 115, and 129. Typical concentrations were 800, 2500, 450, 700, 85, 25, 50, 50, 60, 35, 20, and 25 ppt, respectively. The uniqueness of this class of compounds is illustrated by showing they were poorly related to trace gases found in the US outflow, local pollution, primary biogenic emissions and other oxygenated compounds such as acetone, methanol, and MEK measured by other in situ instrumentation. On the other hand these oxidized volatile organic compounds were related to chemical species in aerosols and their abundance was high during nucleation events. Thus they likely are gas phase species that are formed in parallel to biogenic secondary organic aerosol production. We clearly show these compounds do not originate from local sources. We also show these compounds match the oxidation products of isoprene observed in smog chamber studies, and we therefore suggest they must be mainly produced by oxidation of biogenic precursor compounds.