Exploring within-ecodistrict lake organic matter variability and identifying possible environmental contaminant biomarkers using sedimentomics.

Sedimentomics methods offer insight into the physiological parameters that influence freshwater sediment organic matter (sedOM). To date, most sedimentomics studies characterized variations across large spatial and environmental gradients; here we examine whether sedimentomics methods capture subtle sedOM variations within a relatively homogeneous study area in southwestern Nova Scotia, Canada. Additionally, we explore the lake sedimentome for candidate biomarkers related to ongoing carnivorous animal farming in the region. Sediment cores were recovered from seven lakes across a trophic (oligo- to eu- trophic) and anthropogenic land use gradient (carnivorous animal farming in catchment, downstream of farming, no farming nearby). Subsamples that dated prior to 1910 (pre-carnivorous animal farming) and later than 2010 (during carnivorous animal farming) were analyzed using UHPLC-HRMS in both negative (ESI-) and positive (ESI+) electrospray ionization modes. Cluster analysis (k-means) showed replicate samples from a given lake clustered distinctly from one another in both ESI modes, indicating sedOM captured subtle variations between lake systems. PCA combined with multiple linear regression indicated carnivorous animal farming and OM source explained most of the observed variation in lake sedOM. Principal component analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA) of ESI- and ESI+ data sets identified 103 unique candidate biomarkers. Ten strong candidate biomarkers were identified using graphical methods; more research is required for biomarker verification and molecular characterization. Our results indicate sedimentomics could be used in environmentally homogeneous areas, offering insight into the controls of sedOM cycling. Additionally, we identified prospective biomarkers related to carnivorous animal farming that could be used to understand relative contributions of farming to ongoing eutrophication issues in southwestern Nova Scotia.

Variation of telencephalon morphology of the threespine stickleback (Gasterosteus aculeatus) in relation to inferred ecology.

We tested the hypothesis that increased telencephalon size has evolved in threespine stickleback fish (Gasterosteus aculeatus) from structurally complex habitats using field-caught samples from one sea-run (ancestral) and 18 ecologically diverse freshwater (descendant) populations. Freshwater habitats ranged from shallow, structurally complex lakes with benthic-foraging stickleback (benthics), to deeper, structurally simple lakes in which stickleback depend more heavily on plankton for prey (generalists). Contrary to our expectations, benthics had smaller telencephala than generalists, but the shape of the telencephalon of the sea-run and benthic populations were more convex laterally. Convex telencephalon shape may indicate enlargement of the dorsolateral region, which is homologous with the tetrapod hippocampus. Telencephalon morphology is also sexually dimorphic, with larger, less convex telencephala in males. Freshwater stickleback from structurally complex habitats have retained the ancestral telencephalon morphology, but populations that feed more in open habitats on plankton have evolved larger, laterally concave telencephala.

Implications of a fossil stickleback assemblage for Darwinian gradualism.

Darwin postulated that a complete fossil record would contain numerous gradual transitions between ancestral and descendant species, but 150 years after publication of The Origin of Species, few such transitions have materialized. The fossil stickleback Gasterosteus doryssus and the deposit in which it occurs provide excellent conditions to detect such transitions. Abundant, well-preserved fossils occur in a stratigraphic setting with fine temporal resolution. The paleoecology of G. doryssus resembles the ecology of modern lakes that harbour the phenotypically similar three-spined stickleback Gasterosteus aculeatus. Gasterosteus aculeatus are primitively highly armoured, but G. doryssus comprised two contemporaneous biological species with relatively weak armour, including a near-shore, benthic feeder (benthic) and an offshore planktivore (limnetic). The benthic species expanded its range into the limnetic zone of the lake, where it apparently switched to planktivory and evolved reduced armour within c. 5000 years in response to directional selection. Although gradual evolution of mean phenotypes occurred, a single major gene caused much of evolutionary change of the pelvic skeleton. Thus, Darwin's expectation that transitions between species in the fossil record would be gradual was met at a fine time scale, but for pelvic structure, a well-studied trait, his expectation that gradual change would depend entirely on numerous, small, heritable differences among individuals was incorrect.

Influence of endurance and sprinting exercise on plasma adiponectin, leptin and irisin concentrations in racing Greyhounds and sled dogs.

OBJECTIVE: The objective of this study was to assess the effects of both short-term anaerobic exercise and long-term aerobic exercise on leptin, adiponectin and irisin concentrations in both sprint and endurance canine athletes. DESIGN: Prospective field trial repeated measures. The 25 racing Greyhounds were run over 400 m, with blood samples collected prior to exercise and at 10 min and 120 min after exercise. The 16 sled dogs were run an average of 3.5-5 h/day on 5 out of 8 days of stage stop racing competition, with assessment on days 0, 2 and 8. RESULTS: Baseline leptin concentrations were found to be lower than previously recorded values of domestic dogs, possibly because of a lower body fat content in athletes, with concentrations in sled dogs being slightly higher than those in Greyhounds. Baseline adiponectin concentrations in both groups of dogs, on average, were lower than most previously recorded values in domestic dogs; although unexpected, these findings may be attributed to differences in body fat content of the study population. CONCLUSION: Endurance exercise in sled dogs resulted in a persistent decrease in leptin that appears to be independent of race-associated weight loss, with no appreciable changes in adiponectin or irisin concentrations. The anaerobic exercise of Greyhounds produced no detectable changes in leptin and adiponectin concentrations; however, a significant rise in irisin 10 min post-exercise may be a compensatory mechanism for restoration of ATP homeostasis in skeletal muscle.

The 2014 liver ultrasound tracking benchmark.

The Challenge on Liver Ultrasound Tracking (CLUST) was held in conjunction with the MICCAI 2014 conference to enable direct comparison of tracking methods for this application. This paper reports the outcome of this challenge, including setup, methods, results and experiences. The database included 54 2D and 3D sequences of the liver of healthy volunteers and tumor patients under free breathing. Participants had to provide the tracking results of 90% of the data (test set) for pre-defined point-landmarks (healthy volunteers) or for tumor segmentations (patient data). In this paper we compare the best six methods which participated in the challenge. Quantitative evaluation was performed by the organizers with respect to manual annotations. Results of all methods showed a mean tracking error ranging between 1.4 mm and 2.1 mm for 2D points, and between 2.6 mm and 4.6 mm for 3D points. Fusing all automatic results by considering the median tracking results, improved the mean error to 1.2 mm (2D) and 2.5 mm (3D). For all methods, the performance is still not comparable to human inter-rater variability, with a mean tracking error of 0.5-0.6 mm (2D) and 1.2-1.8 mm (3D). The segmentation task was fulfilled only by one participant, resulting in a Dice coefficient ranging from 76.7% to 92.3%. The CLUST database continues to be available and the online leader-board will be updated as an ongoing challenge.

The Charcôt-Bouchard aneurysm controversy: impact of a new histologic technique.

For over a century a controversy has existed about the prevalence and significance of Charcôt-Bouchard (C-B) aneurysms, especially regarding their relationship to intracerebral hemorrhage (ICH) in man. We reassessed C-B aneurysms by staining thick brain sections from 35 hypertensives and 20 normotensives with the alkaline phosphatase (AP) endothelial stain followed by light microscopy and high-resolution microradiography. Charcôt-Bouchard aneurysms were conspicuously absent in both groups which included four cases of hypertensive ICH. The three-dimensional perspective and enhanced ability to trace vessels with these techniques helped to identify arteriolar coils and twists that can be mistaken for aneurysms when demonstrated by injection methods. Routine brain pathologic sections from 2,800 autopsies over a decade showed rare examples of parenchymal aneurysms. We conclude that elimination in our study of a) injection artifacts and b) misinterpretations shows that C-B aneurysms are uncommon and have little relationship to ICH. Despite this, and in view of the original contribution of Charcôt and Bouchard, the occasional examples of brain parenchymal aneurysms should continue to bear their names.

Arteriolar tortuosity of the white matter in aging and hypertension. A microradiographic study.

Previous studies have shown tortuous arteries and arterioles in the brains of older people, but the effects of age and other factors have not been studied. To examine the effects of hypertension, age, race and sex on white matter (WM) arteriolar tortuosity (AT), we performed high-resolution microradiography and morphometry of human brains taken at autopsy from 44 subjects of various ages (range 30-96 years; 31 hypertensives/13 normotensives). About 70% of tortuosities in the WM were found at the gray-white interfaces of the insular region and adjacent subcortical-WM of the inferior frontal and superior temporal gyri. Six morphologic types of tortuous profiles were identified. The number of tortuous profiles increased with age, but not significantly. Hypertension, sex and race had no effect on tortuosity. Our findings also suggest that 1) WM AT is found mostly at the interfaces between gray matter and WM and, therefore, 2) the physical properties of the WM somehow predispose to the development of AT; 3) AT is not associated with tortuosity in the veins; and 4) the location of complex arteriolar coils supports a recent claim that they can be mistaken for the Charcôt-Bouchard microaneurysms if injection of contrast media and low-magnification radiography of the brain slices are employed for that purpose.

Neuritic plaques and vessels of visual cortex in aging and Alzheimer's dementia.

Changes in microvascular dimensions occurring with normal aging and Alzheimer's dementia were measured in thick sections of postmortem human visual cortex stained for alkaline phosphatase. Capillary density was decreased to the same degree in both normal aged and demented aged subjects. The fields selected for analysis in both groups included all cortical laminae and, where possible, amyloid-cored neuritic plaques. The mean density of such plaques in these selected fields was slightly but not significantly higher in the demented group. In both groups plaques were more plentiful in visual laminae with the highest capillary densities (II-IV), but plaques and vessels were closer to each other in the normal aged than in the demented. Plaque distributions differed; in the normal aged, plaques concentrated in lamina IV; in the demented they were more evenly spread throughout the laminae. Plaque cores were larger in the demented. Amyloid angiopathy was more common and more extensive in the demented group; amyloid-cored plaques were not closely associated with affected vessels. Plaque distributions in Alzheimer subjects with and without amyloid angiopathy differed; plaque density was greatest in those without angiopathy. Alzheimer's dementia was not associated with any decline in microvascularity. Plaque concentration in well vascularized laminae suggests a pathogenetic role for some blood-borne agent. Differences in plaque distributions imply that the role or the agent differs in normal and demented aging, or perhaps between cases with and without amyloid angiopathy.

Electrophysiological indices of frontal lobe development. Relations to cognitive and affective behavior in human infants over the first year of life.

Over the past 8 years we have been involved in a study of the psychophysiological correlates of cognitive and affective behaviors during the first year of life. We have utilized recordings of brain electrical activity (the EEG) to describe differences in regional activation as well as, more recently, changes in regional connectivity. Our studies have indicated an important role for the frontal region in the expression of positive and negative emotions and in the regulation of emotional distress. In addition, individual differences in frontal EEG maturation seem to be associated with improved performance on tasks known to involve specific regions of frontal cortex. The corroborative data from different areas of study (studies of brain-damaged adults; studies of lesions in nonhuman primates) give us confidence that our measures of regional electrical activity are indeed reflecting true brain processes. Our continuing task is to understand the skills that are involved in these complex behaviors (such as AB performance or expression of affect) so as to better understand these important brain-behavior relationships.

Changing practice habits of King County obstetricians.

In 1987, all practicing King County, Washington obstetricians (N = 181) were surveyed to determine the impact of rising malpractice premium rates and the threat of litigation on their obstetric practices. Six percent of respondents anticipated closing their practices over the next year, which means an additional 520 deliveries will have to be absorbed into existing obstetric practices. Of the 71% who increased their professional fees in 1986, 90% attributed the increase to higher malpractice premiums and increased risk of litigation.

Laminar variation in the microvascular architecture of normal human visual cortex (area 17).

Diameters and densities of arterioles and capillaries were measured in thick alkaline phosphatase-stained sections of human visual cortex from normal young adults. Values were compared between laminae. Capillary diameters ranked: IV greater than V-VI greater than II-III greater than I; capillary densities ranked: IV greater than II-III greater than V-VI greater than I. The striking capillary density of lamina IV overlaps the stria Gennarii and, like it, is limited to area 17. The data suggest correlations with similar laminar distributions of some neurotransmitters and of certain common neuropathological lesions.

Stroop color-word interference and electroencephalogram activation: evidence for age-related decline of the anterior attention system.

Groups of healthy, community-dwelling younger and older adults performed a Stroop task in which color and word could be congruent or incongruent and spatially integrated or separated. During the task, continuous electroencephalogram (EEG) was recorded from frontal, parietal, and occipital regions. The magnitude of the Stroop interference effect and task-related EEG activation was greater for older than younger adults when stimuli were integrated. This effect was significant over medial and lateral frontal and parietal, but not occipital, regions. In comparison, interference and EEG activation did not differ for younger and older adults when stimuli were separated. These findings support the hypothesis that the anterior attention system is more sensitive to the effects of increasing age than the posterior attention system.

The effects of morphine and nalorphine on the plasma 11-hydroxycorticosteroid response to insulin-induced hypoglycaemia in patients with rheumatoid arthritis.

Morphine in therapeutic dosage has been shown to impair the plasma 11-hydroxycorticosteroid response to the stress of insulin-induced hypoglycaemia. Nalorphoine in similar dosage produced no impairment of the response to hypoglycaemia.

Features of the cerebral vascular pattern that predict vulnerability to perfusion or oxygenation deficiency: an anatomic study.

In an ongoing study of brain microvasculature in humans at autopsy, we had the opportunity to analyze the overall scheme of this vascular supply. The native endothelial membrane enzyme, alkaline phosphatase, is used to precipitate black lead sulfide salt in the vessel wall, rendering the brain microvasculature visible by both light microscopy and microradiography. There are six distinct patterns of intraparenchymal afferent blood supply to the supratentorial brain: short arterioles from a single source (e.g., those in the cortex); short- to intermediate-length arterioles, single source (anterior two-thirds of the corpus callosum); short- to intermediate length arterioles and arteries, dual source (subcortical U fibers); intermediate-length arterioles and arteries, triple source (extreme/external capsule and claustrum); long arteries and arterioles, single source (centrum semiovale); and large, long muscular arteries, single source (thalamus and basal ganglia). The nature of this arrangement offers some protection to certain regions of the cerebrum from circulatory challenges such as hypotension, while leaving other areas vulnerable. The distal arterioles supplying two of these protected regions, the U-fiber area and the extreme/external capsule and claustrum area, also exhibit the feature of interdigitation, which can offer additional collateral potential from one arteriolar territory to the next. Aging, hypertension, diabetes mellitus, and atherosclerosis can have a significant impact on brain microcirculation. The way in which vascular patterns dictate the distribution of these effects is discussed. The ability to stain the cerebral microvessels and demonstrate the finer points of their patterns in sections and microradiographs has enabled us to resolve some long-standing questions about vascular connections and directions.(ABSTRACT TRUNCATED AT 250 WORDS)

The corpus callosum, a unique white-matter tract: anatomic features that may explain sparing in Binswanger disease and resistance to flow of fluid masses.

The corpus callosum exhibits several unusual features: arteriole-venule pairs, perivascular fibrous alae, and recurrent companion arterioles. These and other anatomic aspects are compared and contrasted with those of the centrum semiovale. Vascular changes occurring with aging or hypertension, commonly seen in the centrum semiovale, rarely develop in the corpus callosum. The vascular supply to the central zone of the genu and body of the corpus callosum, via short penetrating arterioles, is similar to that of the cerebral cortex, whereas the vascular supply to the extreme lateral corpus callosum, centrum semiovale, and basal ganglia is substantially carried by long end-arteries. When observed critically, the anatomic features of the corpus callosum may explain such clinically observed phenomena as its relative resistance to flow of fluid masses, radiation injury, Binswanger disease, lacunar infarction, hypoxia, and hypoperfusion.

Sex differences on a mental rotation task: variations in electroencephalogram hemispheric activation between children and college students.

The area of cognitive research that has produced the most consistent sex differences is spatial ability. In particular, men usually perform better on mental rotation tasks than women. Performance on mental rotation tasks has been associated with right parietal activation levels, both during task performance and prior to performance during baseline recordings. This study examined the relations among sex, age, electroencephalogram (EEG) hemispheric activation (at the 10.5 Hz to 13.5 Hz frequency band), and 2-D mental rotation task ability. Nineteen 8-year-olds (10 boys) and 20 college students (10 men) had EEG recorded at baseline and while performing a mental rotation task. Men had a faster reaction time on the mental rotation task than women, whereas there were no differences between boys and girls. After covarying for baseline EEG power values, men exhibited more activation (lower EEG power values) than women in the parietal and posterior temporal regions, whereas boys' and girls' power values did not differ in the parietal or posterior temporal regions. Furthermore, during the baseline condition, men generally exhibited more activation (lower EEG power values) throughout all regions of the scalp. Results support the hypothesis that a change that affects both brain activation and performance on mental rotation tasks occurs sometime between childhood and adulthood.

Physical stress testing of insulin suspensions and solutions.

Insulin pen-cartridge devices have evolved in order to increase patient compliance and convenience of use in a portable, multiple dosage device. With the advent of a portable insulin containing device, stability considerations have evolved from standard chemical indicators to include the effects of temperature and agitation on physical characteristics. To address these issues, two automated physical stress tests were developed based on market research data and input from regulatory authorities to understand the effect of thermomechanical stress on the product. First, the temperature cycling and resuspension test (TCRT) includes temperature cycling (25-37 degreesC) combined with agitation. The high temperature and extreme agitation test (HTEAT) includes continuous high temperature (37 degreesC) exposure combined with 4 h daily agitation. The total stress exposure is a function of the temperature, agitation, and time. The tests range from moderate stress (TCRT) to considerable stress (HTEAT) determined from the number of cartridge inversions and average daily temperature. Physical stress testing of both insulin suspensions and solution formulations in cartridges were performed and interpreted with respect to multiple endpoints. For suspensions, prolonged exposure to extreme stress caused the protein to form agglomerates, either in the suspension or adhered to the cartridge walls. In contrast, protein solutions subjected to the same extreme stress conditions did not exhibit any visually detectable change. Visual changes in the product under physical stress conditions can increase dose-potency result variability as well as exhibit acid-insoluble aggregates.