Automated detection and enumeration of marine wildlife using unmanned aircraft systems (UAS) and thermal imagery.

Estimating animal populations is critical for wildlife management. Aerial surveys are used for generating population estimates, but can be hampered by cost, logistical complexity, and human risk. Additionally, human counts of organisms in aerial imagery can be tedious and subjective. Automated approaches show promise, but can be constrained by long setup times and difficulty discriminating animals in aggregations. We combine unmanned aircraft systems (UAS), thermal imagery and computer vision to improve traditional wildlife survey methods. During spring 2015, we flew fixed-wing UAS equipped with thermal sensors, imaging two grey seal (Halichoerus grypus) breeding colonies in eastern Canada. Human analysts counted and classified individual seals in imagery manually. Concurrently, an automated classification and detection algorithm discriminated seals based upon temperature, size, and shape of thermal signatures. Automated counts were within 95-98% of human estimates; at Saddle Island, the model estimated 894 seals compared to analyst counts of 913, and at Hay Island estimated 2188 seals compared to analysts' 2311. The algorithm improves upon shortcomings of computer vision by effectively recognizing seals in aggregations while keeping model setup time minimal. Our study illustrates how UAS, thermal imagery, and automated detection can be combined to efficiently collect population data critical to wildlife management.

Survey of total arsenic and arsenic speciation in US-produced rice as a reference point for evaluating change and future trends.

Rice generally contains higher levels of arsenic than most terrestrial-based foods. Studies related to dietary intake of arsenic from rice must take into account arsenic speciation due to toxicity differences in arsenic species. In this study, microwave-assisted extraction with trifluoroacetic acid was used to prepare rice samples for arsenic speciation analysis by high-performance liquid chromatography-inductively coupled plasma mass spectrometry. Fifty-three samples collected directly from the fields in four major rice-producing states in 1980 and 1981 were analysed for total and speciated arsenic and the results were compared with each other and with results for several more recently collected samples from local markets. The average content of total arsenic was 210 ± 190 ng As g(-1). This study demonstrates that US rice samples with higher levels of total arsenic have higher levels of dimethylarsinic acid; however, inorganic arsenic levels, regardless of the total arsenic content, rarely exceed 150 ng As g(-1) dry weight. These data are consistent with more recent findings, thus establishing trends that arsenic content in US-grown rice has been relatively constant throughout the last 30 years. To the authors' knowledge, the presented data are unique in that they provide a historical reference point for arsenic distribution in US-produced rice. These data would be invaluable for several applications including long-term arsenic exposure studies, environmental clean-up assessments, and to establish models for future trends in arsenic contribution in total diet studies.

Differential effects of mitomycin C and doxorubicin on P-glycoprotein expression.

Previous studies have demonstrated that mitomycin C (MMC) and other DNA cross-linking agents can suppress MDR1 (multidrug resistance 1) gene expression and subsequent functional P-glycoprotein (Pgp) expression, whereas doxorubicin and other anthracyclines increase MDR1 gene expression. In the present study, with stably transfected Madin-Darby canine kidney C7 epithelial cells expressing a human Pgp tagged with green fluorescent protein under the proximal human MDR1 gene promoter, we demonstrated that MMC and doxorubicin have differential effects on Pgp expression and function. Doxorubicin caused a progressive increase in the cell-surface expression of Pgp and function. In contrast, MMC initially increased plasma membrane expression and function at a time when total cellular Pgp was constant and Pgp mRNA expression had been shown to be suppressed. This was followed by a rapid and sustained decrease in cell-surface expression at later times, presumably as a consequence of the initial decrease in mRNA expression. These studies imply that there are at least two independent chemosensitive steps that can alter Pgp biogenesis: one at the level of mRNA transcription and the other at the level of Pgp trafficking. Understanding the combined consequences of these two mechanisms might lead to novel chemotherapeutic approaches to overcoming drug resistance in human cancers by altering either Pgp mRNA expression or trafficking to the membrane.

Subunit stoichiometry of a core conduction element in a cloned epithelial amiloride-sensitive Na+ channel.

The molecular composition of a core conduction element formed by the alpha-subunit of cloned epithelial Na+ channels (ENaC) was studied in planar lipid bilayers. Two pairs of in vitro translated proteins were employed in combinatorial experiments: 1) wild-type (WT) and an N-terminally truncated alphaDeltaN-rENaC that displays accelerated kinetics (tauo = 32 +/- 13 ms, tauc = 42 +/- 11 ms), as compared with the WT channel (tauc1 = 18 +/- 8 ms, tauc2 = 252 +/- 31 ms, and tauo = 157 +/- 43 ms); and 2) WT and an amiloride binding mutant, alphaDelta278-283-rENaC. The channels that formed in a alphaWT:alphaDeltaN mixture fell into two groups: one with tauo and tauc that corresponded to those exhibited by the alphaDeltaN-rENaC alone, and another with a double-exponentially distributed closed time and a single-exponentially distributed open time that corresponded to the alphaWT-rENaC alone. Five channel subtypes with distinct sensitivities to amiloride were found in a 1alphaWT:1alphaDelta278-283 protein mixture. Statistical analyses of the distributions of channel phenotypes observed for either set of the WT:mutant combinations suggest a tetrameric organization of alpha-subunits as a minimal model for the core conduction element in ENaCs.

Membrane trafficking of the cystic fibrosis gene product, cystic fibrosis transmembrane conductance regulator, tagged with green fluorescent protein in madin-darby canine kidney cells.

The mechanism by which cAMP stimulates cystic fibrosis transmembrane conductance regulator (CFTR)-mediated chloride (Cl-) secretion is cell type-specific. By using Madin-Darby canine kidney (MDCK) type I epithelial cells as a model, we tested the hypothesis that cAMP stimulates Cl- secretion by stimulating CFTR Cl- channel trafficking from an intracellular pool to the apical plasma membrane. To this end, we generated a green fluorescent protein (GFP)-CFTR expression vector in which GFP was linked to the N terminus of CFTR. GFP did not alter CFTR function in whole cell patch-clamp or planar lipid bilayer experiments. In stably transfected MDCK type I cells, GFP-CFTR localization was substratum-dependent. In cells grown on glass coverslips, GFP-CFTR was polarized to the basolateral membrane, whereas in cells grown on permeable supports, GFP-CFTR was polarized to the apical membrane. Quantitative confocal fluorescence microscopy and surface biotinylation experiments demonstrated that cAMP did not stimulate detectable GFP-CFTR translocation from an intracellular pool to the apical membrane or regulate GFP-CFTR endocytosis. Disruption of the microtubular cytoskeleton with colchicine did not affect cAMP-stimulated Cl- secretion or GFP-CFTR expression in the apical membrane. We conclude that cAMP stimulates CFTR-mediated Cl- secretion in MDCK type I cells by activating channels resident in the apical plasma membrane.

Renal organic anion secretion: evidence for dopaminergic and adrenergic regulation.

To examine possible regulatory control of renal proximal tubule organic anion secretion, winter flounder (Pleuronectes americanus) proximal tubule primary cultures were mounted in Ussing chambers. Unidirectional fluxes of [2,4-(14)C]dichlorophenoxyacetic acid were determined under short-circuited conditions. Phorbol 12-myristate 13-acetate (1 microM) caused a significant (P < 0.01) inhibition of net 2,4-dichlorophenoxyacetic acid secretion. Preincubation with staurosporine (1 microM) blocked the phorbol 12-myristate 13-acetate-induced decrease in secretion. Neither forskolin (10 microM) nor W-7 (20 microM) had any effect on net transport. Elevation of intracellular calcium activity with either A-23187 or thapsigargin produced a slight, transient decrease in transport. Addition of dopamine (1 microM) to the peritubular side, but not the luminal side, caused a significant (P < 0.01) decrease in net secretion. Both the alpha-adrenergic agonist oxymetazoline (10 microM) and depletion of intracellular Na+ transiently, but significantly (P < 0.05), increased net transport. The data indicate that renal organic anion excretion may be regulated through dopaminergic inhibition and alpha-adrenergic stimulation of net transepithelial secretion.

Commercial hickory-smoke flavouring is a human lymphoblast mutagen but does not induce lung adenomas in newborn mice.

Commercial aqueous wood-smoke flavouring induced significant increases in the 6-thioguanine resistance mutation frequency of TK6 human lymphoblasts at 0.1 microliter flavouring/ml of cell suspension. This corresponds to 6 micrograms/ml of dissolved 'solids' as determined by fully drying the aqueous flavouring in a vacuum desiccator. In AHH-1 human lymphoblasts, which contain a cytochrome P-450 monooxygenase system, mutations were induced at 0.3 microliter/ml, corresponding to 18 microliters/ml of dissolved 'solids'. The flavouring did not induce 8-azaguanine resistant mutations in Salmonella typhimurium at concentrations up to 1.5 microliter/ml. At higher concentrations the flavouring was toxic to bacteria. The flavouring did not induce lung adenomas or other tumours in newborn mice when injected ip with total doses of up to 26 microliters over a 3-wk period. Toxicity to the kidney, colon and rectum was observed in some mice at 15 wk of age.

Polyploidization of aortic smooth muscle cells from hypertensive and genetically related normotensive rats.

Abnormalities of growth regulation in arterial smooth muscle cells (SMC) are important in the pathogenesis of vascular disease. Recent studies have demonstrated an accumulation of polyploid SMC in hypertensive, and to a lesser extent in normotensive, arteries. The aim of this study was to evaluate the intrinsic genetic predisposition of aortic SMC from spontaneously hypertensive rats (SHR) to become polyploid in response to in vitro growth stimulation. Flow cytometry revealed that in vitro polyploidization was greatest in Wistar-Kyoto rats (WKY, normotensive inbred rats genetically related to SHR), intermediate but high in SHR and lowest in outbred (Sprague-Dawley) and genetically unrelated inbred (Fischer) rats (P less than 0.001). No differences were observed between neonatal and adult animals of the same strain; non-arterial WKY cells remained diploid. Reproductive clonal populations of polyploid SMC could be isolated from early-passage cultures of SHR and WKY cells. These studies suggest intrinsic differences in in vitro polyploidization among different rat strains, and may improve understanding of SMC growth control.

Strain and site dependence of polyploidization of cultured rat smooth muscle.

Smooth muscle cell (SMC) growth may play an important role in the pathogenesis of vascular diseases such as atherosclerosis and hypertension. Recent studies have demonstrated that, under different growth stimuli in vivo, SMC may respond by proliferation of diploid cells, polyploidization to the tetraploid (or even octaploid) state, or both. In this study, we used flow cytometry to evaluate the intrinsic tendencies of aortic SMC and nonarterial cells from rats of different strains, ages, and blood pressures to polyploidize in response to in vitro growth stimulation. Significant strain-related differences in polyploidization of aortic SMC were found (P less than 0.001): highest in WKY (normotensive inbred rat related to SHR), intermediate in SHR (genetically hypertensive rat), and lowest in Sprague-Dawley and Fischer (normotensive outbred and inbred rats). Animal age had less or no effect on the degree of polyploidization. Nonarterial cells (venous SMC and lung cells) from WKY and SHR remained essentially diploid, suggesting tissue specificity of in vitro polyploidization. Studies of the growth kinetics of uncloned and clonal populations of aortic SMC revealed decreased proliferation as the ploidy increased in WKY, SHR, and Sprague-Dawley. These findings suggest that genetic strain factors as well as cell type/site of origin significantly influence in vitro polyploidization, whereas animal age and blood pressure do not. The findings also emphasize the need to consider ploidy changes when evaluating in vitro SMC growth kinetics. Further studies will improve understanding of SMC growth regulation and the functional significance of vascular polyploidy.

Survival and repair of potentially lethal radiation damage in confluent vascular smooth muscle cell cultures.

Confluent cultures of rat aortic smooth muscle cells demonstrated dose-dependent potentially lethal damage repair (PLDR), with an average repair factor of 4 for a 10 Gy dose. PLDR occurred with a half-time of 2 hours and was nearly maximal by 8 h. Among other factors, PLDR may contribute to the radioresistance of large blood vessels.

Growth kinetics as a function of ploidy in diploid, tetraploid, and octaploid smooth muscle cells derived from the normal rat aorta.

The smooth muscle cell population in major arteries of humans and experimental animals is heterogeneous with regard to cellular DNA content. A proportion of cells has polyploid DNA content and this proportion increases with normal aging and with hypertension. We have isolated pure populations of rat aortic smooth muscle cells containing 2C, 4C, and 8C DNA content by cloning of cultures of cells previously subjected to flow cytometric cell sorting. Karyologic analysis of these clonal populations revealed them to be pure diploid, tetraploid, and octaploid populations, respectively, containing 2N (= 42), 4N, and 8N chromosomes. Cell attachment area and nuclear size appeared to increase with the level of ploidy. Studies of the proliferative characteristics of the cells revealed that the growth rate and ultimate cell densities achieved decreased as the ploidy level increased. The intrinsic cellular radiosensitivity of these clones did not vary with ploidy. Increased smooth muscle cell ploidy is, therefore, associated with a decreased rate of proliferation. The emergence of smooth muscle cells with polyploid DNA content under normal and pathologic conditions is probably due to mitotic polyploidization without net cell proliferation and may be related to the need for expression of differentiated functions.

Transferring a national information system from the public sector to the private sector--how the Administration on Aging did it.

The Administration on Aging (AoA) sponsored a national information system known as the SCAN system. The SCAN bibliographic database went on-line in March 1982. Congress, however, had repealed the authority for the clearinghouse, so the Government let all of the services of SCAN expire by September 1982. The Government then tried to keep the SCAN information accessible by offering it to the private sector. The Government solicited applicants through both the Federal Register and the Commerce Business Daily. As a result, the American Association of Retired Persons (AARP) and AoA signed an agreement calling for AARP to make such of the SCAN information accessible on-line and to update it.

A system of classification of femoral neck fractures with special refereance to choice of treatment.

Classification of femoral neck fractures is important for prognostication, choice of treatment, and evaluation of end-results. The vitality of the patient, the configuration of the fracture, the quality of the bone and the accuracy of the reduction are important considerations. Aids in their evaluation have been presented.