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PubMed1991

Final Exit: a wake-up call to hospice.

The publication of Final Exit resulted in a public response that was exuberant, largely sympathetic and, to many within hospice, disquieting. The book and the public response it engendered can not be understood without exploring the Hemlock Society and the political agenda which both the Society and book advance. Hospice must begin a response to this book, and any discussion with Hemlock supporters, from a basis of consensus. Hospice must acknowledge that those within the euthanasia/assisted suicide movement believe as deeply as we in hospice in the need to address the suffering of people enduring the effects of terminal illness. We must further acknowledge that there remain unmet needs in the care of the dying which for primarily socio-political reasons hospice has been unable to resolve. There are several compelling reasons for hospice as an organized movement to oppose the political initiatives of the Hemlock Society--at least in their present form and within the current social context. These reasons involve core ethical issues and issues of direct social consequence, each of which seems sufficient to reject the current proposals. Hospice programs and personnel must enter this debate in earnest. Before serious consideration is accorded to legalization of euthanasia/assisted suicide, we must insist that genuine access to comprehensive hospice/palliative care becomes a reality for all dying patients and their families.

Attitude to Death↗
PubMed2002

Winter water relations of New England conifers and factors influencing their upper elevational limits. I. Measurements.

The upper elevational limits of tree species are thought to be controlled by abiotic factors such as temperature and the soil and atmospheric conditions affecting plant water status. We measured relative water contents (RWC), water potentials (Psi) and cuticular conductances (g(c)) of shoots of four conifer species-eastern hemlock (Tsuga canadensis (L.) Carr.), eastern white pine (Pinus strobus L.), red pine (P. resinosa Ait.) and red spruce (Picea rubens Sarg.)-during two winters on Mt. Ascutney, Vermont, USA. Some micrometeorological measurements are also reported. Eastern hemlock and white pine were studied near their upper elevational limits at a 640-m site, and red pine was studied near its upper elevational limit at 715 m. Red spruce was also studied at the 715-m site, which is in the middle of its elevational range on this mountain. There was no evidence of winter desiccation stress in any species. The observed distribution of seedlings suggested that the upper elevational limits on shade-intolerant eastern white pine and red pine are set by the absence of suitable seed beds after 100 years without fire. Eastern hemlock is able to reproduce in deep shade on organic substrates, but germination at high elevations may be restricted by low temperatures.

Altitude↗
PubMed1997

Characterization of Nuclear Polyhedrosis Viruses from Three Subspecies of Lambdina fiscellaria

The eastern hemlock looper (EHL), Lambdina fiscellaria fiscellaria, the western hemlock looper (WHL), L. fiscellaria lugubrosa, and the western oak looper (WOL), L. fiscellaria somniaria, are closely related insects that are pests in Canadian forests. We have used restriction endonuclease (REN) and Southern blot analyses to characterize DNA of nuclear polyhedrosis viruses (NPVs) isolated from each of the three subspecies of L. fiscellaria. REN analysis of EHL-NPV, WHL-NPV, and WOL-NPV DNAs revealed that they have nonidentical REN-banding patterns. NPV DNA extracted from WOL larvae collected from Douglas fir trees had a different REN pattern than NPV DNA extracted from WOL larvae collected from Garry oak trees. Hybridization of radiolabeled EHL-NPV genomic DNA revealed that the EHL- and WHL-NPVs share considerable DNA sequence similarity, as radiolabeled EHL-NPV DNA hybridized strongly with all WHL-NPV DNA bands. The EHL-NPV polyhedrin gene hybridized strongly with WHL-NPV DNA, but the hybridization patterns of the two NPVs were different. Very weak hybridization was detected between the EHL-NPV polyhedrin gene and DNAs of the two WOL-NPVs. Nucleotide sequence analysis revealed that the polyhedrin genes of EHL-NPV and WHL-NPV differ in sequence by only eight nucleotide substitutions (five third position and three second position changes, resulting in four amino acid substitutions). Phlyogeneitc analysis using the polyhedrin genes of EHL-NPV and WHL-NPV indicate that these two viruses cluster with the Group II NPVs as described by Zanotto, Kessing, and Maruniak (1993, J. Invertebr. Pathol. 62, 147).

Journal Article↗
PubMed2000

Cytology of Leidyana canadensis (apicomplexa: eugregarinida) in Lambdina fiscellaria fiscellaria larvae (lepidoptera: geometridae).

The eugregarine Leidyana canadensis infects the larval gut of the eastern hemlock looper, Lambdina fiscellaria fiscellaria. Guts of infected larvae were chemically fixed, embedded in epoxy resin, and sectioned for light and electron microscopy to describe the cytology of L. canadensis and its pathology in the larval host. Oocysts of L. canadensis are ingested by larval hemlock looper. Trophozoites emerge from the oocysts, pass through the peritrophic membrane into the ectoperitrophic space, and attach to the epithelium of the midgut by means of an apical epimerite. The epimerite does not actually penetrate the affected epithelial cell; instead, it causes an invagination of the plasma membrane of the cell. The center of the epimerite contains membrane cisternae, and mitochondria line its periphery. Microtubules and mitochondria in the host cell cytoplasm surround the epimerite. At the light microscopic level, there appeared to be septa between the epimerite and the protomerite and between the protomerite and the deutomerite; however, in the electron microscope, no septa were evident. Only differences in the concentrations and nature of the inclusions in the cytoplasms of these three regions were apparent. The deutomerite contains a single nucleus in the central-posterior area. After an undetermined period, the epimerite detaches from the host gut epithelium and is withdrawn into the protomerite, and the trophozoites float freely in the ectoperitrophic space before differentiating into gamonts. Division of the single, large nucleus into numerous small nuclei appears to occur prior to syzygy. Gamonts pair and a cyst wall is laid down around them, forming a gametocyst. Oocysts are extruded from mature gametocysts, in chains, through sporoducts.

Animals↗
PubMed2004

Characterization of humus microbial communities in adjacent forest types that differ in nitrogen availability.

To address the link between soil microbial community composition and soil processes, we investigated the microbial communities in forest floors of two forest types that differ substantially in nitrogen availability. Cedar-hemlock (CH) and hemlock-amabilis fir (HA) forests are both common on northern Vancouver Island, B.C., occurring adjacently across the landscape. CH forest floors have low nitrogen availability and HA high nitrogen availability. Total microbial biomass was assessed using chloroform fumigation-extraction and community composition was assessed using several cultivation-independent approaches: denaturing gradient gel electrophoresis (DGGE) of the bacterial communities, ribosomal intergenic spacer analysis (RISA) of the bacterial and fungal communities, and phospholipid fatty acid (PLFA) profiles of the whole microbial community. We did not detect differences in the bacterial communities of each forest type using DGGE and RISA, but differences in the fungal communities were detected using RISA. PLFA analysis detected subtle differences in overall composition of the microbial community between the forest types, as well as in particular groups of organisms. Fungal PLFAs were more abundant in the nitrogen-poor CH forests. Bacteria were proportionally more abundant in HA forests than CH in the lower humus layer, and Gram-positive bacteria were proportionally more abundant in HA forests irrespective of layer. Bacterial and fungal communities were distinct in the F, upper humus, and lower humus layers of the forest floor and total biomass decreased in deeper layers. These results indicate that there are distinct patterns in forest floor microbial community composition at the landscape scale, which may be important for understanding nutrient availability to forest vegetation.

Bacteria↗
PubMed1991

Responses of plants to simulated saline drift as affected by species and conditions of exposure.

In exposures to simulated saline drift generated from a 0.6% (w/w) chloride (Cl)-solution, under controlled environmental conditions, the median effective doses for the occurrence of any salt-induced foliar injury (expressed as microgCl cm(-2) deposited in six hours) were: 2.9 for Canada hemlock (Tsuga canadensis [L.] Carr.); 10.3 for white flowering dogwood (Cornus florida L.); 43.5 for potato (Solanum tubersum L. cv Superior); 44.2 for northern red oak (Quercus rubra L.); 65.1 for sweet corn (Zea mays L. cv Golden Cross Bantam); and, 123 for bush bean (Phaseolus vulgaris L. cv Pinto). Response of bean was a function of total deposition and independent of its rate with multiple (one per day) 6-h exposures but not with exposures less than 6 h where toxicity (per mass of Cl) increased with an increase in the rate of deposition. Toxicity of particles increased with an increase in the concentration of Cl in the solution (1.6 or 5.0% w/w) from which they were generated with bush bean but not with hemlock. Post-exposure periods that cycled between 50 and 855% relative humidity (RH) produced a greater incidence of salt-induced foliar injury than did a regime of constant 85% RH.

Journal Article↗
PubMed2005

Application of solid-phase extraction to quantitatively determine cyproconazole and tebuconazole in treated wood using liquid chromatography with UV detection.

Solid-phase extraction (SPE) procedures were developed to avoid interference during the quantitative determination of cyproconazole and tebuconazole co-existing in wood extractives. Five species of wood were used, Japanese cedar (Cryptomeria japonica), Japanese larch (Larix leptolepis), Yezo spruce (Picea jezoensis), Sakhalin fir (Abies sachalinensis), and western hemlock (Tsuga heterophylla). Methanol extractives from the heartwood of all wood samples, except western hemlock, interfered with the quantitative determination of cyproconazole and tebuconazole using liquid chromatography (LC) with UV detection (LC-UV). SPE with Oasis MCX was effective in avoiding this interference. This method also reduced the time and volume of mobile phase required for LC-UV, since wood extractives with long retention times were also removed.

Chromatography, Liquid↗
PubMed2005

Quantitative determination of benzalkonium chloride in treated wood by solid-phase extraction followed by liquid chromatography with ultraviolet detection.

Ammoniacal copper quat (ACQ) compound wood preservative is comprised of copper and quaternary ammonium compounds with benzalkonium chloride (BAC) as the active ingredient. Solid-phase extraction (SPE) followed by liquid chromatography with ultraviolet detection (LC-UV) was developed for quantitative determination of BAC in treated wood. Five species of wood were used, Japanese cedar (Cryptomeria japonica), Japanese larch (Larix leptolepis), Yezo spruce (Picea jezoensis), Sakhalin fir (Abies sachalinensis), and western hemlock (Tsuga heterophylla). BAC used in the present study was composed of 66% C12, 33% C14 and less than 1% C16. BAC was added to each wood species (500 mg) then extracted with HCl-ethanol (20 ml) and quantitatively determined with LC-UV (262 nm). Wood extractives from the heartwood of each species, except western hemlock, interfered with quantitative determination of BAC, but SPE with an Oasis MCX cartridge was effective in preventing this. Using the present methods, BAC homologue peaks were clearly confirmed without interference. Recoveries from wood ranged from 92 to 101% and the limit of quantitation was approximately 240 microg/g wood for the C12 and C14 homologues.

Abies↗
PubMed2000

Seedling insensitivity to ozone for three conifer species native to Great Smoky Mountains National Park.

Field symptoms typical of ozone injury have been observed on several conifer species in Great Smoky Mountains National Park, and tropospheric ozone levels in the Park can be high, suggesting that ozone may be causing growth impairment of these plants. The objective of this research was to test the ozone sensitivity of selected conifer species under controlled exposure conditions. Seedlings of three species of conifers, Table Mountain pine (Pinus pungens), Virginia pine (Pinus virginiana), and eastern hemlock (Tsuga canadensis), were exposed to various levels of ozone in open-top chambers for one to three seasons in Great Smoky Mountains National Park in Tennessee, USA. A combination of episodic profiles (1988) and modified ambient exposure regimes (1989-92) were used. Episodic profiles simulated an average 7-day period from a monitoring station in the Park. Treatments used in 1988 were: charcoal-filtered (CF), 1.0x ambient, 2.0x ambient, and ambient air-no chamber (AA). In 1989 a 1.5x ambient treatment was added, and in 1990, additional chambers were made available, allowing a 0.5x ambient treatment to be added. Height, diameter, and foliar injury were measured most years. Exposures were 3 years for Table Mountain pine (1988-90), 3 years for hemlock (1989-91), and 1 and 2 years for three different sets of Virginia pine (1990, 1990-91, and 1992). There were no significant (p<0.05) effects of ozone on any biomass fraction for any of the species, except for older needles in Table Mountain and Virginia pine, which decreased with ozone exposure. There were also no changes in biomass allocation patterns among species due to ozone exposure, except for Virginia pine in 1990, which showed an increase in the root:shoot ratio. There was foliar injury (chlorotic mottling) in the higher two treatments (1.0x and 2.0x for Table Mountain and 2.0x for Virginia pine), but high plant-to-plant variability obscured formal statistical significance in many cases. We conclude, at least for growth in the short-term, that seedlings of these three conifer species are insensitive to ambient and elevated levels of ozone, and that current levels of ozone in the Park are probably having minimal impacts on these particular species.

Journal Article↗
PubMed2006

Geographic biotype and host-associated local adaptation in a polyphagous species, Lambdina fiscellaria (Lepidoptera: Geometridae) feeding on balsam fir on Anticosti Island, Canada.

The debate about mechanisms underlying the evolution of host specialization by herbivorous insects remains open. Natural selection may act locally and lead to different patterns of geographic variation in life history traits of polyphagous herbivores. The hypothesis of genetically-based trade-offs in offspring performance on different hosts has been proposed but this has rarely been demonstrated. Under laboratory conditions, the biological performance of two populations of the hemlock looper Lambdina fiscellaria (Guenée), a highly polyphagous lepidopteran, was compared when reared on three different tree host species: balsam fir, eastern hemlock and sugar maple. One population originated from Anticosti Island, Québec, Canada, where the insect has evolved without having access to two of the three tree species tested, the other being from the mainland where all tree species are present. When reared on balsam fir foliage, which was naturally available to each population, larvae from Anticosti Island underwent four instars compared with five for the mainland population, indicating the existence of geographic biotypes in L. fiscellaria. When reared on the foliage of non-naturally available host trees, larvae from Anticosti Island had a higher incidence of supernumerary instars. This is a unique example where local adaptation to environmental conditions of an insect herbivore is expressed through a differential number of larval instars. Moreover, the Anticosti Island population showed a higher growth related index on the host available to both populations indicating that a fitness trade-off was the evolutionary process underlying the local adaptation of this population on balsam fir.

Abies↗
PubMed2003

Analysis of nrDNA sequences and microsatellite allele frequencies reveals a cryptic chanterelle species Cantharellus cascadensis sp. nov. from the American Pacific Northwest.

In the Pacific Northwest, yellow chanterelles have long been referred to as Cantharellus cibarius, synonymous with the European yellow chanterelle. Broad scale genetic surveys of North American chanterelles with C. cibarius-like morphology have demonstrated that the nrDNA internal transcribed spacer exhibits length variability, suggesting that this common morphology masks a species complex. Recently researchers have used morphological and genetic data to identify the yellow chanterelle most frequently harvested from American Pacific Northwest forests as C. formosus, a species once thought to be rare in the region. We present three genetic data sets and one morphological data set that characterize a previously undescribed, species of yellow chanterelle from the central Cascade Mountains of Oregon. Phylogenetic analyses of the nrDNA large subunit and ITS regions show that C. cascadensis sp. nov., along with two other yellow chanterelle taxa (C. cibarius var. roseocanus and European C. cibarius), are more closely related to white chanterelles (C. subalbidus) than they are to C. formosus. Data from five microsatellite loci provide evidence that C. formosus, C. subalbidus, and C. cascadensis sp. nov. do not interbreed when they co-occur spatially and temporally in Douglas fir-western hemlock forests. This demonstrates that these three sympatric chanterelles are biological species with boundaries congruent with those delineated by nrDNA phylogenetic clades. Morphological data indicate that the colour of the pileus and shape of the stipe can be used to separate fresh collections of the two yellow species now known to co-occur in Douglas fir-western hemlock forests in Oregon.

Alleles↗
PubMed2025

Chromosome scale genomes of two invasive Adelges species enable virtual screening for selective adelgicides.

Two invasive hemipteran adelgids are associated with widespread damage to several North American conifer species. Adelges tsugae, hemlock woolly adelgid, was introduced from Japan and reproduces parthenogenetically in North America, where it has rapidly decimated Tsuga canadensis and Tsuga caroliniana (the eastern and Carolina hemlocks, respectively). Adelges abietis, eastern spruce gall adelgid, introduced from Europe, forms distinctive pineapple-shaped galls on several native spruce species. While not considered a major forest pest, it weakens trees and increases susceptibility to additional stressors. Broad-spectrum insecticides that are often used to control adelgid populations can have off-target impacts on beneficial insects. Whole genome sequencing was performed on both species to aid in development of targeted solutions that may minimize ecological impact. Adelges abietis was sequenced using Illumina Linked-Read technology from 30 pooled individuals, with Hi-C scaffolding performed using data from a single individual collected from the same host plant. Adelges tsugae used Oxford Nanopore long-read sequencing from pooled nymphs. The assembled A. tsugae and A. abietis genomes, pooled from several parthenogenetic females, are 220.75 Mbp and 253.16 Mbp, respectively. Each consists of eight autosomal chromosomes, as well as two sex chromosomes (X1/X2), supporting the XX-XO sex determination system. The genomes are over 96% complete based on BUSCO assessment. Genome annotation identified 11,424 and 12,060 protein-coding genes in A. tsugae and A. abietis, respectively. Comparative analysis of proteins across 29 hemipteran species and 14 arthropod outgroups identified 31,666 putative gene families. Gene family evolution analysis with CAFE revealed lineage-specific expansions in immune-related aminopeptidases (ERAP1) and juvenile hormone binding proteins (JHBP), contractions in juvenile hormone acid methyltransferases (JHAMT), and conservation of nicotinic acetylcholine receptors (nAChR). These genes were explored as candidate families towards a long-term objective of developing adelgid-selective insecticides. Structural comparisons of proteins across seven focal species (Adelges tsugae, Adelges abietis, Adelges cooleyi, Rhopalosiphum maidis, Apis mellifera, Danaus plexippus, and Drosophila melanogaster) revealed high conservation of nAChR and ERAP1, while JHAMT exhibited species-specific structural divergence. The potential of JHAMT as a lineage-specific target for pest control was explored through virtual drug and pesticide screening.

adelgids↗
PubMed1984

Mycorrhizal effects on potassium fluxes by northwest coniferous seedlings.

In ectomycorrhizae, the relative abilities of mycobiont and host plant to take up and store inorganic nutrients are not easily determined due to the intimate physical relationship of the two components forming the association. Since compartmental analysis of solute elution can estimate cellular compartment pool sizes and unidirectional fluxes across membranes, we have used this method to study ectomycorrhizal coniferous roots. Rubidium-86, used as a tracer for potassium, was loaded into and eluted from intact roots of nonmycorrhizal and mycorrhizal (with the fungus Hebeloma crustuliniformme [Bull.: St. Amans Quél] Douglas fir (Pseudotsuga menziesii [Mirb.] Franco), western hemlock (Tsuga heterophylla [Raf.] Sarg.) and Sitka spruce (Picea sitchensis [Bong.] Carr.) seedlings.Mycorrhizas significantly increased (86)Rb uptake rates while decreasing the amount of (86)Rb released to the external solution. Using compartmental analysis, the flux data suggest that the primary mycorrhizal effects were to increase inward potassium fluxes across the fungal tonoplast and to decrease potassium efflux across the fungal tonoplast, as compared with nonmycorrhizal seedling roots. The result was greater potassium storage, presumably in the fungal vacuole. The three coniferous species responded differently to fungal infection with respect to potassium fluxes. Both cytoplasmic and vacuolar fluxes for mycorrhizal hemlock were 2-fold greater than for spruce and 3-fold greater than for Douglas fir. These results demonstrate the usefulness of compartmental analysis for study of ion fluxes in intact mycorrhizal root systems and suggest that the fungal tonoplast may be the site for regulation of potassium fluxes in these coniferous roots.

Journal Article↗
PubMed1994

Distribution of Borrelia burgdorferi in host mice in Pennsylvania.

Host mice (Peromyscus leucopus and Peromyscus maniculatus) were sampled throughout the state of Pennsylvania to determine the geographical and ecological distribution of the Lyme disease spirochete Borrelia burgdorferi. All 67 counties of the state were sampled. A total of 1,619 mice were captured from a total of 157 sites during the period 1990 to 1993 for an overall capture rate of 29.69%. A total of 112 (6.92%) isolations of B. burgdorferi were made. The distribution of isolations revealed the reason for the correlated distribution of human cases of Lyme disease in the state. Significantly more mice were captured and significantly more isolations were made from hemlock (Tsuga canadensis) habitat than from deciduous species forest. Nevertheless, high isolation rates from counties of the southeastern corner of the state illustrate well that hemlock habitat is not essential. Evidence suggests that in some areas, transmission between mice is occurring in some way other than through ticks as vectors. Host mice proved useful for determining the geographical and ecological distribution of B. burgdorferi.

Animals↗
PubMed2000

False expectations? Expectations vs. probabilities for dying.

It is widely recognized that the code of the physician has undergone dramatic changes in the last century--changes which have serious implications for the patient-physician relationship. This is an ethnographic study examining how certain changes in the role and abilities of biomedical physicians have affected patient attitudes and expectations about end-of-life care. In-home interviews were conducted with eighteen persons age fifty-five and older, including a sample of Hemlock Society members. Results indicate a broad spectrum of end-of-life concerns including capacity, autonomy, pain, and burden to loved ones. Most participants reported a reluctance to begin a discussion of death or future deteriorating capacity with their physicians. Instead, when conversations about death were reported, they had been largely limited to the scenarios of catastrophic illness (e.g., hospitalization, ventilator, etc.) and the Living Will. While this discussion does not overlook the utility of the Living Will, it proposes the reliance on this document for preparing patients for end-of-life care is inadequate.

Advance Care Planning↗
PubMedDate not supplied

Older women and mercy killing.

Mercy killing is usually defined as intentional killing, often by family members or friends, with the stated intent to end perceived suffering. International evidence suggests that mercy killing typically involves an older man killing his ailing wife. In this study, we examined U.S. cases of mercy killing recorded by The Hemlock Society for the period 1960-1993. We found that the typical case involved an older woman being killed by a man, often her husband, with her poor health as the justification for the killing. A firearm was often used in these incidents. These patterns of mercy killing are consistent with patterns of homicide-suicide among older adults. Future research should seek to understand why women are typically the targets, and men the agents of mercy killing.

Age Factors↗
PubMedDate not supplied

Spatial analysis of within-population microsatellite variability reveals restricted gene flow in the Pacific golden chanterelle (Cantharellus formosus).

We examined the within-population genetic structure of the Pacific golden chanterelle (Cantharellus formosus) in a 50 y old forest stand dominated by Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) with spatial autocorrelation analysis. We tested the null hypothesis that multilocus genotypes possessed by chanterelle genets were randomly distributed within the study area. Fruit bodies from 203 C. formosus genets were collected from a 50 ha study plot. One hundred six unique multilocus genotypes were identified after scoring these collections at five microsatellite loci. Statistically significant positive spatial autocorrelation was detected indicating the presence of fine-scale genetic structure within the area. Repeated autocorrelation analyses with varied minimum distance classes (50-500 m) detected positive spatial genetic structure up to 400 m. Therefore nonrandom evolutionary processes (e.g., isolation by distance) can cause fine-scale genetic structure in C. formosus. The implications of this research for future broad-scale population studies of this species are that population samples should be separated by at least 400 m to be considered statistically independent. Sampling designs that account for fine-scale genetic structure will better characterize heterogeneity distributed across the landscape by avoiding the effects of pseudo replication.

Basidiomycota↗
PubMed1995

Society needs MD-assisted death, Canadian-trained medical director of US right-to-die society says.

The growth of an American organization that supports the right to die is proof that the public wants and needs physician-assisted death, says a University of Alberta alumnus who is medical director of the Hemlock Society. Dr. Richard MacDonald says he believes individual patients have the right to decide whether they want to live with a certain quality of life. Both the American Medical Association and the CMA have spoken out against physician-assisted death, but MacDonald says this opposition is out of touch with the opinions of individual physicians and patients.

Attitude of Health Personnel↗