Wildfire facilitates upslope advance in a shade-intolerant but not a shade-tolerant conifer.

Wildfires may facilitate climate tracking of forest species moving upslope or north in latitude. For subalpine tree species, for which higher elevation habitat is limited, accelerated replacement by lower elevation montane tree species following fire may hasten extinction risk. We used a dataset of postfire tree regeneration spanning a broad geographic range to ask whether the fire facilitated upslope movement of montane tree species at the montane-to-subalpine ecotone. We sampled tree seedling occurrence in 248 plots across a fire severity gradient (unburned to >90% basal area mortality) and spanning ~500 km of latitude in Mediterranean-type subalpine forest in California, USA. We used logistic regression to quantify differences in postfire regeneration between resident subalpine species and the seedling-only range (interpreted as climate-induced range extension) of montane species. We tested our assumption of increasing climatic suitability for montane species in subalpine forest using the predicted difference in habitat suitability at study plots between 1990 and 2030. We found that postfire regeneration of resident subalpine species was uncorrelated or weakly positively correlated with fire severity. Regeneration of montane species, however, was roughly four times greater in unburned relative to burned subalpine forest. Although our overall results contrast with theoretical predictions of disturbance-facilitated range shifts, we found opposing postfire regeneration responses for montane species with distinct regeneration niches. Recruitment of shade-tolerant red fir declined with fire severity and recruitment of shade-intolerant Jeffrey pine increased with fire severity. Predicted climatic suitability increased by 5% for red fir and 34% for Jeffrey pine. Differing postfire responses in newly climatically available habitats indicate that wildfire disturbance may only facilitate range extensions for species whose preferred regeneration conditions align with increased light and/or other postfire landscape characteristics.

Effects of postfire climate and seed availability on postfire conifer regeneration.

Large, severe fires are becoming more frequent in many forest types across the western United States and have resulted in tree mortality across tens of thousands of hectares. Conifer regeneration in these areas is limited because seeds must travel long distances to reach the interior of large burned patches and establishment is jeopardized by increasingly hot and dry conditions. To better inform postfire management in low elevation forests of California, USA, we collected 5-yr postfire recovery data from 1,234 study plots in 19 wildfires that burned from 2004-2012 and 18 yrs of seed production data from 216 seed fall traps (1999-2017). We used these data in conjunction with spatially extensive climate, topography, forest composition, and burn severity surfaces to construct taxon-specific, spatially explicit models of conifer regeneration that incorporate climate conditions and seed availability during postfire recovery windows. We found that after accounting for other predictors both postfire and historical precipitation were strong predictors of regeneration, suggesting that both direct effects of postfire moisture conditions and biological inertia from historical climate may play a role in regeneration. Alternatively, postfire regeneration may simply be driven by postfire climate and apparent relationships with historical climate could be spurious. The estimated sensitivity of regeneration to postfire seed availability was strongest in firs and all conifers combined and weaker in pines. Seed production exhibited high temporal variability with seed production varying by over two orders of magnitude among years. Our models indicate that during droughts postfire conifer regeneration declines most substantially in low-to-moderate elevation forests. These findings enhance our mechanistic understanding of forecasted and historically documented shifts in the distribution of trees.

Prenatal aromatase inhibition alters postnatal immunity in domestic chickens (Gallus gallus).

In birds, exposure to exogenous testosterone during embryonic development can suppress measures of immune function; however, it is unclear whether these effects are due to direct or indirect action via aromatization. Estradiol (E2) is synthesized from testosterone by the enzyme aromatase, and this conversion is a necessary step in many signaling pathways that are ostensibly testosterone-dependent. Many lines of evidence in mammals indicate that E2 can affect immune function. We tested the hypothesis that some of the immunomodulatory effects observed in response to in ovo testosterone exposure in birds are mediated by conversion to E2 by aromatase, by using fadrozole to inhibit aromatization of endogenous testosterone during a crucial period of embryonic immune system development in domestic chickens (Gallus gallus). We then measured total IgY antibody count, response to PHA challenge, mass of thymus and bursa of Fabricius, and plasma testosterone post-hatch on days 3 and 18. Because testosterone has a reputation for immunosuppression, we predicted that if modulation of an immune measure by testosterone is dependent on aromatization, then inhibition of estrogen production by fadrozole treatment would lead to elevated measures of that parameter. Conversely, if testosterone inhibits an immune measure directly, then fadrozole treatment would likely not alter that parameter. Fadrozole treatment reduced circulating E2 in female embryos, but had no effect on males or on testosterone in either sex. Fadrozole-treated chicks had decreased day 3 plasma IgY antibody titers and a strong trend towards increased day 18 thymic mass. Furthermore, fadrozole treatment generated a positive relationship between testosterone and thymic mass in males, and tended to increase day 18 IgY levels for a given bursal mass in females. There was no effect on PHA response, bursal mass, or plasma testosterone at either age post-hatch. The alteration of several indicators of immune function in fadrozole-treated chicks implicates aromatization as a relevant pathway through which developmental exposure to testosterone can affect immunity in birds.

Effects of the Presser and legislative criteria on classifying New Zealand's fitness to stand trial court outcomes.

New Zealand's legislation mandates the inclusion of several legislative criteria to assist in the determination of defendants' fitness to stand trial (FTST). However, the unlegislated Presser criteria have been described as useful to discriminate between defendants' fitness without formal research to identify them as such. The sample consisted of 252 defendants' FTST forensic assessments between 2005 and 2015 with a mean age of 30.1 years, where 87.7% were male. Defendants were primarily from Maori descent (37.3%), New Zealand European (34.1%) and Pacific Island descent (17.9%). The authors found that all Presser and legislative criteria significantly predicted whether the defendant was fit to stand trial (FST). Both the Presser and legislative criteria have excellent area under the curve (AUC) statistics. However, the Presser criteria, compared to the legislative criteria, improved specificity of court judgements. The Presser criteria may therefore assist in correct FTST court decisions, particularly for borderline-fit defendants.

Life on the edge-a changing genetic landscape within an iconic American pika metapopulation over the last half century.

Declines and extirpations of American pika (Ochotona princeps) populations at historically occupied sites started being documented in the literature during the early 2000s. Commensurate with global climate change, many of these losses at peripheral and lower elevation sites have been associated with changes in ambient air temperature and precipitation regimes. Here, we report on a decline in available genetic resources for an iconic American pika metapopulation, located at the southwestern edge of the species distribution in the Bodie Hills of eastern California, USA. Composed of highly fragmented habitat created by hard rock mining, the ore dumps at this site were likely colonized by pikas around the end of the 19th century from nearby natural talus outcrops. Genetic data extracted from both contemporary samples and archived natural history collections allowed us to track population and patch-level genetic diversity for Bodie pikas across three distinct sampling points during the last half- century (1948-1949, 1988-1991, 2013-2015). Reductions in within-population allelic diversity and expected heterozygosity were observed across the full time period. More extensive sampling of extant patches during the 1988-1991 and 2013-2015 periods revealed an increase in population structure and a reduction in effective population size. Furthermore, census records from the last 51 years as well as archived museum samples collected in 1947 from a nearby pika population in the Wassuk range (Nevada, USA) provide further support of the increasing isolation and genetic coalescence occurring in this region. This study highlights the importance of museum samples and long-term monitoring in contextualizing our understanding of population viability.

Habitat restoration opportunities, climatic niche contraction, and conservation biogeography in California's San Joaquin Desert.

A recent global trend toward retirement of farmland presents opportunities to reclaim habitat for threatened and endangered species. We examine habitat restoration opportunities in one of the world's most converted landscapes, California's San Joaquin Desert (SJD). Despite the presence of 35 threatened and endangered species, agricultural expansion continues to drive habitat loss in the SJD, even as marginal farmland is retired. Over the next decades a combination of factors, including salinization, climate change, and historical groundwater overdraft, are projected to lead to the retirement of more than 2,000 km2 of farmland in the SJD. To promote strategic habitat protection and restoration, we conducted a quantitative assessment of habitat loss and fragmentation, habitat suitability, climatic niche stability, climate change impacts, habitat protection, and reintroduction opportunities for an umbrella species of the SJD, the endangered blunt-nosed leopard lizard (Gambelia sila). We use our suitability models, in conjunction with modern and historical land use maps, to estimate the historical and modern rate of habitat loss to development. The estimated amount of habitat lost since the species became protected under endangered species law in 1967 is greater than the total amount of habitat currently protected through public ownership and conservation easement. We document climatic niche contraction and associated range contraction away from the more mesic margins of the species' historical distribution, driven by the anthropogenic introduction of exotic grasses and forbs. The impact of exotic species on G. sila range dynamics appears to be still unfolding. Finally, we use NASA fallowed area maps to identify 610 km2 of fallowed or retired agricultural land with high potential to again serve as habitat. We discuss conservation strategies in light of the potential for habitat restoration and multiple drivers of ongoing and historical habitat loss.

Apparent climate-mediated loss and fragmentation of core habitat of the American pika in the Northern Sierra Nevada, California, USA.

Contemporary climate change has been widely documented as the apparent cause of range contraction at the edge of many species distributions but documentation of climate change as a cause of extirpation and fragmentation of the interior of a species' core habitat has been lacking. Here, we report the extirpation of the American pika (Ochotona princeps), a temperature-sensitive small mammal, from a 165-km2 area located within its core habitat in California's Sierra Nevada mountains. While sites surrounding the area still maintain pikas, radiocarbon analyses of pika fecal pellets recovered within this area indicate that former patch occupancy ranges from before 1955, the beginning of the atmospheric spike in radiocarbon associated with above ground atomic bomb testing, to c. 1991. Despite an abundance of suitable rocky habitat climate warming appears to have precipitated their demise. Weather station data reveal a 1.9°C rise in local temperature and a significant decline in snowpack over the period of record, 1910-2015, pushing pika habitat into increasingly tenuous climate conditions during the period of extirpation. This is among the first accounts of an apparently climate-mediated, modern extirpation of a species from an interior portion of its geographic distribution, resulting in habitat fragmentation, and is the largest area yet reported for a modern-era pika extirpation. Our finding provides empirical support to model projections, indicating that even core areas of species habitat are vulnerable to climate change within a timeframe of decades.

A novel polymeric coating for enhanced ultrasound visibility of medical devices.

A dynamic novel coating, consisting of a hydrophilic polymeric matrix and a bubbling agent, has been developed for precise entry and positioning of needles, and accurate collection of biopsy samples. These coated biopsy needles have been successfully used in in vitro trials. The results are discussed here. Potential application areas include vascular, cardiovascular and orthopaedics.

Contemporary Drought and Future Effects of Climate Change on the Endangered Blunt-Nosed Leopard Lizard, Gambelia sila.

Extreme weather events can provide unique opportunities for testing models that predict the effect of climate change. Droughts of increasing severity have been predicted under numerous models, thus contemporary droughts may allow us to test these models prior to the onset of the more extreme effects predicted with a changing climate. In the third year of an ongoing severe drought, surveys failed to detect neonate endangered blunt-nosed leopard lizards in a subset of previously surveyed populations where we expected to see them. By conducting surveys at a large number of sites across the range of the species over a short time span, we were able to establish a strong positive correlation between winter precipitation and the presence of neonate leopard lizards over geographic space. Our results are consistent with those of numerous longitudinal studies and are in accordance with predictive climate change models. We suggest that scientists can take immediate advantage of droughts while they are still in progress to test patterns of occurrence in other drought-sensitive species and thus provide for more robust models of climate change effects on biodiversity.

Transjugular portosystemic shunts in pediatric patients awaiting liver transplantation.

Three pediatric patients from 6 to 11 years of age awaiting liver transplantation for end stage liver disease underwent transjugular intrahepatic portosystemic shunt (TIPS) placement for control of variceal bleeding. Two of the three procedures were performed emergently after endoscopic sclerotherapy failed to stop active bleeding. One procedure was performed electively after multiple prior bleeding episodes. The shunts were created from the middle or left hepatic vein to the left portal vein, and none of the subsequent transplant surgeries was complicated by the presence of the stents. No major or minor complications were related to TIPS placement. Two patients underwent concomitant variceal embolization. Bleeding was successfully controlled in each patient. We conclude that TIPS placement in children is technically feasible, does not complicate subsequent surgery, and is useful treating acute variceal hemorrhage in pediatric patients awaiting liver transplantation.

Quantification of temocillin biliary excretion and gallbladder bile concentration in healthy subjects.

The techniques of duodenal perfusion with polyethylene glycol as a nonabsorbable marker, and cholescintiscan using 99Tc HIDA as a gallbladder bile marker, were used to measure the total duodenal output and gallbladder bile concentration of temocillin after administration of an intravenous bolus injection to each of 6 healthy subjects. We carried out 8 studies. 3 with 0.5g temocillin and 5 with 1g temocillin. The plasma half-life of temocillin was 177 (+/- 25) minutes [mean (+/- SD)] and 196 (+/- 29) minutes with the 0.5g and 1g doses, respectively. Urinary excretion accounted for 38% of the total dose given during the study period of 6 hours, and total biliary excretion was recorded as 2.2% of the given dose for both doses. The mean concentration of temocillin in gallbladder bile was 314.7 (+/- 273.2) mg/L after the 0.5g dose and 474.5 (+/- 307.3) mg/L after 1g dose. It was concluded that temocillin is highly concentrated in the normal gallbladder in man.

Review article: quantitative leucocyte scanning in the assessment of inflammatory bowel disease activity and its response to therapy.

Inflammatory bowel disease (IBD) symptoms may be due not only to the effects of bowel inflammation, but also can result from many non-inflammatory consequences of the disease. Clinical scores and health questionnaire ratings produce a global assessment which is useful in the overall evaluation of the impact of the illness on the patient, and the effect of treatment. However many studies have failed to recognize the need to separately assess changes in the degree of bowel inflammation, in addition to a global clinical response. Radiolabelled white cell scanning using 111-indium has been shown to provide an accurate, quantitative and non-invasive method for assessing the degree of bowel inflammation in IBD and its response to therapy, using faecal collection or total body counts of radioactivity. More recently 99mTc hexamethyl propylene amine oxime (HMPAO) labelled white cell scanning has been introduced, which has advantages over the 111-indium method, including reduced radiation dosimetry and enhanced image quality. 99mTc-HMPAO scanning using three-dimensional white cell scanning (single photon emission computerized tomography; SPECT) allows visualization of the entire bowel separate from overlying structures. 99mTc-HMPAO white cell scanning with SPECT has now been computerized and automated to permit measurement of segmental and total bowel radiolabelled white cell infiltrate. This method could potentially provide the gold standard for objective assessment of the response of disease activity in Crohn's disease and ulcerative colitis, and merits application in clinical trials of novel therapies for IBD.

Quadruple antimycobacterial chemotherapy in Crohn's disease: results at 9 months of a pilot study in 20 patients.

Twenty patients with active Crohn's disease, the majority refractory to conventional therapy, were treated with rifampicin, ethambutol, isoniazid, and pyrazinamide or clofazamine for 9 months. After this period, 10 were in remission (Crohn's disease activity index less than 150). Of the 10 not in remission, three had been at 6 months, but had relapsed on treatment. Nine of 10 patients on steroids at the beginning were off steroids at 9 months. Six patients came to surgery during the period, five for stricture formation without evidence of florid Crohn's disease outside the strictured segment. Three young patients with severe Crohn's disease facing total colectomy were spared surgery. No serious drug-related side-effects were encountered. The results of this pilot study suggest that controlled trials of antimycobacterial chemotherapy, using four or more of the best agents available, are worthy of assessment in Crohn's disease.

A narrow range, medium molecular weight pentastarch reduces structural organ damage in a hyperdynamic porcine model of sepsis.

OBJECTIVE: to compare diafiltered 6% pentastarch (Pentafraction--PDP, MWn 120,000 and MWw 280,000) and native pentastarch (Pentaspan--PSP, MWn 63,000 and MWw 264,000 dalton) in a porcine model of faecal peritonitis. DESIGN: Randomised prospective study in 12 adolescent pigs. INTERVENTIONS: Prior to infection the study solution was infused to increase Qt by 25%. Thereafter adjustments in infusion rate were made (up to 1 l/h) in an attempt to maintain Qt at 25% above baseline values. MEASUREMENTS AND RESULTS: Animals were sacrificed at 8 h. Tissue was excised from the right lobe of liver and from the right lung and fixed for later electron microscopy and digital morphometric analysis. Patent sinusoidal lumen was significantly greater in group PDP compared to PSP (11.3% +/- 2.3% of liver tissue versus 4.8% +/- 1.1%, p < 0.05) and this was accounted for by a significantly lower proportion of sinusoidal lumen occluded with white cells (2.1% +/- 0.6% versus 6.6% +/- 1.9%, p < 0.05). Similarly, patent capillary represented a significantly higher proportion of lung tissue for group PDP versus PSP (26.2% +/- 1.9% versus 18.5% +/- 2.7%, p < 0.05). The arithmetic mean alveolar capillary barrier thickness was significantly greater in group PSP than in group PDP (4.3 +/- 0.3 microns versus 2.5 +/- 0.3 microns, p < 0.01). CONCLUSIONS: The molecular weight profile of Pentafraction was associated with less structural organ damage including less tissue oedema and less white cell occlusion.

A preliminary clinical study of gossypol in advanced human cancer.

A total of 34 patients with advanced cancer were given weekly or daily escalating doses of oral gossypol, a cottonseed-oil constituent showing evidence of antineoplastic activity in pre-clinical studies. No major adverse events occurred and there was no evidence of haematological or biochemical disturbance. As determined by dose escalation in 17 patients, the dose-limiting toxicity was emesis in 16 patients. There was no evidence of tumour regression in any of the 20 patients assessed for response. We conclude that gossypol is safe but unlikely to be clinically useful in patients with advanced cancer.

Direct assessment of the mechanism for a raised serum bile acid level in chronic liver disease.

BACKGROUND: Impaired hepatic uptake is the major cause of raised serum bile acid levels in liver disease, but confirmation in humans by direct measurement is lacking. The synthetic gamma-labelled bile acid 75Se-homocholic acid taurine (75SeHCAT) provides a tool for the direct measurement of hepatic bile acid handling. OBJECTIVE: To determine the interrelationships among hepatic handling of 75SeHCAT, the kinetics of its disappearance from plasma and serum bile acid levels in patients with chronic liver disease. DESIGN: We studied 12 patients with primary biliary cirrhosis and 14 with cirrhosis arising from other causes. Fasting serum bile acid levels were measured enzymatically. After intravenous administration of 75SeHCAT, we determined plasma disappearance rates (initial K1, late K2) from serial blood samples and hepatic uptake and excretory rates directly from dynamic abdominal gamma-camera scanning. Both scanning and sampling were carried out over a period of 90 min. RESULTS: Serum bile acid concentrations correlated with K1 and with hepatic uptake (Rs = -0.53, P < 0.01; Rs = -0.47, P < 0.02, respectively) but neither with K2 nor with the excretory rate. K1 and uptake were reduced (P < 0.05) in patients with high serum bile acid levels and in those with varices. Serum bile acid levels were higher in patients with varices (P < 0.05), which might suggest that portosystemic shunting occurred. However, this is unlikely because the varices were not independent of liver function. CONCLUSION: Hepatic bile acid uptake and excretion are independent processes. Hepatic uptake is related to initial, whereas hepatic excretion is related to late, plasma disappearance. Impaired hepatic uptake is a major determinant of the rise in serum bile acid levels in chronic liver disease.

Casey House: interpreting the location of a Toronto AIDS hospice.

This paper focuses on an overtly geographical issue, the introduction of a housing facility for people living with AIDS (PLWAs) into the urban landscape. Specifically, we critically analyze the location of Casey House, an AIDS hospice in Toronto and presently the only facility of its kind in Canada. Three questions are addressed: (i) how did Casey House come to exist?; (ii) why is Casey House located at the corner of Huntly Street and Isabella Street?; and (iii) will Casey House be reproduced? In our response to the first two questions, we draw selectively upon three perspectives (accessibility, structuralist and humanistic) that have been appealed to in analyses of (controversial) health care facility location processes. In the concluding discussion, three relevant spheres of reproduction are considered: locational, institutional and social. In consideration of the obvious constraints on reproduction, we conclude that the creation and location of Casey House may well be a unique geographical event in Canada.

Regional and welfare perspectives on the public-private hospital dichotomy in New Zealand.

Concern with the social welfare implications of dual (public and private) hospital systems has grown over the last decade as national commitments to welfare state ideals have wavered in the continuing atmosphere of fiscal conservatism that has permeated through western democracies. New Zealand provides an excellent example of a health care system in which private hospitals have survived (and recently flourished) alongside those provided by the state. Following a brief survey of the evolution of the New Zealand hospital system, variations in the 'mix' of public and private hospitals are described at the (regional) Hospital Board District level. It is noted that competition for patients and funding between the public and private sectors occurs almost exclusively in the larger, urban hospital districts, and is invariably to the detriment of public hospitals. Districts with a substantial private hospital presence are found to have fewer resources in the public sector (relative to their population) than those which have few or no private hospitals. The welfare implications of this situation are explored. It is proposed that the maintenance of a dual hospital system in New Zealand has provided, in some parts of the country at least, a 'choice' for those able to afford private hospital charges or insurance coverage, but at the expense of those dependent solely upon a (shrinking) public sector.

Space in its place: developing the link in medical geography.

This paper argues that a re-examination of the interrelationship between constructs of place and space is crucial to geography's involvement in the broader endeavour of health research. Place has re-emerged as nexus of ascribed meaning within contemporary social theory. Places, however, are related in space, by distance or proximity. The distinction needs to be made between this orthodox (geometric) view of space and two types of social space: the (experienced) space described by humanist geographers; and the more recent (socio-spatial) conceptualization which is both experienced and (re)produced by societal structures and advocated by social theorists in geography. We argue that advancing a recursive understanding of space and place is an appropriate direction in medical geography. This direction will include both an understanding of the ways in which space shapes the character of places and how the particularities of places resist or set in motion (orthodox) spatial processes. Illustrations are drawn from studies of mental illness and mental health care and primary health care in a remote area of New Zealand.

On the use of socio-demographic indicators in local health planning: a Canadian non-metropolitan perspective.

This paper argues that the use of socio-demographic indicators to represent actual or potential demand for mental health services needs to be informed by knowledge of local settlement conditions and trends. Following a selective review of the literature on the use of socio-demographic indicators in mental health care planning and on the spatial ecology of mental illness, a case study of a non-metropolitan jurisdiction in southern Ontario, Canada is presented. The results of a regression-based analysis reveal a strong association between the socio-demographic composition of populations and hospitalization rates for mental illness. The pattern of correlates appears to be underlain by residential location processes that 'filter' populations on the basis of age and socio-economic status. It is concluded that, in the absence of this knowledge of local social geography, applications of indicators methodologies run the risk of being 'black boxes'.