Effects of Urbanization on Bird Populations in the Canadian Central Arctic

Development of the Hamlet of Baker Lake (Qamani'tuaq) in the central Canadian Arctic during the 1950s was typical of the local urbanization that has occurred in Arctic regions during the latter half of the 20th century. The effects of urbanization on bird populations were examined by comparing populations before and after 1950, comparing populations in anthropogenic ecosystems with natural ones, and recording the presence or absence of exotic species usually associated with human dwellings and settlements. Of a total 60 local species, 21 had not been reported prior to 1950. Most of these were waterfowl, shorebirds, and gulls, all species that benefited from the presence of sewage lagoons and a refuse dump, or were associated with building sites (American robin). Semipalmated plovers were associated with gravel pits and gravel roadsides, whereas semipalmated sandpipers, Lapland longspurs, horned larks, Savannah sparrows, and white-crowned sparrows were most abundant in town. Vagrants from south of the tree line have been reported from the study site. It is hypothesized that climatic amelioration in association with the development of urban ecosystems may have encouraged migration overshoots in these species. These vagrants may be the early colonizers that eventually result in breeding range extensions, as has been observed in several waterfowl species, American robins, and white-throated sparrows. Twelve apparent species losses have occurred since 1950, but these are likely due to general scarcity or lack of observers rather than reduced abundance. No exotic "city" species, such as rock doves, European starlings, or house sparrows, have been recorded in Baker Lake. It is not anticipated that these species would become established or survive at Baker Lake in the near future, because of its isolation and severe winters.Au cours des années 1950, l'aménagement du hameau de Baker Lake (Qamani'tuaq) dans le centre de l'Arctique canadien était typique de l'urbanisation locale qui a eu cours dans les régions arctiques durant la dernière moitié du XXe siècle. On a étudié les répercussions de l'urbanisation sur les populations d'oiseaux en comparant des populations avant et après 1950, en comparant des populations au sein d'écosystèmes anthropiques avec celles d'écosystèmes naturels, et en consignant la présence ou l'absence d'espèces exotiques associées aux habitations et aux établissements humains. Sur un total de 60 espèces locales, 21 n'avaient pas été rapportées avant 1950. Celles-ci étaient composées pour la plupart de sauvagine, d'oiseaux de rivage et de mouettes, espèces qui bénéficiaient toutes de la présence d'étangs d'eaux usées et d'une décharge, ou qui étaient associées avec des chantiers de construction (merle d'Amérique). Les pluviers semipalmés étaient associés aux gravières et aux bords de routes en gravier, alors que les bécasseaux semipalmés, les bruants lapons, les alouettes hausse-col, les bruants des prés et les bruants à couronne blanche se concentraient dans la ville. On a mentionné la présence sur le site de l'étude d'oiseaux égarés venus du sud de la limite des arbres. On émet l'hypothèse que le réchauffement climatique joint à l'expansion d'écosystèmes urbains pourrait avoir favorisé chez ces espèces le prolongement migratoire. Ces oiseaux égarés pourraient être les premiers à coloniser une région qui finit par devenir une extension de leur territoire de reproduction, comme on a pu l'observer chez diverses espèces de sauvagine ainsi que chez le merle d'Amérique et le bruant à gorge blanche. Depuis 1950, il semble s'être produit une perte pour douze espèces, mais cela est probablement dû à une pénurie générale d'observateurs plutôt qu'à une diminution de population. À Baker Lake, on n'a enregistré aucune espèce exotique "des villes", telles que le pigeon biset, l'étourneau sansonnet ou le moineau domestique. On ne s'attend pas à ce que ces espèces s'établissent ou survivent à Baker Lake dans un futur proche, en raison de l'isolation du lieu et de la rigueur de l'hiver

Underwater Archaeology

An overview of 'Underwater Archaeology'. The article covers a number of key themes in underwater archaeology i.e. methodology and techniques, effects of the environment, sites and structures, artifact conservation, curation, and publication

Herbicides for Trefoil Seedings?

Birdsfoot trefoil is an important legume in many parts of Iowa for improving permanent pastures. No other pasture legume now available compares with birdsfoot trefoil in its ability to withstand continuous grazing. Once established, stands may be expected to furnish high-quality pasture for many years

Narcolepsy and Cataplexy – a practical approach to diagnosis and managing the impact of this chronic condition on children and their families

Narcolepsy is a relatively common neurological condition affecting the regulation of normal sleep/wake cycles leading to excessive daytime sleepiness (EDS). It is almost certainly under-recognised as it has a prevalence of 20–50 per 100,000 population and most cases have an onset in adolescence. Cataplexy (attacks of muscle weakness often precipitated by strong emotions) is a hallmark of this condition and represents the intrusion of REM sleep into wakefulness. Narcolepsy is caused by destruction of hypocretin producing cells due to an autoimmune process often by an infective trigger. Hypocretin is found in the hypothalamus and plays a role in stabilisation of the transition between wake and sleep states. In establishing a diagnosis a comprehensive history to exclude other causes of EDS, including poor sleep habits, is essential. Primary sleep related conditions such as sleep apnoea should be excluded. Investigations for confirmation of the diagnosis include Actigraphy, Polysomnography (PSG), Multiple Sleep Latency Testing (MSLT) and CSF analysis. The symptoms of this debilitating condition can have a huge impact on a child's life and are often vastly underestimated. The impact of EDS on cognitive function is an important factor in difficulties at school, mood, quality of life and future career opportunities. Advances in understanding the pathophysiology have led to trials of novel treatment approaches. The aim of this article is to briefly summarise the recent advances in understanding and give an overview of this important condition for those who are involved in the care of a child with this disease

New Records of Vascular Plants in the Yukon Territory V

Based on field reconnaissance in 2000 and 2001 throughout Yukon but particularly in the areas of the Upper Bonnet Plume River, Wind River, Eagle Plains and Vuntut National Park, information is provided on geographically significant plant occurrences. Three native taxa, Draba kananaskis, Hieracium albiflorum and Prunella vulgaris ssp. lanceolata and five introduced taxa, Alopecurus geniculatus, Dactylis glomerata, Elymus junceus, Lotus corniculatus, and Verbena hastata are reported new to the known flora of the Yukon Territory. Signifigant range extensions for 190 native and 24 introduced taxa are included. Maianthemum dilatatum is excluded from the Yukon flora

Torsional motion of the chromophore catechol following the absorption of ultraviolet light

The ability to probe energy flow in molecules, following the absorption of ultraviolet light, is crucial to unraveling photophysical phenomena. Here we excite a coherent superposition of vibrational states in the first excited electronic state (S1) in catechol, resulting in a vibrational wave packet. The observed quantum beats, assigned to superpositions of the low-frequency, and strongly mixed, O–H torsional mode τ2, elegantly demonstrate how changes in geometry upon photoionization from the S1 state to the ground state of the cation (D0) enables one to probe energy flow at the very early stages of photoexcitation in this biological chromophore

A Randomised, Blinded, Placebo-Controlled, Dose Escalation Study of the Tolerability and Efficacy of Filgrastim for Haemopoietic Stem Cell Mobilisation in Patients With Severe Active Rheumatoid Arthritis

Autologous haemopoietic stem cell transplantation (HSCT) represents a potential therapy for severe rheumatoid arthritis (RA). As a prelude to clinical trails, the safety and efficacy of haemopoietic stem cell (HSC) mobilisation required investigation as colony-stimulating factors (CSFs) have been reported to flare RA. A double-blind, randomised placebo-controlled dose escalation study was performed. Two cohorts of eight patients fulfilling strict eligibility criteria for severe active RA (age median 40 years, range 24-60 years; median disease duration 10.5 years, range 2-18 years) received filgrastim (r-Hu-methionyl granulocyte(G)-(SF) at 5 and 10 microg/kg/day, randomised in a 5:3 ratio with placebo. Patients were unblinded on the fifth day of treatment and those randomised to filgrastim underwent cell harvesting (leukapheresis) daily until 2 X 10^6/kg CD34+ cells (haemopoietic stem and progenitor cells) were obtained. Patients were assessed by clinical and laboratory parameters before, during and after filgrastim administration. RA flare was defined as an increase of 30% or more in two of the following parameters: tender joint count, swollen joint count or pain score. Efficacy was assessed by quantitation of CD34+ cells and CFU-GM. One patient in the 5 microg/kg/day group and two patients in the 10 microg/kg/day group fulfilled criteria for RA flare, although this did not preclude successful stem cell collection. Median changes in swollen and tender joint counts were not supportive of filgrastim consistently causing exacerbation of disease, but administration of filgrastim at 10 microg/kg/day was associated with rises in median C-reactive protein and median rheumatoid factor compared with placebo. Other adverse events were well recognised for filgrastim and included bone pain (80%) and increases in alkaline phosphatase (four-fold) and lactate dehydrogenase (two-fold). With respect to efficacy, filgrastim at 10 microg/kg/day was more efficient with all patients (n = 5) achieving target CD34+ cell counts with a single leukapheresis (median = 2.8, range = 2.3-4.8 X 10^6/kg, median CFU-GM = 22.1, range = 4.2-102.9 X 10^4/kg), whereas 1-3 leukaphereses were necessary to achieve the target yield using 5 microg/kg/day. We conclude that filgrastim may be administered to patients with severe active RA for effective stem cell mobilisation. Flare of RA occurs in a minority of patients and is more likely with 10 than 5 microg/kg/day. However, on balance, 10 microg/kg/day remains the dose of choice in view of more efficient CD34+ cell mobilisation

Extreme population inversion in the fragments formed by UV photoinduced S-H bond fission in 2-thiophenethiol

H atom loss following near ultraviolet photoexcitation of gas phase 2-thiophenethiol molecules has been studied experimentally, by photofragment translational spectroscopy (PTS) methods, and computationally, by ab initio electronic structure calculations. The long wavelength (277.5 ≥ λphot ≥ 240 nm) PTS data are consistent with S–H bond fission after population of the first 1πσ* state. The partner thiophenethiyl (R) radicals are formed predominantly in their first excited Ã2A′ state, but assignment of a weak signal attributable to H + R([X with combining tilde]2A′′) products allows determination of the S–H bond strength, D0 = 27 800 ± 100 cm−1 and the Ö[X with combining tilde] state splitting in the thiophenethiyl radical (ΔE = 3580 ± 100 cm−1). The deduced population inversion between the à and [X with combining tilde] states of the radical reflects the non-planar ground state geometry (wherein the S–H bond is directed near orthogonal to the ring plane) which, post-photoexcitation, is unable to planarise sufficiently prior to bond fission. This dictates that the dissociating molecules follow the adiabatic fragmentation pathway to electronically excited radical products. π* ← π absorption dominates at shorter excitation wavelengths. Coupling to the same 1πσ* potential energy surface (PES) remains the dominant dissociation route, but a minor yield of H atoms attributable to a rival fragmentation pathway is identified. These products are deduced to arise via unimolecular decay following internal conversion to the ground (S0) state PES via a conical intersection accessed by intra-ring C–S bond extension. The measured translational energy disposal shows a more striking change once λphot ≤ 220 nm. Once again, however, the dominant decay pathway is deduced to be S–H bond fission following coupling to the 1πσ* PES but, in this case, many of the evolving molecules are deduced to have sufficiently near-planar geometries to allow passage through the conical intersection at extended S–H bond lengths and dissociation to ground ([X with combining tilde]) state radical products. The present data provide no definitive evidence that complete ring opening can compete with fast S–H bond fission following near UV photoexcitation of 2-thiophenethiol

High Prevalence of Pre-Existing Liver Abnormalities Identified Via Autopsies in COVID-19: Identification of a New Silent Risk Factor?

A high prevalence of hepatic pathology (in 17 of 19 cases) was reported in post-mortem (PM) examinations of COVID-19 patients, undertaken between March 2020 and February 2021 by a single autopsy pathologist in two English Coronial jurisdictions. The patients in our cohort demonstrated high levels of recognised COVID-19 risk factors, including hypertension (8/16, 50%), type 2 diabetes mellitus (8/16, 50%) and evidence of arteriopathy 6/16 (38%). Hepatic abnormalities included steatosis (12/19; 63%), moderate to severe venous congestion (5/19; 26%) and cirrhosis (4/19; 21%). A subsequent literature review indicated a significantly increased prevalence of steatosis (49%), venous congestion (34%) and cirrhosis (9.3%) in COVID-19 PM cases, compared with a pre-pandemic PM cohort (33%, 16%, and 2.6%, respectively), likely reflecting an increased mortality risk in SARS-CoV-2 infection for patients with pre-existing liver disease. To corroborate this observation, we retrospectively analysed the admission liver function test (LFT) results of 276 consecutive, anonymised COVID-19 hospital patients in our centre, for whom outcome data were available. Of these patients, 236 (85.5%) had significantly reduced albumin levels at the time of admission to hospital, which was likely indicative of pre-existing chronic liver or renal disease. There was a strong correlation between patient outcome (length of hospital admission or death) and abnormal albumin at the time of hospital admission (p = 0.000012). We discuss potential mechanisms by which our observations of hepatic dysfunction are linked to a risk of COVID-19 mortality, speculating on the importance of recently identified anti-interferon antibodies