The effects of fire on a population of Red-winged Fairy-wrens Malurus elegans in Karri forest in southwestern Australia

1998 ◽  
Vol 4 (3) ◽  
pp. 197 ◽  
Author(s):  
E. Russell ◽  
I. Rowley

In April 1994, an intense fire burnt part of Smith's Brook Nature Reserve near Manjimup, Western Australia where we had studied an individually marked population of the Red-winged Fairy-wren Malurus elegans in Karri Eucalyptus diversicolor forest since 1980. We estimated the population size in a 25 ha area at the start of the breeding season each year 1980?95, including two years post-fire. In the 32 territories present in 1993, the entire area of 26 was almost completely burnt to a height of 10 m, with few remaining unburnt patches. The mean population size for the 13 years 1981?93 was 119 birds in a mean of 29 groups. In November 1993, 126 birds were present in 32 groups. In November 1994, following the April fire, there were 114 birds in 31 groups, but nesting substrate was very scarce, breeding was delayed, and only 0.18 yearling males per group were produced, compared with 0.52 for the years 1981?93. By November 1995, the population had fallen to 73 birds in 23 groups with nine territories vacant. The time necessary for the population to recover to its prefire level was estimated from long-term demographic data to be at least 10 years, longer than the present cycle of 7?9 years for prescribed burns in the southern (Karri) State Forests of Western Australia.

2014 ◽  
Vol 14 (3) ◽  
pp. 230-233 ◽  
Author(s):  
Hideki Ogiwara ◽  
Kodai Uematsu ◽  
Nobuhito Morota

Object Endoscopic choroid plexus coagulation (CPC) with or without endoscopic third ventriculostomy (ETV) has been shown to be effective for selected patients with hydrocephalus. However, whether the effect of the coagulation is temporary and the choroid plexus regenerates or can be obliterated has remained largely unknown. The authors evaluate the effectiveness of CPC and report 3 cases of obliteration demonstrated by direct endoscopic observation. Methods The authors retrospectively analyzed the surgical results of patients with hydrocephalus primarily treated by CPC with or without ETV. Charts were reviewed for demographic data, clinical presentations, surgical therapies, and clinical outcomes. Results Eighteen patients with hydrocephalus were surgically treated using endoscopic CPC between July 2002 and July 2012. In 12 patients, ETV was concurrently performed. The etiology of hydrocephalus was posthemorrhagic in 5 patients, myelomeningocele in 3, postmeningitis in 2, congenital aqueductal stenosis in 1, hydranencephaly in 1, porencephaly in 1, and idiopathic in 5. The mean age at surgery was 8 months (range 0.3–24 months). The mean follow-up was 64 months. In 9 cases (50%), control of hydrocephalus was successful and the patients did not require further surgeries. In 9 patients (50%), treatment failed. Of these, 3 patients underwent repeat ETV 2, 3, and 38 months after the initial surgery. Endoscopic observation of the previous coagulation site revealed no regeneration of the choroid plexus in 2 patients, who underwent repeat ETV 2 and 3 months after CPC. In 1 patient who underwent repeat ETV 38 months after CPC, no regeneration of the choroid plexus, except for that in the proximity of the foramen of Monro, was observed. Conclusions Endoscopic CPC with or without ETV can be a safe and effective treatment alternative to shunt placement in infantile hydrocephalus. Obliteration of the choroid plexus can persist in the relatively long term following CPC, which may contribute to the long-term control of hydrocephalus in successful cases.


2001 ◽  
Vol 41 (1) ◽  
pp. 71 ◽  
Author(s):  
R. K. Khangura ◽  
M. J. Barbetti

Canola crops were monitored throughout the Western Australian wheatbelt during 1996–99 to determine the incidence and severity of crown cankers caused by the blackleg fungus (Leptosphaeria maculans). All crops surveyed had blackleg. The incidence of crown canker was 48–100%, 15–100%, 9–94% and 48–100% during 1996, 1997, 1998 and 1999, respectively. The mean incidence of crown cankers statewide was 85, 63, 55 and 85% in 1996, 1997, 1998 and 1999, respectively. The severity of crown canker (expressed as percentage disease index) ranged between 30 and 96%, 3 and 94%, 5 and 78% and 21 and 96% during 1996, 1997, 1998 and 1999, respectively. These high levels of blackleg can possibly be attributed to the accumulation of large amounts of infested canola residues. In 1999, there were effects of variety, application of the fungicide Impact, distance to last year’s canola residues and rainfall on the incidence and severity of blackleg. However, there were no effects of sowing date or region on the disease incidence or severity once the other factor effects listed above had been considered. In 1995, an additional survey of 19 sites in the central wheatbelt of Western Australia assessed the survival of the blackleg fungus on residues from crops grown in 1992–94. The residues at all sites carried blackleg. However, the extent of infection at any particular site varied from 12 to 100% of stems with the percentage of stems carrying pseudothecia containing ascospores varying between 7 and 96%. The high levels of blackleg disease found in commercial crops are indicative of significant losses in seed yields, making it imperative that management of blackleg be improved if canola is to remain a viable long-term cropping option in Western Australia.


2009 ◽  
Vol 67 (2) ◽  
pp. 304-315 ◽  
Author(s):  
Becky Sjare ◽  
Garry B. Stenson

Abstract Sjare, B., and Stenson, G. B. 2010. Changes in the reproductive parameters of female harp seals (Pagophilus groenlandicus) in the Northwest Atlantic. – ICES Journal of Marine Science, 67: 304–315. Changes in female harp seal (Pagophilus groenlandicus) reproductive parameters from 1980 to 2004, and long-term trends since the early 1950s, are evaluated. Estimates of the total number of seals in the Northwest Atlantic declined from ∼3.0 million in the 1950s to 1.8 million in the early 1970s, then increased steadily to 5.5 million in 1996, at which relatively stable level it has remained since. Pregnancy rates increased from ∼86% in the 1950s to a high of 98% in the mid-1960s, then declined to ∼65–70% by the early 1990s; the rate then varied between 45 and 70% from 2000 to 2004. Concurrently, the mean age at sexual maturity decreased from 5.8 (s.e = 0.02) years in the mid-1950s to 4.1 (s.e. = 0.02) in the late 1970s, increased to 5.5 (s.e. = 0.03) years by the early 1990s, and peaked at 5.7 (s.e. = 0.01) in 1995. From 2000 to 2004, mean age varied from 4.9 (s.e. = 0.01) to 6.0 (s.e. = 0.01) years. Although the direction of change in each of the parameters was consistent with a density-dependent response, changes in population size explained relatively little of the variability observed, suggesting that other ecological or environmental factors were influential.


2011 ◽  
Vol 7 (1) ◽  
pp. 42-46 ◽  
Author(s):  
Hideki Ogiwara ◽  
Arleta Lyszczarz ◽  
Tord D. Alden ◽  
Robin M. Bowman ◽  
David G. McLone ◽  
...  

Object Untethering of a tethered spinal cord (TSC) by transecting or removing a fatty filum terminale is a relatively simple procedure that can prevent or ameliorate neurological symptoms, and the postoperative prognosis is usually good. Progressive neurological deterioration caused by recurrent tethering has been rarely reported. The authors present their experience in cases in which a sectioned fatty filum terminale has become retethered. Methods The authors retrospectively analyzed the surgical results of pediatric patients with fatty filum terminale–TSC treated by transection of the filum. The patients' charts were reviewed for demographic data, clinical presentation, surgical therapy, and follow-up data. Results Of the 225 children who underwent TSC release by sectioning the fatty filum from 1992 to 2005, there were 6 patients (2.7%; 3 males, 3 females) in whom the fatty filum retethered. The mean age at the first diagnosis of TSC was 5.2 years (range 2 months–12.3 years). The mean duration from the first untethering procedure to retethering was 5.4 years. The mean age at the time of retethering was 10.6 years (range 7–17.5 years). Symptoms of retethering were urinary incontinence, low-back pain, difficulty walking, constipation, leg pain, and worsening foot deformity. Patients underwent cystometrography at the time retethering was indicated by increased bladder capacity, large post-void residual volume, decreased bladder capacity, increase in filling pressure, and poor sensation of filling. Magnetic resonance imaging revealed adherence of the rostral stump of the sectioned filum to the midline dorsal dural surface. All patients underwent the second untethering procedure. Four patients improved neurologically and experienced no retethering thereafter (mean follow-up period 5.5 years). Two patients experienced additional retethering after temporary improvement following the second untethering procedure. Conclusions Retethering of the spinal cord is a rare condition occurring after the sectioning of a fatty filum terminale. Awareness of this rare sequela is necessary for appropriate long-term management of TSC caused by a fatty filum terminale. Cystometrography is useful for detecting the lesion and confirming the diagnosis of retethering.


1986 ◽  
Vol 48 (2) ◽  
pp. 125-131 ◽  
Author(s):  
William G. Hill ◽  
Jonathan Rasbash

SummaryThe effects of mutation on mean and variance of response to selection for quantitative traits are investigated. The mutants are assumed to be unlinked, to be additive, and to have their effects symmetrically distributed about zero, with absolute values of effects having a gamma distribution. It is shown that the ratio of expected cumulative response to generation t from mutants, , and expected response over one generation from one generation of mutants, , is a function of t/N, where t is generations and N is effective population size. Similarly, , is a function of t/N, where is the increment in genetic variance from one generation of mutants. The mean and standard deviation of response from mutations relative to that from initial variation in the population, in the first generation, are functions of . Evaluation of these formulae for a range of parameters quantifies the important role that population size can play in response to long-term selection.


Author(s):  
Bilal Gumus ◽  
Ali Albaz ◽  
Fatih Düzgün ◽  
Oktay Ucer ◽  
Gokhan Temeltas ◽  
...  

Objective: The aim of this study is to evaluate the outcome of ablation therapy in our clinic for the treatment of patients with small renal mass Materials and Methods: We retrospectively evaluated the technic and follow-up data of 30 patients with 36 tumors who underwent Radiofrequency Ablation (RFA) and Microwave Ablation (MWA) in our clinic. Demographic data, ablation type, tumor characteristics, peroperative and postoperative complications and treatment success of the patients were evaluated. Results: A total of 36 tumors who underwent ablation treatments, 23 were treated with RFA, 13 with MWA. The mean tumor size was 28.9 ± 6.92 mm in RFA and 29.3 ± 7.70 mm in MWA. 12 (52.1%) of the RFA procedures were applied to the right kidney while 11 (47.8%) were applied to the left kidney. 6 (46.1%) of the MWA procedures were performed on the right kidney and 7 (53.8%) on the left kidney. Of the 36 tumors, 4 (11.1%) were located central and 32 (88.8%) were peripheral. Complications occurred in 2 patients. In one of these patients, acute renal failure and urea creatinine were found to be elevated. In the other patient, local pain was found in the ablation side and minor bleeding was detected at the ablation site in USG. The mean follow-up period was 49.6 ± 24.7 months in patients with RFA and mean follow-up was 16 ± 8,05 months in MWA treatments. The overall success in MWA administration was calculated as 76.9%, while the overall success in RFA was 80%. Conclusion: Long-term oncologic efficacy of RFA appears to be successful in the treatment of T1a renal carcinomas. Further studies can be conducted to elucidate the influence of MWA on long-term oncological outcomes.


1991 ◽  
Vol 18 (3) ◽  
pp. 249 ◽  
Author(s):  
MG Brooker ◽  
I Rowley

This paper describes the effects of wildfire on the nesting behaviour of some species of birds in a heathland community at Gooseberry Hill, Western Australia. The most severe fire during the nine year (1981-89) study was a hot summer burn in January 1985, which destroyed 95% of the study area. In the spring following that fire, 81% of the species previously known to breed in the area were still able to nest. The nesting substrate, height, site and aspect for three of the most abundant species (splendid fairy-wrens, western thornbills and yellow-rumped thornbills) were examined in detail. In the immediate post-fire year, all three used as nest sites only those plant species which regenerate by sprouting. The mean height of splendid fairy-wren nests in shrubs was lower than in unburnt habitat, although the wrens also built some nests in unusually high sites in trees in the first two seasons after fire. The mean height of western thornbill nests did not change but nest placement in a favoured substrate, Xanthorrhoea preissii, varied according to time since fire. Yellow-rumped thornbill nests built in burnt habitat tended to be higher and in a more restricted range of substrates than previously. Breeding of splendid fairy-wrens was delayed by three to five weeks in the first year after fire and the number of nests built per group had almost doubled by the second season. Only 59% of adult female western thornbills attempted to nest in the season immediately following the 1985 fire and the onset of breeding in burnt habitat was up to five weeks later than in unburnt. The delay by splendid fairy-wrens and western thornbills was attributed to a shortage of nesting material and adequate food for egg production, respectively, whereas the increase in the number of nests built by splendid fairy-wrens was attributed to a high rate of nest failure. At least two species (white-browed scrubwren and white-cheeked honeyeater) did not nest for two years after the 1985 fire and Acanthiza apicalis has not nested up to the present time (five years). The fire-modified habitat appeared beneficial to little button-quail and elegant parrot, which nested on the study area only after fire. White-winged triller and dusky woodswallow were more numerous breeders after fire than previously. Our findings highlight the importance of detailed long-term studies for estimating adequate fire-free intervals necessary for the conservation of resident avian species. A minimum period of at least 10 years is suggested for heathlands of south-western Australia.


1987 ◽  
Vol 65 (10) ◽  
pp. 2430-2435 ◽  
Author(s):  
D. A. Boag ◽  
M. A. Schroeder

The number of spruce grouse (Falcipennis (Canachites) franklinii) present in the spring population on a 247-ha block of pine-dominated habitat in southwestern Alberta was counted annually over a 21-year period. During the first 5 years of this study, the population increased steadily from 7.3 to 16.6 grouse/100 ha. Subsequently, for a period of 11 years, numbers were relatively stable at higher densities (19.0–29.1 grouse/100 ha). During the last 5-year period, the population declined to levels lower than at the onset of the study (16.6–4.9 grouse/100 ha). Year to year fluctuations in the size of this population were considered in the light of two hypotheses put forward to explain such fluctuations (spacing behaviour and breeding success). We concluded that both hypotheses were needed to explain our observations. During those years when spring population size fell below the mean number of grouse recorded over the 21-year period (17.8/100 ha), there was some evidence that breeding success in one year may have influenced population size the following spring but we found no evidence that spacing behaviour was important in limiting numbers under these conditions. On the other hand, when the size of the spring population was greater than the mean there was no evidence that breeding success influenced changes in population size the following spring, but there was evidence that spacing behaviour was limiting recruitment. The long-term change in population size appeared to be tied to the status of the fire sere inhabited: maturation of the forest (principally an increase in the height) was accompanied by a decline in population size.


2020 ◽  
Vol 72 (4) ◽  
pp. 1195-1200
Author(s):  
Elena Schembari ◽  
Maria Sofia ◽  
Rosario Lombardo ◽  
Valentina Randazzo ◽  
Ornella Coco ◽  
...  

AbstractSublay mesh repair seems to be the most effective method for treating incisional hernias (IHs). The aim of this study was to report our experience with retromuscular repair and self-gripping mesh for the treatment of midline IHs. In addition, we provided a systematic review of the literature regarding the use of this novel combination. All patients undergoing elective IH repair from June 2016 to November 2018 were included. The self-gripping mesh was placed in the sublay position. Demographic data, defect sizes, postoperative complications and follow-up durations were collected. A systematic review of the available literature was conducted in January 2020 using main databases. A total of 37 patients (20/17M/F) were included in this study, and the mean age and body mass index (BMI) were 58 years and 27 kg/m2, respectively. Minor complications occurred in six patients. Long-term follow-up demonstrated recurrence in three patients. Regarding the review, five publications were considered relevant. The highest complication rate was 28.6%, and the recurrence rate varied from 0 to 5.1%. This is the first review of the literature regarding sublay IH repair using a self-gripping mesh. The low rates of postoperative complications and recurrence in our experience and those reported by most of the reviewed articles demonstrate that this is a safe and effective method for repairing IHs.


Author(s):  
Jung Joo Lee ◽  
Gwanghui Ryu ◽  
Kyung Eun Lee ◽  
Sang Duk Hong ◽  
Yong Gi Jung ◽  
...  

Objectives. Fibro-osseous lesions of the paranasal sinuses can present various clinical conditions. This study aimed to report the long-term clinical course of benign fibro-osseous lesions (BFOLs) in the paranasal sinuses, including clinical and radiologic features. Methods. Radiologically confirmed BFOLs except osteoma cases were reviewed retrospectively between 1994 and 2016. We compared demographic data between the surgery and observation groups. Reason for image study, radiographic features, histopathology, and clinical course with serial image scans were analyzed.Results. A total of 183 subjects were selected from a thorough review of head and neck radiologic tests (n= 606,068) in a tertiary referral hospital over 22 years. The mean age was 28.6


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