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2.
Front Robot AI ; 10: 1137750, 2023.
Article in English | MEDLINE | ID: mdl-37064575

ABSTRACT

Surveying active nuclear facilities for spread of alpha and beta contamination is currently performed by human operators. However, a skills gap of qualified workers is emerging and is set to worsen in the near future due to under recruitment, retirement and increased demand. This paper presents an autonomous ground vehicle that can survey nuclear facilities for alpha, beta and gamma radiation and generate radiation heatmaps. New methods for preventing the robot from spreading radioactive contamination using a state-machine and radiation costmaps are introduced. This is the first robot that can detect alpha and beta contamination and autonomously re-plan around the contamination without the wheels passing over the contaminated area. Radiation avoidance functionality is proven experimentally to reduce alpha and beta contamination spread as well as gamma radiation dose to the robot. The robot's survey area is defined using a custom designed, graphically controlled area coverage planner. It was concluded that the robot is highly suited to certain monotonous room scale radiation surveying tasks and therefore provides the opportunity for financial savings, to mitigate a future skills gap, and provision of radiation surveys that are more granular, accurate and repeatable than those currently performed by human operators.

3.
Chaos ; 26(11): 113101, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27908021

ABSTRACT

Equilibrium statistical mechanics allows the prediction of collective behaviors of large numbers of interacting objects from just a few system-wide properties; however, a similar theory does not exist for far-from-equilibrium systems exhibiting complex spatial and temporal behavior. We propose a method for predicting behaviors in a broad class of such systems and apply these ideas to an archetypal example, the spatiotemporal chaotic 1D complex Ginzburg-Landau equation in the defect chaos regime. Building on the ideas of Ruelle and of Cross and Hohenberg that a spatiotemporal chaotic system can be considered a collection of weakly interacting dynamical units of a characteristic size, the chaotic length scale, we identify underlying, mesoscale, chaotic units and effective interaction potentials between them. We find that the resulting equilibrium Takahashi model accurately predicts distributions of particle numbers. These results suggest the intriguing possibility that a class of far-from-equilibrium systems may be well described at coarse-grained scales by the well-established theory of equilibrium statistical mechanics.

4.
J Paediatr Child Health ; 49(1): 38-42, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23279160

ABSTRACT

AIM: The study aims to investigate the prevalence of off-label prescribing in the general paediatric ward at a major teaching hospital in Tasmania, Australia. METHOD: The drug charts and medical records from two groups of 150 consecutive paediatric patients, admitted 6 months apart in July 2009 and January 2010, were studied retrospectively. Patients were required to spend at least one night in hospital and be aged less than 12 years. Each prescribed drug was compared with the approved product information to determine if the usage was off-label. Data concerning documented informed consent and adverse drug reactions were also recorded. RESULTS: Three hundred patients were prescribed a total of 887 medicines. Of these, 31.8% were off-label and 57.3% of children received an off-label medication. There was no significant seasonal variation in patient characteristics or prescriptions. Drugs were most commonly off-label due to their dosage or frequency of administration. Of the 106 different drugs used, the use of 51 was off-label on at least one occasion, and for 30 drugs their use was off-label on more than 75% of occasions. The drugs most commonly used off-label were oxycodone, salbutamol and paracetamol. No informed consent documentation was identified, and two of five recorded adverse drug reactions were associated with off-label drug use. CONCLUSION: Off-label use of medicines occurred frequently in paediatric inpatients. The available evidence often supported off-label medication use. An improved system for the revision of approved drug information and an Australian guideline for paediatric prescribing are needed.


Subject(s)
Hospitals, Teaching/statistics & numerical data , Off-Label Use/statistics & numerical data , Pediatrics , Practice Patterns, Physicians'/statistics & numerical data , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Retrospective Studies , Seasons , Tasmania
5.
Lasers Med Sci ; 26(5): 641-4, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21748324

ABSTRACT

Basal cell carcinomas (BCC) have a specialized microvasculature system that can be targeted by the 585-nm pulsed dye laser (PDL) utilizing the theory of selective photothermolysis. Seven volunteers with nine well-defined, biopsy-proven BCCs, were treated with the PDL (585-nm wavelength, a single 450-µs pulse, 7-mm spot size, and 9.0 J/cm(2) energy). The lesions, along with a 4-mm border of normal skin were treated. Pain assessment was carried out immediately after the laser treatment. A deep shave biopsy with histological examination occurred 4 weeks after the laser treatment. Pain was assessed on a scale of 0 (no pain) to 10 (worst pain possible). The average patient score was 2.1 (range 1-4). On histology, 5/9 (55.6%) sites demonstrated no evidence of BCC; however, 4/9 (44.4%) sites showed residual BCC. Although the PDL was able to clear over half of the BCCs in this study, there was an unacceptably high persistence rate of 44.4%. The PDL did not achieve the clearance rate that can be attained with current standard BCC treatment modalities. At this time, we do not recommend that a single treatment with the 585-nm PDL can be used as a primary therapy for BCC.


Subject(s)
Carcinoma, Basal Cell/surgery , Lasers, Dye/therapeutic use , Skin Neoplasms/surgery , Adult , Aged , Carcinoma, Basal Cell/blood supply , Female , Humans , Lasers, Dye/adverse effects , Male , Middle Aged , Skin Neoplasms/blood supply , Treatment Failure , Treatment Outcome
7.
Lasers Med Sci ; 24(5): 801-10, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19572180

ABSTRACT

UNLABELLED: The aim of this study was to compare the effects of the pulsed-dye laser (PDL) at a wavelength of 585 nm with those at 595 nm in the treatment of post-surgical scars, starting on the day of suture removal. The study was a prospective, non-randomized, double-blind, controlled, clinical trial, set in an outpatient clinic. Fifteen outpatients with 21 post-operative scars at least 3 cm long were recruited, and 14 patients with 19 scars completed the study. Scars were divided into three equal portions. Each outer portion was randomly allocated to PDL at 585 nm or at 595 nm (3.5 J/cm(2), 450 micros, 10 mm spot size), and the center was an untreated control; treatment was composed of three laser sessions at 4-week intervals. A blinded examiner evaluated the three scar sections using the Vancouver scar scale for pigmentation, vascularity, pliability, and height. Cosmetic appearance was evaluated with a visual analog scale. Punch biopsies of three randomly selected scars were evaluated. Pigmentation: more scars after laser treatments were of normal color than in the control, but the difference was not statistically significant. Vascularity: after treatment, more scars had normal vascularity in all three groups than at baseline (P < 0.05); the largest increase was with a wavelength of 585 nm (10.5-94.7%), then 595 nm (15.8-78.9%), then control (5.2-36.6%). Pliability: there was more normal pliability in all three groups than at baseline (P < 0.05), with greater improvements in the laser-treated groups. Height: significantly more flat scars after 585 nm PDL (63.2%) than at baseline (21.1%) (P < 0.05). We observed a slight but non-significant decrease in the scar heights with 595 nm PDL in comparison with the control. HISTOLOGY: after laser irradiation, the treated sections were more similar to a non-scarring process than the control. Cosmetic outcome: visual analog scales increased in all groups (P < 0.05), but the greatest increases were observed in the 585 nm and 595 nm laser-treated groups (50% and 60%, respectively) compared with controls (30%). There were significantly higher scores with the lasers than for the control (P < 0.001) at each visit after baseline. Both the 585 nm and 595 nm PDL treatments were effective in improving the appearance and normalizing the vascularity and pliability of post-operative scars. Both wavelengths improved the scars' visual appearance more than controls. We found that 585 nm appears to be the preferred wavelength, as it substantially normalized the height in addition to the vascularity and pliability in a significant number of scars.


Subject(s)
Cicatrix/surgery , Lasers, Dye/therapeutic use , Postoperative Complications/surgery , Aged , Aged, 80 and over , Cicatrix/pathology , Dermatologic Surgical Procedures , Double-Blind Method , Elasticity , Female , Humans , Male , Microcirculation , Middle Aged , Postoperative Complications/pathology , Prospective Studies , Skin/blood supply , Skin/pathology , Skin Pigmentation , Sutures
8.
Oecologia ; 154(3): 445-54, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17846798

ABSTRACT

A seed size-seed number trade-off exists because smaller seeds are produced in greater number but have a lower probability of establishment. This reduced establishment success of smaller-seeded species may be determined by biophysical constraints imposed by scaling rules. Root and shoot diameter, root growth extension rate (RGER) and shoot length at death for dark-grown seedlings are predicted to scale with the cube root of seed embryo and endosperm mass (m). We confirmed this expectation for ten neotropical gap-dependent tree species with an embryo and endosperm dry mass>1 mg. However, for nine smaller seeded species (m<1 mg) with photoblastic germination, root and shoot diameters were larger than expected, and consequently, RGER was slower than expected. The maximum shoot thrust of seedlings from seeds with masses>or=1 mg was comparable to the estimated force required to displace overlying litter, supporting the hypothesis that photoblastic behaviour only occurs in seeds with insufficient shoot thrust to displace overlying leaves. Using the model soil water, energy and transpiration to predict soil drying in small and large gaps, we showed that: (1) gaps that receive a significant amount of direct sunlight will dry more quickly than small gaps that do not, (2) compared to the wet-season, soil that is already dry at depth (i.e. the dry-season) will dry faster after rainfall (this drying would most likely kill seedlings from small seeds) and (3) even during the wet-season, dry periods of a few days in large gaps can kill shallow-rooted seedlings. We conclude that the smaller the seed, the more vulnerable its seedling would be to both covering by litter and soil drying because it can only emerge from shallow depths and has a slow RGER. Consequently, we suggest that these allometrically related factors contribute to the reduced establishment success of smaller-seeded species that underpins the seed size-seed number trade-off.


Subject(s)
Seedlings/metabolism , Seeds/metabolism , Trees/growth & development , Agar , Plant Roots/growth & development , Plant Shoots/growth & development , Soil , Time Factors
9.
Int J Dermatol ; 46(2): 186-7, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17269973

ABSTRACT

A 42-year-old black woman presented with dermatosis papulosa nigra lesions of 15 years' duration. Coincident with the diagnosis of symptomatic iron-deficiency anemia about 1 year ago, she reported an "explosion" in number and size of the lesions progressing from her face to her trunk and arms. Physical examination revealed numerous 1-5-mm, black, smooth, verrucous papules predominantly on the forehead, malar region of the face, neck, and upper trunk (Figs 1 and 2). The lesions on the back were situated in a "Christmas tree" pattern and included two 1-cm papules. She had multiple 1-mm papules on the upper arms. A biopsy confirmed the diagnosis of dermatosis papulosa nigra, showing parakeratosis, acanthosis, hyperpigmentation, thick interwoven tracts of epithelial cells, and horn cysts. Given the eruptive nature of her disease, the possibility of an underlying malignancy was entertained. Six weeks later, she went to the emergency room for severe weakness; a colonoscopy revealed an ascending colon adenocarcinoma with a negative metastatic work-up.


Subject(s)
Acanthosis Nigricans/complications , Adenocarcinoma/diagnosis , Colonic Neoplasms/diagnosis , Parakeratosis/complications , Paraneoplastic Syndromes/diagnosis , Adenocarcinoma/complications , Adult , Black or African American , Colonic Neoplasms/complications , Female , Humans
10.
Clin Dermatol ; 24(1): 26-32, 2006.
Article in English | MEDLINE | ID: mdl-16427503

ABSTRACT

Considered the most common skin disorder, acne affects millions of people every year. This multifactorial condition of the pilosebaceous follicle is a combination of at least four different primary pathogeneses. In recent years, acne therapies have been improving, becoming more effective, and targeting one or more of these causes. Many current therapies have drawbacks involving patient compliance, systemic toxicities, and bacterial resistance. Lasers are now established options in the armamentarium to treat acne. The 532-nm potassium titanyl phosphate laser, 585- and 595-nm pulsed dye lasers, 1450-nm diode laser, and 1540-nm erbium glass laser have been used with variable efficacy. Lasers may be best used in combination with other therapies to enhance their results. Photodynamic therapy has been successful with substances such as 5-aminolevulinic acid and indocyanine green. Lasers remain viable alternatives for people who may not desire or be able to use topical or systemic formulations. Drawbacks associated with lasers include potential pain, skin discoloration, and cost of treatment. Typically, multiple sessions are required to achieve the desired results, with future maintenance treatments possible to maintain the outcomes. With additional clinical trials underway, laser treatment of acne will surely advance and continue to be optimized in the future.


Subject(s)
Acne Vulgaris/radiotherapy , Laser Therapy , Humans
11.
J Drugs Dermatol ; 4(3): 352-4, 2005.
Article in English | MEDLINE | ID: mdl-15898292

ABSTRACT

Basal cell carcinomas (BCCs) that arise in sun-protected sites are quite uncommon. We report a case of BCC of the areola, which is extremely rare. Mohs micrographic surgery was used for the treatment. The etiologic factors of BCCs in sun-protected areas are discussed, and previous studies regarding the treatment modalities are reviewed.


Subject(s)
Carcinoma, Basal Cell/pathology , Nipples/pathology , Skin Neoplasms/pathology , Carcinoma, Basal Cell/surgery , Humans , Male , Middle Aged , Nipples/surgery , Skin Neoplasms/surgery
13.
Dermatol Surg ; 31(11 Pt 1): 1440-1; discussion 1441, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16416614

ABSTRACT

BACKGROUND: A variety of uses have been described for cotton-tipped applicators. OBJECTIVE: We describe an additional application in surgeries involving the nose. This technique uses 8-inch obstetrics-gynecology applicators with oversized cotton tips, unlike most articles, which report the use of 6-inch applicators with smaller cotton heads. The applicators function to stabilize and support the nasal structures and thus provide a steadier operating field. CONCLUSION: It can be used in procedures of the nose, including curettage, electrocautery, hemostasis, and Mohs and other surgical excisions.


Subject(s)
Cotton Fiber , Dermatology/instrumentation , Mohs Surgery , Nose Neoplasms/surgery , Humans
14.
J Cosmet Dermatol ; 3(3): 182-3, 2004 Jul.
Article in English | MEDLINE | ID: mdl-17134441

ABSTRACT

Propionibacterium acnes (P. acnes) and sebaceous glands are involved in the pathogenesis of acne. Although often effective, traditional therapies can have drawbacks, such as photosensitivity, other toxicities, polypharmacy and frequent dosing. Lasers have been studied to seek a solution that may overcome these disadvantages. Lasers and other light therapies target the wavelengths of the porphyrins in P. acnes to induce thermal damage that causes the bacterium's destruction. Pulsed-dye laser (PDL) or a system of light pulses and heat with wavelengths between 430 and 1100 nm are both efficacious. The 1450-nm diode laser targets sebaceous glands and is also effective. Topical indocyanine green (ICG) photodynamic therapy (PDT), using the near-infrared (NIR) laser, targets either P. acnes or sebaceous glands. ICG-PDT has fewer adverse effects than aminolevulinic acid-PDT. Lasers are still a relatively new therapy for acne and may be best used in an adjuvant role.

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