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A survey has been carried out of graduates and employers working in the sustainable energy (SE) industry in Australia. The aims were to identify the key areas of content to be included in University level SE training and the type of degree structures that are most appropriate for SE professionals. Attention was also directed to the mode of instruction (online, blended or face-to-face) and the role of work-integrated learning (WIL). This paper presents the results of the survey, which provide guidance to Universities seeking to develop new, or revise existing, SE education offerings. The results of the survey clearly indicate that responding students and employers prefer a generalist degree in engineering, with a stream in sustainable energy as the initial qualification for professionals in this field. Specialist degrees at postgraduate level were also considered appropriate for continuing professional education (CPE). Both graduates and employers agreed on key areas to be included in the SE courses. These key areas are generic skills (research methods, team work, report writing), generation technologies (especially PV, wind and biomass), and enablers (such as economics, policy and project management). The graduates, many of whom came from overseas countries, generally agreed about the course content and its relevance to employment in their countries. Face-to-face or blended learning was preferred by both groups as the mode of instruction for the first degree. Online learning was considered a valuable adjunct in the undergraduate course and more suitable for CPE in postgraduate courses. WIL and more practical work were considered important, especially in the first degree. There was some disagreement about the appropriate length of work placements, with graduates preferring 6–8 weeks and employers 10–12 weeks. This work should provide a basis for further course development and curriculum reform for sustainable energy education.

Abstract Background Insulin-like growth factor-1 (IGF-1) is important in normal growth, development, and homeostasis. Current use of oral contraceptives (OC) decreases IGF-1 concentrations; however, the effect of past use, age/timing of use, and type of OC used on IGF-1 levels is unknown. OC are the most commonly used form of birth control worldwide. Both IGF-1 and OC use have been linked to premenopausal breast and colorectal cancers, osteoporosis and cardiovascular disease (CVD). Understanding the effects of different patterns of OC use on IGF-1 levels may offer insight into its influence on disease risk in young women. Methods In a cross-sectional study of 328 premenopausal women ages 18 to 21 and 31 to 40 we examined the relationship between different patterns of OC use and circulating IGF-1 using adjusted linear regression analysis. Information on OC use was obtained through an interviewer administered questionnaire. Plasma IGF-1 was assessed with enzyme linked immunosorbent assay (ELISA). Results Among women aged 18 to 21, ever OC use was significantly associated with decreased IGF-1 levels compared to never use (β = -57.2 ng/ml, 95% confidence interval (CI): -88.7, -25.8). Among women aged 31 to 40, past users who first used OC at 25 years of age or older (β = 43.8 ng/ml, 95% CI: 8.8, 78.8), in the last 15 years (β = 35.1 ng/ml, 95% CI: 9.3, 61.0) or after 1995 (β = 46.6 ng/ml, 95% CI: 13.4, 79.8) had significantly higher IGF-1 levels compared to never users. Conclusion This is the first study to highlight the long term effects of OC use after cessation on IGF-1 levels among premenopausal women, which previously were thought to be transitory. Future studies of past use and IGF-1 levels are required and must consider age/timing of use and type/generation of OC used. Additional studies are needed to confirm the potential mediation of IGF-1 levels in the links between OC use and health outcomes.

Mobile ad hoc networks (MANETs) have inherently dynamic topologies. Under these difficult circumstances, it is essential to have some dependable way of determining the reliability of communication paths. Mobility metrics are well suited to this purpose. Several mobility metrics have been proposed in the literature, including link persistence, link duration, link availability, link residual time, and their path equivalents. However, no method has been provided for their exact calculation. Instead, only statistical approximations have been given. In this paper, exact expressions are derived for each of the aforementioned metrics, applicable to both links and paths. We further show relationships between the different metrics, where they exist. Such exact expressions constitute precise mathematical relationships between network connectivity and node mobility. These expressions can, therefore, be employed in a number of ways to improve performance of MANETs such as in the development of efficient algorithms for routing, in route caching, proactive routing, and clustering schemes.

Objective: Non-alcoholic fatty liver disease (NAFLD) affects 1 in 3 adults and contributes to advanced liver injury and cardiometabolic disease. While recent evidence points to involvement of the brain in NAFLD, the downstream neural circuits and neuronal molecular mechanisms involved in this response, remain unclear. Here, we investigated the role of a unique forebrain-hypothalamic circuit in NAFLD., Methods: Chemogenetic activation and inhibition of circumventricular subfornical organ (SFO) neurons that project to the paraventricular nucleus of the hypothalamus (PVN; SFO→PVN) in mice were used to study the role of SFO→PVN signaling in NAFLD. Novel scanning electron microscopy techniques, histological approaches, molecular biology techniques, and viral methodologies were further used to delineate the role of endoplasmic reticulum (ER) stress within this circuit in driving NAFLD., Results: In lean animals, acute chemogenetic activation of SFO→PVN neurons was sufficient to cause hepatic steatosis in a liver sympathetic nerve dependent manner. Conversely, inhibition of this forebrain-hypothalamic circuit rescued obesity-associated NAFLD. Furthermore, dietary NAFLD is associated with marked ER ultrastructural alterations and ER stress in the PVN, which was blunted following reductions in excitatory signaling from the SFO. Finally, selective inhibition of PVN ER stress reduced hepatic steatosis during obesity., Conclusions: Collectively, these findings characterize a previously unrecognized forebrain-hypothalamic-ER stress circuit that is involved in hepatic steatosis, which may point to future therapeutic strategies for NAFLD., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

Dysregulation in the paraventricular nucleus of the hypothalamus (PVN) is associated with a variety of diseases including those related to obesity. Although most investigations have focused on molecular changes, structural alterations in PVN neurons can reveal underlying functional disruptions. Although electron microscopy (EM) can provide nanometer resolution of brain structures, an inherent limitation of traditional transmission EM is the single field of view nature of data collection. To overcome this, we used large-field-of-view high-resolution backscatter scanning electron microscopy (bSEM) of the PVN. By stitching high-resolution bSEM images, taken from normal chow and high-fat diet mice, we achieved interactive, zoomable maps that allow for low-magnification screening of the entire PVN and high-resolution analyses of ultrastructure at the level of the smallest cellular organelle. Using this approach, quantitative analysis across the PVN revealed marked electron-dense regions within neuronal nucleoplasm following high-fat diet feeding, with an increase in kurtosis, indicative of a shift away from a normal distribution. Furthermore, measures of skewness indicated a shift toward darker clustered electron-dense regions, potentially indicative of heterochromatin clusters. We further demonstrate the utility to map out healthy and altered neurons throughout the PVN and the ability to remotely perform bSEM imaging in situations that require social distancing, such as the COVID-19 pandemic. Collectively, these findings present an approach that allows for the precise placement of PVN cells within an overall structural and functional map of the PVN. Moreover, they suggest that obesity may disrupt PVN neuronal chromatin structure. NEW & NOTEWORTHY Paraventricular nucleus of the hypothalamus (PVN) alterations are linked to obesity-related conditions, but limited knowledge exists about neuroanatomical changes in this region. A large-field-of-view backscatter scanning electron microscopy (bSEM) method was used, which allowed the identification of up to 40 PVN neurons in individual samples. During obesity in mice, bSEM revealed changes in PVN neuronal nucleoplasm, possibly indicating chromatin clustering. This microscopy advancement offers valuable insights into neuroanatomy in both healthy and disease conditions.

Purpose: Health care professionals are expected to take on an active role in the implementation of risk-based cancer prevention strategies. This study aimed to explore health care professionals' (1) self-reported familiarity with the concept of polygenic risk score (PRS), (2) perceived level of knowledge regarding risk-stratified breast cancer (BC) screening, and (3) preferences for continuing professional development., Methods: A cross-sectional survey was conducted using a bilingual-English/French-online questionnaire disseminated by health care professional associations across Canada between November 2020 and May 2021., Results: A total of 593 professionals completed more than 2 items and 453 responded to all questions. A total of 432 (94%) participants were female, 103 (22%) were physicians, and 323 (70%) were nurses. Participants reported to be unfamiliar with (20%), very unfamiliar (32%) with, or did not know (41%) the concept of PRS. Most participants reported not having enough knowledge about risk-stratified BC screening (61%) and that they would require more training (77%). Online courses and webinar conferences were the preferred continuing professional development modalities., Conclusion: The study indicates that health care professionals are currently not familiar with the concept of PRS or a risk-stratified approach for BC screening. Online information and training seem to be an essential knowledge transfer modality., Competing Interests: Conflict of Interest The authors declare no conflict of interest., (Copyright © 2022 American College of Medical Genetics and Genomics. Published by Elsevier Inc. All rights reserved.)

Metabolic syndrome encompasses a spectrum of conditions that increases the risk for cardiovascular and metabolic diseases. It is widely accepted that the sex hormone estrogen plays a protective metabolic role in premenopausal women, in part through central nervous system (CNS) mechanisms. However, most work to date has focused on the loss of estrogen in females (e.g., menopause). Interestingly, transgender individuals receiving feminizing gender affirming therapy (i.e., estrogen) are relatively protected from metabolic syndrome conditions, pointing to a role for CNS estrogen in the development of metabolic syndrome in men. Here, we show that estrogen signaling in the brain protects males from metabolic syndrome and obesity related complications. First, short-term CNS specific supplementation of low-dose 17-β-estradiol in diet-induced obese male mice resulted in a significant reduction in body weight in parallel with a decrease in food intake without alterations in energy expenditure. In conjunction, central supplementation of estrogen reduced visceral adiposity, including epididymal and abdominal regions, with slighter decreases in subcutaneous inguinal and thermogenic brown adipose tissue. Furthermore, central estrogen administration reduced the liver manifestation of metabolic syndrome including hepatomegaly and hepatic steatosis. Collectively, these findings indicate that a lack of estrogen action in the brain may predispose males to metabolic syndrome pathogenesis.

The success of risk-stratified approaches in improving population-based breast cancer screening programs depends in no small part on women's buy-in. Fear of genetic discrimination (GD) could be a potential barrier to genetic testing uptake as part of risk assessment. Thus, the objective of this study was twofold. First, to evaluate Canadian women's knowledge of the legislative context governing GD. Second, to assess their concerns about the possible use of breast cancer risk levels by insurance companies or employers. We use a cross-sectional survey of 4293 (age: 30-69) women, conducted in four Canadian provinces (Alberta, British Colombia, Ontario and Québec). Canadian women's knowledge of the regulatory framework for GD is relatively limited, with some gaps and misconceptions noted. About a third (34.7%) of the participants had a lot of concerns about the use of their health information by employers or insurers; another third had some concerns (31.9%), while 20% had no concerns. There is a need to further educate and inform the Canadian public about GD and the legal protections that exist to prevent it. Enhanced knowledge could facilitate the implementation and uptake of risk prediction informed by genetic factors, such as the risk-stratified approach to breast cancer screening that includes risk levels.

Risk-stratified screening for breast cancer (BC) is increasingly considered as a promising approach. However, its implementation is challenging and needs to be acceptable to women. We examined Canadian women's attitudes towards, comfort level about, and willingness to take part in BC risk-stratified screening. We conducted an online survey in women aged 30 to 69 years in four Canadian provinces. In total, 4293 women completed the questionnaire (response rate of 63%). The majority of women (63.5% to 72.8%) expressed favorable attitudes towards BC risk-stratified screening. Most women reported that they would be comfortable providing personal and genetic information for BC risk assessment (61.5% to 67.4%) and showed a willingness to have their BC risk assessed if offered (74.8%). Most women (85.9%) would also accept an increase in screening frequency if they were at higher risk, but fewer (49.3%) would accept a reduction in screening frequency if they were at lower risk. There were few differences by province; however, outcomes varied by age, education level, marital status, income, perceived risk, history of BC, prior mammography, and history of genetic test for BC (all p ≤ 0.01). Risk-based BC screening using multifactorial risk assessment appears to be acceptable to most women. This suggests that the implementation of this approach is likely to be well-supported by Canadian women.

Introduction: Women with breast implants may experience breast implant illness (BII). BII is comprised of a collection of systemic symptoms, such as fatigue and pain, that are postulated to be related to having breast implants., Case Presentation: This case report documents the naturopathic treatment of a 35-year-old female patient diagnosed with fibromyalgia, tension headaches, and chronic anxiety, perceived to be linked to and exacerbated by her textured cohesive gel implants. The patient sought naturopathic treatment for support during the explant process of her breast implants.Naturopathic treatment was provided over a 3-month period in conjunction with prescribed medication for her anxiety and tension headaches., Conclusion: At 3 months post-naturopathic treatment, the patient experienced a reduction in anxiety, fatigue, and self-reported pain. The integration of alternative therapies with prescribed pharmaceutical treatment appeared to positively impact the health of this patient., (Copyright © 2020 InnoVision Professional Media Inc.)

Patent bibliometrics data are the most reliable business performance metric for applied research and development activities when investigating the knowledge domains or the technological evolution of vehicle powertrain technologies in the automotive industry. Our paper describes a global patents dataset for the internal combustion engine vehicles (ICEV), hybrid electric vehicles (HEV) and battery electric vehicles (BEV) over 1985-2016. We extracted the patents granted in each powertrain field from Thomson Reuters' Derwent Innovations Index (DII). We applied a combined search strategy of international patent classifications (IPCs) and keywords as well as 'patent families' and 'priority dates' to construct our global patents dataset. This strategy returned a total of 78,732 patents, within which we identified 49,154 ICEV patents; 10,888 HEV patents; and 18,690 BEV patents. Our database includes numerous descriptive features of each patent such as title, abstract, claim, priority, application and publication dates, IPCs, assignees/applicants, inventors, and cited references. These data are associated with the research article 'The evolution of dynamic interactions between the knowledge development of powertrain systems' [1]. The full dataset, which is attached to this article, may be useful to both researchers and practitioners interested in investigating, modelling or forecasting the complexity and evolution of the technical and knowledge domains of the vehicle powertrains, across a variety of instruments such as social network analysis and regression models., Competing Interests: None., (© 2020 The Authors.)

The emergence of networks is a crucial channel for automotive organisations to build and diffuse the required environmental innovations in the transportation sector and accelerate the transition to the green mobility economy. This article contains the dataset regarding the global patents networks shaped both within and between the three vehicle powertrains of internal combustion engine vehicle (ICEV), hybrid electric vehicle (HEV) and battery electric vehicle (BEV) for the period of 1985-2016. The data was acquired from Thomson Reuters' Derwent Innovations Index (DII) platform using the elements of 'patent families' and 'priority dates'. We describe the dataset for the three major automotive periods of 'towards sustainable mobility' (1985-1996), 'towards hybridisation' (1997-2007), and 'towards mass commercialisation' (2008-2016). The dataset bears on two levels, individual and mutual, and we used a separate combined search strategy of keywords and IPCs codes (international patent classification) for each level. At individual level, we explored the internal network features of each powertrain individually (i.e. ICEV, HEV, and BEV). Monitoring a total of 78,732 patents in the three individual powertrain networks, we discovered a total of 1856 unique parent organisations connecting vis-à-vis 5849 bilateral relationships and operating around 4450 joint patents. At mutual level, we explored the mutually common network features of the powertrains (i.e. ICEV-HEV, HEV-BEV, and BEV-ICEV). Monitoring a total of 4702 patents in the three mutual powertrain networks, we discovered a total of 102 unique parent organisations connecting vis-à-vis 384 bilateral relationships and operating around 303 joint patents. These organisations were found specialised around 435 unique subgroup-level IPC codes, of which 134 codes were related to environmentally friendly innovations. The dataset presented in this article is used in [1] and allows researchers not only to map and model the network dynamics and structures within and between the powertrains at global level, but also to analyse and forecast their knowledge flows, technical domains and environmental innovations aspect, using a wide range of models such as social network analysis or regression., (© 2019 The Author(s).)

Background: Mammographic density is one of the strongest risk factors for breast cancer. In the general population, mammographic density can be modified by various exposures; whether this is true for women a strong family history is not known. Thus, we evaluated the association between reproductive, hormonal, and lifestyle risk factors and mammographic density among women with a strong family history of breast cancer but no BRCA1 or BRCA2 mutation., Methods: We included 97 premenopausal and 59 postmenopausal women (age range: 27-68 years). Risk factor data was extracted from the research questionnaire closest in time to the mammogram performed nearest to enrollment. The Cumulus software was used to measure percent density, dense area, and non-dense area for each mammogram. Multivariate generalized linear models were used to evaluate the relationships between breast cancer risk factors and measures of mammographic density, adjusting for relevant covariates., Results: Among premenopausal women, those who had two live births had a mean percent density of 28.8% vs. 41.6% among women who had one live birth (P=0.04). Women with a high body weight had a lower mean percent density compared to women with a low body weight among premenopausal (17.6% vs. 33.2%; P=0.0006) and postmenopausal women (8.7% vs. 14.7%; P=0.04). Among premenopausal women, those who smoked for 14 years or longer had a lower mean dense area compared to women who smoked for a shorter duration (25.3cm 2 vs. 53.1cm 2 ; P=0.002). Among postmenopausal women, former smokers had a higher mean percent density (19.5% vs. 10.8%; P=0.003) and dense area (26.9% vs. 16.4%; P=0.01) compared to never smokers. After applying the Bonferroni correction, the association between body weight and percent density among premenopausal women remained statistically significant., Conclusions: In this cohort of women with a strong family history of breast cancer, body weight was associated with mammographic density. These findings suggest that mammographic density may explain the underlying relationship between some of these risk factors and breast cancer risk, and lend support for the inclusion of mammographic density into risk prediction models.

Nutrient availability influences intestinal epithelial stem cell proliferation and tissue growth. Increases in food result in a greater number of epithelial cells, villi height and crypt depth. We investigated whether this nutrient-driven expansion of the tissue is the result of a change in the mode of intestinal epithelial stem cell division and if LKB1-AMPK signaling plays a role. We utilized in vivo and in vitro experiments to test this hypothesis. C57BL/6J mice were separated into four groups and fed varying amounts of chow for 18 h: (1) ad libitum, (2) 50% of their average daily intake (3) fasted or (4) fasted for 12 h and refed. Mice were sacrificed, intestinal sections excised and immunohistochemically processed to determine the mitotic spindle orientation. Epithelial organoids in vitro were treated with no (0 mM), low (5 mM) or high (20 mM) amounts of glucose with or without an activator (Metformin) or inhibitor (Compound C) of LKB1-AMPK signaling. Cells were then processed to determine the mode of stem cell division. Fasted mice show a greater % of asymmetrically dividing cells compared with the other feeding groups. Organoids incubated with 0 mM glucose resulted in a greater % of asymmetrically dividing cells compared with the low or high-glucose conditions. In addition, LKB1-AMPK activation attenuated the % of symmetric division normally seen in high-glucose conditions. In contrast, LKB1-AMPK inhibition attenuated the % of asymmetric division normally seen in no glucose conditions. These data suggest that nutrient availability dictates the mode of division and that LKB1-AMPK mediates this nutrient-driven effect on intestinal epithelial stem cell proliferation. Impact statement The underlying cell biology of changes in the polarity of mitotic spindles and its relevance to tissue growth is a new concept and, thus, these data provide novel findings to begin to explain how this process contributes to the regeneration and growth of tissues. We find that short-term changes in food intake in vivo or glucose availability in vitro dictate the mode of division of crypt cells. In addition, we find that LKB1-AMPK signaling modulates the glucose-induced changes in the mode of division in vitro. Identifying mechanisms involved in the mode of division may provide new targets to control tissue growth.

Background: Traditionally, chronic wound infection is diagnosed by visual inspection under white light and microbiological sampling, which are subjective and suboptimal, respectively, thereby delaying diagnosis and treatment. To address this, we developed a novel handheld, fluorescence imaging device (PRODIGI) that enables non-contact, real-time, high-resolution visualization and differentiation of key pathogenic bacteria through their endogenous autofluorescence, as well as connective tissues in wounds., Methods and Findings: This was a two-part Phase I, single center, non-randomized trial of chronic wound patients (male and female, ≥18 years; UHN REB #09-0015-A for part 1; UHN REB #12-5003 for part 2; clinicaltrials.gov Identifier: NCT01378728 for part 1 and NCT01651845 for part 2). Part 1 (28 patients; 54% diabetic foot ulcers, 46% non-diabetic wounds) established the feasibility of autofluorescence imaging to accurately guide wound sampling, validated against blinded, gold standard swab-based microbiology. Part 2 (12 patients; 83.3% diabetic foot ulcers, 16.7% non-diabetic wounds) established the feasibility of autofluorescence imaging to guide wound treatment and quantitatively assess treatment response. We showed that PRODIGI can be used to guide and improve microbiological sampling and debridement of wounds in situ, enabling diagnosis, treatment guidance and response assessment in patients with chronic wounds. PRODIGI is safe, easy to use and integrates into the clinical workflow. Clinically significant bacterial burden can be detected in seconds, quantitatively tracked over days-to-months and their biodistribution mapped within the wound bed, periphery, and other remote areas., Conclusions: PRODIGI represents a technological advancement in wound sampling and treatment guidance for clinical wound care at the point-of-care., Trial Registration: ClinicalTrials.gov NCT01651845; ClinicalTrials.gov NCT01378728.

Defects in iron absorption and utilization lead to iron deficiency and anemia. While iron transport by transferrin receptor-mediated endocytosis is well understood, it is not completely clear how iron is transported from the endosome to the mitochondria where heme is synthesized. We undertook a positional cloning project to identify the causative mutation for the hemoglobin-deficit (hbd) mouse mutant, which suffers from a microcytic, hypochromic anemia apparently due to defective iron transport in the endocytosis cycle. As shown by previous studies, reticulocyte iron accumulation in homozygous hbd/hbd mice is deficient despite normal binding of transferrin to its receptor and normal transferrin uptake in the cell. We have identified a strong candidate gene for hbd, Sec15l1, a homologue to yeast SEC15, which encodes a key protein in vesicle docking. The hbd mice have an exon deletion in Sec15l1, which is the first known mutation of a SEC gene homologue in mammals.

Understanding iron metabolism has been enhanced by identification of genes for iron deficiency mouse mutants. We characterized the genetics and iron metabolism of the severe anemia mutant hea (hereditary erythroblastic anemia), which is lethal at 5 to 7 days. The hea mutation results in reduced red blood cell number, hematocrit, and hemoglobin. The hea mice also have elevated Zn protoporphyrin and serum iron. Blood smears from hea mice are abnormal with elevated numbers of smudge cells. Aspects of the hea anemia can be transferred by hematopoietic stem cell transplantation. Neonatal hea mice show a similar hematologic phenotype to the flaky skin (fsn) mutant. We mapped the hea gene near the fsn locus on mouse chromosome 17 and show that the mutants are allelic. Both tissue iron overloading and elevated serum iron are also found in hea and fsn neonates. There is a shift from iron overloading to iron deficiency as fsn mice age. The fsn anemia is cured by an iron-supplemented diet, suggesting an iron utilization defect. When this diet is removed there is reversion to anemia with concomitant loss of overloaded iron stores. We speculate that the hea/fsn gene is required for iron uptake into erythropoietic cells and for kidney iron reabsorption.

Maternal nutrition and growth hormone (GH) treatment during early- to mid-pregnancy can each alter the subsequent growth and differentiation of muscle in progeny. We have investigated the effects of varying maternal nutrition and maternal treatment with porcine (p) GH during the second quarter of pregnancy in gilts on semitendinosus muscle cross-sectional area and fibre composition of progeny, and relationships between maternal and progeny measures and progeny muscularity. Fifty-three Large White x Landrace gilts, pregnant to Large White x Duroc boars, were fed either 2.2 kg (about 35 % ad libitum intake) or 3.0 kg commercial ration (13.5 MJ digestible energy, 150 g crude protein (N x 6.25)/kg DM)/d and injected with 0, 4 or 8 mg pGH/d from day 25 to 50 of pregnancy, then all were fed 2.2 kg/d for the remainder of pregnancy. The higher maternal feed allowance from day 25 to 50 of pregnancy increased the densities of total and secondary fibres and the secondary:primary fibre ratio in semitendinosus muscles of their female progeny at 61 d of age postnatally. The densities of secondary and total muscle fibres in semitendinosus muscles of progeny were predicted by maternal weight before treatment and maternal plasma insulin-like growth factor-II during treatment. Maternal pGH treatment from day 25 to day 50 of pregnancy did not alter fibre densities, but increased the cross-sectional area of the semitendinosus muscle; this may be partially explained by increased maternal plasma glucose. Thus, maternal nutrition and pGH treatment during the second quarter of pregnancy in pigs independently alter muscle characteristics in progeny.

Objective: To compare the cost and performance of 2 types of laparoscopic instrumentation: reusable laparoscopic hook cautery instruments and curved scissors, or limited-reuse laparoscopic hook cautery instruments and curved scissors., Design: A randomized trial., Setting: The operating room of a tertiary care hospital., Method: All general surgeons performing laparoscopic procedures at the hospital were randomized to be supplied with either reusable or limited-reuse hook cautery and curved scissors. Instrument use was recorded, together with principal outcome measures., Outcome Measures: Life expectancy of the instruments, the number of cases for which they were used, the number, nature and cost of repairs, their purchase cost and surgeon satisfaction., Results: Reusable hook cautery instruments were less expensive than their limited-reuse counterparts. Excellent surgeon satisfaction was reported with the use of this type of instrument. The limited-reuse curved scissors arm of the study was terminated early because of a breach in study protocol., Conclusions: Reusable hook cautery instruments were better than their limited-reuse counterparts. Rigorous attempts to compare the cost of laparoscopic instruments may be limited by their rapid evolution in design and the availability of many types of instruments on the market.