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1.
Sci Data ; 11(1): 358, 2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38594314

ABSTRACT

This paper presents a standardised dataset versioning framework for improved reusability, recognition and data version tracking, facilitating comparisons and informed decision-making for data usability and workflow integration. The framework adopts a software engineering-like data versioning nomenclature ("major.minor.patch") and incorporates data schema principles to promote reproducibility and collaboration. To quantify changes in statistical properties over time, the concept of data drift metrics (d) is introduced. Three metrics (dP, dE,PCA, and dE,AE) based on unsupervised Machine Learning techniques (Principal Component Analysis and Autoencoders) are evaluated for dataset creation, update, and deletion. The optimal choice is the dE,PCA metric, combining PCA models with splines. It exhibits efficient computational time, with values below 50 for new dataset batches and values consistent with seasonal or trend variations. Major updates (i.e., values of 100) occur when scaling transformations are applied to over 30% of variables while efficiently handling information loss, yielding values close to 0. This metric achieved a favourable trade-off between interpretability, robustness against information loss, and computation time.


Subject(s)
Datasets as Topic , Software , Principal Component Analysis , Reproducibility of Results , Workflow , Datasets as Topic/standards , Machine Learning
2.
Environ Manage ; 71(2): 439-450, 2023 02.
Article in English | MEDLINE | ID: mdl-36449050

ABSTRACT

Adaptive management (AM) is often proposed as a means to resolve uncertainty in the management of socio-ecological systems but successful implementation of AM is rare. We report results from a 26 year, five-treatment, AM experiment designed to inform decision makers about the response of juvenile salmonids (Oncorhynchus spp.) to flow releases from a dam on the regulated Bridge River, British Columbia, Canada. Treatments consisted of a baseline (no dam release) and four different dam release regimes that followed a semi-natural hydrograph but varied in the magnitude of spring-summer freshet flows. We found total salmonid biomass was highest at the lowest flow release, and decreased with increasing flow, consistent with a priori predictions made by an expert solicitation process. Species-specific responses were observed that in some cases could be attributed to interactions between the flow regime and life history. The relationship between juvenile biomass and flow resulting from the experiment can inform decisions on water management for this river. The documentation of successful AM experiments is sorely needed to allow for reflection on the circumstances when AM is likely to deliver desirable outcomes, and to improve other decision processes that require fewer resources and less time to implement.


Subject(s)
Ecology , Rivers , Ecosystem , Seasons , British Columbia
3.
Ecol Appl ; 32(8): e2709, 2022 12.
Article in English | MEDLINE | ID: mdl-36131546

ABSTRACT

Variation among populations in life history and intrinsic population characteristics (i.e., population diversity) helps maintain resilience to environmental change and dampen interannual variability in ecosystem services. As a result, ecological variation, and the processes that generate it, is considered central to strategies for managing risks to ecosystems in an increasingly variable and uncertain world. However, characterizing population diversity is difficult, particularly in large and remote regions, which often prevents its formal consideration in management advice. We combined genetic stock identification of archived scale and tissue samples with state-space run-reconstruction models to estimate migration timing and annual return abundance for eight geographically and genetically distinct Chinook salmon populations within the Canadian portion of the Yukon River. We found that among-population variation in migration timing and return abundances resulted in aggregate return migrations that were 2.1 times longer and 1.4 times more stable than if they had composed a single homogeneous population. We then fit state-space spawner-recruitment models to the annual return abundances to characterize among-population diversity in intrinsic productivity and population size and their consequences for the fisheries they support. Productivity and carrying capacity varied among populations by approximately 2.4-fold (2.9 to 6.9 recruits per spawner) and three-fold (8800 to 27,000 spawners), respectively. This diversity implies an equilibrium trade-off between harvesting of the population aggregate and the conservation of individual populations whereby the harvest rate predicted to maximize aggregate harvests comes at the cost of overfishing ~40% of the populations but with a relatively low risk of extirpating the weakest ones. Our findings illustrate how population diversity in one of the largest salmon-producing river basins in the world contributes to fishery stability and food security in a region where salmon have high cultural and subsistence value. More generally, our work demonstrates the utility of molecular analyses of archived biological material for characterizing diversity in biological systems and its benefits and consequences for trade-offs in decision-making.


Subject(s)
Fisheries , Salmon , Animals , Salmon/genetics , Ecosystem , Conservation of Natural Resources , Canada
4.
J Knee Surg ; 35(8): 874-883, 2022 Jul.
Article in English | MEDLINE | ID: mdl-33231280

ABSTRACT

Different combinations of irrigation solutions have been used in attempt to eradicate microorganisms for the prevention and treatment of prosthetic joint infections (PJIs). Clorpactin WCS-90 was evaluated as an alternative irrigation intraoperative technique for the treatment of PJI using both debridement, antibiotics, and implant retention (DAIR) and 2-stage total knee arthroplasty (TKA) procedures. We retrospectively reviewed PJIs irrigated with Clorpactin between January 2015 and January 2020. We found 13 patients who underwent a DAIR procedure for an acutely infected primary TKA, 18 patients underwent a 2-stage procedure for a chronically infected primary TKA, two patients underwent a DAIR procedure for an acutely infected revision TKA, and 18 patients underwent a 2-stage procedure for a chronically infected revision TKA. The odds of reinfection and need for additional surgery were analyzed at a mean follow-up of 20 to 26 months between groups. Only one patient (7.69%) became reinfected in the acute infected primary TKA group, three patients (16.67%) in the chronic infected primary TKA group, 0 patients (0%) in the acute infected revision TKA group, and six patients (33.33%) in the chronic infected revision TKA group. When the acute primary TKA infection group was compared with the chronic revision TKA infection group, the odds of reinfection (Chi-square test [χ2] = 21.7, df 3, p < 0.001) and odds of additional surgery (χ2 = 13.6, df 3, p < 0.003) were significantly higher for the chronic revision TKA infection group. Overall, the reinfection rate for DAIR revisions was 6.67% (range = 0-7.69) and 2-stage revisions was 25.00% (range = 16.67-33.33). The use of Clorpactin WCS-90 irrigation prior to wound closure is a useful option for the treatment of acute and chronic knee PJIs. Our study provides evidence that infection eradication with the use of Clorpactin is comparable to other irrigation methods and surgical techniques in reported literature.


Subject(s)
Arthritis, Infectious , Arthroplasty, Replacement, Knee , Prosthesis-Related Infections , Anti-Bacterial Agents/therapeutic use , Arthritis, Infectious/surgery , Arthroplasty, Replacement, Knee/adverse effects , Benzenesulfonates , Debridement/methods , Humans , Knee Joint/surgery , Prosthesis-Related Infections/therapy , Reinfection , Reoperation/methods , Retrospective Studies , Treatment Outcome
5.
PLoS One ; 15(12): e0237052, 2020.
Article in English | MEDLINE | ID: mdl-33332352

ABSTRACT

Over 1 billion USD are devoted annually to rehabilitating freshwater habitats to improve survival for the recovery of endangered salmon populations. Mitigation often requires the creation of new habitat (e.g. habitat offsetting) to compensate population losses from human activities, however offsetting schemes are rarely evaluated. Anadromous Pacific salmon are ecologically, culturally, and economically important in the US and Canada, and face numerous threats from degradation of freshwater habitats. Here we used a matrix population model of coho salmon (Oncorhynchus kisutch) to determine the amount of habitat offsetting needed to compensate mortality (2-20% per year) caused by a range of development activities. We simulated chronic mortality to three different life stages (egg, parr, smolt/adult), individually and simultaneously, to mimic impacts from development, and evaluated if the number of smolts produced from constructed side-channels demographically offset losses. We show that under ideal conditions, the typical size of a constructed side-channel in the Pacific Northwest (PNW) (3405 m2) is sufficient to compensate for only relatively low levels of chronic mortality to either the parr or smolt/adult stages (2-7% per year), but populations do not recover if mortality is >10% per year. When we assumed lower productivity (e.g.; 25th percentile), we found that constructed channels would need to be 2.5-4.5 fold larger as compared to the typical size built in the PNW, respectively, to maintain population sizes. Moreover, when we imposed mortality to parr and smolt/adult stages simultaneously, we found that constructed side-channels would need to be between 1.8- and 2.3- fold larger that if the extra chronic mortality was imposed to one life stage only. We conclude that habitat offsetting has the potential to mitigate chronic mortality to early life stages, but that realistic assumptions about productivity of constructed side-channels and cumulative effects of anthropogenic disturbances on multiple life stages need to be considered.


Subject(s)
Salmon/growth & development , Animals , Canada , Ecosystem , Fresh Water , Northwestern United States , Oncorhynchus kisutch/growth & development , Rivers , Seasons , United States
6.
Cureus ; 12(10): e11138, 2020 Oct 24.
Article in English | MEDLINE | ID: mdl-33240727

ABSTRACT

Background There are various algorithms for the treatment of prosthetic joint infections (PJI). Currently, a two-stage hip exchange is considered the "gold standard" of care for treatment of chronic hip PJIs. However, there has been recent debate whether a one- or two-stage exchange offers the correct treatment. One-stage exchange arthroplasty has particularly gained interest due to less morbidity, mortality, and functional impairment. Methods In a retrospective case series, the outcome of patients with chronic hip PJIs treated with our one-stage exchange arthroplasty was analyzed. Between January 2015 and January 2020, eight patients underwent a one-stage exchange hip arthroplasty by a single surgeon at a single institution for a chronically infected total hip arthroplasty (THA). Original diagnosis of PJI was made in accordance with the 2011 version of the Musculoskeletal Infection Society (MSIS) criteria. The femoral stem was cemented with antibiotic-impregnated cement, and the polyethylene acetabular liner was cemented directly onto the acetabular bone with antibiotic-impregnated cement. Results Of the eight patients, three were female and five were male with a mean age of 70.5 years (SD 11.2, range 53-87). Six patients (75%) had infection eradication with retention of a stable implant and no additional surgery at a mean follow-up of 35.7 months (range 17-50). One patient (12.5%) underwent closed reduction for a dislocated THA at one month; however, this patient remained infection-free at the most recent follow-up of 41 months. One patient (12.5%) who was the oldest patient (87 years) died 18 days postoperatively. Overall, all living patients (87.5%) retained their one-stage exchange THA. One patient (12.5%, CI 95% 0.3-52.7) required additional surgery in the form of a closed reduction and zero patients (0.0%, CI 95% 0.0-36.9) required additional open surgery.  Conclusion Single-stage exchange arthroplasty with an antibiotic-impregnated cemented femoral stem and antibiotic-impregnated cemented polyethylene acetabular liner may be a useful option for the treatment of chronic hip PJIs. Our case series provides evidence that infection eradication and function preservation are possible using our one-stage exchange arthroplasty technique in a chronically infected THA. However, a multi-center study with randomization is necessary to further validate our results.

7.
Environ Manage ; 60(4): 588-597, 2017 10.
Article in English | MEDLINE | ID: mdl-28523376

ABSTRACT

Biodiversity offset programs attempt to minimize unavoidable environmental impacts of anthropogenic activities by requiring offsetting measures in sufficient quantity to counterbalance losses due to the activity. Multipliers, or offsetting ratios, have been used to increase the amount of offsets to account for uncertainty but those ratios have generally been derived from theoretical or ad-hoc considerations. I analyzed uncertainty in the offsetting process in the context of offsetting for impacts to freshwater fisheries productivity. For aquatic habitats I demonstrate that an empirical risk-based approach for evaluating prediction uncertainty is feasible, and if data are available appropriate adjustments to offset requirements can be estimated. For two data-rich examples I estimate multipliers in the range of 1.5:1 - 2.5:1 are sufficient to account for the uncertainty in the prediction of gains and losses. For aquatic habitats adjustments for time delays in the delivery of offset benefits can also be calculated and are likely smaller than those for prediction uncertainty. However, the success of a biodiversity offsetting program will also depend on the management of the other components of risk not addressed by these adjustments.


Subject(s)
Biodiversity , Environmental Restoration and Remediation/methods , Fisheries , Uncertainty , Water Quality , Animals , Canada , Conservation of Natural Resources , Ecosystem , Environmental Restoration and Remediation/economics , Fresh Water , Risk , Time Factors
8.
Child Abuse Negl ; 32(5): 517-28, 2008 May.
Article in English | MEDLINE | ID: mdl-18513796

ABSTRACT

OBJECTIVE: To establish the prevalence, typology and nature of attempted or completed incidents of stranger-perpetrated sexual abuse or abduction of children "away from home". METHODS: A questionnaire was completed by 2,420 children (83% response rate) aged 9-16 years in 26 elementary and high schools in North-West England. RESULTS: Of these children, 19.0% (n=461) reported that they had been the victims of any attempted or completed sexual abuse or abduction incident away from home at some point in their lives. Of these children, 161 (6.7% of the original sample) reported that the "last" incident had been perpetrated by a stranger. Based upon these last incidents, four main types of attempted or completed CSA or abduction incident were identified: indecent exposure (40.8% of victims), touching (25.8%), and abduction (23.1%), each occurring on their own; and incidents involving multiple types of act (10.2%). The majority of these abductions (91.1%) and touching incidents (50.9%) were attempted as opposed to completed. Rates of victimization were generally higher among girls than boys (10.4% vs. 4.2%, p<.001). A sizeable minority of victims had experienced sexual abuse or abduction previously (28.8%). The large majority of incidents were carried out by males (88.2%). Most incidents occurred when children were accompanied by their peers (67.9%). Many victims were frightened by their experience (46.9% very frightened) and the large majority made a disclosure (79.9%). Only a minority of incidents were reported to the police (33.3%). CONCLUSIONS: Incidents of attempted and completed stranger CSA and abduction are distinct from CSA and abduction by known persons, go against stereotypes, are complex, and give rise to a number of key issues that may have implications for prevention and intervention. PRACTICE IMPLICATIONS: Professionals involved in child protection should undertake work to reduce the risk of existing victims of CSA or abduction becoming victims of stranger CSA or abduction, and the risk of attempted incidents becoming completed ones. They also need to encourage the disclosure and reporting of attempted and completed stranger CSA and abduction incidents.


Subject(s)
Child Abuse, Sexual/statistics & numerical data , Crime/statistics & numerical data , Pedophilia/epidemiology , Adolescent , Child , Child Abuse, Sexual/prevention & control , Child Abuse, Sexual/psychology , Crime/psychology , Crime Victims/legislation & jurisprudence , Crime Victims/psychology , Cross-Sectional Studies , Data Collection , Fear , Female , Humans , Incidence , Male , Pedophilia/psychology , Police , Self Disclosure , United Kingdom
9.
Conserv Biol ; 22(2): 351-61, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18241234

ABSTRACT

The endangered population of sockeye salmon (Oncorhynchus nerka) in Cultus Lake, British Columbia, Canada, migrates through commercial fishing areas along with other, much more abundant sockeye salmon populations, but it is not feasible to selectively harvest only the latter, abundant populations. This situation creates controversial trade-offs between recovery actions and economic revenue. We conducted a Bayesian decision analysis to evaluate options for recovery of Cultus Lake sockeye salmon. We used a stochastic population model that included 2 sources of uncertainty that are often omitted from such analyses: structural uncertainty in the magnitude of a potential Allee effect and implementation uncertainty (the deviation between targets and actual outcomes of management actions). Numerous state-dependent, time-independent management actions meet recovery objectives. These actions prescribe limitations on commercial harvest rates as a function of abundance of Cultus Lake sockeye salmon. We also quantified how much reduction in economic value of commercial harvests of the more abundant sockeye salmon populations would be expected for a given increase in the probability of recovery of the Cultus population. Such results illustrate how Bayesian decision analysis can rank options for dealing with conservation risks and can help inform trade-off discussions among decision makers and among groups that have competing objectives.


Subject(s)
Bayes Theorem , Conservation of Natural Resources/methods , Fisheries/economics , Fisheries/methods , Models, Theoretical , Salmon/physiology , Animals , British Columbia , Computer Simulation , Population Dynamics
10.
Water Res ; 39(16): 3967-81, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16112711

ABSTRACT

The Ribble drainage basin is the single UK sentinel study area chosen for examining the implementation of the EU Water Framework Directive (WFD 20/60/EC). The study which has generated the data for this paper was initiated to quantify 'catchment-derived' fluxes of faecal indicators originating from both point and diffuse sources to inform the competent authorities on the potential for, and prioritization of, further options for reducing the faecal indicator loadings to this crucial coastal environment. It represents the first UK drainage basin-scale 'profile' of faecal indicator sources as recommended by WHO [1999. Health Based Monitoring of Recreational Waters: The Feasibility of a New Approach; the "Annapolis Protocol". World Health Organisation Geneva, Switzerland; 2003. Guidelines for Safe Recreational-Water Environments Volume 1: Coastal and Fresh-Waters. World Health Organisation Geneva, Switzerland] and incorporated into current drafts of the revised Bathing Water Directive [Anon, 2004. Council of the European Communities Amended proposal for a Directive of the European Parliament and of the Council concerning the management of bathing water quality. Brussels 23rd June]. This paper focuses on the relationships between land use and faecal indicator organism concentrations in surface waters within this very large drainage basin (1583 km2) containing some extensive urban areas. A geographical information system comprising readily available digital elevation, remotely sensed land cover and digital map data was used to generate the land use variables for subcatchments draining to 41 locations across the study area. Presumptive concentrations of coliforms, Escherichia coli and enterococci (colony forming unit (cfu) 100 ml(-1)) were measured at each location on at least 20 occasions over a 44-day period within the 2002 bathing season. The sampling programme targeted hydrograph events. Hydrometric records were used to allocate results as either base flow or high flow. At each site, geometric mean faecal indicator organism concentrations were significantly elevated at high flow compared to base flow. Stepwise regression modelling produced statistically significant models predicting geometric mean base and high-flow faecal indicator organism concentrations from land use variables (r2: 49.5-68.1%). The dominant predictor variable in each case was the proportion of built-up land in subcatchments, suggesting that this land use type, with associated sewage-related inputs, is a critical source of faecal indicator organisms in this drainage basin.


Subject(s)
Environmental Monitoring/statistics & numerical data , Feces , Geographic Information Systems , Water Pollutants/analysis , Biomarkers , Cities , Forecasting , Humans , Models, Theoretical , Recreation , Sewage , United Kingdom , Water Movements
11.
J Environ Manage ; 69(3): 261-73, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14580727

ABSTRACT

Changes in land use can potentially reduce the quality of fish habitat and affect the economic value of commercial and sport fisheries that rely on the affected stocks. Parks and protected areas that restrict land-use activities provide benefits, such as ecosystem services, in addition to recreation and preservation of wildlife. Placing values on these other benefits of protected areas poses a major challenge for land-use planning. In this paper, we present a framework for valuing benefits for fisheries from protecting areas from degradation, using the example of the Strait of Georgia coho salmon fishery in southern British Columbia, Canada. Our study improves upon previous methods used to value fish habitat in two major respects. First, we use a bioeconomic model of the coho fishery to derive estimates of value that are consistent with economic theory. Second, we estimate the value of changing the quality of fish habitat by using empirical analyses to link fish population dynamics with indices of land use in surrounding watersheds. In our example, we estimated that the value of protecting habitat ecosystem services is C$0.93 to C$2.63 per ha of drainage basin or about C$1322 to C$7010 per km of salmon stream length (C$1.00=US$0.71). Sensitivity analyses suggest that these values are relatively robust to different assumptions, and if anything, are likely to be minimum estimates. Thus, when comparing alternative uses of land, managers should consider ecosystem services from maintaining habitat for productive fish populations along with other benefits of protected areas.


Subject(s)
Conservation of Natural Resources , Environment Design , Fisheries , Models, Economic , Oncorhynchus kisutch , Animals , Animals, Wild , British Columbia , Cost-Benefit Analysis , Ecosystem , Population Dynamics , Quality Control , Recreation , Water Pollution/prevention & control
12.
Oecologia ; 103(3): 319-326, 1995 Aug.
Article in English | MEDLINE | ID: mdl-28306825

ABSTRACT

Clinal variation in life histories can be genetically based, resulting from selection imposed by different environments, or it may be due to the differential expression of phenotypically plastic traits. We examined the cline in voltinism in the egg-diapausing cricket Allonemobius socius, with populations spanning the switch from a univoltine to a bivoltine phenology. A common garden experiment was employed, using environments that mimicked photoperiod and temperature conditions found in the field. There were only small differences in development time among populations, and the difference in phenology observed in the field is likely due to clinal variation in the length of the growing season. We found large genetically-based differences in the reaction norm for egg diapause that were further magnified by environmental cues. The synergism of genetic and environmental effects was an example of cogradient selection. In the zone of transition between phenologies, voltinism appeared to be a conditional strategy, rather than a genetic polymorphism. First-generation females from this area can lay either direct-developing or diapause eggs depending on the likelihood that a second generation will have sufficient time to develop. For this species, the cline in voltinism is the result of a combination of environmental effects on development, and genetic and environmental influences on egg diapause propensity.

13.
Oecologia ; 93(2): 263-267, 1993 Mar.
Article in English | MEDLINE | ID: mdl-28313616

ABSTRACT

We experimentally tested a series of hypotheses proposed by Masaki (1979, 1986) for the evolution of ovipositor length in crickets. Female crickets use the ovipositor to bury eggs in the soil, where it was hypothesized to protect their eggs from desiccation, cold and other disturbance. However, we found no effect of depth on the overwinter survival of eggs of three species of Nemobiinae. The probability of hatchlings reaching the soil surface was negatively correlated with depth documenting a significant cost to females laying eggs deep in the soil. Hatchling survival may be an important agent of selection on ovipositor length in habitats of different soil moistures. Hatchling survival in the soil was also correlated with body size, which may impose a constraint on egg-size fecundity trade-offs. Females of a bivoltine population of Allonemobius socius lay eggs at shallower depths when reared under summer compared to fall conditions and, therefore, may be able to respond to selection through behavioral plasticity when morphological adaptation is constrained by allometry.

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