Predicting impacts of water conservation with a stochastic sewer model.

Population growth and climate change put a strain on water resources; hence, there are growing initiatives to reduce water use. Reducing household water use will likely reduce sewer input. This work demonstrates the use of a stochastic sewer model to quantify the effect water conservation has on sewer hydraulics and wastewater concentration. Probabilistic discharge patterns have been developed using SIMDEUM WW® and fed into hydraulic modelling software InfoWorks ICM® to produce likely flow and quality profiles for five future water use scenarios. The scenarios tested were developed to outline how commercial and political factors may change water use in future. Scenario testing revealed that 15-60% water reduction reflected a 1-48% drop in the morning peak flow. The water use reduction was predicted to increase wastewater concentrations of chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and total phosphorus (TPH) by 55-180%, 19-116% and 30-206% respectively. The sewer flow model was developed, calibrated and validated using a case study in the Wessex Water region of the UK and all future scenarios were compared to the validated baseline case. This wastewater flow and quality model allows scenario testing, which could help redesign future sewer networks to better prepare for water conservation strategies.

No clinical difference between fixed- and mobile-bearing cruciate-retaining total knee arthroplasty: a prospective randomized study.

PURPOSE: It is hypothesized that mobile polyethylene bearings in total knee arthroplasty (TKA) may confer benefits with regard to range of motion and have improved clinical outcome scores in comparison with an arthroplasty with a fixed-bearing design. Our study compares clinical outcomes between patients who undergo TKA with either a rotating platform or fixed bearing using a posterior cruciate-retaining design. METHODS: Three hundred and thirty-one patients were randomized to receive either a rotating-platform (161 patients) or a fixed-bearing (170 patients) implant. All patients were assessed pre-operatively and at 1 and 2 years post-operatively using standard tools (range of movement, Oxford Knee Score, American Knee Society Score, SF12 and Patella Score). RESULTS: There was no difference in pre- to 2-year post-operative outcomes between the groups with regard to improvement in range of motion (10° ± 16 vs. 9° ± 15), improvement in Oxford Knee Score (-17.6 ± 9.9 vs. -19.1 ± 8.4), improvement in American Knee Society Score (49.5 ± 24.7 vs. 50.7 ± 21.0), function (23.6 ± 19.6 vs. 25.0 ± 22.5) and pain (34.9 ± 16.2 vs. 35.8 ± 14.1) subscores, improvement in SF12 Score (10.0 ± 16.3 vs. 12.3 ± 15.8) or improvement in Patella Score (9.7 ± 7.4 vs. 10.6 ± 7.1). CONCLUSION: No difference was demonstrated in clinical outcome between patients with a rotating-platform and fixed-bearing posterior cruciate-retaining TKA at 2-year follow-up. LEVEL OF EVIDENCE: I.

A comparison of lateral release rates in fixed- versus mobile-bearing total knee arthroplasty.

BACKGROUND: With increasing functional demands of patients undergoing total knee arthroplasty, mobile-bearing (MB) implants were developed in an attempt to increase the functional outcome of such patients. In theory, with MB implants, the self-alignment should reduce the rate of lateral release of the patella, which is usually performed to optimise patellofemoral mechanics. This study reports on the lateral release rates for the P.F.C. Sigma® MB posterior-stabilised total knee replacement (TKR) implant compared with its fixed-bearing (FB) equivalent. MATERIALS AND METHODS: A total of 352 patients undergoing TKR were randomly allocated to receive either MB (176 knees) or FB (176 knees) posterior-stabilised TKR. Further sub-randomisation into patellar resurfacing or retention was performed for both designs. The need for lateral patellar release was assessed during surgery using a 'no thumb technique', and after releasing the tourniquet if indicated. RESULTS: The lateral release rate was the same for FB (10 %) and MB implants (10 %) (p = 0.9). However, patellar resurfacing resulted in lower lateral release rates when compared to patellar retention (6 vs 14 %; p = 0.0179) especially in MB implants (3 %). CONCLUSIONS: It has been previously reported that alterations to the design of the P.F.C. system with a more anatomical trochlea in the femoral component improved patellar tracking. The addition of a rotating platform tibial component to the P.F.C. Sigma system has, on its own, had no impact on the lateral release rate in this study. Optimising patellar geometry by patellar resurfacing appears more important than tibial-bearing design. Although MB implants appear to reduce the need for lateral release in the P.F.C. Sigma Rotating Platform, this only occurs when the patellar geometry has been optimised with patellar resurfacing. LEVEL OF EVIDENCE: Level 2.

Are we ready to "think ahead"? Acceptability study using an innovative end of life planning tool.

This is a cross sectional study in 5 GP Training Practices, sample size 100 clinically stable patients, attending for routine care. Purpose of the study was explained and informed written consent was sought. Participants were provided with 'Think Ahead,' an innovative end of life planning tool, devised by The Forum on The End of Life, based on best international practice, presented in a questionnaire format, detailing main decision centres relevant in end of life planning. Participants completed telephone surveys at 1 and 3 weeks, ascertaining their experience with 'Think Ahead;' 92/100 completed both surveys. Results indicate high levels of acceptability and positive experience for most participants. A majority (63%) indicated 'no difficulty' in completing 'Think Ahead;' 74% indicated reported they did not find completing the folder to cause upset; 87% indicated they felt the folder should be more widely available, and 68% indicated they felt 'Think Ahead' would be of general interest. The study was effective in encouraging discussion on end of life issues with family (83%) with 49% indicating they had done so in detail, and 34% indicating having 'done so somewhat,' having read 'Think Ahead; 27% indicated aspects of it were upsetting. Results will be used to inform further development of the tool. General Practice consulting is a suitable context in which to systematically present 'Think Ahead.'

Public Valuation of Direct Restorations: A Discrete Choice Experiment.

Direct posterior dental restorations are commonly provided following management of dental caries. Amalgam use has been phased down and the feasibility of a phase-out by 2030 is being explored. Alternative direct restorative materials differ in their outcomes and provision. This research aimed to elicit the UK population's preferences for different attributes of restorations and their willingness to pay (WTP) for restorative services and outcomes. A discrete choice experiment (DCE) was designed with patient and public involvement and distributed to a representative sample of the UK general population using an online survey. Respondents answered 17 choice tasks between pairs of scenarios that varied in levels of 7 attributes (wait for filling, clinician type, filling color, length of procedure, likely discomfort after filling, average life span of filling, and cost). An opt-out (no treatment) was included. Mixed logit models were used for data analysis. Marginal WTP for attribute levels and relative attribute importance were calculated. In total, 1,002 respondents completed the DCE. Overall, respondents were willing to pay £39.52 to reduce a 6-wk wait for treatment to 2 wk, £13.55 to have treatment by a dentist rather than a therapist, £41.66 to change filling color from silvery/gray to white, £0.27 per minute of reduced treatment time, £116.52 to move from persistent to no postoperative pain, and £5.44 per year of increased restoration longevity. Ability to pay affected willingness to pay, with low-income respondents more likely to opt out of treatment and value restoration color (white) and increased longevity significantly lower than those with higher income. Clinicians should understand potential drivers of restoration choice, so they can be discussed with individual patients to obtain consent. It is important that policy makers consider general population preferences for restorative outcomes and services, with an awareness of how income affects these, when considering the potential phase-out of amalgam restorations.

Amalgam Phase-Down Part 1: UK-Based Posterior Restorative Material and Technique Use.

INTRODUCTION: A European Union amalgam phase-down has recently been implemented. Publicly funded health care predominates in the United Kingdom with the system favoring amalgam use. The current use of amalgam and its alternatives has not been fully investigated in the United Kingdom. OBJECTIVES: The study aimed to identify direct posterior restorative techniques, material use, and reported postoperative complication incidence experienced by primary care clinicians and differences between clinician groups. METHODS: A cross-sectional survey was distributed to primary care clinicians through British dentist and therapist associations (11,092 invitations). The questionnaire sought information on current provision of direct posterior restorations and perceived issues with the different materials. Descriptive statistical and hypothesis testing was performed. RESULTS: Dentists' response rate was 14% and therapists' estimated minimum response rate was 6% (total N = 1,513). The most commonly used restorative material was amalgam in molar teeth and composite in premolars. When placing a direct posterior mesio-occluso-distal restoration, clinicians booked on average 45% more time and charged 45% more when placing composite compared to amalgam (P < 0.0001). The reported incidences of food packing and sensitivity following the placement of direct restorations were much higher with composite than amalgam (P < 0.0001). Widely recommended techniques, such as sectional metal matrix use for posterior composites, were associated with reduced food packing (P < 0.0001) but increased time booked (P = 0.002). CONCLUSION: Amalgam use is currently high in the publicly funded sector of UK primary care. Composite is the most used alternative, but it takes longer to place and is more costly. Composite also has a higher reported incidence of postoperative complications than amalgam, but time-consuming techniques, such as sectional matrix use, can mitigate against food packing, but their use is low. Therefore, major changes in health service structure and funding and posterior composite education are required in the United Kingdom and other countries where amalgam use is prevalent, as the amalgam phase-down continues. KNOWLEDGE TRANSFER STATEMENT: This study presents data on the current provision of amalgam for posterior tooth restoration and its directly placed alternatives by primary care clinicians in the United Kingdom, where publicly funded health care with copayment provision predominates. The information is important to manage and plan the UK phase-down and proposed phase-out of amalgam and will be of interest to other, primarily developing countries where amalgam provision predominates in understanding some of the challenges faced.

Amalgam Phase-Down Part 2: UK-Based Knowledge, Opinions, and Confidence in the Alternatives.

INTRODUCTION: Amalgam use has recently been phased down, and the potential for a phase-out is being investigated. OBJECTIVES: The study aimed to identify knowledge of the phase-down and opinions of a potential phase-out of amalgam by UK primary care clinicians and assess their confidence in using different materials in different situations. METHODS: An anonymized, prepiloted cross-sectional e-survey was used to assess primary care clinicians' knowledge and opinions of the amalgam phase-down and potential phase-out and their confidence in using amalgam and the alternatives in different situations. In total, 11,902 invitations were distributed through British dentist and therapist associations. Prior hypotheses were tested alongside descriptive statistics. RESULTS: Response rate was 13% (n = 1,513). Knowledge of the amalgam phase-down was low, with just 3% clinicians correctly identifying all patient groups in whom amalgam use should be avoided in the United Kingdom. Postgraduate education on posterior composite placement was high (88%), but a large majority had personal and patient-centered concerns over the suitability of the alternatives and lacked confidence when placing composite in comparison to amalgam in difficult situations (P < 0.0001). Logistic regressions revealed that the best predictors of high confidence in placing mesio-occluso-distal composites and composites in difficult situations were being a private general dentist or being primarily a composite user. CONCLUSION: Primary care clinicians have major personal and patient-centered concerns regarding the amalgam phase-down (of which they have limited knowledge) and potential phase-out. Many lack confidence in using the alternative, composite, to restore posterior teeth in difficult situations, whereas confidence in using amalgam in similar situations is high. Effective education of clinicians and understanding patients' needs, alongside policy changes, are required to enable a successful amalgam phase-down and potential phase-out. KNOWLEDGE TRANSFER STATEMENT: This study shows that UK primary care clinicians are worried about the phase-down of amalgam for themselves and their patients. Many lack confidence in the alternative, composite, when used in difficult situations, which is in stark contrast to amalgam. Knowledge of the phase-down is limited. There is a need for more effective education of clinicians, an understanding of patients' values, and policy changes to ensure the success of the phase-down and potential phase-out of amalgam.

Effect of body mass index and osteoarthritis on outcomes following arthroscopic meniscectomy: a prospective nationwide study.

BACKGROUND: Current evidence suggests limiting arthroscopic meniscectomy to those patients with no or early arthritis however outcomes of arthroscopic meniscectomy with patients of a higher body mass index (BMI) are not as widely available. The aim of this study was to determine if patient reported outcome scores for arthroscopic meniscectomy are adversely affected by the degree of knee osteoarthritis or patient BMI. METHODS: All patients who underwent arthroscopic meniscectomy within the NHS in Scotland between the 6th of February and 29th of April 2012 were audited as part of the Scottish Government Musculoskeletal Audit and were eligible for inclusion within this study. A total of 270 patients returned both their pre-operative and post-operative EuroQol 5Q5D5L descriptive questionnaire and Knee injury and Osteoarthritis Outcomes Scores. Patients were stratified according to BMI, degree of osteoarthritis, history of injury, and duration of knee symptoms. RESULTS: Pre-operative to post-operative EuroQol index scores [0.642±0.253 to 0.735±0.277, median±SD] and Knee injury and Osteoarthrtis Outcome Scores [44.63±18.78 to 62.28±24.94, median±SD] improved across all patients (p<0.0001). This was irrespective of degree of BMI, history of injury, or duration of symptoms. There was no such improvement in patients with moderate to severe osteoarthritis. Those patients with a BMI >35 kg/m2 had lower post-operative scores than the pre-operative scores of those of BMI <30 kg/m2. CONCLUSIONS: Arthroscopic meniscectomy is beneficial regardless of patient BMI, duration of symptoms, history of injury, or in the presence of early osteoarthritis.

Falcine chondrosarcoma: case report and literature review.

We present a case of falcine chondrosarcoma in a 58-year-old man. Only a few other examples of chondrosarcomas in this location and a total of approximately 50 intracranial cases have been reported. Because its rarity prevents any group of neurosurgeons from collecting a large experience in managing this tumor, we reviewed descriptions of previous cases to determine the natural history of intracranial chondrosarcomas. The distinguishing features of this rare tumor are compared with previous examples of intracranial tumors derived from cartilage and more common tumors in the parasagittal region, such as meningioma.

Intramedullary cystic teratoid tumor of the cervical spinal cord in association with a teratoma of the ovary.

A 15-year-old black female student came to the hospital because of disturbance of her gait. On examination, there was a dermal sinus in the skin overlying the spine of the seventh cervical vertebra, and myelography with computed tomography scan demonstrated a block to the flow of metrizamide contrast material at T-5 with cephalad extension of an intradural cystic lesion to the C-5 level. An x-ray examination of the abdomen at the time demonstrated a tooth-shaped radiodensity in the left hypogastrium. On exploration of the spine via C5-T5 laminectomy an intramedullary cystic teratoid tumor was found which was partially excised. At later exploration of the abdomen, a teratoma of the left ovary was removed. The pathology and natural history of teratomas and teratoid tumors is discussed along with surgical management of these tumors.

Excision of a large pineal region hemangiopericytoma (angioblastic meningioma, hemangiopericytoma type).

A large hemangiopericytoma was located posterocentrally. The patient presented with headaches and papilledema. Surgical management consisted of total gross excision by a combined right occipital transtentorial and right occipitoparietal transfalcine approach under magnification in three stages over a 6-week period. Removal was aided by dilatation of the right temperooccipital horn ("trapped ventricle") and meningioma-like encapsulation allowed separation of the tumor from the brain and surrounding structures after internal debulking of the tumor. Subsequent peritoneal shunting of the trapped ventricular horn and 5000 rads of radiotherapy were given to the patient. She remains well with an inferior quadrantanopsia on the left side more than 1 year after treatment. Meningiomas of the pineal region, the relationship of meningioma to hemangiopericytoma and malignant mesenchymal tumors (sarcomas) are considered in reference to presumed cells of origin.

Prevention of persistent infection in calves by vaccination of dams with noncytopathic type-1 modified-live bovine viral diarrhea virus prior to breeding.

OBJECTIVE: To determine the ability of a modified-live virus (MLV) bovine viral diarrhea virus (BVDV) type 1 (BVDV1) vaccine administered to heifers prior to breeding to stimulate protective immunity that would block transmission of virulent heterologous BVDV during gestation, thus preventing persistent infection of a fetus. ANIMAL: 40 crossbred Angus heifers that were 15 to 18 months old and seronegative for BVDV and 36 calves born to those heifers. PROCEDURE: Heifers were randomly assigned to control (n = 13) or vaccinated (27) groups. The control group was administered a multivalent vaccine where-in the BVDV component had been omitted. The vaccinated heifers were administered a single dose of vaccine (IM or SC) containing MLV BVDV1 (WRL strain). All vaccinated and control heifers were maintained in pastures and exposed to BVDV-negative bulls 21 days later. Thirty-five heifers were confirmed pregnant and were challenge exposed at 55 to 100 days of gestation by IV administration of virulent BVDV1 (7443 strain). RESULTS: All control heifers were viremic following challenge exposure, and calves born to control heifers were persistently infected with BVDV. Viremia was not detected in the vaccinated heifers, and 92% of calves born to vaccinated heifers were not persistently infected with BVDV. CONCLUSIONS AND CLINICAL RELEVANCE: These results document that vaccination with BVDV1 strain WRL protects fetuses from infection with heterologous virulent BVDV1.

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: II. Characteristics and tolerances of the pocket mouse and incidence of disease.

Pocket mice are facultative homoiotherms with the ability to drop their metabolic rate dramatically while at rest or in response to environmental stresses. Under these conditions, they characteristically enter a state of prolonged torpor. These animals require no drinking water and they can live in darkness for many months without apparent ill effect. They tolerate a wide range of ambient temperature, ralative humidity, and oxygen pressure and have survied without food for a mean of 14 d at an ambient temperature of 20 degrees C (68 degrees F). Studies carried out on the pocket mouse colony used for the Apollo XVII flight revealed, in the animals tested, no serological evidence of viral disease, no pathogenic enterobacteria or respiratory Mycoplasma on culture, a 25% incidence of sarcosporidiosis, and a 2% incidence of chronic meningitis or meningoencephalitis. The conclusion reached is that the pocket mouse is a highly adaptive animal and very well suited for space flight.

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: XII. Results of examination of the calvarium, brain, and meninges.

Tissue reactions were found around the monitor (dosimeter) assemblies that had been implanted beneath the scalp of the five pocket mice that flew on Apollo XVII. Mitosis in the dentate gyrus of the hippocampal formation was considerably reduced in comparison with that in control animals. Otherwise the brain tissue as well as the menings in the flight animals appeared unaltered. Since the animals were exposed primarily to high Z-high energy (HZE) cosmic ray particles at the lower end of the high LET spectrum, the lack of changes in the brain cannot be taken as evidence that the brain will suffer no damage from the heavier HZE particles on prolonged manned missions.

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: X. Results of ear examination.

In the five pocket mice flown on Apollo XVII, no evidence was found that the inner ear had been damaged, though poor fixation precluded detailed study. On the other hand, the middle ear cavity was involved in all the mice, hemorrhage having occurrred in response to excursions in pressure within the canister that housed the mice during their flight. The same occurred in flight control mice which had been subjected to pressure excursions of much the same magnitude. A greater degree of exudation into air cells and greater leukotaxis were noted in the flight animals than in the control animals. There was no increase in leukocyte population along the paths of the 23 cosmic ray particles registered in the subscalp dosimeters that traversed the middle ear cavities of the flight mice. The increased exudation and the greater response by leukocytes in the flight mice may have been causally related to the lesions found in their olfactory mucosa but there were no data in support of this possibility.

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: IX Results of examination of the nasal mucosa.

The olfactory epithelium, but not the nasal respiratory epithelium, of the four pocket mice (Perognathus longimembris) that survived their flight on Apollo XVII showed both diffuse alterations and numerous disseminated focal lesions. The olfactory mucosa of the mouse that died during flight was also affected, but to a minor degree insofar as could be determined. All this was in contrast to the normal appearance of the olfactory mucosa of the numerous control animals. A number of possible causes were considered: systemic or regional infection; inhaled particulate material (seed dust); by-products from the KO2 bed in aerosol or particulate form; gas contaminants originating in the flight package; volatile substances from the dead mouse; weightlessness; and cosmic ray particle radiation. Where feasible, studies were conducted in an effort to rule in or rule out some of these potentially causative factors. No definitive conclusions were reached as to the cause of the lesions in the flight mice.

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: appendix III. evaluation of viscera and other tissues.

Histopathological findings in the lungs, livers, bone marrows, small intestines, gonads, kidneys, and other tissues of the four pocket mice (Perognathus longimembris) that survived the Apollo XVII flight were evaluated in the light of their immediate environment and as targest of HZE cosmic ray particles. Results of this study failed to disclose changes that could be ascribed to the HZE particle radiation. Decreased numbers of erythropoietic cells in the bone marrow of the flight mice were probably related to the increased oxygen pressure. The small intestine showed no changes. Ovaries and tests appeared normal. Two of the three surviving male flight mice displayed early stages of spermatogenesis, just as ground-based controls did at the same season. Abnormalities were also not found in the thyroid, parathyroids, adrenals, or kidneys. The status of the juxtaglomerular apparatus could not be evaluated. The lungs exhibited nonspecific slight rections. A variety of incidental lesions were noted in the livers of both the flight mice and their controls. The heart muscle showed nothing that could be regarded as pathological. Sections of skeletal muscle examined were free from significant change.

Antibiotic-related acute kidney injury in patients undergoing elective joint replacement.

The aim of this study was to determine if a change in antibiotic prophylaxis for routine hip and knee replacement was associated with an increased risk of acute renal impairment. We identified 238 patients (128 knees and 110 hips) who had received a single prophylactic dose of 1.5 g cefuroxime before joint replacement. We compared them with prospectively collected data from 254 patients (117 knees and 137 hips) who received a single prophylactic dose of 2 g flucloxacillin and a height- and gender-determined dose of gentamicin. The primary outcome measure was any new renal impairment as graded by clinically validated criteria. We identified four patients (1.69%) in the cefuroxime group who developed renal impairment. All four had mild impairment and all renal function was normal by the third post-operative day. The incidence of new-onset renal impairment was significantly higher in the flucloxacillin-and-gentamicin group at 9.45% (24 patients) (p < 0.001). Three of these patients remained with acute renal impairment after a week, although the serum creatinine levels in all subsequently returned to normal.

A prospective randomised study comparing rotating platform and fixed bearing total knee arthroplasty in a cruciate substituting design--outcomes at two year follow-up.

BACKGROUND: Fixed bearing (FB) total knee replacement is a well established technique against which new techniques must be compared. Mobile bearing (MB) prostheses, in theory, reduce polyethylene wear but the literature is yet to provide evidence that they are superior in terms of function or long-term survivorship. In addition there has been no comparison of patella resurfacing on the outcome of either design. The aims of this randomised prospective study were firstly to determine whether a mobile bearing prosthesis produced better clinical outcome and range of motion at two year follow-up and secondly to assess the effect of patella resurfacing on the outcomes of both types of bearing design. METHODS: Three hundred fifty-two patients were randomised into receiving either a PFC Sigma© cruciate sacrificing total knee arthroplasty either with a mobile bearing or a fixed bearing, with a sub-randomisation to either patella resurfacing or patella retention. All patients participated with standard clinical outcome measures and had their range of motion measured both pre-operatively and at follow-up. RESULTS: The mobile bearing TKR design had no impact on range of motion; Oxford Knee Score and American Knee Society knee and function scores when compared to its fixed bearing equivalent. CONCLUSIONS: At two year follow-up there was no difference between the PFC Sigma© fixed and mobile bearing designs. With no clinical difference between the cohorts, we cannot recommend one design over the other. Long term benefits, particularly with regards to polyethylene wear, may yet be demonstrated. Level of evidence--1B.