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Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.
Various medications and devices are available for facilitation of emergent endotracheal intubations (EETIs). The objective of this study was to survey which medications and devices are being utilized for intubation by Canadian physicians.
A clinical scenario-based survey was developed to determine which medications physicians would administer to facilitate EETI, their first choice of intubation device, and backup strategy should their first choice fail. The survey was distributed to Canadian emergency medicine (EM) and intensive care unit (ICU) physicians using web-based and postal methods. Physicians were asked questions based on three scenarios (trauma; pneumonia; heart failure) and responded using a 5-point scale ranging from “always” to “never” to capture usual practice.
The survey response rate was 50.2% (882/1,758). Most physicians indicated a Macintosh blade with direct laryngoscopy would “always/often” be their first choice of intubation device in the three scenarios (mean 85% [79%-89%]) followed by video laryngoscopy (mean 37% [30%-49%]). The most common backup device chosen was an extraglottic device (mean 59% [56%-60%]). The medications most physicians would “always/often” administer were fentanyl (mean 45% [42%-51%]) and etomidate (mean 38% [25%-50%]). EM physicians were more likely than ICU physicians to paralyze patients for EETI (adjusted odds ratio 3.40; 95% CI 2.90-4.00).
Most EM and ICU physicians utilize direct laryngoscopy with a Macintosh blade as a primary device for EETI and an extraglottic device as a backup strategy. This survey highlights variation in Canadian practice patterns for some aspects of intubation in critically ill patients.
To determine the effect of graft choice (allograft, bone-patellar tendon-bone autograft, or hamstring autograft) on deep tissue infections following anterior cruciate ligament (ACL) reconstructions.
Retrospective cohort study.
SETTING AND POPULATION
Patients from 6 US health plans who underwent ACL reconstruction from January 1, 2000, through December 31, 2008.
We identified ACL reconstructions and potential postoperative infections using claims data. A hierarchical stratified sampling strategy was used to identify patients for medical record review to confirm ACL reconstructions and to determine allograft vs autograft tissue implanted, clinical characteristics, and infection status. We estimated infection rates overall and by graft type. We used logistic regression to assess the association between infections and patients’ demographic characteristics, comorbidities, and choice of graft.
On review of 1,452 medical records, we found 55 deep wound infections. With correction for sampling weights, infection rates varied by graft type: 0.5% (95% CI, 0.3%-0.8%) with allografts, 0.6% (0.1%–1.5%) with bone-patellar tendon-bone autografts, and 2.5% (1.9%–3.1%) with hamstring autograft. After adjusting for potential confounders, we found an increased infection risk with hamstring autografts compared with allografts (odds ratio, 5.9; 95% CI, 2.8–12.8). However, there was no difference in infection risk among bone-patellar tendon-bone autografts vs allografts (odds ratio, 1.2; 95% CI, 0.3–4.8).
The overall risk for deep wound infections following ACL reconstruction is low but it does vary by graft type. Infection risk was highest in hamstring autograft recipients compared with allograft recipients and bone-patellar tendon-bone autograft recipients.
A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
Background: Gamma Knife (GK) radiosurgery for pediatric arteriovenous malformations (AVM) of the brain presents a non-invasive treatment option. We report our institutional experience with GK for pediatric AVMs. Methods: We performed a retrospective review of all pediatric patients treated with GK for cerebral AVMs at our institution from November 2003 up to and including September 2014. Patient demographics, AVM characteristics, treatment parameters and AVM responses were recorded.Results: Nineteen patients were treated, with 4 lost to follow-up. The mean age was 14.2 years (range. 7-18 years), with 10 being males (52.6%). The mean AVM diameter and volume were 2.68 cm and 3.10 cm3 respectively. The mean Spetzler-Martin (SM) and Pollock grades of the treated AVMs were 2.4 and 0.99 respectively. The mean follow-up was 62 months. All AVMs treated demonstrated a response on follow-up imaging. Nine of 15 (60.0%) patients displayed obliteration of their AVMs. Nine of 11 patients with a minimum of 3 years follow-up (81.8%) displayed obliteration, with SM and Pollock grades correlating to the chance of obliteration in this group. Two patients developed post-GK edema requiring short course dexamethasone therapy. No other major complications occurred. No permanent complications occurred.Conclusions: GK radiosurgery for pediatric AVMs offers a safe and effective treatment option, with low permanent complication rates during early follow-up.
For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.
To explore the feasibility of identifying anterior cruciate ligament (ACL) allograft implantations and infections using claims.
Retrospective cohort study.
We identified ACL reconstructions using procedure codes at 6 health plans from 2000 to 2008. We then identified potential infections using claims-based indicators of infection, including diagnoses, procedures, antibiotic dispensings, specialty consultations, emergency department visits, and hospitalizations. Patients’ medical records were reviewed to determine graft type, validate infection status, and calculate sensitivity and positive predictive value (PPV) for indicators of ACL allografts and infections.
A total of 11,778 patients with codes for ACL reconstruction were identified. After chart review, PPV for ACL reconstruction was 96% (95% confidence interval [CI], 94%–97%). Of the confirmed ACL reconstructions, 39% (95% CI, 35%–42%) used allograft tissues. The deep infection rate after ACL reconstruction was 1.0% (95% CI, 0.7%–1.4%). The odds ratio of infection for allografts versus autografts was 0.41 (95% CI, 0.19–0.78). Sensitivity of individual claims-based indicators for deep infection after ACL reconstruction ranged from 0% to 75% and PPV from 0% to 100%. Claims-based infection indicators could be combined to enhance sensitivity or PPV but not both.
While claims data accurately identify ACL reconstructions, they poorly distinguish between allografts and autografts and identify infections with variable accuracy. Claims data could be useful to monitor infection trends after ACL reconstruction, with different algorithms optimized for different surveillance goals.
Temperate and boreal forests in Canada and the northeastern United States have been invaded by several exotic species, including European earthworms (family Lumbricidae) and garlic mustard. Earthworms and garlic mustard co-occur and are both known to adversely impact some native plant species. However, relatively little is known about potential interactions between these two invaders. In a series of growth chamber experiments, we determined the palatability of garlic mustard and six native herbaceous forest species (shooting star, columbine, wild geranium, sweet cicely, butterfly milkweed, and yellow jewelweed) to the common nightcrawler. We also assessed the ability of the common nightcrawler to bury and digest garlic mustard and wild geranium. When offered seeds from garlic mustard and a native plant species, the earthworms ingested more garlic mustard seeds than seeds from four of the six native species. In a mesocosm experiment, the common nightcrawlers apparently digested 72 and 27% of garlic mustard and wild geranium seeds, respectively, that were placed on the soil surface. No seeds were observed on the soil surface at the end of the experiment but the majority of recovered seeds for both species were found within the top 10 cm (3.94 in). More seeds were recovered in 0- to 10-cm and 31- to 40-cm sections for wild geranium than for garlic mustard. No difference in seed recovery was detected at the other depths. Garlic mustard seed is readily consumed by common nightcrawlers and appears to be preferred over some native plant species suggesting that common nightcrawlers may reduce the size of the garlic mustard seed bank.
Conjugated linoleic acid (CLA) reduces mammary milk fat synthesis in a dose-dependent manner. Our objective was to determine the effects of lipid-encapsulated CLA (LE-CLA) supplementation on milk production, reproductive performance and metabolic responses in lactating dairy cows fed a grass silage-based diet. Seventy-two Holstein-Friesian cows (32 primiparous and 40 multiparous) were used in a completely randomized block design. Cows received either 80 g of LE-CLA daily or 60 g of calcium salts of palm fatty acids daily (control) from parturition until 60 days in milk. LE-CLA contained a 50:50 mix of cis-9,trans-11 CLA and trans-10,cis-12 CLA, resulting in a daily intake of 6 g of each isomer. Milk production and dry matter intake were recorded daily, and blood samples were collected 3-times a week. Blood samples were analysed for circulating concentrations of glucose, non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), insulin and insulin-like growth factor-I (IGF-I). Progesterone was measured in blood samples collected after the first post-partum insemination. Ovarian ultrasound examinations commenced at 8–10 d post partum and were carried out 3-times a week until first ovulation. LE-CLA treatment resulted in decreased milk fat concentration, with consequent improvements in energy balance and body condition score (BCS). The peak concentration of NEFA in blood was reduced by LE-CLA, but circulating concentrations of insulin, glucose, IGF-I, BHBA and progesterone were not affected. There was no effect of LE-CLA supplementation on the post-partum interval to first ovulation. Services per conception tended to be reduced. The reduction in milk energy output and improvement in energy status and BCS in LE-CLA-supplemented cows provides a strong rationale for further studies with greater cow numbers to test effects on reproductive performance.
Tests were performed to determine whether combining two thrips lures, ethyl nicotinate (EN) and ethyl isonicotinate (EI), in the same water trap increased the numbers of New Zealand flower thrips (NZFT), Thrips obscuratus Crawford, and onion thrips, T. tabaci Lindeman (Thysanoptera: Terebrantia: Thripidae), caught in the field relative to traps with a single lure. Traps with both lures (1:1 ratio; mixture or separate adjacent vials) caught 5–9 times more female onion thrips (thelyotokous populations are the most prevalent in New Zealand) than traps with EN only (P<0.001), but in similar numbers to traps with EI only. Traps with both lures caught 2–3 times as many male and female NZFT than traps with EI only, but in similar numbers to traps with EN only. Thus, a combination of the two lures in one trap could be used to detect and monitor flying onion thrips and NZFT simultaneously.
Developer-funded archaeology on the Isle of Sheppey resulted in the discovery of not one but two Neolithic causewayed enclosures on the same hilltop in very close (c. 300 m) proximity. In the later Bronze Age enclosures and cremation cemeteries were constructed immediately to the east, followed by Iron Age enclosures and, ultimately, field systems dating to the later Iron Age onwards.
A radiocarbon programme enabled the chronological sequence and hiatus between all of these events to be discerned, but the majority of this paper explores the physical, chronological, and social relationship between the two Neolithic causewayed enclosures. These were of different forms and, although on the same hilltop, they each seem to have had distinctly different viewsheds over the Thames and the Swale respectively. There are subtle, but potentially significant, differences in the material culture and deposition which allow exploration of the possible functions and role(s) of the two largely contemporaneous sites. Questions may be addressed such as whether they performed the same functions for two communities or had separate and distinct roles for a single community. Beyond the Neolithic, the paper also explores the nature of the later use of the hilltop. The Bronze Age enclosures, though agricultural in function, clearly seem to respect their Neolithic predecessors invoking a remembrance of space, which is lost by the Iron Age. The shift away from the special function of this landscape in the Neolithic to a subsequent agricultural use is explored, as is the hiatus in use and subsequent re-use of the area.
Abstract. The polities of Canada and the United States are
purportedly engaged in the process of value convergence; however, with
regard to the legitimacy of foreign military intervention, divergence
seems a more apt characterization. This research explores whether the
current discord between Canada and the US reflects an aberration, or a
realization of entrenched normative differences, over what justifies the
use of military force. A series of regression models tests the hypothesis
that justice considerations prompted the military interventions of both
the US and Canada during the Cold War. The results herein fail to confirm
this hypothesis, and in the process highlight the ways in which each
country employed ‘justice’ selectively in the service of
broader foreign policy objectives.
Résumé. Les constitutions politiques des
États-Unis et du Canada sont supposées tendre vers des
valeurs communes; cependant, en ce qui concerne la reconnaissance de la
légitimité des interventions militaires à
l'étranger, la divergence semble être une
caractérisation plus juste. Cette recherche explore si le
désaccord actuel entre les États-Unis et le Canada
reflète une certaine aberration ou la réalisation de
différences profondément ancrées, concernant la
justification de l'utilisation de la force militaire. Une
série de modèles régressifs teste
l'hypothèse selon laquelle des considérations de
justice ont provoqué les interventions militaires des
États-Unis et du Canada durant la guerre froide. Les
résultats infirment cette hypothèse, et soulignent, en
même temps, les façons dont chacun des deux pays a
employé la “ justice ” de manière
sélective pour servir des objectifs plus vastes de politique
We investigated the relationship among gender of resident, staff social interaction, and agitation in 46 (31 male and 15 female) nursing home residents with clinically significant agitation. Direct observations were conducted of resident behaviors and environmental contextual events using a computer-assisted, real-time observational system. The system recored frequency, duration, and temporal sequencing of events. Results show that female residents displayed almost three times the amount of agitation as male residents (35% vs. 13% of total observation time, respectively), although men in the study were more likely to receive psychoactive drugs for their agitation. Staff spent similar amounts of time verbally interacting and touching male and female residents. Sequential analyses were conducted to examine the likelihood of staff verbal and touch interactions both preceding and following resident agitation using Bakeman and Quera's (1995) SDIS-GSEQ program. Results suggest that staff touch and verbal interaction elicit agitation in a significant proportion of residents. Once agitation occurs, staff were likely to respond by interacting verbally, but not physically, with the resident.
Objective: To assess the outcome of treatment, a cross section of women from seven inpatient centres treating alcoholics were interviewed twice: as they entered treatment (n=114) and one year later (n=74) when they returned to the community.
Method: The patients were interviewed as they began treatment and 65% were traced for interviews one year later. Measures of self esteem, emotional health and drinking patterns are presented over time.
Results: Approximately one half of the women were abstinent when interviewed again and improved emotional health was related to abstinence. Of those who continued to drink many reduced their intake. A logistic regression analysis was applied to the data to explain the results. Among the major findings was the ability of therapists to predict subsequent drinking with a high degree of accuracy.
Conclusions: All of the services have abstinence as their goal. This could be challenged since at follow up only half of the women are abstinent. Controlled drinking may well be a valid objective if abstinence fails or could well be a valid objective for some patients.
This Z-part document updates and replaces the previously published Centers for Disease Control and Prevention Guideline for Prevention of Nosocomial Pneumonia (Infect Control 1982;3:327-33, Respir Care 1983;28:221-32, and Am J Infect Control 1983;11:230-44). The revised guideline is designed to reduce the incidence of nosocomial pneumonia and intended for use by personnel who are responsible for surveillance and control of infections in acute-care hospitals. The guideline may not be applicable in long-term care facilities because of the unique characteristics of these settings.
The revised guideline addresses common problems encountered by infection control practitioners regarding the prevention and control of nosocomial pneumonia in U.S. hospitals. Sections on the prevention of bacterial pneumonia in tnechanically ventilated and/or critically ill patients, care of respiratory-therapy devices, prevention of cross-contamination, and prevention of viral lower respiratory tract infections, such as respiratory syncytial virus (RSV) and influenza infections, have been expanded and updated. New sections on Legionnaires' disease and pneumonia due to Aspergillus spp. have been added. Lower respiratory tract infection due to Mycobacterium tuberculosis is not addressed in this document: it is covered in separate guidelines.
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