One size fits all? Stature estimation from footprints and the effect of substrate and speed on footprint creation

Estimation of stature from footprint lengths is a common prediction in forensic cases and in paleoanthropology upon the discovery of fossil footprints. Many studies, which have estimated stature from footprints, generally use a “one-size-fits-all” approach that usually involves applying a known ratio of foot length to total stature to do so, although this method has fallen out of practice in forensic cases in recent years but is still commonly used for fossil trace evidence. Yet, we know that substrate and speed can change the dimensions of a footprint, so why are these “one-size-fits-all” approaches still used today? We tested footprint production across different substrates at a walk, a fast walk, and a jog. We calculated how accurately footprint dimensions were impressed between these different conditions and identified sources of error in footprint lengths, and the percentage changes of how significantly a footprint can change in length between different conditions. We provide a table with different ratios that we encourage practitioners/field scientists to refer to and use when estimating stature from footprints, with respect to the substrate on which the footprint was created and the speed at which it was created. We actively encourage researchers to add the ratios by testing more substrates so that in the future stature can be more accurately estimated, thus aiding the paleoanthropological community, but also forensic investigations by statistically highlighting how different conditions can affect trace dimensions.     

Laminectomies and achondroplasia: does body mass index influence surgical outcomes?

Obesity is a widespread and potentially serious health problem in individuals with achondroplasia. In addition to obesity, such individuals commonly experience lumbar spinal stenosis. Although laminectomies have long been the method of choice for thorough lumbar decompression, to the best of our knowledge, the relationship between body mass index (BMI) and surgical outcomes after laminectomy in patients with achondroplasia has not been investigated in a large patient population. Through a retrospective medical record review of the initial laminectomies of all individuals with achondroplasia at our institution for whom adequate records were available, we evaluated the influence of BMI on surgical outcomes after laminectomy via four criteria: (1) change in Rankin score; (2) change in walking distance; (3) intra-operative and post-operative complications; and (4) need for subsequent revision laminectomies. The 49 individuals (mean BMI: 31.5 kg/m(2) at the time of laminectomy) were stratified into the standard BMI categories: normal (<25 kg/m(2)), overweight (25-29.9 kg/m(2)), obese Class I (30-34.9 kg/m(2)), and a combined obese Class II (35-39.9 kg/m(2)) and obese Class III (>40 kg/m(2)). Our analysis indicated that there was no statistical difference between these groups in terms of the four criteria. When the study group was categorized into non-obese (normal weight and overweight) and obese (obese Classes I and II/III) groups, there was also no statistically significant improvement difference in terms the same four criteria. Our data suggest that obesity does not pose additional risks to laminectomy in individuals with achondroplasia.     

Are body dissatisfaction, eating disturbance, and body mass index predictors of suicidal behavior in adolescents? A longitudinal study

Disordered eating, body dissatisfaction, and obesity have been associated cross sectionally with suicidal behavior in adolescents. To determine the extent to which these variables predicted suicidal ideation and attempts, the authors examined these relationships in a longitudinal design. The study population included 2,516 older adolescents and young adults who completed surveys for Project EAT-II (Time 2), a 5-year follow-up study of adolescents who had taken part in Project EAT (Time 1). Odds ratios for suicidal behaviors at Time 2 were estimated with multiple logistic regression. Predictor variables included Time 1 extreme and unhealthy weight control behaviors (EWCB and UWCB), body dissatisfaction, and body mass index percentile. Suicidal ideation was reported by 15.2% of young men and 21.6% of young women, and suicide attempts were reported by 3.5% of young men and 8.7% of young women. For young women, suicidal ideation at Time 2 was predicted by Time 1 EWCB. The odds ratio for suicide attempts was similarly elevated in young women who had reported EWCB at Time 1. These odds ratios for both suicidal ideation and suicide attempts remained elevated even after controlling for Time 2 depressive symptoms. In young men, EWCB was not associated with suicidal ideation or suicide attempts 5 years later. Body mass index and body dissatisfaction did not predict suicidal ideation or suicide attempts in young men or young women. These results emphasize the importance of EWCB.     

Is body mass index the prognostic factor in breast cancer?: a meta-analysis.

This study was performed to integrate the results of previous studies that investigated the relationship between body mass index (BMI) and prognosis in breast cancer. We reviewed the English literatures using the MEDLINE database from 1966 to 1999. The materials included 12 published articles with a total of 8,029 cases of breast cancer. The effect size was obtained from hazard ratio in each study. Homogeneity test was conducted before the integration of each effect size and the result demonstrated that the studies were heterogeneous. A random effect model was used to integrate the overall effect size. The integrated effect size was 1.56 (95% confidence interval, 1.22-2.00). In addition, publication bias should be accounted for because each published study was asymmetric in shape revealed by funnel plot. These results suggest that BMI have a prognostic significance in breast cancer. We believe that well-designed longitudinal studies, involving a large number of samples are required to resolve these issues.     

Why is the body mass index calculated as mass/height2, not as mass/height3?

BACKGROUND: The body mass index or BMI, mass/height(2), is used to predict fatness and health. It is an approximation to the Benn index, mass/height(p), where p (typically 1.1-2.5 for adult populations) makes the index uncorrelated with height. Mass/height(3) is an index of body build that is independent of scale and statistics. AIM: To explain why p varies and is less than three, show how statistical methods can distort perceptions of mass-height relationships, and clarify the nature of the BMI. METHODS: A hypothetical adult population is modelled statistically, with mass being approximately proportional to height(3) and with neither variable determining the other. Values of p are calculated both for the model and for real adults. RESULTS: In both cases p increases with the correlation between mass and height. Both p and that correlation are usually lower for women than for men. CONCLUSIONS: In adult populations mass must vary more nearly with height(3) than with height(2), although, for reasons explained, conventional statistical techniques suggest otherwise. Nevertheless the BMI is a valid predictor of fatness from mass and height in adults and is properly divisible into fat mass and fat-free mass indices. The validity of the latter three indices for children is questionable.     

Bacterial and viral co-infections complicating severe influenza: Incidence and impact among 507 U.S. patients, 2013–14

BackgroundInfluenza acts synergistically with bacterial co-pathogens. Few studies have described co-infection in a large cohort with severe influenza infection.ObjectivesTo describe the spectrum and clinical impact of co-infections.Study designRetrospective cohort study of patients with severe influenza infection from September 2013 through April 2014 in intensive care units at 33 U.S. hospitals comparing characteristics of cases with and without co-infection in bivariable and multivariable analysis.ResultsOf 507 adult and pediatric patients, 114 (22.5%) developed bacterial co-infection and 23 (4.5%) developed viral co-infection. Staphylococcus aureus was the most common cause of co-infection, isolated in 47 (9.3%) patients. Characteristics independently associated with the development of bacterial co-infection of adult patients in a logistic regression model included the absence of cardiovascular disease (OR 0.41 [0.23–0.73], p = 0.003), leukocytosis (>11 K/μl, OR 3.7 [2.2–6.2], p < 0.001; reference: normal WBC 3.5–11 K/μl) at ICU admission and a higher ICU admission SOFA score (for each increase by 1 in SOFA score, OR 1.1 [1.0–1.2], p = 0.001). Bacterial co-infections (OR 2.2 [1.4–3.6], p = 0.001) and viral co-infections (OR 3.1 [1.3–7.4], p = 0.010) were both associated with death in bivariable analysis. Patients with a bacterial co-infection had a longer hospital stay, a longer ICU stay and were likely to have had a greater delay in the initiation of antiviral administration than patients without co-infection (p < 0.05) in bivariable analysis.ConclusionsBacterial co-infections were common, resulted in delay of antiviral therapy and were associated with increased resource allocation and higher mortality.     

Do physical activity and body mass index modify the association between chronic musculoskeletal pain and insomnia? Longitudinal data from the HUNT study,Norway

We investigated the prospective association between chronic musculoskeletal pain and risk of insomnia, and if leisure‐time physical activity and body mass index modify this association. The study comprised historical data on 11 909 women and 9938 men in the Norwegian HUNT study without sleep problems at baseline in 1995–97 and followed‐up for insomnia in 2006–08. Poisson regression was used to estimate adjusted risk ratios (RRs) with 95% confidence intervals (CIs). Compared to pain‐free participants, any chronic pain was associated with a RR of insomnia of 2.27 (95% CI: 1.93, 2.66) in women and 1.58 (95% CI: 1.28, 1.95) in men, whereas reporting ≥5 chronic pain sites gave RRs of 3.20 (95% CI: 2.60, 3.95) and 2.40 (95% CI: 1.76, 3.27), respectively. Analysis of joint effects showed that: (i) compared to pain‐free physically active people, RRs in people with ≥5 chronic pain sites were 3.77 (95% CI: 2.42–5.85) if they were inactive and 2.76 (95% CI: 2.29, 3.31) if they were active; and (ii) compared to pain‐free people with normal weight, RRs in people with ≥5 chronic pain sites were 3.52 (95% CI: 2.81, 4.40) if they were obese and 2.93 (95% CI: 2.24, 3.84) if they had normal weight. In conclusion, chronic musculoskeletal pain increases the risk of insomnia, particularly among those who report several pain sites. Although there was no clear evidence of modifying effects, our results suggest that a healthy active lifestyle reduces the risk of insomnia in people with chronic musculoskeletal pain.     

Does the relationship of ambulatory blood pressure to position and location vary by age,sex, race/ethnicity,or body mass index?

The effects of position and location on ambulatory blood pressure, and the variability in these effects across individuals was examined. The extent to which the variability among individuals could be predicted by age, sex, race/ethnicity, and body mass was also assessed. The data include 24-hour ambulatory blood pressure recordings of 246 subjects from an ongoing worksite study. A random coefficients model yielded estimates of within-person and between-person effects. The position and location of individuals significantly affect their ambulatory blood pressure. As position changes from reclining to sitting to standing, blood pressure increases, after controlling for location. Likewise, blood pressure is typically higher at work than at home, controlling for position. The effects on blood pressure of both position and location vary considerably across persons. Interpersonal variability, measured by the standard deviation, is typically 30–75% as large as the variability in mean levels of blood pressure. There is also an interaction effect of position and location: the difference in blood pressure between standing and sitting down at work is not the same as the corresponding difference at home. Age, sex, race/ethnicity, and body mass index (BMI) predict 17% of the interpersonal variability in average systolic blood pressure while sitting at home, and 6% in diastolic blood pressure. The analysis of whether the effects of position or location vary by age, sex, race/ethnicity or BMI shows that the difference between work and home blood pressures is not significantly related to any of these four factors. However, the difference between awake and sleep diastolic blood pressures can be predicted, in part, by age and perhaps race/ethnicity. As age increases, the drop in diastolic blood pressure during sleep is attenuated. Hispanics also appear to experience a smaller drop in blood pressure during sleep. The drop in blood pressure associated with lying down (while awake) is similarly related to age and race/ethnicity. The increase in blood pressure associated with standing (vs. sitting) while at work is also attenuated in older individuals. Although significant interaction effects were demonstrated, these four major risk factors for hypertension predicted only small percentages of the interpersonal variability in the effects of position and location on blood pressure. Am. J. Hum. Biol. 10:459–470, 1998. © 1998 Wiley-Liss, Inc.     

Relationships between a walk test,body size and metabolic risk among a New Zealand Māori community

Abstract

Aims: Programmes to prevent or delay chronic disease incorporate promotion of physical activity, particularly walking. The objective of this study was to test the associations of the ability to walk quickly with measures of adiposity and metabolic risk including dysglycaemia.

Subjects and methods: Participants (3209), without known diabetes, in a lifestyle trial undertook a 4-minute walk test (4MWT) following measurements of fasting lipids, 75 g oral glucose tolerance test, anthropometry and blood pressure. Lower socio-economic status was defined by possession of a ‘community services card’ (CSC). Dysglycaemia (diabetes, impaired glucose tolerance and impaired fasting glucose) and metabolic syndrome (MS) were defined by WHO and ATPIII criteria, respectively.

Results: Controlling for age, length of the walk-course and height, distance walked during the 4MWT decreased linearly (p < 0.001) with increasing waist, body mass index, %fat mass and MS risk. On average those with dysglycaemia walked 15.2 (95% CI 9.3, 20.8) m less than ‘normal’ participants independent of gender. In the best-fit regression model, distance walked was associated with reduced distances walked 1.3 (1.2, 1.5) m/year of age, 0.9 (0.8, 1.1) m/kg fat, 15.7 (11.2, 19.5) m with a CSC and 8.0 (5.8,10.2) m if currently smoking. Each additional MS factor was associated with a reduction of the distance walked by 6.6 (4.6, 8.6) m.

Conclusion: Increasing numbers of MS components are associated with slower walking. The 4MWT is an easy assessment of functional limitation, which may have use in guiding intervention.     

Growth references for 0–19 year-old Norwegian children for length/height,weight, body mass index and head circumference

Background: Previous growth references for Norwegian children were based on measurements from the 1970s and 1980s. New reference data, collected through the Bergen Growth Study and the Medical Birth Registry of Norway, are presented as LMS values.

Materials and methods: A cross-sectional sample of children aged 0–19 years in stratified randomized design measured in 2003–2006 as a part of the Bergen Growth Study (n = 7291) and birth data of children born in 1999–2003 from the Medical Birth Registry of Norway (n = 12 576) was used to estimate the new references by the means of the LMS method. Measurement reliability was assessed by test-rest studies.

Results: New references were constructed for length/height, weight, body mass index (BMI) and head circumference. Length/height and weight for children aged 0–4 years were similar to previous Norwegian references, but mean height increased up to a maximum of 3.4 cm in boys and 2.5 cm in girls during the pubertal years. Mean height was similar to (or slightly higher) in comparison with other recent European references. Reliability of the measurements compared well with published estimates.

Conclusion: Because of the observed secular trends in growth, it is advised to use the new references, which have been endorsed by the Norwegian Department of Health.     

Drug problems and psychological distress among a community sample of adults: Predictors,consequences, or confound?

Although the comorbidity of drug abuse and psychological distress is well established in adult-treatment samples, the directionality of this association is in question. There is less evidence that this relationship exists among community samples of adults. The prospective relationships between psychological distress and drug problems (e.g., alcohol, marijuana, and cocaine) were examined in a community sample of 470 adults. Results addressed three theories—self-medication/self-derogation, impaired functioning, and general deviance—to explain the relationship between drug use and psychological distress. Although the latent constructs of Polydrug Problems was largely unaffected by Psychological Distress and generally had no effect on Psychological Distress, several specific effects emerged. Providing support for the impaired-functioning theory, adults who abused drugs early on experienced later impaired functioning, anxiety, suicidal ideation, psychoticism, hostility, and decreased purpose in life four years later. Providing support for both the self-medication and self-derogation theories, those who experienced aspects of psychological distress (e.g., dysphoria, suicidal ideation) reported drug problems four years later. Moderate cross-sectional support was also found for the general deviance theory in that Social Conformity reduced or eliminated the associations between Polydrug Problems and the measures of psychological distress. Implications of these findings are discussed. © 1999 John Wiley & Sons, Inc.     

How do attitudes toward mental health treatment vary by age,gender, and ethnicity/race in young adults?

This article investigates attitudes toward seeking mental health treatment in a national epidemiological sample. Young adults reported the most negative attitudes, as compared to older adults. Males reported more negative attitudes, as compared to females, a consistent finding in young adults. The gender difference was not consistent in Latinos and African Americans. Although African Americans reported more positive attitudes than Anglos, this effect was not observed in young adults. Latinos reported similar attitudes toward mental health treatment, as compared to Anglos, a consistent finding in young adults. Results show that attitudes toward mental health treatment in young adult males are the most negative of all groups. Latinos and African Americans do not necessarily demonstrate more negative attitudes toward mental health treatment than Anglos. Within‐group differences in ethnic/racial minority groups may not be similar to differences seen in Anglo populations. © 2005 Wiley Periodicals, Inc. J Comm Psychol 33: 611–629, 2005.     

Geographical altitude,size, mass and body surface area in children (1–4 years) in the Province of Jujuy (Argentina)

Background: Highland child populations show low growth rates.

Aim: To evaluate the variation of size, mass and body surface area of Jujenean infants (1–4 years) as a function of geographic altitude.

Subjects and methods: Nutritional status of 8059 healthy infants was determined based on weight and height data; body mass index, ponderal index, body surface area, body surface area/mass and ectomorphy were calculated. Variables were standardized with a provincial mean and WHO references. Data were grouped by age, sex and geographic altitude: Highlands (≥2500?masl) and Lowlands (<2500?masl). Chi-square, correlation and t-tests were applied.

Results: Highlands infants had higher prevalence of stunting, reduced height, weight, body surface area and ectomorphy; also higher body mass index, ponderal index and body surface area/mass. The population average z-score for height, weight and body surface area was positive in Lowlands and negative in Highlands. The opposite happened with body mass index, ponderal index and body surface area/mass. In Highlands and Lowlands the average z-score reference was negative for weight and height and positive for body mass index. Correlations between indices were high and significant, higher in Highlands.

Conclusion: Jujenean children differ in size, mass and body surface area based on the geographical altitude and adverse nutritional and socioeconomic factors.     

Limb–body wall defect. Is there a defensible hypothesis and can it explain all the associated anomalies?

Aside from gastroschisis and omphalocele, major defects of the ventral body (thoracoabdominal) wall are relatively uncommon and almost universally lethal. They are most often associated with other anomalies including those of the limbs that may range from amelia to mild positional deformations, unusual craniofacial malformations, and a variety of visceral abnormalities that include the heart, lungs, genitourinary system, and gut. This complex of ventral wall anomalies has been discussed under a broad and changing nomenclature that has included amniotic band disruption complex, amnion rupture sequence, limb-body wall defect (or complex), and simply body wall complex. Three major theories have been suggested to explain this complex: early amnion rupture (operating through uterine pressure and/or disruption by amniotic bands), vascular compromise (primarily hypoperfusion), and an early intrinsic defect of the developing embryo. We present four patients that illustrate the spectrum of ventral body wall defects, and from there critique the current hypotheses of pathogenesis. We conclude that this association of malformations originates as early as the embryonic disc stage, and that some of the observed associated anomalies are secondary complications of the primary disturbance in embryogenesis. We propose a new explanation for the atypical facial clefts and cranial malformations that are often observed.