Bayesian community-wide culture-independent microbial source tracking

Contamination is a critical issue in high-throughput metagenomic studies, yet progress toward a comprehensive solution has been limited. We present SourceTracker, a Bayesian approach to estimate the proportion of contaminants in a given community that come from possible source environments. We applied SourceTracker to microbial surveys from neonatal intensive care units (NICUs), offices and molecular biology laboratories, and provide a database of known contaminants for future testing.

Distributed representation of objects in the human ventral visual pathway

Brain imaging and electrophysiological recording studies in humans have reported discrete cortical regions in posterior ventral temporal cortex that respond preferentially to faces, buildings, and letters. These findings suggest a category-specific anatomically segregated modular organization of the object vision pathway. Here we present data from a functional MRI study in which we found three distinct regions of ventral temporal cortex that responded preferentially to faces and two categories of other objects, namely houses and chairs, and had a highly consistent topological arrangement. Although the data could be interpreted as evidence for separate modules, we found that each category also evoked significant responses in the regions that responded maximally to other stimuli. Moreover, each category was associated with its own differential pattern of response across ventral temporal cortex. These results indicate that the representation of an object is not restricted to a region that responds maximally to that object, but rather is distributed across a broader expanse of cortex. We propose that the functional architecture of the ventral visual pathway is not a mosaic of category-specific modules but instead is a continuous representation of information about object form that has a highly consistent and orderly topological arrangement.

Detection of organophosphate flame retardants in furniture foam and U.S. house dust

Restrictions on the use of polybrominated diphenyl ethers (PBDEs) have resulted in the increased use of alternate flame retardant chemicals to meet flammability standards. However, it has been difficult to determine which chemical formulations are currently being used in high volumes to meet flammability standards since the use of flame retardant formulations in consumer products is not transparent (i.e., not provided to customers). To investigate chemicals being used as replacements for PentaBDE in polyurethane foam, we analyzed foam samples from 26 different pieces of furniture purchased in the United States primarily between 2003 and 2009. Samples included foam from couches, chairs, mattress pads, pillows, and, in one case, foam from a sound-proofing system of a laboratory-grade dust sieve, and were analyzed using gas chromatography mass spectrometry. Fifteen of the foam samples contained the flame retardanttris(1,3-dichloro-2-propyl) phosphate (TDCPP; 1-5% by weight), four samples contained tris(1-chloro-2-propyl) phosphate (TCPP; 0.5 -22% by weight), one sample contained brominated chemicals found in a new flame retardant mixture called Firemaster 550 (4.2% by weight), and one foam sample collected from a futon likely purchased prior to 2004 contained PentaBDE (0.5% by weight). Due to the high frequency of detection of the chlorinated phosphate compounds in furniture foam,we analyzed extracts from 50 house dust samples collected between 2002 and 2007 in the Boston, MA area for TDCPP, TCPP, and another high volume use organophosphate-based flame retardant used in foam, triphenylphosphate (TPP). Detection frequencies for TDCPP and TPP in the dust samples were > 96% and were log normally distributed, similar to observations for PBDEs. TCPP was positively detected in dust in only 24% of the samples, but detection was significantly limited by a coelution problem. The geometric mean concentrations for TCPP, TDCPP, and TPP in house dust were 570, 1890, and 7360 ng/g, respectively, and maximum values detected in dust were 5490, 56,080 and 1,798,000 ng/g, respectively. These data suggest that levels of these organophosphate flame retardants are comparable, or in some cases greater than, levels of PBDEs in house dust. The high prevalence of these chemicals in foam and the high concentrations measured in dust (as high as 1.8 mg/g) warrant further studies to evaluate potential health effects from dust exposure, particularly for children.

Experience-based design: from redesigning the system around the patient to co-designing services with the patient

Involving patients in service improvement and listening and responding to what they say has played a key part in the redesign of healthcare processes over the past five years and more. Patients and users have attended stakeholder events, participated in discovery interviews, completed surveys, mapped healthcare processes and even designed new hospitals with healthcare staff. However, to date efforts have not necessarily focused on the patient's experience, beyond asking what was good and what was not. Questions were not asked to find out details of what the experience was or should be like ("experience" being different from "attitudes") and the information then systematically used to co-design services with patients. Knowledge of the experience, held only by the patient, is unique and precious. In this paper, attention is drawn to the burgeoning discipline of the design sciences and experience-based design, in which the traditional view of the user as a passive recipient of a product or service has begun to give way to the new view of users as integral to the improvement and innovation process.

Novel and high volume use flame retardants in US couches reflective of the 2005 PentaBDE phase out

California's furniture flammability standard Technical Bulletin 117 (TB 117) is believed to be a major driver of chemical flame retardant (FR) use in residential furniture in the United States. With the phase-out of the polybrominated diphenyl ether (PBDE) FR mixture PentaBDE in 2005, alternative FRs are increasingly being used to meet TB 117; however, it was unclear which chemicals were being used and how frequently. To address this data gap, we collected and analyzed 102 samples of polyurethane foam from residential couches purchased in the United States from 1985 to 2010. Overall, we detected chemical flame retardants in 85% of the couches. In samples purchased prior to 2005 (n = 41) PBDEs associated with the PentaBDE mixture including BDEs 47, 99, and 100 (PentaBDE) were the most common FR detected (39%), followed by tris(1,3-dichloroisopropyl) phosphate (TDCPP; 24%), which is a suspected human carcinogen. In samples purchased in 2005 or later (n = 61) the most common FRs detected were TDCPP (52%) and components associated with the Firemaster550 (FM 550) mixture (18%). Since the 2005 phase-out of PentaBDE, the use of TDCPP increased significantly. In addition, a mixture of nonhalogenated organophosphate FRs that included triphenyl phosphate (TPP), tris(4-butylphenyl) phosphate (TBPP), and a mix of butylphenyl phosphate isomers were observed in 13% of the couch samples purchased in 2005 or later. Overall the prevalence of flame retardants (and PentaBDE) was higher in couches bought in California compared to elsewhere, although the difference was not quite significant (p = 0.054 for PentaBDE). The difference was greater before 2005 than after, suggesting that TB 117 is becoming a de facto standard across the U.S. We determined that the presence of a TB 117 label did predict the presence of a FR; however, lack of a label did not predict the absence of a flame retardant. Following the PentaBDE phase out, we also found an increased number of flame retardants on the market. Given these results, and the potential for human exposure to FRs, health studies should be conducted on the types of FRs identified here.

The influence of chair height on lower limb mechanics during rising

The mechanics of the lower limb were analyzed in young, adult normal subjects when rising from a seated position. Limb mechanics were described in terms of flexion-extension motion and moments at the hip, knee and ankle while rising from four seat heights corresponding to 65, 80, 100, and 115% of the subject's knee joint height. The results indicate that the maximum moment tending to flex the hip joint was higher than that occurring at the knee or ankle. The magnitude of the maximum flexion moment at the hip was not substantially influenced by chair height, changing by less than 12% between the highest and lowest chair heights. Conversely, the maximum knee flexion moments were found to be highly dependent on chair height and nearly doubled from the highest to the lowest position. The magnitude of the moments at the ankle did not change with chair height and were significantly lower than the magnitude of the moments found during normal walking. The magnitude of motion and moments at the hip were greater during chair-rising than during stair-climbing or walking. The range of motion required at the knee for the lower chair heights was also greater than was reported during stair-climbing studies. Thus, the combination of moments in joint angles during chair-rising are unique among common activities of daily living and should be considered in chair selection as well as in the guidelines for prosthetic devices.

Biomechanics of slips

The biomechanics of slips are an important component in the prevention of fall-related injuries. The purpose of this paper is to review the available literature on the biomechanics of gait relevant to slips. This knowledge can be used to develop slip resistance testing methodologies and to determine critical differences in human behaviour between slips leading to recovery and those resulting in falls. Ground reaction forces at the shoe-floor interface have been extensively studied and are probably the most critical biomechanical factor in slips. The ratio of the shear to normal foot forces generated during gait, known as the required coefficient of friction (RCOF) during normal locomotion on dry surfaces or 'friction used/achievable' during slips, has been one biomechanical variable most closely associated with the measured frictional properties of the shoe/floor interface (usually the coefficient of friction or COF). Other biomechanical factors that also play an important role are the kinematics of the foot at heel contact and human responses to slipping perturbations, often evident in the moments generated at the lower extremity joints and postural adaptations. In addition, it must be realized that the biomechanics are dependent upon the capabilities of the postural control system, the mental set of the individual, and the perception of the environment, particularly, the danger of slipping. The focus of this paper is to review what is known regarding the kinematics and kinetics of walking on surfaces under a variety of environmental conditions. Finally, we discuss future biomechanical research needs to help to improve walkway-friction measurements and safety.

Stocks and flows of PBDEs in products from use to waste in the U.S. and Canada from 1970 to 2020

The time-dependent stock of PBDEs contained in in-use products (excluding building materials and large vehicles) was estimated for the U.S. and Canada from 1970 to 2020 based on product consumption patterns, PBDE contents, and product lifespan. The stocks of penta- and octaBDE peaked in in-use products at 17,000 (95% confidence interval: 6000-70,000) and 4,000 (1,000-50,000) tonnes in 2004, respectively, and for decaBDE at 140,000 (40,000-300,000) tonnes in 2008. Products dominating PBDE usage were polyurethane foam used in furniture (65% of pentaBDE), casings of electrical and electronic equipment or EEE (80% of octaBDE), and EEE and automotive seating (35% of decaBDE for each category). The largest flow of PBDEs in products, excluding automotive sector, to the waste phase occurred between 2005 and 2008 at ∼10,000 tonnes per year. Total consumption of penta-, octa-, and decaBDE from 1970 to 2020 in products considered was estimated at ∼46,000, ∼25,000, and ∼380,000 tonnes, respectively. Per capita usage was estimated at 10-250, 10-150, and 200-2000 g·capita(-1)·y(-1) for penta-, octa-, and decaBDE, respectively, over the time span. Considering only the first use (no reuse and/or storage) of PBDE-containing products, approximately 60% of the stock of PBDEs in 2014 or ∼70,000 tonnes, of which 95% is decaBDE, will remain in the use phase in 2020. Total emissions to air of all PBDEs from the in-use product stock was estimated at 70-700 tonnes between 1970 and 2020, with annual emissions of 0.4-4 tonnes·y(-1) for each of penta- and octaBDE and 0.35-3.5 tonnes·y(-1) for decaBDE in 2014.

Organophosphorus flame retardants and plasticizers in air from various indoor environments

Eleven organophosphorus compounds (OPs) that are used as plasticizers and flame retardants were analysed in duplicate samples of indoor air from 17 domestic and occupational environments. Solid-phase extraction (SPE) columns were used as adsorbents and analysis was performed using GC with a nitrogen phosphorus selective detector. The total amounts of OPs in the air samples ranged between 36 and 950 ng m(-3); tris(chloropropyl) phosphate (TCPP) and tris(2-chloroethyl) phosphate (TCEP) being the most abundant (0.4 to 730 ng m(-3)), followed by tributyl phosphate (0.5-120 ng m(-3)). Public buildings tended to have about 3-4 times higher levels of OPs than domestic buildings. The relative amounts of individual OPs varied between the sites and generally reflected the building materials, furniture and consumer products used in the sampled environments. Potential sources of these compounds include, inter alia, acoustic ceilings, upholstered furniture, wall coverings, floor polish and polyvinylchloride floor coverings. A correlation was observed between the TCEP concentrations in the air in the sampled environments and previously reported concentrations in dust, but no such correlation was seen for the heavier and less volatile tris(2-butoxyethyl) phosphate (TBEP). Based on estimated amounts of indoor air inhaled and dust ingested, adults and children in the sampled environments would be exposed to up to 5.8 microg kg(-1) day(-1) and 57 microg kg(-1) day(-1) total OPs, respectively.

Physical environmental stimuli that turn healthcare facilities into healing environments through psychologically mediated effects: systematic review

AIM

This paper reports a systematic review to determine the effects of physical environmental stimuli in healthcare settings on the health and well-being of patients.

BACKGROUND

The concept of healing environments suggests that the physical environment of the healthcare setting can encourage the healing process and patients' feelings of well-being. Understanding the effects of physical environmental stimuli will allow us to design healthcare environments that generate these potential health benefits.

METHOD

A search was conducted using the MedLine, PsychInfo, Embase, CINAHL, Iconda, ScienceDirect, Compendex and the ISI Citation Indexes databases. Studies were included if they concerned interventions involving health effects of environmental stimuli in healthcare settings on patients, and were based on controlled clinical trials published in peer-reviewed journals. Both clinical and psychological outcome measures were included. The search was completed in 2005.

FINDINGS

Of the over 500 potentially relevant studies identified, only 30 met all criteria and were included in this review. Predominantly positive effects were found for sunlight, windows, odour and seating arrangements. Inconsistent effects were found for sound, nature, spatial layout, television and multiple stimuli interventions. In general, both the size and direction of effects seem highly dependent on characteristics of patient populations and healthcare settings.

CONCLUSIONS

Studies that manipulate several environmental stimuli simultaneously clearly support the general notion that the physical healthcare environment affects the well-being of patients. However, when scrutinizing the effects of specific environmental stimuli, conclusive evidence is still very limited and difficult to generalize. The field thus appears to be in urgent need of well-conducted, controlled clinical trials. At present, and on the basis of the available research, it would be premature to formulate evidence-based guidelines for designing healthcare environments.

Effect of multidimensional lifestyle intervention on fitness and adiposity in predominantly migrant preschool children (Ballabeina): cluster randomised controlled trial

OBJECTIVE

To test the effect of a multidimensional lifestyle intervention on aerobic fitness and adiposity in predominantly migrant preschool children.

DESIGN

Cluster randomised controlled single blinded trial (Ballabeina study) over one school year; randomisation was performed after stratification for linguistic region.

SETTING

40 preschool classes in areas with a high migrant population in the German and French speaking regions of Switzerland.

PARTICIPANTS

652 of the 727 preschool children had informed consent and were present for baseline measures (mean age 5.1 years (SD 0.7), 72% migrants of multicultural origins). No children withdrew, but 26 moved away.

INTERVENTION

The multidimensional culturally tailored lifestyle intervention included a physical activity programme, lessons on nutrition, media use (use of television and computers), and sleep and adaptation of the built environment of the preschool class. It lasted from August 2008 to June 2009.

MAIN OUTCOME MEASURES

Primary outcomes were aerobic fitness (20 m shuttle run test) and body mass index (BMI). Secondary outcomes included motor agility, balance, percentage body fat, waist circumference, physical activity, eating habits, media use, sleep, psychological health, and cognitive abilities.

RESULTS

Compared with controls, children in the intervention group had an increase in aerobic fitness at the end of the intervention (adjusted mean difference: 0.32 stages (95% confidence interval 0.07 to 0.57; P=0.01) but no difference in BMI (-0.07 kg/m(2), -0.19 to 0.06; P=0.31). Relative to controls, children in the intervention group had beneficial effects in motor agility (-0.54 s, -0.90 to -0.17; P=0.004), percentage body fat (-1.1%, -2.0 to -0.2; P=0.02), and waist circumference (-1.0 cm, -1.6 to -0.4; P=0.001). There were also significant benefits in the intervention group in reported physical activity, media use, and eating habits, but not in the remaining secondary outcomes.

CONCLUSIONS

A multidimensional intervention increased aerobic fitness and reduced body fat but not BMI in predominantly migrant preschool children. Trial registration Clinical Trials NCT00674544.

Biomechanical analyses of rising from a chair

Quantification of the biomechanical factors that underlie the inability to rise from a chair can help explain why this disability occurs and can aid in the design of chairs and of therapeutic intervention programs. Experimental data collected earlier from 17 young adult and two groups of elderly subjects, 23 healthy and 11 impaired, rising from a standard chair under controlled conditions were analyzed using a planar biomechanical model. The joint torque strength requirements and the location of the floor reaction force at liftoff from the seat in the different groups and under several conditions were calculated. Analyses were also made of how body configurations and the use of hand force affect these joint torques and reaction locations. In all three groups, the required torques at liftoff were modest compared to literature data on voluntary strengths. Among the three groups rising with the use of hands, at the time of liftoff from the seat, the impaired old subjects, on an average, placed the reaction force the most anterior, the healthy old subjects placed it intermediately and the young subjects placed it the least anterior, within the foot support area. Moreover, the results suggest that, at liftoff, all subjects placed more importance on locating the floor reaction force to achieve acceptable postural stability than on diminishing the magnitudes of the needed joint muscle strengths.

A universal graph deep learning interatomic potential for the periodic table

Interatomic potentials (IAPs), which describe the potential energy surface of atoms, are a fundamental input for atomistic simulations. However, existing IAPs are either fitted to narrow chemistries or too inaccurate for general applications. Here we report a universal IAP for materials based on graph neural networks with three-body interactions (M3GNet). The M3GNet IAP was trained on the massive database of structural relaxations performed by the Materials Project over the past ten years and has broad applications in structural relaxation, dynamic simulations and property prediction of materials across diverse chemical spaces. About 1.8 million materials from a screening of 31 million hypothetical crystal structures were identified to be potentially stable against existing Materials Project crystals based on M3GNet energies. Of the top 2,000 materials with the lowest energies above the convex hull, 1,578 were verified to be stable using density functional theory calculations. These results demonstrate a machine learning-accelerated pathway to the discovery of synthesizable materials with exceptional properties.

The influence of backrest inclination and lumbar support on lumbar lordosis

The influence of backrest inclination and lumbar support on the shape of the lumbar spine in sitting positions has been studied radiographically on 38 healthy subjects. Four angles of backrest inclination and four different sizes of lumbar support were studied. In addition, the lumbar support was placed at three different lumbar levels. When sitting down from a standing position, the pelvis rotates and the lumbar lordosis decreases. Increases in the backrest-seat angle had only minor effect on the lumbar lordosis. A lumbar support, on the other hand, had a significant influence: the lordosis increased with increasing support. The location of the lumbar support with respect to the level of the spine did not significantly influence the measured angles.

Healing Spaces: Elements of Environmental Design That Make an Impact on Health

The "ambiance" of a space has an effect on people using the space. In recent years, design for health care environments has begun to include esthetic enhancements in an attempt to reduce stress and anxiety, increase patient satisfaction, and promote health and healing. In this paper, the authors survey the existing research on those elements of the built and natural environment most often asserted by proponents as being inherently healing or promoting health. We postulate a hierarchy of effect of environmental elements ranging from simply nontoxic to safe (both physically and psychologically) to "providing a positive context" to being actively salutogenic. Most relevant research has been concentrated on a limited number of settings and is inadequate to inform the creation of design guidelines for the physical elements of an optimal healing environment. Opportunities exist to make meaningful contributions in this area that are likely to make a significant impact on health outcomes of human beings.

Family-centered care in the NICU

Family-centered care is a philosophy of care that embraces a partnership between staff and families. Families, patients, and staff benefit in a family-centered care environment and the design of the newborn intensive care unit (NICU) must not interfere with its successful implementation. Unrestricted parental presence in the NICU, parental involvement in infant caregiving, and open communication with parents are basic tenets of family-centered care. By virtue of their continual presence and role in the NICU, nurses are in a unique position to support family-centered care.

Linking PBDEs in house dust to consumer products using X-ray fluorescence

The indoor environment is an important source of exposure to polybrominated diphenyl ethers (PBDEs), a class of fire retardants used in many household products. Previous attempts to link PBDE concentrations in house dust to consumer products have been hampered by the inability to determine the presence of PBDEs in otherwise similar products. We used a portable X-rayfluorescence (XRF) analyzer to nondestructively quantify bromine concentrations in consumer goods. In the validation phase, XRF-measured bromine was highly correlated with GC/MS-measured bromine for furniture foam and plastic from electronics (n = 29, r = 0.93, p < 0.0001). In the field study phase, the XRF-measured bromine in room furniture was associated with pentaBDE concentrations in room dust in the bedroom (r = 0.68, p = 0.001) and main living area (r = 0.51, p = 0.02). We also found an association between XRF-measured bromine levels in electronics and decaBDE levels in dust, largely driven by the high levels in televisions (r = 0.64, p = 0.003 for bedrooms). For the main living area, predicting decaBDE in dust improved when we included an interaction effect between the bromine content of televisions and the number of persons in the house (p < 0.005), a potential surrogate for television usage.

Accumulation of chlorpyrifos on residential surfaces and toys accessible to children

Quantitative examination of major pathways and routes of exposure to pesticides is essential for determining human risk. The current study was conducted in two apartments and examines the accumulation of the pesticide chlorpyrifos in childrens' toys after the time suggested for reentry after application. It has been established for the first time that a semivolatile pesticide will accumulate on and in toys and other sorbant surfaces in a home via a two-phase physical process that continues for at least 2 weeks postapplication. A summation of the above for a 3-6-year-old child yielded an estimated nondietary total dose of 208 microg/kg/day. Potential exposure from the inhalation pathway was negligible, while dermal and nondietary oral doses from playing with toys contributed to 39 and 61% of the total dose, respectively. If children with high frequency mouthing behavior are considered as candidates for acute exposure to chlorpyrifos residues, the estimated acute dose could be as high as 356 microg/kg/day. Routine reapplication of pesticides could lead to continued accumulation in toys and other sorbant surfaces, e.g., pillows, with large sorbant reservoirs, which can become a long-term source of exposure to a child. Estimates of a child's nondietary exposure to chlorpyrifos associated with toys and other sorbant surfaces for a period of 1 week following application appear to be of public health concern, and studies of actual childhood exposure from this pathway are warranted in the home environment. The above information should be used to determine if current procedures for postapplication reentry are sufficient and to evaluate the need for procedures to store frequently used household toys, pillows, and other sorbant objects during insecticidal application.

Interior surface materials in the home and the development of bronchial obstruction in young children in Oslo, Norway

OBJECTIVES

This study assessed the role of polyvinyl chloride (PVC) plastics and textile materials in the home in the development of bronchial obstruction during the first 2 years of life.

METHODS

The study was a matched pair case-control study based on a cohort of 3754 newborns in Oslo in 1992 and 1993 who were followed up for 2 years. The case group consisted of 251 children with bronchial obstruction; the control group was matched one-to-one for date of birth.

RESULTS

In conditional logistic regression analysis, the risk of bronchial obstruction was related to the presence of PVC flooring (adjusted odds ratio [OR] = 1.89; 95% confidence interval [CI] = 1.14, 3.14) and textile wall materials (adjusted OR = 1.58; 95% CI = 0.98, 2.54). The reference category was wood or parquet flooring and painted walls and ceiling. Further analysis revealed an exposure-response relationship between the assessed amount of PVC and other plasticizer-containing surface materials and the risk of bronchial obstruction.

CONCLUSIONS

This study provides new evidence of the role of PVC and textile wall materials in the development of bronchial obstruction in young children.

Images of recovery: a photo-elicitation study on the hospital ward

The authors attempted to discover the part the physical setting of the ward plays in patients' recovery by asking patients to take photographs of their ward, its spaces and objects, and then interviewing them about these images in hospital and subsequently in their homes. Photography allowed the patients to identify and capture aspects of the setting that they found salient and provided the photo-elicitation material for the interviews. Based on these data, the authors present (a) a critical discussion of the use of photography as method and its implications for qualitative analysis, (b) an overview of the kinds of image taken with respect to the ward and the course of patients' recovery, and (c) a theoretical analysis, employing Walter Benjamin's use of the concept of mimesis, that understands recovery as a bodily act in response to the shock to the senses that hospitalization and surgery produce.

Sitting biomechanics part I: review of the literature

OBJECTIVE

To develop a new sitting spinal model and an optimal driver's seat by using review of the literature of seated positions of the head. spine, pelvis, and lower extremities.

DATA SELECTION

Searches included MEDLINE for scientific journals, engineering standards, and textbooks. Key terms included sitting ergonomics, sitting posture, spine model, seat design, sitting lordosis, sitting electromyography, seated vibration, and sitting and biomechanics.

DATA SYNTHESIS

In part I, papers were selected if (1) they contained a first occurrence of a sitting topic, (2) were reviews of the literature, (3) corrected errors in previous studies, or (4) had improved study designs compared with previous papers. In part II, we separated information pertaining to sitting dynamics and drivers of automobiles from part 1.

RESULTS

Sitting causes the pelvis to rotate backward and causes reduction in lumbar lordosis, trunk-thigh angle, and knee angle and an increase in muscle effort and disc pressure. Seated posture is affected by seat-back angle, seat-bottom angle and foam density, height above floor, and presence of armrests.

CONCLUSION

The configuration of the spine, postural position, and weight transfer is different in the 3 types of sitting: anterior, middle, and posterior. Lumbar lordosis is affected by the trunk-thigh angle and the knee angle. Subjects in seats with backrest inclinations of 110 to 130 degrees, with concomitant lumbar support, have the lowest disc pressures and lowest electromyography recordings from spinal muscles. A seat-bottom posterior inclination of 5 degrees and armrests can further reduce lumbar disc pressures and electromyography readings while seated. To reduce forward translated head postures, a seat-back inclination of 110 degrees is preferable over higher inclinations. Work objects, such as video monitors, are optimum at eye level. Forward-tilting, seat-bottom inclines can increase lordosis, but subjects give high comfort ratings to adjustable chairs, which allow changes in position.

Home hazards and falls in the elderly: the role of health and functional status

OBJECTIVES

This study was undertaken to determine whether vigorous and frail older people who identify environmental hazards in their homes have an increased risk for falls.

METHODS

A 1-year prospective study was conducted among 266 female and 59 male community-dwelling volunteers aged 60 to 93 years who had fallen at least once during the previous year. Composite measures of home safety and of frailty were derived using principal components analysis. Participants were divided into vigorous and frail groups, and associations between baseline home safety measures and falls at home over the follow-up year were compared between the two groups.

RESULTS

Frail individuals were more than twice as likely as vigorous individuals to fall during follow-up (rate ratio [RR] = 2.24; 95% confidence interval [CI] = 1.54, 3.27). In the study group as a whole, falls were not strongly associated with the presence of home hazards. However, when compared with vigorous older persons living with fewer home hazards, vigorous older persons living with more home hazards were more likely to fall. The increased risk for falls among vigorous elderly was limited to falls where home hazards were present. By contrast, living with more home hazards was not associated with increased likelihood of falls among frail older persons.

CONCLUSIONS

While frail older persons experience higher overall fall rates, vigorous older persons should not be overlooked in fall prevention projects.

Measurement of airborne mite antigen in homes of asthmatic children

The airborne concentration of major house dust mite antigen Der p1 was measured by low volume sampling (2 litres/min) in the homes of 68 allergic, asthmatic children. The presence of detectable airborne antigen was strongly associated with sensitivity to the mite, whereas there was no significant relation between sensitivity and the previously recommended threshold level of 2 micrograms Der p1 per g carpet dust. There was a significant association with lower threshold levels in carpet dust (0.5 microgram/g) but at no level was the association as strong as that with air measurements. Concentrations of airborne antigen were higher in rooms with wool carpets than in those with synthetic carpets or hard floors, but there was no significant difference between the dust levels of Der p1 in the two carpet types. Air sampling is a more appropriate method of assessing antigen exposure than dust sampling for asthmatic patients.

Office ergonomics training and a sit-stand workstation: effects on musculoskeletal and visual symptoms and performance of office workers

Work Related Musculoskeletal Disorders (WMSDs) among office workers with intensive computer use is widespread and the prevalence of symptoms is growing. This randomized controlled trial investigated the effects of an office ergonomics training combined with a sit-stand workstation on musculoskeletal and visual discomfort, behaviors and performance. Participants performed a lab-based customer service job for 8 h per day, over 15 days and were assigned to: Ergonomics Trained (n = 11) or Minimally Trained (n = 11). The training consisted of: a 1.5-h interactive instruction, a sit/stand practice period, and ergonomic reminders. Ergonomics Trained participants experienced minimal musculoskeletal and visual discomfort across the 15 days, varied their postures, with significantly higher performance compared to the Minimally Trained group who had a significantly higher number of symptoms, suggesting that training plays a critical role. The ability to mitigate symptoms, change behaviors and enhance performance through training combined with a sit-stand workstation has implications for preventing discomforts in office workers.

The effects of an enhanced environment on nursing home residents who pace

This study sought to enhance the well-being of older nursing home residents who pace and wander by enriching their nursing home environment. Visual, auditory, and olfactory stimuli were added to the nursing home unit environment to simulate two types of environments: a home environment and an outdoor nature environment. Participants seemed to prefer the enhanced environments by choosing to spend more time in them, and by sitting on benches in those environments. There was a trend toward less trespassing, exit-seeking, and other agitated behaviors being exhibited in the enhanced environment, and residents were observed to manifest more pleasure in it. Staff members and family members definitely expressed a preference for the enhanced environment over the regular one. Although effects on residents were limited, this approach offers a low-cost method for making the nursing home environment a better place for those residents.