Variation In Activity Levels Research Articles

Bio-activity assessment of fruits using Generalized Difference and Parameterized Fujii method

In this research work, both qualitative and quantitative measurement of biospeckle activity of three Indian fruits namely apple, pear and tomato have been carried out using Generalized Difference and Parameterized Fujii methods. Different activity area of the fruits can be easily visualized through the spectral maps. The variation of activity level of the fruits during shelf life storage has been studied through activity graphs. Comparative studies of activities of all the fruits are also presented and relatively high activity was found in apple compared to pear and tomato.

Poor nutrition during pregnancy and lactation negatively affects neurodevelopment of the offspring: evidence from a translational primate model

Studies of the effects of prenatal nutrition on neurodevelopment in humans are complicated because poor nutrition occurs in the context of psychosocial stressors and other risk factors associated with poor developmental outcomes. Under controlled experimental conditions, we tested an effect of prenatal nutrition on neurodevelopmental outcomes in the nonhuman primate. Juvenile offspring of 19 female baboons, whose diets were either restricted [maternal nutrition restriction (MNR)] or who were fed ad libitum (control), were administered the progressive ratio task from the Cambridge Neuropsychological Test Automated Battery. Activity, persistence, attention, and emotional arousal were coded from videotapes. These established, reliable methods were consistent with those used to assess individual differences in the behaviors of school-age children. MNR offspring (3 female and 4 male offspring) had significantly fewer responses and received fewer reinforcements on the progressive ratio task than did control offspring (8 female and 4 male offspring). MNR offspring showed a more variable activity level and less emotional arousal than did control offspring. Female MNR offspring showed more variable and lower levels of persistence and attention than did female control offspring. Thus, under controlled experimental conditions, data support a main effect of prenatal nutrition on highly translatable neurodevelopmental outcomes. Nutritional interventions during pregnancy have been successfully used to target neurodevelopmental problems, such as increasing folic acid intake during pregnancy to decrease the incidence of neural tube defects. Results from the current study can be used to support the testing of nutritional preventive interventions for the most-common childhood behavior problems.

Objectively Measured Sedentary Behavior and Physical Activity in Office Employees

Employee presenteeism is the extent to which health conditions adversely affect at-work productivity. Given the links between health and activity, this study examined associations between objectively measured physical activity, sedentary behavior, and presenteeism. Participants were 108 office employees (70% women, mean age 40.7 ± 11.2 years). Activity was measured using ActiGraph GT3X+ accelerometers to determine sedentary (≤150 counts) and light (151 to 1689 counts) activity; presenteeism with the Work Limitations Questionnaire. Fifty-seven percent of time was spent in sedentary behavior and 38% in light activity. The median Work Limitations Questionnaire Index was 4.38; 6% of participants reported at least moderate impairment. Significant associations were reported for time spent in sedentary behavior before/after work (odds ratio [OR] = 2.58; 95% CI: 1.08 to 6.20) and in light activity, overall (OR = 0.43; 95% CI: 0.19 to 0.97) and during workday lunch hours (OR = 0.34; 95% CI: 0.15 to 0.77), and presenteeism. Future studies should seek greater variation in employee levels of activity and presenteeism to confirm these relationships.

Flexibility of Older Adults Aged 55–86 Years and the Influence of Physical Activity

Cross-sectional age-related differences in flexibility of older adults aged 55–86 years of varying activity levels were examined. Shoulder abduction and hip flexion flexibility measurements were obtained from 436 individuals (205 men, 71 ± 9 years; 231 women, 72 ± 8 years). Total physical activity was assessed using the Minnesota Leisure-Time Physical Activity Questionnaire. Shoulder abduction showed a significant decline averaging 5 degrees/decade in men and 6 degrees/decade in women. Piecewise linear regression showed an accelerated decline in men starting at the age of 71 years of 0.80 degrees/year, whereas in women the onset of decline (0.74 degrees/year) was 63 years. Men and women showed a significant decline in hip flexion (men: 6 degrees/decade; women: 7 degrees/decade). Piecewise linear regression revealed a rate of decline of 1.16 degrees/year beginning at 71 years in men and in women a single linear decline of 0.66 degrees/year. Multiple regression analysis showed that age and physical activity accounted for only 9% of the variance in hip flexion in women and 10% in men, with age but not physical activity remaining significant. Similarly for shoulder abduction, age was significant but not physical activity, in a model that described 8% of the variance for both sexes.

Movement Patterns in the Smallest Viper, Bitis schneideri

Moving from one location to another provides animals with obvious benefits, but also incurs costs. When and how far an animal chooses to move is thus of fundamental importance to all aspects of its biology. We investigated movement patterns in a population of Namaqua Dwarf Adders (Bitis schneideri) in southern Africa through the use of radio telemetry. We measured how many individuals moved at different times of the day, at different times of the year, and differences in displacement frequency between sexes. We also assessed the influence of environmental variables (air temperature, relative humidity, atmospheric pressure, and wind speed) on activity levels. Snakes moved almost exclusively during the day-light hours, despite our expectations from the literature. Namaqua Dwarf Adders show limited seasonal variation in activity levels, with males moving more frequently during spring months than in other seasons. Our analysis indicated that movement was linked most closely to environmental conditions during the winter season, when conditions were generally less suitable for movement. We hypothesize that the observed variation in movement patterns at all temporal scales is the result of the selective pressure imposed by the costs of activity during sub-optimal environmental conditions.

Adopting an active lifestyle during adulthood and health-related quality of life: the Doetinchem Cohort Study.

We examined health-related quality of life in adults who became physically active at recommended levels over a 10-year period compared with adults with different physical activity patterns. Methods. We examined men and women aged 26 to 70 years (mean [SD] = 47.4 [10.1]) in the Doetinchem Cohort Study 3 times between 1995 and 2009. We distinguished participants who became physically active (n = 618), remained active (n = 1286), remained inactive (n = 727), became physically inactive (n = 535), or with varying activity levels (n = 455) over 10 years. We used multivariable linear regression analyses to determine differences in health-related quality of life (survey similar to the 36-Item Short-Form Health Survey) at 10-year follow-up. Results. Adults who became physically active reported better physical functioning, vitality, and general health after 10 years than did persistently inactive adults and adults who became inactive. They also reported less bodily pain and better social functioning than adults who became inactive. No differences were observed with adults who remained active or with varying activity levels. Conclusions. Adopting a physically active lifestyle may result in a better health-related quality of life, comparable to remaining physically active over 10 years.

Mouse Shoulder Morphology Responds to Locomotor Activity and the Kinematic Differences of Climbing and Running

Mechanical loads play a significant role in determining long bone shape and strength, but less work has explored how these loads influence flat bones like the scapula, which has been shown to vary with locomotor preference among primate taxa. Here, we tested the effects of voluntary running and climbing exercise in mice to examine how the mechanical loads borne from different locomotor patterns influence shoulder morphological development. Ninety-nine female wild-type mice were distributed equally among sedentary control, activity-wheel running, and vertical climbing experimental conditions. Running mice had the lowest body masses, larger intrinsic shoulder muscles, and the most pronounced differences in scapular size and shape relative to the other groups. Climbing mouse scapular morphology also differed significantly from the control individuals, but these differences were not as marked as those between the running and control mice. This might be attributable in part to greater levels of activity in the wheel-runners relative to the climbers. Additionally, climbing mice held their bodies closer to the substrate and maintained more flexed limbs and posterior hand positions compared with the kinematics of running. As a result, climbers differed significantly from both the running and control mice in developing a relatively broader infraspinous region, which is likely related to preferential recruitment of the infraspinatus and teres minor muscles to maintain flexed shoulder postures. The results of this study demonstrate that variation in activity level and type of locomotor regime over a significant portion of the life history influences muscle and bone development in the shoulder.

Influence of respirometry methods on intraspecific variation in standard metabolic rates in newts

Standard metabolic rate (SMR) is both a highly informative and variable trait. Variation in SMR stems not only from diverse intrinsic and extrinsic factors, but also from the use of diverse methods for metabolic measurements. We measured CO2 production (V˙CO2) and oxygen consumption rates (V˙O2) using two flow-through respirometry modes, continuous and intermittent (stop-flow), to evaluate their potential contribution to SMR variation in Alpine newts, Ichthyosaura alpestris. Both respirometry modes yielded similar and repeatable V˙CO2 values. Although V˙O2 was highly repeatable, continuous respirometry produced lower V˙O2 than the intermittent method. During intermittent measurements, the total number of activity bouts was higher than during continuous respirometry trials. Statistical correction for disparate activity levels minimized variation in oxygen consumption between respirometry modes. We conclude that use of either method of flow-through respirometry, if properly applied, introduced less noise to SMR estimates than a variation in activity levels.

ARB and Cardioprotection

A growing body of evidence has suggested that the use of angiotensin II (Ang II) type 1 (AT1) receptor blockers (ARBs) leads to a significant decrease in mortality and morbidity in patients with congestive heart failure. The AT1 receptor is a seven-transmembrane G protein-coupled receptor, and is involved in regulating the physiological and pathological process of the cardiovascular system. Systemically and locally generated Ang II has agonistic action on AT1 receptor. However, recent in vitro studies have demonstrated that AT1 receptor is structurally flexible and instable, and has significant and varying levels of spontaneous activity in an Ang II-independent manner. Furthermore, mechanical stress activates AT1 receptor by inducing conformational switch without the involvement of Ang II. Experimental studies have demonstrated that Ang II-independent activation of AT1 receptor is profoundly relevant to the pathogenesis of cardiac remodeling in vivo, and that these agonist-independent activities of AT1 receptor can be inhibited by inverse agonists, but not by neutral antagonists. Therefore, inverse agonist activity emerges as an important pharmacological parameter that contributes to cardioprotective effects of ARBs through inhibiting both Ang II-dependent and -independent activation of AT1 receptor.

Novel Associations of Nonstructural Loci with Paraoxonase Activity

The high-density-lipoprotein-(HDL-) associated esterase paraoxonase 1 (PON1) is a likely contributor to the antioxidant and antiatherosclerotic capabilities of HDL. Two nonsynonymous mutations in the structural gene, PON1, have been associated with variation in activity levels, but substantial interindividual differences remain unexplained and are greatest for substrates other than the eponymous paraoxon. PON1 activity levels were measured for three substrates—organophosphate paraoxon, arylester phenyl acetate, and lactone dihydrocoumarin—in 767 Mexican American individuals from San Antonio, Texas. Genetic influences on activity levels for each substrate were evaluated by association with approximately one million single nucleotide polymorphism (SNPs) while conditioning on PON1 genotypes. Significant associations were detected at five loci including regions on chromosomes 4 and 17 known to be associated with atherosclerosis and lipoprotein regulation and loci on chromosome 3 that regulate ubiquitous transcription factors. These loci explain 7.8% of variation in PON1 activity with lactone as a substrate, 5.6% with the arylester, and 3.0% with paraoxon. In light of the potential importance of PON1 in preventing cardiovascular disease/events, these novel loci merit further investigation.

Activity engagement is related to level, but not change in cognitive ability across adulthood.

It is unclear whether the longitudinal relation between activity participation and cognitive ability is due to preserved differentiation (active individuals have higher initial levels of cognitive ability), or differential preservation (active individuals show less negative change across time). This distinction has never been evaluated after dividing time-varying activity into its two sources of variation: between-person and within-person variability. Further, few studies have investigated how the association between activity participation and cognitive ability may differ from early to older adulthood. Using the PATH Through Life Project, we evaluated whether between- and within-person variation in activity participation was associated with cognitive ability and change within cohorts aged 20-24 years, 40-44 years, and 60-64 years at baseline (n = 7,152) assessed on three occasions over an 8-year interval. Multilevel models indicated that between-person differences in activity significantly predicted baseline cognitive ability for all age cohorts and for each assessed cognitive domain (perceptual speed, short-term memory, working memory, episodic memory, and vocabulary), even after accounting for sex, education, occupational status, and physical and mental health. In each case, greater average participation was associated with higher baseline cognitive ability. However, the size of the relationship involving average activity participation and baseline cognitive ability did not differ across adulthood. Between-person activity and within-person variation in activity level were both not significantly associated with change in cognitive test performance. Results suggest that activity participation is indeed related to cognitive ability across adulthood, but only in relation to the starting value of cognitive ability, and not change over time.

Intramuscular PEG-Asparaginase At 1000 U/m2 Achieves Adequate Trough Activity Levels in the Majority of Patients Treated on the UKALL 2003 Childhood Acute Lymphoblastic Leukemia (ALL) Protocol

Abstract 2573 Introduction:Polyethylene glycol conjugated L-asparaginase (PEG-ASNase) is used in varying doses between 1000–2500 U/m2 in the therapy of ALL and associated with a wide variation in pharmacokinetics. UKALL 2003 used intramuscular PEG-ASNase at 1000 U/m2. Patients & Methods:Patients enrolled in the UKALL 2003 trial (ISRCTN: 07355119), were consented for trough asparaginase activity analysis during therapy. National Cancer Institute (NCI) standard risk (SR) patients with rapid early response and non-high risk (HR) cytogenetics (Lancet Oncol. 2010;11:429) received a 3 drug induction (Dexamethasone, Vincristine & PEG-ASNase). All other patients received additional Daunorubicin. PEG-ASNase was given on days 4 and 18 of induction, and at least once post induction. Trough plasma asparaginase activity was measured by the indooxine method (Anal. Biochem. 2002;309:117). The lower limit of assay detection was 34 U/L. Adequate asparaginase activity was defined as a trough level of > 100 U/L. IgG and IgM antibodies to PEG-ASNase and native asparaginase were measured by indirect ELISA. Asparaginase activity was correlated with defined risk factors, minimal residual disease (MRD) at day 28 of induction and development of anti-asparaginase antibodies using the chi-squared test. Results:Between July 2008 to July 2011, 482 patients aged 1–25 years from 27 centres were recruited. Numbers of samples assayed in induction were 335 & 371 after first and second doses respectively. Overall, 86% (n=606/706) of samples had adequate activity during induction time points. There was > 10 fold variation in activity levels (Figure 1). Three hundred and nine out of 706 samples had activity > 3 times the therapeutic threshold, while 51/100 samples with inadequate activity had no detectable drug levels (median: below detection limit, range: < 34–99 U/L). Thus, increasing the dose of PEG-ASNase in induction is unlikely to benefit patients with inadequate activity. Compared to SR patients, NCI HR patients had a higher incidence of inadequate asparaginase activity in induction (p=0.002). Inadequate asparaginase activity correlated with high MRD (≥ 10−4) in SR patients (p=0.045), especially those with good risk cytogenetics (p=0.012), and in particular the high hyperdiploid subgroup (p=0.03). Inadequate asparaginase activity during induction did not correlate with MRD in HR patients (p=0.699), possibly because these patients received in addition Daunorubicin (Table 1). [Display omitted] [Display omitted] Results of serial asparaginase activity (at least one time point each in induction and post induction), measured in 282 patients are summarised in Table 2. Antibodies were detected in 18 of 81 patients tested. All had anti-PEG and 7 in addition also had anti-asparaginase antibodies. While all antibody positive patients had inadequate asparaginase activity at one time point, 17 had adequate activity prior to antibody detection, suggesting immune-mediated drug inactivation at re-exposure. Antibodies were not detected in 14/15 patients who had inadequate activity at first exposure, so the mechanism here remains unclear. [Display omitted] The reported incidence of asparaginase toxicity in this study was 6.6% (n=32/482). This included hypersensitivity (n=17/482) that was almost exclusively seen in HR patients (n=16/17), thrombosis (n=10/482) and pancreatitis (n=5/482). Conclusions:Intramuscular PEG-ASNase given fortnightly at 1000 U/m2 during induction provides adequate asparaginase activity in 86% of patients. Monitoring asparaginase activity may benefit patients who receive 3 drug induction and improve the resolution of the current prognostic classification. Disclosures:Off Label Use: PEG-asparaginase. Essink:medac: Employment. Kuehnel:medac: Employment.

Anticipation and tracking of pulsed resources drive population dynamics in eastern chipmunks

Pulsed systems are characterized by boom and bust cycles of resource production that are expected to cascade through multiple trophic levels. Many of the consumers within pulsed resource systems have specific adaptations to cope with these cycles that may serve to either amplify or dampen their community-wide consequences. We monitored a seed predator, the eastern chipmunk (Tamias striatus), in an American beech (Fagus grandifolia) dominated forest, and used capture-mark-recapture analyses to estimate chipmunk vital rates and relate them to interannual variation in beech seed production. The summer activity and reproduction of adults anticipated autumn beech production, with high activity and intense reproduction occurring in summers prior to beech masts. Chipmunks also reproduced every spring following a beech mast. However, adult survival was independent of beech production. In contrast, juvenile survival was lower in years of mast failure than in years of mast production, but their activity was consistently high and independent of beech production. Population growth was strongly affected by the number of juveniles and therefore by beech seed production, which explains nearly 70% of variation in population growth. Our results suggest that a combination of resource-dependent reproduction and variable activity levels associated with anticipation and response to resource pulses allows consumers to buffer potential deleterious effects of low food abundance on their survival.

In situ method for measurements of community clearance rate on shallow water bivalve populations

An open‐top chamber was designed for measuring ambient community clearance rate on undisturbed bivalve populations in the field. The chamber was pressed 5–10 cm down in the sediment on the mussel bed. It holds approximately 30–40 cm water column equal to a volume of 43–77 L. It was provided with an air lift connected to a SCUBA diver pressure tank generating a continuous and gentle water circulation. This ensures a complete mixture of suspended particles, and thereby, a maximum filtration by the bivalves. An in situ fluorometer was mounted to record plant pigment reduction due to mussel clearance in real‐time. To calibrate the in situ fluorometer triplicate water samples were obtained initially in each of the bivalve filtration measurements. The water samples were filtrated, extracted, and later analyzed for plant pigment concentration on a laboratory spectrophotometer. The main conclusion is that bivalve community clearance was an order of magnitude lower than predicted from laboratory extrapolations, which we explain by a natural variable activity level among the individuals in a given bivalve assemblage.

Patterns of activity and fatality of migratory bats at a wind energy facility in Alberta, Canada

AbstractStudying migratory behavior of bats is challenging. Thus, most information regarding their migratory behavior is anecdotal. Recently, however, fatalities of migratory bats at some wind energy facilities across North America have provided the opportunity and impetus to study bat migration at fine spatial and temporal scales. Using acoustic monitoring and carcass searches, we examined temporal and spatial variation in activity levels and fatality rates of bats at a wind energy facility in southern Alberta, Canada. Our goals were to better understand the influence of weather variables and turbine location on the activity and fatality of hoary bats (Lasiurus cinereus) and silver‐haired bats (Lasionycteris noctivagans), and to use that understanding to predict variation in fatality rates at wind energy facilities and recommend measures to reduce fatalities. Overall activity of migratory bats and of silver‐haired bats increased in low wind speeds and warm ambient temperatures, and was reduced when the wind was from the North or Northeast, whereas hoary bat activity increased with falling barometric pressure. Fatalities of migratory bats in general increased with increased activity of migratory bats, increased moon illumination, and falling barometric pressure and were influenced by the interaction between barometric pressure change and activity. Fatalities of silver‐haired bats increased with increased activity, moon illumination, and winds from the south‐east. Hoary bat fatalities increased with falling barometric pressure. Our results indicate that both the activity and fatality of migratory bats are affected by weather variables, but that species differ in their responses to environmental conditions. Spatially, fatalities were not influenced by the position of turbines within a turbine row, but were influenced by the location of turbines within the facility. Our findings have implications for our understanding of bat migration and efforts to reduce fatalities at wind energy facilities. To maximize the reduction of bat fatalities, operators of wind energy facilities could incorporate migratory bats' response to environmental variables, such as barometric pressure and fraction of moon illuminated, into their existing mitigation strategies. © 2011 The Wildlife Society.

Changes in Flexibility in Older Adults Aged 55-86 Years and the Influence of Physical Activity

Joint flexibility may decrease with age and this has the potential to affect normal daily function. The literature describing the influence of physical activity on flexibility on the aging process is limited. PURPOSE: To examine the cross-sectional age-related differences in flexibility in a large sample of independently living men and women aged 55-86 years of varying activity levels. METHODS: Flexibility measurements were obtained from a total of 439 individuals (208 men, mean age 70.5 ± 8.8 years; 231 women, mean age 71.5 ± 8.4 years). Flexibility was determined for both shoulder abduction (degrees) and hip flexion (degrees) using a Leighton Flexometer. Total physical activity was assessed using the Minnesota Leisure-Time Physical Activity Questionnaire. RESULTS: A mean lower body flexibility of 108 ± 20.7 degrees was observed for hip flexion in 402 individuals (183 men, 219 women). Women had significantly greater hip flexion (p=0.00) versus men. Upper body flexibility as assessed by shoulder abduction was measured in 436 individuals (205 men, 231 women) resulting in a mean of 138 ± 16 degrees. There was no significant difference based on sex (p=0.72). Age-related differences in flexibility were fit by linear regression yielding significant declines in hip flexion of 0.6 degrees/year in males and 0.7 degrees/year in females and in shoulder abduction of 0.5 degrees/year in males and 0.6 degrees/year in females. The mean total physical activity levels of the 434 individuals was 406± MET/min/day (men 386 ± 182, women 423 ± 215, p=0.06). The influence of age and level of physical activity on flexibility was determined by multiple regression. This model accounted for only 9% of the variance in hip flexion in women and 10% in men, with age remaining significant but the contribution of physical activity levels to lower body flexibility not significant for either males (p=0.71) or females (p=0.42). Similarly for shoulder abduction, age was significant but physical activity was not in a model that described 8% of the variance for both females (p=0.14) and males (p=0.57). CONCLUSIONS: A lower flexibility of the hip and shoulder joints by ∼6 degrees per decade, was observed across ages 55 to 86 years. Physical activity levels of older adults did not contribute to (or explain) the variance in hip and shoulder flexibility measures.

Application of a Generalized Scan Statistic Model to Evaluate TOF PET Images

Noise equivalent counts (NEC) have been used as a measure or proxy of PET image quality for many years. It has been shown to be a useful metric, for example to determine clinical patient dosage. However, NEC should be used cautiously in evaluating image quality since it is a global data quality measure that does not take into account localized effects due to spatial resolution and image reconstruction, as well as the effect of time-of-flight (TOF) imaging on resultant images. In this work, we study the use of a numerical observer that uses a generalized scan-statistic model to estimate lesion detectability with localization in a uniform background phantom, for varying activity levels and scan times. Data were acquired on a clinical whole-body TOF PET scanner. Data show that ALROC increases as a function of NEC but at high activity levels it approaches a peak value earlier than the NEC peak. Also, the ALROC for images acquired with the same NEC, but at two different activity levels and scan times, is similar. Our results show that with TOF information we can either achieve improved clinical performance for heavy patients, or reduce the scan time or injected activity while maintaining similar ALROC value as in a Non-TOF image.

In-Vitro Evaluation of Stem Bark Extracts of &lt;i&gt;Daniellia oliveri&lt;/i&gt; (Hutch and Dalz) for Antimicrobial Activity

A comparative study of the antimicrobial properties of ethanol, methanol, acetone, cold and hot water extracts of Daniellia oliveri was carried out. The extracts were assayed by the minimum inhibitory concentration broth microdilution and minimum bactericidal concentration methods before they were submitted to phytochemical screening. Three Gram positive, three Gram negative bacteria and yeast were used in the assay. All the extracts showed varied activity levels against the test microorganisms. Ethanol, methanol and acetone extract had better antimicrobial activity than the aqueous extracts within the concentration range of 6.25 – 100 mg/ml assayed. The activity was more pronounced against the Gram positive and fungal organisms than the Gram negative bacteria. This study shows that ethanol is the best solvent for extracting pharmacologically active compounds from plant materials. Its extract had the lowest bactericidal concentration of 6.25-25 mg/ml on organisms challenged. Results suggest that the D. oliveri has potential for use as pharmaceutical as well as in ethnomedicinal treatment of infections and diseases.Keywords: Daniellia oliveri, Inhibitory concentration, Bactericidal concentration, Antimicrobial activity

Author's Reply

This study was funded and designed to isolate the effects of the Riddell (Elyria, OH) helmet and shoulder pads used by National Football League linemen. Its design highlights small differences in heat gain, but it does not translate well to on-field football training because the treadmill exercise was performed to exhaustion (in 9 of 10 participants in full gear), and participants were not given any chance to rest, drink fluids, or remove the helmet. The extrapolation upward of the top line in revised Figure 2 is speculation, not science. One could equally speculate that the middle line has no plateau and so extrapolate it upward. In contrast to this heat-chamber study, on-field football training in the heat is stop and go, with regular breaks, sometimes cooling breezes, fluids encouraged, and the helmet often removed during rest breaks, teaching times, and sideline waits. For these reasons, other researchers find that core temperature on field during football training waxes and wanes in response to varying activity levels and that rest breaks allow for adequate heat dissipation.1 Also, in another heat-chamber study, designed to mimic drills by linemen in practice, the heat-gain effect of football gear, compared with that of shorts alone, was variable and minimal, perhaps because the collegiate players in the study partly offset the cost of added gear by lowering their intensity, as could occur in a real field setting.2 And recall that the college fullback who died from heat stroke after an intense workout in the summer of 2001 wore no football gear, just a T-shirt and shorts. All things considered, although more research is needed, this study does not show that the helmet and shoulder pads pose a substantial risk for heat stroke in football training.

Assessment of gamma emitting radionuclides in the aquatic ecosystem of Kakrapar Atomic Power Station and evaluation of radiological doses to aquatic plants

During operation and maintenance of Pressurised Heavy Water Reactors (PHWRs) at Kakrapar Atomic Power Station (KAPS), low level radioactive liquid waste is generated and released to the aquatic ecosystem (Moticher lake). The silt and aquatic weed (Hydrilla verticillata) samples collected from different locations in Moticher lake were analysed for 137Cs, 134Cs, 65Zn, 60Co, 54Mn and 40K during 2007–2008. A wide variation in activity levels of 137Cs, 134Cs, 65Zn, 60Co, 54Mn and 40K in silt and weed samples were observed in aquatic system of KAPS. The activity buildup in the silt is confined to a small area in the Moticher lake. The activity levels were found to be insignificant at 1 km away from discharge point (upstream and downstream). An attempt was made to evaluate the radiological dose to aquatic weed (Hydrilla verticillata), which was found to be well within the dose limit prescribed by US DOE. The total radiological dose due to the naturally occurring radionuclide (40K) is comparatively higher than that of other reactor released gamma emitting radionuclides.