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Trunk muscle activation in the back and hack squat at the same relative loads.
Get PDFThe hack squat (HS) is likely to produce a greater 1 repetition maximum (1RM) compared to the back squat (BS). This can be attributed to the support of the trunk during the HS compared to no support during BS. This support however, may compromise trunk muscle activation (TMA), therefore producing different training adaptations. Accordingly, the purpose of this study was to compare 1RM in BS and HS and TMA at 4 relative loads, 65, 75, 85 and 95% of maximal system mass. Ten males completed 3 test sessions:1) BS and HS 1RM, 2) HS & BS neuromuscular test familiarization, and, 3) Neuromuscular test for 3 reps at 4 loads for BS and HS. BS TMA was significantly greater (p<0.05) than HS for all muscles and phases except rectus abdominus in concentric phase. TMA increased (p<0.05) with load in all muscles for both exercises and phases apart from lumbar sacral erector spinae in HS eccentric phase. Mean HS 1RM and submaximal loads were significantly (p<0.0001) higher than the equivalent BS loads. Duration of the eccentric phase was higher (p<0.01) in HS than BS but not different in concentric phase. Duration increased significantly (p<0.01) with load in both exercises and both phases. Despite higher absolute tests loads in HS, TMA was higher in BS. TMA is sensitive to load in both exercises. BS is more effective than HS in activating the muscles of the trunk and therefore arguably more effective in developing trunk strength and stability for dynamic athletic performance
Adiposity, fitness, health-related quality of life and the reallocation of time between children’s school day activity behaviours: a compositional data analysis
Get PDFSedentary time (ST), light (LPA), and moderate-to-vigorous physical activity (MVPA) constitute the range of school day activity behaviours. This study investigated whether the composition of school activity behaviours was associated with health indicators, and the predicted changes in health when time was reallocated between activity behaviours. Accelerometers were worn for 7-days between October and December 2010 by 318 UK children aged 10-11, to provide estimates of school day ST, LPA, and MVPA. BMI z-scores and percent waist-to-height ratio were calculated as indicators of adiposity. Cardiorespiratory fitness (CRF) was assessed using the 20-m Shuttle Run Test. The PedsQLTM questionnaire was completed to assess psychosocial and physical health-related quality of life (HRQL). Log-ratio multiple linear regression models predicted health indicators for the mean school day activity composition, and for new compositions where fixed durations of time were reallocated from one activity behaviour to another, while the remaining behaviours were unchanged. The school day activity composition significantly predicted adiposity and CRF (p=0.04-0.002), but not HRQL. Replacing MVPA with ST or LPA around the mean activity composition predicted higher adiposity and lower CRF. When ST or LPA were substituted with MVPA, the relationships with adiposity and CRF were asymmetrical with favourable, but smaller predicted changes in adiposity and CRF than when MVPA was replaced. Predicted changes in HRQL were negligible. The school day activity composition significantly predicted adiposity and CRF but not HRQL. Reallocating time from ST and LPA to MVPA is advocated through comprehensive school physical activity promotion approaches
Dressing Strategy and Grinding Control for Cylindrical Microstructural Surface
Get PDFSurface structural texture is designed to achieve specific functional performance for many advanced applications. After a brief review of current manufacturing methods for textural surface, this paper focuses on the study of microstructural surface creation by grinding. The axial and peripheral cross-sections of textured wheels under different dressing overlap ratio Ud are illustrated. A set of microstructural texturing models are proposed and the influences of dressing and grinding parameters are discussed. The texture formation is analysed in considering each cutting point in grinding kinematic movement. A significant effect of the grinding contact length on the texture formation is noticed, which defines a texture pattern limitation for grinding to manipulate. Typical surface texture characteristics are introduced to assess the structural surface features and the corresponding theoretical models are validated by experimental results. The relationships between the textural gouge size and the kinematic conditions of dressing and grinding have been delineated for the guidance of grinding texturing strategy. The component waviness on textured components clearly shows the importance of rotational ratio on the layout of microstructural texture. The paper lays down an important foundation for surface microstructural texturing by grinding
Racing the King Tide : Auntie’s Story
No full textThe island communities celebrate the feast of St. John the Baptist (San Juan) every 24th of June by going out to the sea with their families. Despite knowing that their home would also be flooded while they are away, Servillana’s family continue to cheerfully observe the long-standing tradition. They reveal their resilient spirit, assured by the thought that the tide will inevitably ebb at the end of the day.
Although the mass migration theory claims that communities living in low-lying islands will inevitably relocate away from their homes as a result of sea level rise, the communities of Tubigon so far continue living on their islands, striving to maintain their cultural practices and social relations despite the challenges of tidal flooding. This shows that, compared to sea level rise, the communities’ sense of identity and attachment to place could play a greater role in their final decision to relocate or not
Africa Is Much Bigger Than You Think It Is
Get PDFHistorically, Africa has tended to be misrepresented in maps. In the commonly used Mercator method of mapping a sphere (the Earth) onto a at plane (a map), countries further away from the equator are distorted and enlarged. Consequently, Africa is diminished and presented as smaller than it actually is. This work seeks to correct this misrepresentation by showing the continent in relation to something we associate as being large - the Moon. Both images are to the same scale and sized correctly relative to each other
Facial expression recognition in dynamic sequences: An integrated approach
Get PDFAutomatic facial expression analysis aims to analyse human facial expressions and classify them into discrete categories. Methods based on existing work are reliant on extracting information from video sequences and employ either some form of subjective thresholding of dynamic information or attempt to identify the particular individual frames in which the expected behaviour occurs. These methods are inefficient as they require either additional subjective information, tedious manual work or fail to take advantage of the information contained in the dynamic signature from facial movements for the task of expression recognition.
In this paper, a novel framework is proposed for automatic facial expression analysis which extracts salient information from video sequences but does not rely on any subjective preprocessing or additional user-supplied information to select frames with peak expressions. The experimental framework demonstrates that the proposed method outperforms static expression recognition systems in terms of recognition rate. The approach does not rely on action units (AUs), and therefore, eliminates errors which are otherwise propagated to the final result due to incorrect initial identification of AUs. The proposed framework explores a parametric space of over 300 dimensions and is tested with six state-of-the-art machine learning techniques. Such robust and extensive experimentation provides an important foundation for the assessment of the performance for future work. A further contribution of the paper is offered in the form of a user study. This was conducted in order to investigate the correlation between human cognitive systems and the proposed framework for the understanding of human emotion classification and the reliability of public databases
Reticulocyte hemoglobin content in a large sample of the general Dutch population and its relation to conventional iron status parameters.
Get PDFBACKGROUND: No full consensus exists on which iron status parameters to use for iron status assessment. In this study, we assessed the usefulness of measurement of the hemoglobin content of reticulocytes (CHr) in the general population. METHODS: The following iron status parameters were assessed in 1024 adults: CHr, reticulocytes, hemoglobin (Hb), ferritin, serum iron, transferrin, transferrin saturation and mean corpuscular volume (MCV). Mean parameter values and correlation coefficients for CHr and other parameters were calculated. In addition, mean CHr levels in subgroups based on low and normal values of other iron status parameters were compared. RESULTS: Mean CHr values in men were 31.81 (SD = 1.50) pg and in women 31.32 (SD = 1.51) pg. A positive correlation was observed between CHr and Hb, ferritin, serum iron, transferrin saturation and MCV; a negative correlation was observed between CHr and transferrin. CHr levels were lower in subjects with low values of Hb, ferritin, serum iron and MCV compared to subjects with normal values for these parameters. CONCLUSION: Mean CHr values in this population were comparable to values reported in small healthy control groups. Associations with other parameters were in agreement with associations reported in literature. CHr measurement might have additional value in iron status assessment
Rigid and concave, 2,4-cis-substituted azetidine derivatives: A platform for asymmetric catalysis.
Get PDFA series of single enantiomer, 2,4-cis-disubstituted amino azetidines were synthesised and used as ligands for copper-catalysed Henry reactions of aldehydes with nitromethane. Optimisation of ligand substituents and the reaction conditions was conducted. The enantiomeric excess of the formed products was highest when alkyl aldehydes were employed in the reaction (>99% e.e.). The absolute stereochemistry of one representative azetidine derivative salt was determined by analysis of the Flack parameter of an XRD single crystal structure. The origin of selectivity in catalysis was investigated computationally, revealing the importance of the amino-substituent in determining the stereochemical outcome. A racemic platinum complex of a cis-disubstituted azetidine is examined by XRD single crystal structure analysis with reference to its steric parameters, and analogies to the computationally determined copper complex catalyst are drawn. A preliminary example of the use of a cis-disubstituted azetidine scaffold in thiourea H-bonding catalyst is noted in the supporting information
Cardiovascular Responses During Resistance Exercise in Patients with Parkinson Disease
Get PDFBackground: Patients with Parkinson disease (PD) present cardiovascular autonomic dysfunction which impairs blood pressure control. However, cardiovascular responses during resistance exercise are unknown in these patients.
Objective: Investigate the cardiovascular responses during resistance exercise performed with different muscle masses, in patients with PD.
Design: Two groups, repeated-measures design.
Setting: Exercise Hemodynamic Laboratory, School of Physical Education and Sport, University of São Paulo.
Participants: Thirteen patients with PD (4 women, 62.7±1.3 years, stages 2-3 of modified Hoehn and Yahr scale; "on" state of medication) and thirteen paired controls without PD (7 women, 66.2±2.0years)
Interventions: Both groups performed, in a random order, bilateral and unilateral knee extension exercises (2 sets, 10–12 RM, 2 min of interval).
Main Outcome Measurements: Systolic blood pressure (SBP) and heart rate (HR) were assessed before (pre) and during the exercises.
Results: Independent of set and exercise type, SBP and HR increases were significantly lower in PD than the control group (combined values: +45±2 vs. +73±4 mmHg and +18±1 vs. +31±2 bpm, P =.003 and .007, respectively). Independently of group and set, the SBP increase was greater in the bilateral than the unilateral exercise (combined values: +63±4 vs +54±3 mmHg, P=.002), while the HR increase was similar. In addition, independently of group and exercise type, the SBP increase was higher in the 2nd than the 1st set (combined values: +56±4 vs +61±4 mmHg, P=.04), while the HR increases were similar.
Conclusions: Patients with PD present attenuated 25 increases in SBP and HR during resistance exercise in comparison with healthy subjects. These results support that resistance exercise is safe and well tolerated for patients with PD from a cardiovascular point of view supporting its recommendation for this population
Conscientious objection to participation in abortion by midwives and nurses: a systematic review of reasons.
Get PDFBACKGROUND: Freedom of conscience is a core element of human rights respected by most European countries. It allows abortion through the inclusion of a conscience clause, which permits opting out of providing such services. However, the grounds for invoking conscientious objection lack clarity. Our aim in this paper is to take a step in this direction by carrying out a systematic review of reasons by midwives and nurses for declining, on conscience grounds, to participate in abortion. METHOD: We conducted a systematic review of ethical arguments asking, "What reasons have been reported in the argument based literature for or against conscientious objection to abortion provision by nurses or midwives?" We particularly wanted to identify any discussion of the responsibilities of midwives and nurses in this area. Search terms were conscientious objection and abortion or termination and nurse or midwife or midwives or physicians or doctors or medics within the dates 2000-2016 on: HEIN legal, Medline, CINAHL, Psychinfo, Academic Search Complete, Web of Science including publications in English, German and Dutch. Final articles were subjected to a rigorous analysis, coding and classifying each line into reason mentions, narrow and broad reasons for or against conscientious objection. RESULTS: Of an initial 1085 articles, 10 were included. We identified 23 broad reasons, containing 116narrow reasons and 269 reason mentions. Eighty one (81) narrow reasons argued in favour of and 35 against conscientious objection. Using predetermined categories of moral, practical, religious or legal reasons, "moral reasons" contained the largest number of narrow reasons (n = 58). The reasons and their associated mentions in this category outnumber those in the sum of the other three categories. CONCLUSIONS: We identified no absolute argument either for or against conscientious objection by midwives or nurses. An invisibility of midwives and nurses exists in the whole debate concerning conscientious objection reflecting a gap between literature and practice, as it is they whom WHO recommend as providers of this service. While the arguments in the literature emphasize the need for provision of conscientious objection, a balanced debate is necessary in this field, which includes all relevant health professionals
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