Feedback control of human metabolic work rate during robotics-assisted treadmill exercise

A novel approach is presented which suggests the use of human metabolic work rate to define and regulate exercise intensity during robotics-assisted treadmill training. The work describes the design and technical validation of the new method.A feedback structure is proposed which provides automatic regulation of metabolic work rate, in conjunction with an embedded feedback loop for volitional control of mechanical work rate. Human metabolic work rate was derived in real time from breath-by-breath measurements of oxygen uptake and carbon dioxide output.The results show that the feedback method provides close to nominal performance for square-wave and ramp reference tracking tasks and that good disturbance rejection properties are obtained. A collateral finding of this work is an estimate of 14.5% of the metabolic efficiency of robotics-assisted treadmill exercise.The use of feedback control of human metabolic work rate provides a direct measure of exercise intensity as perceived by the exercising human as it directly reflects the energy requirements of the working muscles. This complements previous approaches to guiding robotics-assisted treadmill training based on mechanical work rate, heart rate or oxygen uptake. The new approach based on metabolic work rate may have advantages in populations with compromised and widely varying exercise responses. This provides a new approach for driving and controlling active patient participation during robotics-assisted treadmill exercise.     

Prioritizing sleep for healthy work schedules

ABSTRACT: Good sleep is advantageous to the quality of life. Sleep-related benefits are particularly helpful for the working class, since poor or inadequate amounts of sleep degrade work productivity and overall health. This review paper explores the essential role of sleep in healthy work schedules and primarily focuses on the timing of sleep in relation to the work period (that is, before, during and after work). Data from laboratory, field and modeling studies indicate that consistent amounts of sleep prior to work are fundamental to improved performance and alertness in the workplace. In addition, planned naps taken during work maintain appropriate levels of waking function for both daytime and night-time work. Clearly, sufficient sleep after work is vital in promoting recovery from fatigue. Recent data also suggest that the time interval between shifts should be adjusted according to the biological timing of sleep. Although sleep is more likely to be replaced by job and other activities in the real life, research shows that it is worthwhile to revise the work schedules in order to optimize sleep before, sometime during and after the work period. Therefore, we suggest establishing work-sleep balance, similar to work-life balance, as a principle for designing and improving work schedules.     

So you think you want to save the world

There is increasing interest among both medical and other professional communities in becoming involved in global health, development, and other charitable work. There has also been a proliferation of opportunities in the field. Nonetheless, it is still difficult to find practical information on the daily realities of development work or advice on the difficulties inherent to this type of work. This article is intended for individuals who are interested in becoming involved in global health and development work. Through a discussion that touches on development economics, the history, psychology, and current state of development aid, the common conflicts, as well as the rewards of development work, this article aims to prepare the interested individual for the experience of global health and development work. The article also provides practical suggestions and references for those searching for an opportunity in the field, with an emphasis on global health opportunities.     

Working ability between air and trimix breathing gas under 8 ATA air condition

Pneumatic caisson work in Japan has come into operation since 1924. Afterward, this technique of compressed air work has been widely utilized in the construction of foundation basements, shafts of the bottom tunnel shields for subway and so forth. While using this technique of compressed air work means that workers have to be exposed to hyperbaric environment, this technique has risks of not only decompression sickness (DCS) but also toxicity of poisonous gas and/or oxygen deficiency. However, this technique is independent of city construction work and the operation of compressed air work higher than 5ATA (4.0 kg/cm2G) is actually been planning recently. Accordingly unmanned caisson work is considered as a better technique for such higher pressurized work, even though workers must enter into hyperbaric working fields for maintenance or repair of unmanned operated machinery and materials. This research is to establish the safe work under hyperbaric air environment at 8ATA.     

Great depth pneumatic caisson and its load work involved with the efficiency of respiratory protection

Pneumatic caisson work in Japan has been in operation since 1924. Afterward, this technique of compressed air work has been utilized in the constructions like as foundation works, the basements, and shafts of the bottom tunnel or shields for subway and so forth. While, it means for people to be exposed to hyperbaric environment that they use compressed air work, this technique has risks to be suffered from not only decompression sickness (DCS) but toxicity of poisonous gas or oxygen deficiency. However, this technique is necessary for urban civil engineering and recent compressed air works over than 1.0 kg/cm2 has been increased in 1.5 times more than in 1970's and the higher compressed air work more than 4.0 kg/cm2 will be actually planned in near future. So unmanned caisson work is considered as a better technique for such high pressure work, even though people must enter into hyperbaric working fields for maintenance or repair of unmanned operated machinery and materials. This research is to establish the safety work under hyperbaric environment within 7 kg/cm2. It is necessary for us to establish the system not only to keep safety but to maintain working efficiency. According to obtain the purpose, the effect of respiratory protection has been investigated and work load under hyperbaric caisson work has also been studied.     

The cellular measurement of time.

This review describes three biological processes in which there is evidence for single cells being able to measure elapsed time. We describe the work that has led to this view, and review more recent work that has provided new insights into possible mechanisms for the measurement of time.     

A comparison of the effects of mixed static and dynamic work with mainly dynamic work in hot conditions

Current physiological criteria for limiting work in hot conditions are frequently based on responses to mainly dynamic work (eg treadmill walking). Their applicability to industrial situations containing mixed static and dynamic work is questioned, since the physiological responses to static work are different from those of dynamic work. Each of eight subjects attempted a one hour uphill treadmill walk (mainly dynamic work), and an uphill treadmill walk whilst intermittently carrying a 20 kg weight in the arms (mixed static and dynamic work). The external work rates in the two conditions were equal, effected by lowering the treadmill gradient in the loaded condition. Experiments were conducted in a hot climate (33 degrees C dry bulb, 25 degrees C wet bulb). Oxygen consumption, minute ventilation, sweat rate and rated perceived exertion were all significantly higher (p less than 0.001) for the mixed static and dynamic work than for the dynamic work. This was also the case for heart rate and forearm skin temperature (p less than 0.01), and for auditory canal temperature (p less than 0.05). There was no significant difference between the two types of work for mean skin temperature, calf skin temperature and chest skin temperature. These results show that for the same external work, physiological strain and perceived exertion are greater for mixed static and dynamic work (carrying a load in the arms) than for mainly dynamic work (walking on a treadmill). They suggest that it is not appropriate to make direct comparisons of laboratory studies based on dynamic work, with practical situations containing mixed static and dynamic work in the heat.     

Applying concepts of generalizability theory on clinical trial data to investigate sources of variation and their impact on reliability

This work aims at applying concepts of generalizability theory to data resulting from clinical trials. The focus is to study the sources of variance and their impact on the reliability and generalizability of a psychiatric measurement scale. The goal is to identify, measure, and thereby potentially find strategies to reduce the influence of these sources on the measurement in question for future trials. This approach was originally devised by Cronbach and his associates and is known as generalizability theory. This work shows how full modeling power in mixed models can be used to study generalizability using data from five double-blind randomized clinical trials, comparing the effects of risperidone to conventional antipsychotic agents for the treatment of chronic schizophrenia.     

NEW LIGHT ON THE SCALING OF METABOLIC RATE WITH THE SIZE OF ALGAE

The scaling of metabolic rate with the size of algae has been discussed and researched at length. The observation that algae usually have exponents b in the equation R = a· W ^{− b} (where R is the specific growth rate, W is the organism [cell] biomass, and a and b are constants) equal to or higher than the value of −0.25 for many other organisms is generally related to resource-saturated (maximal) values of R. Recent work has shown that the exponent b for light-limited growth is more negative than −0.25. This was predicted from considerations of the package effect in photon absorption, as modulated by the volume-specific pigment content of the cells, and the photosynthetic unit size. Further work is needed to extrapolate these findings to fluctuating light environments. This minireview puts the recent work into a broader context and suggests how further work could quantify the roles of optical thickness and of spatial and temporal variations in the radiation field in determining metabolic rates.     

Life cycle assessment of Australian sugarcane products with a focus on cane processing

Purpose  

This work generates attributional life cycle assessment (LCA) results for products produced from Australian sugarcane—raw sugar, molasses, electricity (from bagasse combustion), and ethanol (from molasses). It focuses on cane processing in sugar mills and is a companion to the work presented in (Renouf et al. 2010), where the focus is on cane growing. This work also examines the preferred approach for assigning impacts to the multiple products from cane processing, and the influence that variability in cane growing has on the results.     

Identifiability of DNA distribution from flow cytometric data with cell debris

In flow cytometric measurement of cell DNA distribution one of the major problems is accounting for the effect of fragmentation in the staining process. This work considers a recent probabilistic model that has been proposed for the fragmentation process and species under which conditions it is possible to uniquely identify the DNA distributions of the original population using flow cytometric data. Attention is given both to the normal and to the polyploid case. This work was partially supported by a grant of the Italian National Research Council, Special Project “Oncology”, contract number 84.00632.44.     

Anti-tumor Effects of Gene Therapy with GALV Membrane Fusion Glycoprotein in Lung Adenocarcinoma

The divergence of protein (Hedgehog) in different organisms remains an unresolved issue to comprehend how the pathway in Hh signaling evolves. Insights into this question can help one identify the key molecules in Hh signaling. This work proposes a protein-associated factor in cells. The development of a non-reductionist theory of cellular functions in medicine is not sufficient. It is necessary to find the parameters with regards to molecules/genes that can elicit functions. This work shows that molecular interactions of gene products can be accomplished by biophysics logic. Defining the protein-associated factors in molecular activities and identifying its roles in molecular transduction are important. A misregulation in molecular switch can account for complex biomolecular consequences. This work shows the potential of the factor on homo-sapiens and unlocks its implications to gene multi-tasking functionality. The associated factor notion should facilitate the medical development in cancer therapeutics.     

Quantitative Modeling of the High-Throughput Production and In Vivo Kinetics of (Drug-Encapsulating) Liposomes

In developing liposomes for in vivo use, it is important to design the liposomes to have optimal in vivo kinetics, and it is also necessary to identify optimal high-throughput production conditions for these liposomes. Previous work has not definitively established the general relationship between liposomes'' configuration and composition, and their in vivo kinetics. Also, no straightforward method exists to calculate optimal liposome high-throughput production conditions for specific liposome compositions. This work presents first-principles quantitative correlations describing liposomes'' in vivo drug leakage and vascular mass transfer kinetics. This work further presents a simple quantitative model relating specific liposome compositions to ideal high-throughput production parameters. The results have implications for the identification of promising liposome compositions via high-throughput screening methodologies, as well as the design and optimization of high-throughput reactors for liposome production.     

心理疲劳的研究进展

心理疲劳是指重复单一作业或从事紧张程度较大的工作,神经系统紧张程度过高,从而出现的心理不安和疲乏感。心理疲劳会造成个体各种心理疾病以及重大事故的出现,但至今心理疲劳的概念还未有统一的标准,病因病机不明确,本文意在探讨其研究进展。笔者对于心理疲劳的国内外研究进展进行了文献整理,从心理疲劳的定义、表现、病因病机以及检测方法四个方面论述,发现心理疲劳由工作强度与持续时间、心理负荷、工作方法和熟练程度、环境因素以及体质、健康和营养状况等原因引起不同脑区的神经系统的变化以及相应物质代谢产生的疲劳。目前对心理疲劳的研究方法和手段有待改进,可将脑磁图、正电子发射断层扫描技术、功能核磁共振成像技术大量应用到研究中,探索其神经生理机制,为预防和治疗心理疲劳提供思路和方法。     

Urbanization and Daughter-Biased Parental Investment in Fiji

Parental investment decisions guide parental actions regarding children's productive work and are shaped by ecological context. Urban ecology enhances long-term payoffs to investment in human capital, increasing opportunity costs for work performed by children, and decreased workload should result. Using an embodied capital framework, self-reported data on urban and rural Indo-Fijian children's work activities are compared. Results show higher workloads for older children, rural children, and girls. High scholastic achievement is associated with lower workloads for girls, but not boys. This pattern is interpreted as daughter-biased investment in the context of urbanization.     

Transformative Education: Chronicling a Pedagogy for Social Change

This article chronicles the work of the Llano Grande Center for Research and Development, an educational nonprofit organization in South Texas, by following the narrative of one of its students and two of the authors, who are also founders of Llano Grande. Through the use of ethnography, visuals, and storytelling, they present an emerging theory of practice and a hybrid methodology that has contributed to the development of the work, the school, and the community. An activist agenda informed by practice and supported with theory is woven through the text in biographical form. The text also documents the cornerstones of the work: building strong relationships; work originating from self, place, and community; and engaging in meaningful work. When integrated into a seamless practice, this combination of guiding principles yields a certain power that youth and adults alike begin to negotiate within and between their peers, teachers, and community for change. This sense of self, efficacy, and power then informs much of their work as adults.  [Latino epistemology and education, activist ethnography, Llano Grande Center, storytelling, community as text, pedagogy of hope]     

高校生物化学首堂课教学方法探索与实践

生物化学作为医学、生命科学等专业学生必修的一门学科基础课程,理论性强、概念抽象、内容较多、逻辑关系复杂,是教学难度相对较大的一门课程。本文通过阐述在首堂课授课过程中,从任课教师如何塑造良好的自身形象,如何形象生动地引入生物化学的研究内容,如何通过展现生物化学的魅力来激发学生的学习热情和兴趣,如何使用巧妙的方法学好这门课程,以及如何将课程思政理念融入到生物化学课程中等诸多方面,探讨了在授课过程中的一些教学方法和实践,以期改变生物化学课堂不受学生喜爱的现状,为生物化学课程教学改革提供一些思路和参考。     

Influences of mother's work,childhood place of residence,and exposure to media on breast-feeding patterns: experience of Nigeria and Uganda

This study uses data from the Nigerian Demographic and Health Survey collected in 1990 and the Ugandan Demographic and Health Survey collected in 1995 to examine the implications of mother's work, childhood place of residence, and exposure to the media for breast-feeding patterns (exclusivity and intensity) in Nigeria and Uganda. Nigeria and Uganda present an interesting contrast because Nigeria is more modernized and economically developed than Uganda, thus providing a good indication of the influence of modernization on breast-feeding patterns. Mother's work status is defined by considering whether mothers earned cash from work and took their children to work, hence emphasizing the compatibility of work with child care. Work least compatible with child care had a negative effect on breast-feeding intensity in Nigeria. The negative effect of mother's work on exclusive breast-feeding (that is, if the mothers used formula or milk instead) observed for some working mothers in Nigeria and Uganda was partly confounded by urban residence, exposure to media, and other socioeconomic factors. Mother's work did not have a negative effect on breast-feeding intensity in Uganda. The relationship between mother's work, urban residence, media exposure, and breast-feeding practice seems to be stronger in Nigeria than Uganda.     

A mechanical investigation of the retting process in dew-retted hemp (Cannabis sativa)

Hemp (Cannabis sativa) produces phloem fibres, which are formed in bundles towards the periphery of the stem. This study investigated one aspect of the retting process, the dissociation of these fibres from the core of the stem, which is influenced by the action of micro-organisms. Peel tests were used to investigate the work required to remove a tissue peel, rich in fibres, from the core of the stem. Two separate experiments studied (1) the effects of tissue dehydration as stems were dried out in the oven; and (2) the progress of retting in stems that were dew-retted in the field. A comparison between two different types of peel tests, where the stems were clamped either vertically or horizontally in the jaws of a tensile testing machine and the load applied vertically, showed that the work required to peel stems in the vertical position was over 20% greater than that for the horizontal position. Freshly harvested stems were dehydrated in an oven at 40°C over a period of 42 h and as the moisture content decreased there was a significant increase in the work to peel. In contrast, stems that had been dew-retted in the field showed a significant decrease in work to peel. When the moisture content of stems dried in the oven decreased below 12%, the work to peel rapidly decreased. As the plant tissues dehydrated their fracture characteristics changed and this was reflected in the increase in the work to peel seen in the oven-dried samples. This, however, was not evident in the field-retted samples, in which there was a decrease in work to peel. The field-retted samples were exposed to the activity of micro-organisms for a prolonged period of time compared with the oven-dried samples; this increased the potential degradation caused by microbial enzymes. Thus, the reduced work to peel in dew-retted stems is thought to be due to the colonisation of the stem by micro-organisms and the subsequent retting process. The dramatic decrease in work to peel at low moisture content in the oven-dried stems is thought to result from mechanical changes leading to brittle fracture characteristics. This study indicates that peel tests can be used to objectively monitor the reduction in work to peel for dew-retted stems and relate this reduction to the progress of retting. Thus, peel tests may be used to monitor the effects of different factors on the process of retting in hemp.     

The structure and mechanism of methanol dehydrogenase

This is a review of recent work on methanol dehydrogenase (MDH), a pyrroloquinoline quinone (PQQ)-containing enzyme catalysing the oxidation of methanol to formaldehyde in methylotrophic bacteria. Although it is the most extensively studied of this class of dehydrogenases, it is only recently that there has been any consensus about its mechanism. This is partly due to recent structural studies on normal and mutant enzymes and partly due to more definitive work on the mechanism of related alcohol and glucose dehydrogenases. This work has also led to conclusions about the subsequent path of electrons and protons during the reoxidation of the reduced quinol form of the prosthetic group.