Circulatory and Respiratory Systems

11 94 0
Circulatory and Respiratory Systems

Đang tải... (xem toàn văn)

Tài liệu hạn chế xem trước, để xem đầy đủ mời bạn chọn Tải xuống

Thông tin tài liệu

Journal of Water and Environment Technology, Vol. 7, No. 4, 2009 - 277 - Children’s Health Deficits due to Diarrhoea: Effects of Water Supply and Sanitation Systems in Slums with Different Water Logging Conditions Kabirul Ahsan MOLLAH*, Kei NISHIDA*, Naoki KONDO* and   Zentaro YAMAGATA* * Interdisciplinary Graduate School of Medicine and Engineering, the University of Yamanashi 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan ABSTRACT This population-based epidemiologic study investigated the associations of individuals’ socio- demographic statuses, sanitary systems and habits, water supply and drainage conditions with diarrhoea incidences among 707 children younger than 5 years who were living in slum communities with various water logging patterns in Dhaka, Bangladesh. We conducted a home- visiting survey during the pre-monsoon period from December 2006 to April 2007. Nine slum communities were selected that had been experiencing five different water logging conditions. One non-water logging community was selected as a control. The Disability Adjusted Life Years (DALYs) were calculated using data on diarrhoea morbidity and mortality. Although DALYs lost because of diarrhoea were very small in a non-inundation type community, but were the highest in persistent drainage inundation type communities. Among the factors correlated with DALYs, control variables for mother’s illiteracy and household income strongly attenuated most of these correlations to statistical null, except for mother’s age (less than 15 years-old), using hanging latrine and not washing hands before eating, and after defecation. In conclusion, water logging conditions and socio-economic statuses may strongly contribute to diarrhoea incidence in the city’s slum communities. In such communities, interventions to address both water logging and socio-economic conditions may be critical for reducing diarrhoea incidences. Keywords: DALY, diarrhoea, poor urban community, water logging. INTRODUCTION Poor environmental sanitation and the unsafe disposal of human and solid wastes contribute to the high incidence of water-borne diseases, including diarrhoeal diseases, malaria and dengue fever (WHO/UNICEF 2001). Many of these infections occur in developing nations that have sanitation problems (Nsubuga et al. 2004). In these nations, most low-lying lands used for squatter settlements or slums have hanging latrines or open-field defecation. Due to lack of access to potable water supplies, the poor rely mainly on shallow wells, rivers, streams and ponds for daily water needs (Nevondo and Cloete 1999). In most cases, water from these sources, which may be faecally contaminated, is used directly without treatment (WHO 1993). During 2002, it was estimated that 4% (60.7 million Disability Adjusted Life Years [DALYs]) of the global burden of disease and 1.6 million deaths per year were attributed to unsafe water supplies and sanitation, including lack of hygiene (WHO 2002). Acute diarrhoeal diseases are the major causes of morbidity and mortality in developing countries, such as Bangladesh, where 1 in 10 children die before their fifth birthday (Bern et al. 1992; Petri et al. 2000). Bangladesh’s capital city, Dhaka, is a typical flood- prone urban habitat. It is periodically Circulatory and Respiratory Systems Circulatory and Respiratory Systems Bởi: OpenStaxCollege Animals are complex multicellular organisms that require a mechanism for transporting nutrients throughout their bodies and removing wastes The human circulatory system has a complex network of blood vessels that reach all parts of the body This extensive network supplies the cells, tissues, and organs with oxygen and nutrients, and removes carbon dioxide and waste compounds The medium for transport of gases and other molecules is the blood, which continually circulates through the system Pressure differences within the system cause the movement of the blood and are created by the pumping of the heart Gas exchange between tissues and the blood is an essential function of the circulatory system In humans, other mammals, and birds, blood absorbs oxygen and releases carbon dioxide in the lungs Thus the circulatory and respiratory system, whose function is to obtain oxygen and discharge carbon dioxide, work in tandem The Respiratory System Take a breath in and hold it Wait several seconds and then let it out Humans, when they are not exerting themselves, breathe approximately 15 times per minute on average This equates to about 900 breaths an hour or 21,600 breaths per day With every inhalation, air fills the lungs, and with every exhalation, it rushes back out That air is doing more than just inflating and deflating the lungs in the chest cavity The air contains oxygen that crosses the lung tissue, enters the bloodstream, and travels to organs and tissues There, oxygen is exchanged for carbon dioxide, which is a cellular waste material Carbon dioxide exits the cells, enters the bloodstream, travels back to the lungs, and is expired out of the body during exhalation Breathing is both a voluntary and an involuntary event How often a breath is taken and how much air is inhaled or exhaled is regulated by the respiratory center in the brain in response to signals it receives about the carbon dioxide content of the blood However, 1/11 Circulatory and Respiratory Systems it is possible to override this automatic regulation for activities such as speaking, singing and swimming under water During inhalation the diaphragm descends creating a negative pressure around the lungs and they begin to inflate, drawing in air from outside the body The air enters the body through the nasal cavity located just inside the nose ([link]) As the air passes through the nasal cavity, the air is warmed to body temperature and humidified by moisture from mucous membranes These processes help equilibrate the air to the body conditions, reducing any damage that cold, dry air can cause Particulate matter that is floating in the air is removed in the nasal passages by hairs, mucus, and cilia Air is also chemically sampled by the sense of smell From the nasal cavity, air passes through the pharynx (throat) and the larynx (voice box) as it makes its way to the trachea ([link]) The main function of the trachea is to funnel the inhaled air to the lungs and the exhaled air back out of the body The human trachea is a cylinder, about 25 to 30 cm (9.8–11.8 in) long, which sits in front of the esophagus and extends from the pharynx into the chest cavity to the lungs It is made of incomplete rings of cartilage and smooth muscle The cartilage provides strength and support to the trachea to keep the passage open The trachea is lined with cells that have cilia and secrete mucus The mucus catches particles that have been inhaled, and the cilia move the particles toward the pharynx The end of the trachea divides into two bronchi that enter the right and left lung Air enters the lungs through the primary bronchi The primary bronchus divides, creating smaller and smaller diameter bronchi until the passages are under mm (.03 in) in diameter when they are called bronchioles as they split and spread through the lung Like the trachea, the bronchus and bronchioles are made of cartilage and smooth muscle Bronchi are innervated by nerves of both the parasympathetic and sympathetic nervous systems that control muscle contraction (parasympathetic) or relaxation (sympathetic) in the bronchi and bronchioles, depending on the nervous system’s cues The final bronchioles are the respiratory bronchioles Alveolar ducts are attached to the end of each respiratory bronchiole At the end of each duct are alveolar sacs, each containing 20 to 30 alveoli Gas exchange occurs only in the alveoli The alveoli are thin-walled and look like tiny bubbles within the sacs The alveoli are in direct contact with capillaries of the circulatory system Such intimate contact ensures that oxygen will diffuse from the alveoli into the blood In addition, carbon dioxide will diffuse from the blood into the alveoli to be exhaled The anatomical arrangement of capillaries and alveoli emphasizes the structural and functional relationship of the respiratory and circulatory systems Estimates for the surface area of ... I NTERNATIONAL J OURNAL OF E NERGY AND E NVIRONMENT Volume 3, Issue 4, 2012 pp.521-530 Journal homepage: www.IJEE.IEEFoundation.org ISSN 2076-2895 (Print), ISSN 2076-2909 (Online) ©2012 International Energy & Environment Foundation. All rights reserved. Integration of energy and environmental systems in wastewater treatment plants Suzanna Long 1 , Elizabeth Cudney 2 1 Department of Engineering Management and Systems Engineering, 600 W, 14 th Street, 215 EMGT Building, Rolla, MO-65401, 573-341-7621, U.S.A. 2 Department of Engineering Management and Systems Engineering, 600 W, 14 th Street, 217 EMGT Building, Rolla, MO-65401, 573-341-7931, U.S.A. Abstract Most wastewater treatment facilities were built when energy costs were not a concern; however, increasing energy demand, changing climatic conditions, and constrained energy supplies have resulted in the need to apply more energy-conscious choices in the maintenance or upgrade of existing wastewater treatment facilities. This research develops an integrated energy and environmental management systems model that creates a holistic view of both approaches and maps linkages capable of meeting high-performing energy management while meeting environmental standards. The model has been validated through a case study on the Rolla, Missouri Southeast Wastewater Treatment Plant. Results from plant performance data provide guidance to improve operational techniques. The significant factors contributing to both energy and environmental systems are identified and balanced against considerations of cost. Copyright © 2012 International Energy and Environment Foundation - All rights reserved. Keywords: Energy conservation; Environmental management; Process integration; Strategic management; Wastewater treatment systems. 1. Introduction Green environmental practices are increasingly important in combating serious global energy and environmental issues. Water and wastewater facilities are among the largest and most energy-intensive systems owned and operated by local governments and account for approximately 30 to 50% of municipal energy use. Most wastewater treatment facilities were built when energy costs were not a concern; however, increasing energy demand, changing climatic conditions, and constrained energy supplies have resulted in the need to apply more energy-conscious choices in the maintenance or upgrade of existing wastewater treatment facilities. Energy represents the largest controllable cost of water and wastewater treatment since energy use directly affects the amount of greenhouse gas (GHG) emissions, and indirectly affects the biological oxygen demand (BOD), chemical oxygen demand (COD), and pollutions levels. By controlling the level of energy consumption, wastewater treatment facilities can reduce the operating costs, increase efficiency, and reduce pollution in an effort to provide cleaner environments. In addition, increased training on advanced equipment by well-trained employees can lead to improved effluent and surface water quality and more compliant facilities [1, 2]. A strategic process to control these various factors could provide significant benefits to local governments and the communities they serve. International Journal of Energy and Environment (IJEE), Volume 3, Issue 4, The 8051 Microcontroller and Embedded Systems Using Assembly and C Second Edition Muhammad Ali Mazidi Janice Gillispie Mazidi Rolin D. McKinlay CONTENTS  Introduction to Computing  The 8051 Microcontrollers  8051 Assembly Language Programming  Branch Instructions  I/O Port Programming  8051 Addressing Modes  Arithmetic & Logic Instructions And Programs  8051 Programming in C  8051 Hardware Connection and Hex File  8051 Timer/Counter Programming in Assembly and C  8051 Serial Port Programming in Assembly and C  Interrupts Programming in Assembly and C  8051 Interfacing to External Memory  8051 Real World Interfacing I: LCD,ADC AND SENSORS  LCD and Keyboard Interfacing  8051 Interfacing with 8255 Home Automation, Networking, and Entertainment Lab Dept. of Computer Science and Information Engineering National Cheng Kung University, TAIWAN Chung-Ping Young 楊中平 INTRODUCTION TO COMPUTING The 8051 Microcontroller and Embedded Systems: Using Assembly and C Mazidi, Mazidi and McKinlay Department of Computer Science and Information Engineering National Cheng Kung University, TAIWAN 2 HANEL OUTLINES  Numbering and coding systems  Digital primer  Inside the computer Department of Computer Science and Information Engineering National Cheng Kung University, TAIWAN 3 HANEL NUMBERING AND CODING SYSTEMS Decimal and Binary Number Systems  Human beings use base 10 ( decimal ) arithmetic ¾ There are 10 distinct symbols, 0, 1, 2, …, 9  Computers use base 2 ( binary ) system ¾ There are only 0 and 1 ¾ These two binary digits are commonly referred to as bits Department of Computer Science and Information Engineering National Cheng Kung University, TAIWAN 4 HANEL NUMBERING AND CODING SYSTEMS Converting from Decimal to Binary  Divide the decimal number by 2 repeatedly  Keep track of the remainders  Continue this process until the quotient becomes zero  Write the remainders in reverse order to obtain the binary number Ex. Convert 25 10 to binary Quotient Remainder 25/2 = 12 1 LSB (least significant bit) 12/2 = 6 0 6/2 = 3 0 3/2 = 1 1 1/2 = 0 1 MSB (most significant bit) Therefore 25 10 = 11001 2 Department of Computer Science and Information Engineering National Cheng Kung University, TAIWAN 5 HANEL NUMBERING AND CODING SYSTEMS Converting from Binary to Decimal  Know the weight of each bit in a binary number  Add them together to get its decimal equivalent  Use the concept of weight to convert a decimal number to a binary directly Ex. Convert 11001 2 to decimal Weight: 2 4 2 3 2 2 2 1 2 0 Digits: 11001 Sum: 16 +8 +0 +0 +1 = 25 10 Ex. Convert 39 10 to binary 32 + 0 + 0 + 4 + 2 + 1 = 39 Therefore, 39 10 = 100111 2 Department of Computer Science and Information Engineering National Cheng Kung University, TAIWAN 6 HANEL NUMBERING AND CODING SYSTEMS Hexadecimal System  Base 16, the hexadecimal system, is used as a convenient representation of binary numbers ¾ ex. It is much easier to represent a string of 0s and 1s such as 100010010110 as its hexadecimal equivalent of 896H F111115 E111014 D110113 C110012 B101111 A101010 910019 810008 701117 601106 501015 401004 300113 200102 100011 000000 HexBinaryDecimal Department of Computer Science and Information Engineering National Cheng Kung University, TAIWAN 7 HANEL NUMBERING AND CODING SYSTEMS Converting between Binary and Hex  To represent a binary number as Chapter three: Structural design, modeling, and simulation 159 ADXL150/ADXL250 Increasing the i MEM S Accelerometer’s Output Scale Factor Figure 15 shows the basic connections for using an external buffer amplifier to increase die output scale factor. The output multiplied by the gain of the buffer, which is simply the value of resistor R3 divided by RI. Choose a convenient scale factor, keeping in mind that the buffer pin not only ampli- fies the signal, but my noise or drift as well. Too much pin can also cause the buffer to saturate and clip the output waveform. Note that the “+” input of the external op amp uses the offset null pin of the ADXL150/ADXL250 as a reference, biasing the op amp at midsupply, saving two resistors and reducing power consumption. The offset null pin connects to the V S /2 reference point inside the accelerometer via 30 kΩ, so it is important not to load this pin with more dim a few microamps. It is important to use a single-supply or “rail-to-rail” op amp for the external buffer as it needs to be able to swing close to the supply and ground. The circuit of Figure 15 is entirely adequate for many applica- tions, but its accuracy is dependent on the pretrimmed accuracy of the accelerometer and this will vary by product type and grade. For the highest possible accuracy, an external trim is mended. As shown by Figure 20, this consists of a potentiometer Rla, in series with a fixed resistor, Rlb. Another to select resistor values after measuring the device’s scale (see Figure 17). AC Coupling If a dc (gravity) response is not required—for example ** tion measurement applications—ac coupling can be ** between the accelerometer’s output and the external op** input as shown in Figure 16. The use of ac coupling ** eliminates my zero g drift and allows the maximum ** amp gain without clipping. Resistor R2 and capacitor C3 together form a high ** whose corner frequency is 1/(2 x R2 C3). This filter ** the signal from the accelerometer by 3 dB at the **, and it will continue to reduce it at a rate of 6 ** (20 dB per decade) for signals below the corner frequ ** Capacitor CBS should be a nonpolarized, low leakage type ** If ac coupling is used, the self-test feature must be ** the accelerometer’s output rather than at the external ** output (since the self-test output is a dc voltage). © 2001 by CRC Press LLC 160 Chapter three: Structural design, modeling, and simulation ADXL150/ADXL250 Adjusting the Zero g Bias Level When a true dc (gravity) response is needed, the output from the accelerometer must be dc coupled to the external amplifier’s input. For high gain applications, a zero g offset trim will also be needed. The external offset trim permits the user to set the zew g offset voltage to exactly +2.5 volts (allowing the maxi- mum output swing from the external amplifier without clipping with a +5 supply). With a dc coupled connection, any difference between the zero g output and +2.5 V will be amplified along with the signal. To obtain the exact zero g output desired or to allow the maximum output voltage swing from the external amplifier, the zero g offset will need to be externally trimmed using the circuit of Figure 20. The external amplifier’s maximum output swing should be limited to ±2 volts, which provides a safety margin of ±0.25 volts before clipping. With a +2.5 volt zero g level, the maximum gain will equal: The device scale factor and zero g offset levels can be calibrated using the earth’s gravity, as explained in the section “calibrating the ADXL150/ADXL250.” Using the Zero g “Quick-Cal” Method In Figure 18 (accelerometer alone, no external op amp), a trim potentiometer connects directly to the accelerometer’s zero g null pin. The “quick offset calibration” scheme shown in Figure 17 is preferred over using a potentiometer, which could change its setting over time due to vibration. The “quick offset calibra- [...]... permitting integrins to transmit forces for matrix remodeling and cell migration Integrins that are activated directly by extracellular factors are able to transmit information into cells from their environment During integrin outside in signaling, the binding of integrins to their extracellular ligands changes the integrin conformation and promotes integrin clustering The 2 unidirectional signalings, in. .. signal in the 2 directions with different consequences During integrin inside–out signaling, an intracellular activator, such as talin or kindlins, binds to integrin and causes a conformational change that increases its affinity for extracellular ligands Integrin inside–out signaling enables strong interactions between integrins and extracellular matrix proteins, thereby controling adhesion strength and. .. and (7) enzymes (Vol 4 – Chaps 1 Signaling Lipids to 9 Other Major Signaling Mediators) Integrins are major plasmalemmal receptors that are responsible for dynamical interactions between cells and their environment Cell- surface integrins recognize and bind extracellular matrix proteins and control the organization of the cytoskeleton, in addition to initiating signaling pathways that regulate the cell. .. of modeling equation set and minor are rejected 1 Signaling receptors involved in cell adhesions are described in Vol 1 (Chap 7 Plasma Membrane) Intracellular receptors sense steroid and thyroid hormones, vitamin-A and -D, metabolites (e.g., fatty and bile acids and sterols), and xenobiotics M Thiriet, Signaling at the Cell Surface in the Circulatory and Ventilatory Systems, Biomathematical and Biomechanical... regulation] and autocrine signaling) and others (intercellular communication) using various types of messengers Chemical intercellular communications occur via direct contact (juxtacrine signaling) as well as over short (auto- and paracrine signaling) and long (endocrine signaling) distances In juxtacrine signaling, plasma membranes of interacting cells come into contact Ligand–receptor interactions at. .. closely linked, as ligand binding associated with outside in signaling stimulates integrins and, conversely, integrin activation increases ligand binding for inside–out signaling 1.1.5.3 Modularity of Intracellular Signaling Cascades Signaling networks contain diverse functional modules (subnetworks) that can be rapidly connected to shift from one subcellular localization and function to others Signaling. .. series Biomathematical and Biomechanical Modeling of the Circulatory and Ventilatory Systems aims at presenting major sets of signaling receptors mainly located at the plasma membrane, 1 in a modeling framework rather than biological perspective Collecting ... lungs and blood takes place in the alveolus Concept in Action Watch this video for a review of the respiratory system 3/11 Circulatory and Respiratory Systems The Circulatory System The circulatory. .. the cells Art Connection 2/11 Circulatory and Respiratory Systems Air enters the respiratory system through the nasal cavity, and then passes through the pharynx and the trachea into the lungs... 8/11 Circulatory and Respiratory Systems The heart contains two pumps that move blood through the pulmonary and systemic circulations There is one atrium and one ventricle on the right side and

Ngày đăng: 30/10/2017, 23:25

Từ khóa liên quan

Mục lục

  • Circulatory and Respiratory Systems

  • The Respiratory System

  • The Circulatory System

  • The Heart

  • The Cardiac Cycle

  • Blood Vessels

  • Section Summary

  • Art Connections

  • Review Questions

  • Free Response

Tài liệu cùng người dùng

Tài liệu liên quan