Variant Mutant77.78%

Ox Mutant

Oxen

Oxen are still commonly used for tillage and weed control in many tropical areas of the world.

From: The Triazine Herbicides, 2008

Related terms:

Arecaceae

Fabaceae

Sandalwood

Ornamentals

Proteins

Mull

Amazona

Primulaceae

Byrsonima

Trichilia

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Nitric Oxide, Part G Oxidative and Nitrosative Stress in Redox Regulation of Cell Signaling

Mahsa Rouhanizadeh, ... Tzung Hsiai, in Methods in Enzymology, 2008

5.1.2 MEMS LC for separation of LDL particles

Ox-LDL is considered an emergent marker for unstable angina (Ehara et al., 2001a). Currently, conventional desktop HPLC has been used as a gold standard to obtain LDL subspecies through chromatograms (Sevanian et al., 1994).

The goal is to develop a lab-on-a-chip HPLC system with which measurement of circulating ox-LDL can be achieved with a shorter sample time, higher throughput, less sample volume consumption, improved sensitivity, and, finally, lower cost. The MEMS HPLC system is comprised of a high-pressure parylene LC column, interdigital conductivity sensor, and integrated heater for on- chip temperature control (Fig. 7.17) (Qing et al., 2004). The system for on-chip chromatography tasks is packaged with a PCB board for electric contacts, a MEMS LC chip with backside holes, a mini O ring for sealing, and the chemically inert PEEK jig to integrate the fitting with the MEMS LC chip (Fig. 7.18) (Qing et al., 2004). Channel-anchoring techniques have been developed to increase the pressure compatibility of the Parylene microfluidic system to at least 800 psi (Qing et al., 2004). When the MEMS LC column is packed with ion-exchange chromatography beads, LDL subspecies are separated by anion-exchange chromatography into native LDL (nLDL- reduced state) and ox-LDL in terms of LDL− and LDL2−, with LDL2− being more electronegative (Sevanian et al., 1997). The LDL chromatogram is obtained using isocratic elution and on-chip conductivity sensing (Fig. 7.19). The conductivity of the mobile phase solution provides a baseline signal. When separated LDL subspecies pass by the detector, changes of solution conductivity are detected.

Figure 7.17. MEMS LC system. The top diagram illustrates the key components, including the column packed with beads and on-chip conductivity sensor. The photograph shows column. The column inner diameter is 50 μm and the length is 1 cm.

Figure 7.18. Packaging of MEMS LC.

Figure 7.19. Chromatogram obtained from MEMS LC. The flow rate was controlled by applying sinusoidal potential at 1 Vpp and 10 kHz. The elution was isocratic. The eluent contains 80% of buffer A (20 mM Tris, pH 7.2) and buffer B (20 mM Tris, 1 M NaCl, pH 7.2). The separation column was packed with 7-μm beads.

The LDL sample contains 680 ng of nLDL and 120 ng of LDL− and LDL2− as validated by HPLC. The result is compared with the chromatogram obtained from HPLC with salt gradient elution and UV detection (Fig. 7.20). Results demonstrate the feasibility to separate native LDL particles from the oxidized LDL at 680 and 120 ng, respectively.

Figure 7.20. Chromatogram obtained from HPLC with the identical LDL sample and buffer solutions A and B. The elution contains a salt gradient from 100% A and 0% B to 62% A and 38% B. The flow rate was 1 ml/min. Identical beads used for the MEMS LC were packed in the Hamilton PRP-X500 (4.6 × 50-mm) separation column.

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Canning of soup

In A Complete Course in Canning and Related Processes (Fourteenth Edition), 2016

13.3.15 Ox tail soup

Recipe 13.13: Ox tail soup

IngredientMetric unitsImperial unitsOx tails454.5 kg1000 lbs.Water473 L125 gal.Sherry wine1.9 L½ gal.Caramel0.96 L1 quartButter4.5 kg10 lbs.Chopped carrots11.4 kg25 lbs.Chopped onions11.4 kg25 lbs.Chopped turnips11.4 kg25 lbs.Salt1.8 kg4 lbs.Whole cloves227 g½ lb.Black pepper227 g½ lb.Bay leaves114 g¼ lb.

Joint or chop in 1 in. (2.54 cm) pieces the oxtails, place the larger ones in a small cage; melt the butter in an iron pot, and brown the small pieces; skim out and place in another small cage. In another separate cage place the vegetables with the bay leaves and cloves. Place all in tank with the cool water, turn on steam, bring to boil, and simmer 1.5 h; then remove cage containing small pieces of tail. Cook remainder a half hour, or until the large pieces are very tender; then take them out, separate meat, and return to kettle. Shut off steam; remove the vegetables; add the salt, pepper, sherry, and caramel; divide the small joints among the cans, fill with hot liquor, seal, and process.

Condensed ox tail soup

Make same as ox tail soup, using 379 L (100 gal.) water and double the quantity of everything except ox tails and butter, and add 0.9 kg (2 lbs.) of extract of beef. Thicken with 4.5 kg (10 lbs.) of cornstarch, mixed with cold water, before the salt, pepper, sherry, and caramel are added.

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Historical perspectives of the meat and animal industry and their relationship to animal growth, body composition, and meat technology

Steven M. Lonergan, ... Dennis N. Marple, in The Science of Animal Growth and Meat Technology (Second Edition), 2019

Historical Relationship Between Man and Domestic Animals

The drawings (Fig. 1.1) on the walls of caves and tombs dating back 4–5 thousand years ago indicate an important and positive relationship between man and domestic animals. This positive relationship still exists today for many people. The domestication of the dog probably took place in Eastern Asia about 15,000 or more years ago. This is based on recent DNA evidence. They were domesticated for companionship and often were part of the family thousands of years ago.

Religion and Animals

In Asian countries, oxen and water buffalo were used for transportation and field work and often they became part of the family. Many families would not eat meat from the water buffalo or oxen. Some domesticated animals became part of man's religion and also became part of their social culture. The Buddhist religion is an example of this. Many Buddhists are vegetarians and some are against the slaughter of animals for meat consumption. The Hindu religion considers cattle sacred and they are protected in India.

Medical Science and Animals

The foundation of medical science was greatly influenced through the use of domesticated animals for medical experiments, and the longer life expectancy of man continues today because of the medical science database that was obtained from using domestic animals as experimental models. It is of interest that the physiological functions of pigs are very similar to humans. Therefore the pig is a very good model for human medical research. Fig. 1.6 shows the influence of vitamin B12 on the growth rate of pigs used as an experimental model for the impact of vitamin requirements. The pig on the left received no supplemental B12 and the pig on the right received B12 in the ration. Note the difference in size. Early studies used the pig as an experimental animal to determine B12 requirements for humans. Our society was built with the use of domesticated animals as a source of critical medicines. An example would be the hormone insulin, which can be extracted from the pancreas of the pig. When this procedure is used, the pancreas is harvested during the slaughter process. The extracted insulin was a "life saver" for people who had diabetes. Insulin obtained from animals was the major source until molecular genetic techniques were developed and bacteria were modified to produce insulin. Without domesticated animals, our society would not be as advanced socially, scientifically, or technically.

Fig. 1.6. An example of pigs in an experiment to study vitamin B12 on growth rate and general health conditions. The pig on the left received no supplemental source of vitamin B12, and the pig on the right received 5 μg of vitamin B12 per pound of ration.

From the Council of Agricultural Science and Technology (CAST), Ames, Iowa, Food From Animals, 1980. Courtesy of Vaughn C. Speer, Animal Science Department, Iowa State University, Ames, IA.

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HUMAN NUTRITION | Cardiovascular and Obesity Health Concerns

L. Ovesen, in Encyclopedia of Meat Sciences, 2004

The Effect of Fatty Acids in Meat on Blood Lipids

Meat from pig, ox and lamb contributes with about 20% of the intake of saturated fatty acids in most Western countries (see CHEMICAL AND PHYSICAL CHARACTERISTICS OF MEAT | Adipose tissue). Since stearic acid constitutes about one-third of the total amount of saturated fatty acids in meat fat, the fat is expected to be less cholesterol-increasing than other dietary fats with a corresponding content of saturated fatty acids, however, with more present as short chained fatty acids and less as stearic acids. This is also what has been shown in several studies where fats with different fatty acid compositions have been tested for their effect on blood cholesterol. Butterfat is characterized by a relatively high content of palmitic acid and myristic acid, and olive oil with a high content of oleic acid. When, for instance, the cholesterol-increasing effect of beef fat is compared with that of butterfat and olive oil, intake of butterfat results in the highest blood cholesterol levels. However, cholesterol levels are higher with intake of beef fat than with the intake of olive oil.

Beef, lamb and pork fat, therefore, must be designated as cholesterol increasing. Meat protein does not have an unfavourable effect on cholesterol levels. A reduced risk of myocardial infarction of 30% to 70% has been demonstrated from an increased intake of fish, fruits and vegetables, and a corresponding lower intake of total fat and saturated fatty acids from fats and meat. The decreased risk of myocardial infarction is primarily ascribed to the high intake of marine and vegetable ω-3 fatty acids, and antioxidants and dietary fibre, and not per se to the decreased intake of meat fat.

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Volume 2

Christian D. Ellson, Michael B. Yaffe, in Handbook of Cell Signaling (Second Edition), 2010

The phox (phagocyte oxidase) homology (PX) domains are members of an expanding family of established phosphoinositide-binding domains that includes PH domains, FYVE domains, C2 domains, ENTH domains, and tubby domains. The large differences in structure between these domains suggest that their lipid-binding function arose through the convergent evolution of different structures for the same biological function of lipid binding. Additionally, the PX domain has been shown to participate in a variety of lipid binding-independent functions by acting as a protein–protein interaction module. The examples presented in this chapter show how the understanding of the functional roles that PX domains play in the regulation of their parent proteins has progressed, and it will be important for future work to further elucidate their various mechanisms of action.

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BEEF

R.L. Joseph, in Encyclopedia of Food Sciences and Nutrition (Second Edition), 2003

Introduction

Beef is 'the flesh of ox, bull or cow' (Oxford English Dictionary). Boeuf (Anglo-French) is derived from the Latin bos, bovis (ox), and until the eighteenth century beef meant both animal and meat. The etymology suggests that the meat was for the Norman ruling class, and was not commonly eaten by Anglo-Saxon folk even in the late thirteenth century as Middle English was forming.

Beef has enjoyed a special status since Bos spp. were domesticated in Neolithic times in South-west Asia. The bull was a totem for warrior nomads; eating his flesh transferred his power. The docility and strength of draft oxen, the versatile milk, the valuable hides and attractive meat have made the Bos genus economically vital to humans.

Today beef cattle are raised all over the world (Table 1). The natural environment of Bos taurus is temperate grasslands. B. indicus prefers savannah. Crossbreeds such as Santa Gertrudis grow well in hot dry areas, such as the south-west USA.

Table 1. World production of beef and veala

RegionLive (× 103)Slaughtered (× 103)Carcass weight (kg, mean)Production (kt)1979–81World1 218 277223 14319844 090Africa172 20320 6831422932North/Central America173 51048 91125412 402USA112 15237 29227110 092South America239 24634 0232016853Asia350 40421 3821142435China52 567235075177India186 500171080137Europe133 37748 03722010 551France23 82578412341832Germanyb20 67273532591890UK13 32140972601063Oceania34 79012 7151732198USSR114 74837 39118067201989World1 281 472236 57720949 436Africa185 79423 2771483455North/Central America166 99952 63126714 028USA99 18036 37629310 655South America261 09634 0062097100Asia391 55629 5991193532China661 1416658F99662FIndia195 500292580234FEurope125 56943 38824210 500France21 7806900F2491716FGermanyb20 36978142582005UK11 9023374284958Oceania30 85810 3751952021Former USSR119 60043 300F2038800F

'F' is Food and Agriculture Organization estimate.

All data from FAO (1989) FAO Yearbook of Production, vol. 43. Rome: Food and Agriculture Organization.

aAverage per annum.bSummed over FRG and GDR figures.

Different breeds have been developed over the centuries to maximize returns under local conditions. The compact, early-fattening Aberdeen Angus and Hereford are productive in harsher nutritional and climatic environments. The great draft cattle of Europe, like Charolais and Chianina, put on muscle quickly in larger quantity and are heavier at slaughter. They are leaner, more productive, and are gradually replacing the earlier-maturing breeds.

Many European countries, and New Zealand, produce beef from the dairy herd, whose cows are selected mainly for milk production. Beef bulls on surplus heifers produce beef calves. Pure dairy calves may be raised for beef, in the UK, Ireland, and New Zealand, or veal, in France and The Netherlands, or pet food, in the USA.

Modern economic pressures intensify and concentrate animal production. Many once strong local rare breeds are facing extinction; in the British Isles and USA alone about 30 are listed. Their rich gene pool must be maintained so a wide genetic base will be available to accommodate future natural or market constraints on production.

Comparison of systems converting feed into saleable meat is complex. Prices of land, stock, and feed change yearly. Support schemes alter markets. Health and diet are important to consumers, so a demand for 'natural' feeding has reinforced economic pressures towards increased use of grass and less use of animal-derived feeds.

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The Relation Between Space and Math

Kelly S. Mix, Yi-Ling Cheng, in Advances in Child Development and Behavior, 2012

II Definitions

When I first began cutting up oxen, all I could see was the ox itself. After three years I no longer saw the whole ox. And now—now I go at it by spirit and don't look with my eyes. Perception and understanding have come to a stop and spirit moves where it wants. I go along with the natural makeup, strike in the big hollows, guide the knife through the big openings, and follow things as they are…

Tao Te Ching

When psychologists speak of the relation between spatial ability and mathematics, they often do so in very general terms as if these were unitary constructs. This construal implies that any task that measures spatial ability measures the same thing, and by extension, any evidence of stronger spatial skills will have a significant relation to mathematical ability. But those who study space know this is not the case, just as those who study math know that math ability is not a unitary construct. Thus, any attempts to link the two domains must be sensitive to the fact that there are multiple spatial abilities and multiple math abilities, all of which interact in a complex matrix that is likely changing over time.

But what might these abilities be? Psychologists have developed techniques for grouping performance on various tasks to identify common factors, or categories of ability. In this section, we take a closer look at what these studies have concluded and why.

A What is Spatial Ability?

1 Factor Analyses

One approach to defining spatial ability was undertaken by factor analysts in the early twentieth century (e.g., Cox, 1928; Kelley, 1928; McFarlane, 1925; Spearman & Jones, 1950; Thurstone, 1938). The goal was to define the structure of human intelligence, of which spatial cognition was an important aspect. One of the first challenges was to determine whether spatial cognition was separable from general intelligence. This separation was not immediately apparent—several early factor analyses failed to find evidence for an independent contribution (e.g., Line, 1931; Stephenson, 1931). Smith (1964) concluded that spatial ability is best defined as a "high g" ability, rather than "other-than-g," because it loads so highly on IQ. Recent literature reviews also regard spatial ability as only partially separable from general intelligence (e.g., Höffler, 2010; Miyake, Friedman, Rettinger, Shah, & Hegarty, 2001). However, evidence for an independent spatial factor did emerge, and appeared to be based on spatial visualization and imagery tasks, such as figure construction, pattern perception, and spatial analogies (Koussy, 1935; Slater, 1940; Smith, 1935 cf. 1964).

Attempts to identify subfactors within spatial ability also have had mixed results (Smith, 1964). Some researchers failed to obtain evidence for these distinctions. For example, Slater (1940) hypothesized that mental manipulation of space would load on a different factor than recognition of forms but found that measures targeted at these skills all loaded on the same factor. Among those reporting evidence for subfactors, there is disagreement about the number of independent factors, what comprises each factor, or what to call them (Carroll, 1993; Höffler, 2010; Lohman, 1979; Michael, Guilford, Fruchter, & Zimmerman, 1957; Thurstone, 1944). Indeed, one of the most confusing aspects of the spatial literature is that factor names have been used interchangeably, such that the same terms can refer to the same constructs, partially overlapping constructs, or completely different constructs. Similarly, what appears to be the same construct is often called different names by different researchers, and these differences may or may not map onto scientifically verified distinctions.

Nonetheless, early factor analyses seemed to converge on roughly three definitions (see Table I). These divisions were confirmed in more recent factor analyses (e.g., Carpenter & Just, 1986; Carroll, 1993; Lohman, 1979) and still form the core definitions of spatial ability used today (e.g., Höffler, 2010; Uttal et al., under review). However, there is a great deal of overlap and noise around these category boundaries, with divisions shifting as specific tasks are included or excluded (Carroll, 1993; Höffler, 2010; Lohman, 1988). Miyake et al. (2001) concluded that spatial factors are best understood as "separable, but related constructs" (p. 625), rather than mutually exclusive, independent abilities.

Table I. Definitions of Spatial Ability Identified by Factor Analysts (1925–1979)

Spatial orientationThe ability to perceive the positions of various objects in space, relative to each other and relative to the viewer, particularly across changes in orientation.Mental rotationMental manipulation/rotation of remembered objects or elements in a scene.Spatial visualizationAbility to perceive complex spatial patterns and comprehend imaginary movements in space.

More recent factor analyses have tried to incorporate visuospatial working memory (VSWM). Working memory was originally posited by Baddeley and Hitch (1974) to explain how people can perform multiple tasks simultaneously, apparently exceeding short-term memory limits, as long as information is processed in different modalities (e.g., Brooks, 1968). They described three different kinds of working memory (i.e., phonological, visuospatial, and executive control) each with its own capacity. Support for these divisions came from studies showing: (1) performance decrements when tasks were presented simultaneously in the same format (e.g., people performed worse on two visuospatial tasks than they did on a verbal task and visual task) and (2) different patterns of neurological activity for the various tasks, particularly involving patients with some form of brain damage (see Baddeley, 2000 for a review). Thus, it could be argued that VSWM is distinct from other kinds of working memory. But is this ability distinct from other aspects of intelligence? And more to the point, is it distinct from other kinds of spatial ability?

Sorting out these relations has been complicated. First, working memory and general intelligence are highly correlated (Colom, Rebollo, Palacios, Juan-Espinosa, & Kyllonen, 2004; Kyllonen & Christal, 1990). Second, spatial ability has high correlations with general intelligence, and working memory is itself highly correlated with spatial ability, perhaps even more so than it is with "g" (Süb, Oberauer, Wittman, Wilhelm, & Schulze, 2002). In fact, the three constructs are so tightly interrelated that Lohman (1996) suggested they might be interchangeable, indicating that intelligence is to a large extent the ability to spatially manipulate mental models. However, not everyone agrees. A recent meta-analysis of research on working memory and general intelligence concluded that VSWM, general intelligence, and spatial ability are actually distinct constructs (Ackerman, Beier, & Boyle, 2005). Moreover, a confirmatory factor analysis conducted by these authors revealed that although VSWM is highly associated with spatial factors, this association disappears when executive control is included in the model. This finding suggests that whatever relations exist between spatial tasks and visuospatial memory, they are mediated by executive control and thus do not rule out the possibility of a division between the two (Miyake et al., 2001).1

2 Meta-Analyses

Another approach to defining spatial ability is via meta-analysis. In this approach, researchers group studies or tasks based on a conceptual or statistical criterion. For example, in Linn and Peterson's (1985) meta-analysis of sex differences in spatial ability, tasks were first grouped using broad categories identified in previous psychometric and cognitive research. Then, the homogeneity of effect sizes within each group was examined and groups were further partitioned as needed to achieve homogeneity. Three categories were identified this way: (1) spatial perception, (2) mental rotation, and (3) spatial visualization (see Table II).2

Table II. Definitions of Spatial Ability Identified by Meta-Analysis (1975–2011)

Outcome categoryDescriptionExamples of measuresUttal et al.'s 2 × 2 frameworkLinn and Peterson (1985)DisembeddingPerceiving objects, paths, or spatial configurations amidst distracting background informationEmbedded figures task, flexibility of closure, mazesIntrinsic and staticSpatial visualizationSpatial visualizationPiecing together objects into more complex configurations or visualizing and mentally transforming objects, often from 2D to 3D or vice versaForm board, block design, paper folding, mental cutting, paper foldingIntrinsic and dynamicSpatial visualizationMental rotationRotating 2D or 3D objectsVandenberg mental rotation, cube comparison, purdue spatial visualization test, card rotationIntrinsic and dynamicMental rotationSpatial perceptionUnderstanding abstract spatial principles, such as horizontal invariance or verticalityWater-level, water-clock, plumb-line, cross-bar, rod, and frame testExtrinsic and staticSpatial perceptionPerspective takingVisualizing an environment in its entirety from a different positionPiaget's three mountains task, Guilford–Zimmerman-spatial orientationExtrinsic and dynamicNot included

(Adapted from Uttal et al., under review)

More recently, Uttal et al. (under review) conducted a meta-analysis of the spatial training literature using a five-category definition. They reasoned that spatial tasks could be divided along two dimensions (i.e., intrinsic–extrinsic and static–dynamic) based on performance differences obtained in previous research. The intrinsic–extrinsic dimension contrasts spatial relations inherent to objects, such as the location of object parts, with spatial relations among objects and between objects and the larger space around them, such as wayfinding. This distinction maps onto the mental rotation versus perspective-taking distinction discussed earlier. The second dimension, static versus dynamic, differentiates tasks based on whether they involve movement or transformation. For example, reading a map is a static task, whereas paper folding is dynamic.

By crossing these two dimensions, four categories emerged. One of these was novel and did not map onto categories identified in previous research. It contained extrinsic-dynamic tasks, such as Piaget's three mountains problem and other perspective-taking tasks. The other three categories mapped more or less directly onto the categories identified in previous research (e.g., Linn & Peterson, 1985); however, to achieve an even more direct mapping, Uttal et al. separated mental rotation from spatial visualization though both categories are intrinsic and dynamic. The resulting framework consisted of five categories (see Table II). Contrary to the results of previous meta-analyses, Uttal et al. did not obtain significant differences among effect sizes for these groupings. There was a significant difference between the category with the largest effect sizes (spatial perception) and the category with the smallest effect sizes (disembedding); otherwise the five categories were not statistically distinct.

These attempts to define spatial ability are important because each definition may reflect a unique type of spatial processing that has its own connections to mathematical ability. Early factor analyses established the existence of a distinct cognitive factor related to visual imagery/mental manipulation that could be called spatial ability. Subsequent research indicated that this factor actually comprises at least a few overlapping subfactors, including orientation in space and mental rotation. More recent factor analyses have identified visual spatial working memory as an additional construct, and the cognitive and neurological literatures suggest further subgroups, such as disembedding and perspective-taking, though these subdivisions have not been confirmed statistically. However, it is important to bear in mind that all spatial abilities relate strongly to each other and to overall intelligence. Indeed, another way to construe the relation between space and IQ is that superior intelligence relies on facility with visuospatial manipulation more than even verbal ability (Colom, Contreras, Botella, & Santacreu, 2002; Lohman, 1996; Smith, 1964). Because of this, it remains possible that spatial training for math could be quite general and still be effective.

B What is Mathematical Ability?

The same definitional problem that plagues spatial ability also exists with mathematical ability. During the same era that factor analysts were attempting to define spatial ability, they also tried to tease out a distinct factor for mathematical ability and its component processes. As was the case for spatial ability, some investigators initially reported that math ability was indistinguishable from general intelligence and thus could not be considered a separate factor (Fouracre, 1926; Spearman & Jones, 1950; Werdelin, 1958; Wilson, 1933). However, evidence has subsequently revealed a cluster of tasks that were uniquely mathematical, including arithmetic, numeracy, and what might be considered the mechanical aspects of mathematics (e.g., Barakat, 1951; Holzinger & Harman, 1938; Wrigley, 1958). The existence of this factor suggested that individual differences in math performance were due to differences in general intelligence and also capacity with this numerical factor. Interestingly, a third factor, spatial visualization, also predicted success on other, more conceptual math tasks, such as geometry and algebra (Barakat, 1951; Holzinger & Swineford, 1946; Werdelin, 1958; Wrigley, 1958).

More typically, separate math skills have been defined in attempts to develop curricula for teaching. A recent example is the Common Core State Standards, developed by a panel of math experts as a framework to guide math instruction in grades K-12 (http://www.corestandards.org/). For each grade level, the authors identified key topics and performance benchmarks. The topics themselves are organized into categories of math competence that are more or less consistent throughout the grades. In first grade, for example, categories include: (1) operations and algebraic thinking, (2) number and base-ten operations, (3) measurement and data, and (4) geometry. In grade eight, they are (1) the number system, (2) expressions and equations, (3) functions, (4) geometry, and (5) statistics and probability. In first grade, a benchmark for understanding algebra is the ability to solve addition and subtraction equations with flexible understanding of the equal sign; whereas in eighth grade, children are expected to know how to simplify a linear equation with one variable. These categories also align with the way math courses are offered in school and thus reflect at least an intuitive guess at the way various math skills cluster in terms of psychological process. However, there is not yet direct evidence supporting these divisions at a process level.

There have been surprisingly few attempts to group mathematical tasks at a cognitive processing level. Instead, mathematical tasks tend to be grouped by subject area (e.g., algebra vs. geometry) or specific task (e.g., counting vs. calculation). It is unclear whether these distinctions reflect differences in psychological processing. On one hand, it could be argued that there are psychologically salient differences within the same mathematical subject areas and tasks. We know, for example, that enumerating sets containing fewer than four items involves a different process than enumerating larger sets (e.g., Trick & Pylyshyn, 1994). It likewise seems plausible that solving word problems is psychologically different than solving number fact problems. On the other hand, there may be psychological processes that unite tasks across these groups, leading to fewer or at least different divisions. For example, algebra proofs may be more similar to geometry proofs in terms of cognitive process than they seem with respect to math curriculum.

If the association between spatial ability and mathematics is based on shared cognitive processes, and if these processes are variable within each domain, then the relation between space and math could involve many local connections among tasks and thus many causal mechanisms. However, our review did not provide clear evidence that this is the case. On one hand, there are a priori reasons to expect space and math to be decomposable. There also is evidence from factor analyses and performance differences to indicate certain subdivisions, particularly for spatial ability. On the other hand, there is evidence that these subdivisions are unstable, overlapping, and tightly tied to both general intelligence and working memory. Further research is needed to identify the psychologically meaningful distinctions in these two domains before we can determine whether cross-domain relations are likely to be general, specific, or a mixture of the two.

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Methods in Cell Biology

Ken-ichi Wakabayashi, in Methods in Cell Biology, 2009

I Introduction

Intracellular redox (reduction–oxidation) poise is kept reduced mainly by the glutathione and thioredoxin systems. However, it can become more oxidized due to the generation of reactive oxygen species (ROS) in response to stress or intrinsic cellular activity. Such alterations in the cellular redox poise are important in the regulation of many kinds of cellular functions, such as transcription factor activation, defense against oxidative stress, apoptosis [for review see Oktyabrsky and Smirnova (2007)]. Previously, Chlamydomonas outer arm dynein ATPase and flagellar beating were both shown to be modulated by redox poise (Harrison et al., 2002; Wakabayashi and King, 2006), which changes in response to alterations in ambient light conditions in vivo (Forti et al., 2003).

Chlamydomonas outer arm dynein contains at least three subunits that have redox-sensitive vicinal dithiol(s): LC3, LC5, and DC3. LC3 is a 17-kDa polypeptide which binds the N-terminal stem of the β and γ heavy chains (Sakakibara et al., 1993; Sakato et al., 2007) and has one complete redox-active thioredoxin motif (36WCGPCK41) and a second potentially redox-sensitive vicinal dithiol (65VCAEKCN71) (Harrison et al., 2002; Patel-King et al., 1996; Sakato et al., 2007). LC5 is a 14-kDa protein which has one complete thioredoxin motif (33WCGPCK38) and binds the stem of the α heavy chain (Harrison et al., 2002). DC3 is a 21 kDa protein that is the smallest subunit of the outer dynein arm-docking complex (ODA-DC); this structure mediates the binding of outer arm dyneins to specific sites on the doublet microtubules (Casey et al., 2003b; Takada and Kamiya, 1994). DC3 has a vicinal dithiol (65DCDGCI70) within an EF hand and binds Ca2+ only when it is reduced (Casey et al., 2003a). These three redox-sensitive proteins associate with other proteins in a redox-sensitive manner, and these redox targets can change in response to alterations in ambient light conditions or following treatment with H2O2 (Wakabayashi and King, 2006). These data strongly suggest that a redox regulatory pathway functions in the Chlamydomonas flagellum and that redox-sensitive dynein subunits participate in this pathway.

The presence of thioredoxins in dynein is not specific to Chlamydomonas, as similar modules have been found in the intermediate chain 1 (IC1) protein of sperm flagellar outer arm dynein from the sea urchin Anthocidaris crassispina (Ogawa et al., 1996) and the ascidian Ciona intestinalis (Padma et al., 2001). In addition, two proteins related to Chlamydomonas LC5 and Ciona IC1, TXNDC3 and TXNDC6, are expressed in human ciliated organisms (Padma et al., 2001; Pazour et al., 2006; Sadek et al., 2003, 2001). Thus, the presence of thioredoxins in axonemal dyneins has been evolutionarily conserved. DC3 is a member of a subfamily of EF-hand proteins termed calmodulin, troponin C (CTER and the essential and regulatory light chains of myosin). DC3 has a homologue in Plasmodium, and these proteins represent a distinct subfamily within the CTER grouping (Casey et al., 2003b).

Here I describe (1) how to modulate the redox state of flagellar proteins including three redox-sensitive dynein subunits in vitro (including motility assessment of demembranated cell models after modulation of the redox state), (2) how to assess the in vivo redox state of those proteins, and (3) how to screen for proteins which interact with these dynein components in a redox-sensitive manner. These techniques can be adapted to proteins other than dynein subunits that contain cysteine residues, to determine whether those proteins are redox sensitive, and/or whether they interact with other polypeptides via intermolecular disulfide bonds.

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Scientific tests

Elaine M Aldred BSc (Hons), DC, Lic Ac, Dip Herb Med, Dip CHM, ... Kenneth Vall, in Pharmacology, 2009

Qualitative Analysis In Brief

Goldbeater's Skin Test

A membrane prepared from the intestine of an ox behaves similarly to an untanned hide. The skin is soaked in 2% hydrochloric acid then rinsed with distilled water and put into the test solution for 5 minutes. The skin is then transferred to a 1% solution of ferrous sulphate. A brown or black colour occurs if tannins are present in the test solution.

Chromatography

This is used to separate compounds out of a mixture. The test compound is dissolved in a solvent and then passed through a stationary phase substance. This substance remains static and the dissolved compounds either move through or adhere to it. High-performance liquid chromatography is the most common type of chromatography used in the quality control of herbs. The groups of chemicals are forced through the stationary phase in a column at high pressure, to speed the process up. The points at which the various chemicals stop are analysed by computer. This enables manufacturers or scientists to quickly analyse plant chemicals and isolate them.

Spectrometry

An optical instrument is used to measure light of specific frequencies but varying intensity. This enables scientists to calculate the concentration of a particular compound in a test solution. The concentration of a particular compound in a chosen plant can then be determined.

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Porphyrins and the Porphyrias

J. Jerry Kaneko, in Clinical Biochemistry of Domestic Animals (Sixth Edition), 2008

5 Protoporphyrinogen

Within the mitochondria, coproporphyrinogen III oxidase (COPROgenIII-Ox) catalyzes the decarboxylation of the two propionic acid groups on the A and B pyrrole rings of COPROgenIII to vinyl groups and the resulting product is protoporphyrinogen III (PROTOgenIII). COPROgenIII-Ox is highly specific for COPROgenIII, and this explains the presence of only type III porphyrin isomers in nature. This also means that COPROgenI is a terminal intermediate that is oxidized to coproporphyrin I, the end product of this path (Figure 8-5). COPROgenIII, when in excess, is also oxidized to coproporphyrin III. Similarly, the UROgens I and III can be oxidized to their end products, the uroporphyrins I and III. Figure 8-5 illustrates that each of the -gen forms can be oxidized into their free forms, which are the forms usually found in the circulatory system. These free porphyrins and protoporphyrins are photoreactive and are the causative agents of the photosensitivity in the porphyrias.

Figure 8-5. Alternate pathways for porphyrin synthesis. Normally, enzymes 3 and 4 function together in a coordinated manner to form heme. In the absence of enzyme 4, the alternate and terminal pathway to form the I isomers is taken. The circled numbers correspond to the enzymes listed in Table 8-2.

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Kidney International

Volume 81, Issue 3, 1 February 2012, Pages 229-232

Commentary

Prehypertension and chronic kidney disease: the ox or the plow?

Author links open overlay panelJohn P.Middleton1Steven D.Crowley1

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https://doi.org/10.1038/ki.2011.393Get rights and content

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Nearly ten years ago, practice recommendations supported use of the clinical classification of 'prehypertension' for people with systolic blood pressure of 120–139 mm Hg or diastolic pressure of 80–89 mm Hg. This recommendation was based on observations that these ranges of blood pressure were associated with enhanced cardiovascular and cerebrovascular risks compared with blood pressure less than 120/80 mm Hg. Recent observations, including the report by Yano and colleagues, also suggest that prehypertension is an important risk factor for the development of chronic kidney disease.

The relationship between elevated systemic blood pressure (BP) and kidney disease, either by cause or by consequence, is immutable. People with BP that far exceeds average values are at risk of developing chronic kidney disease (CKD). The CKD that results from hypertension is a leading cause of end-stage kidney disease in the United States, and the ethnic predilection for hypertensive nephrosclerosis contributes to an incidence rate of end-stage kidney disease that is 3.6 times higher in African Americans than in whites in the US.1 Moreover, for the approximately 26 million people in the US who are living with CKD, overt hypertension is a near certainty.2 The consequences of hypertension are profound for patients with CKD, in whom a 10-mm Hg elevation of systolic pressure is associated with a 35% increase in hospitalization for cardiovascular and cerebrovascular disease.3 Decades of clinical trials demonstrate that if BP is controlled in adults with CKD, particularly with the use of angiotensin-converting enzyme inhibitors (ACEis) or angiotensin receptor blockers (ARBs), the medical complications of kidney disease progression can be substantially reduced.4., 5., 6. Related observations were recently reported in children and adolescents. The Effect of Strict Blood Pressure Control and ACE Inhibition on Progression of Chronic Renal Failure in Pediatric Patients (ESCAPE) Trial demonstrated that targeting a BP below the 50th percentile for age, sex, and height significantly reduced the risk of progression of CKD.7 Based on these compelling observations, the consensus practice guidelines endorse the use of ACEis or ARBs and achievement of a goal BP of <130/80 mm Hg in patients who are known to have CKD.8 However, these proven therapies for hypertension are not reaching patients who have CKD. For patients in the United States with stage 3 or 4 CKD (a glomerular filtration rate less than 60 ml/min per 1.73 m2), the rate of adequate BP management is abysmal: only 24–58% of patients with CKD are prescribed either ACEis or ARBs.9,10 Moreover, only 20% of patients with CKD are treated with antihypertensive medications and are achieving the recommended target BP of <130/80 mm Hg.1 As depicted in the scheme in Figure 1, effective delivery of proven BP therapies to patients in the community who are known to have CKD could result in health benefits to millions of people.

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Figure 1. The idealized continuum of care for chronic kidney disease in a population: opportunities for improvement by providers within the care system and by patients. BP, blood pressure; CKD, chronic kidney disease; GFR, glomerular filtration rate.

A high priority for public health, however, must also be applied to the question of how identification of less dramatic elevations of BP foretell the development of CKD. The category of 'prehypertension' was introduced in 2003 as part of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7), and it is defined as a systolic pressure of 120–139 mm Hg or diastolic pressure of 80–89 mm Hg.8 The JNC 7 recommended that patients with prehypertension be prescribed health-promoting lifestyle modifications in order to prevent cardiovascular disease. In part, support for this new classification of hypertension was derived from studies such as the Women's Health Initiative that associated prehypertension with an increased risk of cardiovascular and cerebrovascular complications, a risk that was not fully explained by associated comorbidities such as diabetes, obesity, hyperlipidemia, and advanced age.11 More recently, the potential influence of prehypertension on the risk of CKD was emphasized. In a 20-year follow-up of a health registry in Norway, the Health Study in Nord-Trøndelag (HUNT) evaluated outcomes in an ethnically homogeneous population of more than 70,000.12 HUNT determined that the presence of prehypertension in obese people (body mass index ≥30.0 kg/m2) increased the risk of treated end-stage kidney disease or CKD-related death. In the United States, a link was also established between prehypertension and CKD in different populations. In a study of more than 300,000 people enrolled in the Kaiser health plan, Hsu and colleagues determined that people with BP in the prehypertension range had a 1.6- to 2-fold greater risk of developing end-stage kidney disease than Kaiser enrollees with BP less than 120/80 mm Hg.13 In the nearly 18,000 adults surveyed in the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2006, the unadjusted prevalence of CKD among adults with prehypertension was 13.9% compared with 9.9% of those surveyed who had measured BP less than 120/80 mm Hg.14 After adjustment for age, ethnicity, and sex, the prevalence of CKD in prehypertensive NHANES participants was 17.3% compared with 13.4% of those with normal BP. Albuminuria alone (CKD stages 1 and 2) accounted for more than 60% of the cases of CKD in the NHANES participants who had prehypertension.14 These cross-sectional studies implicate prehypertension as an important condition for the genesis of CKD, but these data fail to consistently establish whether the elevations in BP precede kidney disease. Furthermore, these studies were not able to determine whether achievement of lower BP over time could reduce the risk of progressive kidney failure.

This compilation of observations on elevations of BP and the development of CKD is now supplemented by an interesting study by Yano and colleagues15 (this issue). These investigators take advantage of a remarkable (and enviable) national public-health screening program in Japan. In this program, nearly half a million residents of Japan were screened for metabolic syndrome and hypertension. Yano and colleagues undertook this analysis using the nationwide data set in order to assess the prevalence of CKD within different BP categories. The authors determine that in people with prehypertension with normal BP (120–129/80–84 mm Hg) and in those with prehypertension with high-normal BP (130–139/85–89 mm Hg), the prevalence of CKD was 0.7–1.7 and 2–4.2% higher, respectively, than in Japanese men and women who had optimal BP. After adjustment for age, cigarette use, and alcohol intake, the odds ratio for CKD risk was more consistently elevated in men than in women. The data on the Japanese cohort described in this paper exhibit similarities to the NHANES data in the United States, as summarized above. However, in the population described by Yano and colleagues, the majority of the patients classified as having CKD had estimated glomerular filtration rates below 60 ml/min per 1.73 m2. The authors also describe an important interaction in their cohort, as the presence of obesity strengthened the association between CKD and severity of BP classification, particularly in the males in their study. This is a potentially important descriptive study, as the prevalence of advanced CKD is higher in Japan than in other parts of the world.

A few elements of the study by Yano and colleagues15 deserve particular attention. First, the reader should note that even though the glomerular filtration rate estimate was determined from serum creatinine concentration, the equation used in the study was specific for Asian populations and differs from equations such as the Modification of Diet in Renal Disease (MDRD)-derived estimate. Second, the authors determine that those who participated in the survey who had daily intake of alcohol were less likely to have demonstrated CKD. But the nature of their data collection did not allow the authors to address this unexpected relationship further. Third, because of the nature and timing of the public-health program, the authors were not able to determine whether lesser degrees of hypertension were also associated with abject clinical consequences such as end-stage renal disease or cardiovascular death. Finally, the study design once again does not permit conclusions as to whether prehypertension contributes to CKD or the converse. These results will be fascinating to consider in future studies, particularly those that address the long-term consequences of prehypertension.

These consistent relationships between mild elevations in BP and the prevalence of CKD across diverse populations support the notion that prehypertension renders patients susceptible to progressive kidney damage. On one hand, patients diagnosed with prehypertension may experience more severe and pathogenic elevations in BP that remain undocumented in traditional clinic settings. To support this, clinical trials confirm that BP measured in the office may not reflect 24-h patterns in BP variation, and that sustained control of 24-h ambulatory BP may account for the superior efficacy of ACEis in reducing target organ damage.16 Office measurements of BP therefore probably underestimate the episodes during which patients with prehypertension experience BP spikes that exceed the kidney autoregulatory threshold and thus permit transmission of elevated pressures to the renal vasculature. Beyond hemodynamic consequences of BP spikes, the onset of CKD may also be precipitated by activation of local inflammatory cascades within the kidney. Transient increases in BP damage the endothelium within the renal vasculature and trigger activation of the proinflammatory nuclear factor-κB signaling pathway.17 This vascular injury stimulates immune responses that lead to infiltration of mononuclear cells that propagate parenchymal injury in the kidney and exacerbate BP elevation despite the absence of a known putative antigen.18 Indeed, suppression of immune-cell proliferation can even protect from the ensuing hypertension and associated renal injury in some models.19 This subclinical renal injury leads to further elevations in BP with increases in dietary salt,17 marking a vicious cycle in which prehypertension begets low-grade renal inflammation leading to frank stage I hypertension and progressive CKD. These studies raise the possibility that modulating BP and/or immune responses in patients with prehypertension might have beneficial effects on the progression of CKD.

Nevertheless, it must be recognized that aggressive treatment for all patients with prehypertension would encumber extraordinary resources and effort, as more than 30% of the populations in the United States, Europe, and Japan fulfill this classification. The interesting observations of Yano and colleagues15 do fall short of determining a causal relationship between early elevations of BP and the onset of kidney disease. In addition, the authors accurately state that they did not address whether it would be cost-effective to screen or to treat people with prehypertension in Japan. Skeptics will probably state that any assumption of causality between prehypertension and CKD will be placing the plow before the oxen. The preponderance of data demonstrates that delivery of effective antihypertensive therapies will reduce cardiovascular, cerebrovascular, and kidney risks. Therefore, these observations might serve as a call to action, bearing in mind the proverb, 'the plow goes not well if the plowman hold it not.'