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Weaknesses: Only one underlying cause of death (not multiple causes) was indicated on death certificate importance of water 100 mg kamagra chewable with mastercard, resulting in possible distortion of association between exposure and disease which antihypertensive causes erectile dysfunction buy discount kamagra chewable 100mg line. Strengths/ Weaknesses Strengths: -Person-years at risk stratified by age impotence leaflets cheap 100mg kamagra chewable mastercard, gender erectile dysfunction pills don't work effective 100 mg kamagra chewable, and arsenic level. Weaknesses: -Ecological study design (no individual monitoring data, individual exposures not available). Weaknesses: -Possible diagnosis bias, since data were collected from various community hospitals. Strengths/ Weaknesses Strengths: -Cases were identified from government operated National Cancer Registration Program. Strengths: -Residents in the study area were similar in terms of socioeconomic status, living environments, lifestyles, dietary patterns, and health service facilities. Weaknesses: -Relatively more controls were chosen from the highly exposed city of Antofagasta than from the lower exposure cities of Arica and Iquique resulting in possible underestimation of risk. Weaknesses: -Lack of a cancer registry, arsenic exposure misclassification (use of current water source arsenic measurements possibly causing underestimation of exposure), and recall bias. Strengths: -Extensive documentation of arsenic in drinking water in the Antofagasta water system. Weaknesses: -Residence was determined from death certificates and relates to residence at the time at death. Weaknesses: -Possible biases resulting from a lack of individual exposure data and confounders. North America cancer studies Study Period 39 years (endpoint 1978 diagnosis) Subjects/ Controls 71 National Bladder Cancer Study participants 160 National Bladder Cancer Study participants without bladder cancer Exposure Assessment Mean arsenic level (ppb) = 5. Strengths/ Weaknesses Strengths: -Age, gender, smoking status, years of chlorinated surface water exposure, history of bladder infection, education, occupation, population size of geographic area, and urbanization were addressed. Strengths: -Evaluated the effects of age, gender, race, educational attainment, smoking status, skin reaction to first exposure to the sun, history of radiotherapy (potential confounders). Weaknesses: -Latency of arsenicinduced skin cancer unknown, follow-up period may have been inadequate. This difference would probably mean that more exposed cases were missed in analyses of recent exposure, biasing the odds ratio toward the null. This allowed newly diagnosed melanoma cases to be identified for a specific period and ensured a greater degree of certainty regarding the accuracy of diagnosis. Weaknesses: -A limitation was that toenail samples were collected 23 years after diagnosis, resulting in possible exposure misclassification. Weaknesses: -Skin cancers were selfreported and not confirmed by a medical records review. Weaknesses: -Possible differences in reporting and classification of underlying causes of death. Weaknesses: -Possible recall and misclassification bias resulting from the collection of exposure histories through interviews. Finland cancer studies Study Period 1981 1995 Subjects/ Controls 61 bladder cancer cases and 49 kidney cancer cases 275 referents Exposure Assessment Water arsenic concentration (ppb): <0. Weaknesses: -Possible misclassification and possible recall bias resulting from the study choosing to use water consumption from the 1970. Weaknesses: -Socioeconomic status, race, occupation and living in a rural area were possible confounders. The data from these studies are distributed among 22 key-event categories, with the data from different experiments from a single publication often being summarized under different key-event categories. The advantage of distributing the data in this way is that it helped to focus on a particular key event for each set of data. The disadvantage of using this approach is that it spatially separated the different parts of each experiment. An exception to this procedure is the category Immune System Response, in which results from different parts of each experiment are presented in successive rows. A brief discussion of the approaches and conventions used in preparing the tables is included here. An attempt was made to provide a summary of the main findings of each experiment, with the expectation that any reader wanting more detail would read the publication. A search for any specific citation should make it easy to pull together the information from the numerous parts of some studies that related to different categories. Although, for example, cytotoxicity data are generally summarized in the Cytotoxicity category, exceptions sometimes were made in an attempt to decrease the size of the table. For example, if data presented on apoptosis contained only slight, but interesting, data on cytotoxicity, a brief summary of those cytotoxicity findings was sometimes added at the end of the results column in the row that described the results on apoptosis. When an experiment that tested only one concentration yielded interesting results, the results column is sometimes merged with one or more columns to its left in that same row so the long description of results did not drastically increase the height of the table. In vivo experiments on laboratory animals were almost always restricted to experiments in which the route of exposure was oral. In most cases this meant that the arsenical was administered in drinking water or was given by gavage. Numerous studies were excluded on other non-mammalian species, including, for example, fish, nematodes, and algae. Tables C-2 and C-3 list all doses or concentrations tested as well as the duration of testing. It was often necessary to estimate the concentrations or doses tested from figures. In the rare instances in which there was no zero-dose control group, this omission is mentioned in the results section. As long as this was made clear, it was felt that this approach would be most useful to readers who want to know the lowest concentration level at which a particular effect would probably occur. Arrows are used to indicate changes that were increases or decreases from the control. In most cases, the changes in magnitude of effects relative to the control were described as, for example, "2. When those ratios were based on estimates made from a graph, they are generally preceded by a "" mark; if they were calculated from tabulated values, they are generally presented without that mark. When doses were reported in mg arsenic/L or in ppm As, it was assumed that the doses included adjustment to determine the amount of arsenic administered. In a few publications it was unclear if the reported doses were for the compound or for the amount of arsenic administered. Partly because of this uncertainty, all doses shown in the table that were corrected to the amount of arsenic from values that were clearly reported as concentrations of some arsenical compound (or for which that was assumed to be the case) are preceded by an asterisk. Species of arsenic are shown in Tables C-2 and C-3, and AsV is almost always sodium arsenate. A significantly higher proportion of several genes between patients cancer endemic area of southwest the patients with the arsenic-induced cancer had the with As-related Taiwan, where people had proteins present for Bcl-2 (33/33 vs. Comparison of All 25 arsenical keratosis Immunohistochemical staining patterns of integrin Taiwan, expression of patients with patients were from 1, 21, and 31 were observed. The various patterns of staining among the patients in several integrins arsenical arseniasis-endemic areas of comparison to the controls showed decreased between people keratosis southwest Taiwan, where expression of all 3 integrins in both arsenical with arsenicwater is contaminated by keratosis and in perilesional skin. None showed the related keratosis high concentrations of normal expression pattern of all 3 integrins. Control However, there was no association with the normal skin specimens were obtained from the non-sun-exposed occurrence of basal cell carcinoma or squamous cell skin of 8 age-comparable carcinoma and the expression pattern of any of the 3 integrins. Apoptosis Possible West Bengal, Compared 177 arsenic- Homozygotes for alleles at 2 of the polymorphisms association of India exposed subjects with were significantly over represented in the specific p53 keratosis (mean of 177 ppb individuals with keratosis. Used reflected in significantly higher arsenic content in arsenic concentration nails and hair. When the arsenicism (mean of comparison was restricted to female never-smokers, 343±258 ppb of arsenic in 312 differentially expressed genes were identified Argos et al. Asymptomatic and symptomatic unexposed subjects (mean exposed groups demonstrated rather similar of 7. They saw no solution, solution who ranged from 4 months to 27 difference in chromosome breakage between the (lymphocytes) developed years, and in most cases groups. Inorganic and an even bigger in comparison to healthy lymphocytes) solution were arsenic treatments ceased untreated males. Comparisons were psoriasis also made to 30 apparently patients not healthy untreated males. They frequency in epithelial cells obtained from the arsenic in also considered the buccal mucosa. They clastogenic and possibly even aneuploidogenic arsenic in also considered the properties.
This curve describes the relationship between the amount of water a particular soil can hold and the energy erectile dysfunction pills online order kamagra chewable 100mg with visa, or matric potential loss of erectile dysfunction causes order kamagra chewable 100 mg on line, required to overcome adhesive and cohesive forces to extract water from the soil erectile dysfunction over 75 cheap 100mg kamagra chewable mastercard. Soil water flow can vary from very slow in soil with small pores erectile dysfunction ginkgo biloba order kamagra chewable 100 mg without a prescription, to very fast in soil with large interconnected pores. The soil micro-organisms are largely aquatic in nature and do not inhabit the air-filled pores. There are also short-term experimental campaigns with multi-scale soil water sampling (Crow et al. Satellite-based measurements of soil water are generally based on measuring microwave emissions that vary because of the sensitivity of the soil dielectric constant to its wetness. These approaches use radiative transfer models to simulate the transfer of radiation emitted from the soil through the vegetation canopy and atmosphere to the satellite sensor. These simulation models are driven by observations of precipitation, temperature and other meteorology and simulate the surface hydrological cycle with soil water as a prognostic state variable. This area is relatively dry with around 500 mm yr-1 of precipitation and so irrigation from groundwater has become an important feature of agricultural intensification. Coupled with intensive irrigation and fertilizer application, this has led to declines in soil water quality through salinization and nitrogen leaching (Kendy et al. Severe droughts in the 1970s and 1980s led to the deaths of hundreds of thousands of people across the Sahel (Sheffield and Wood, 2011). Nonetheless, the use of satellite and modelling technologies has the potential to provide drought and famine early warning (Anderson et al. On the time-scale of years, the El Niсo Southern Oscillation is the prime control on the global variability in soil water. These are the North China Plan, the Horn of Africa and the southwestern United States. Effect of different amendments on soil chemical characteristics, grain yield and elemental content of wheat plants grown on salt-affected soil irrigated with low quality water. Nutrient balances and economic performance in urban and peri-urban vegetable production systems of three west African cities. Soil parameter estimates for the soil types of the world for use in global and regional modelling (Version 2. Compaction of agricultural and forest subsoils by tracked heavy construction machinery. L`йrosion йolienne dans le Sahel nigйrien: influence des pratiques culturales actuelles et mйthodes de lutte. Processes of soil acidification during nitrogen cycling with emphasis on legume based pastures. Human alteration of the global nitrogen and phosphorus soil balances for the period 1970-2050. One Century of Arsenic Exposure in Latin America: A Review of History and Occurrence from 14 Countries. Timing effects of deep tillage on penetration resistance and wheat and soybean yield. Long-term effects of deforestation on soil properties and vegetation in a tropical lowland forest in Colombia. Rates and spatial variations of soil erosion in Europe: A study based on erosion plot data. Nutrient balances in African land use systems across different spatial scales: A review of approaches, challenges and progress. A quasi-global evaluation system for satellite-based surface soil moisture retrievals. Up-scaling sparse ground-based soil moisture observations for the validation of coarseresolution satellite soil moisture products. Economic costs of reservoir sedimentation: A regional approach to estimating cropland erosion damage. Updating global Hg emissions from small-scale gold mining and assessing its environmental impact. The Netherlands, Wageningen, International Institute of Land Reclamation and Improvement. Fertilizer inputs, nutrient balance, and soil nutrientsupplying power in intensive, irrigated rice systems. Towards constraining the magnitude of global agricultural sediment and soil organic carbon fluxes. Evaluating global trends (1988-2010) in harmonized multi-satellite surface soil moisture. The International Soil Moisture Network: A data hosting facility for global in situ soil moisture measurements. Population density, soil nutrient depletion, and economic growth in sub-Saharan Africa. Warming of the Indian Ocean threatens eastern and southern African food security but could be mitigated by agricultural development. Multimodel Estimate of the Global Terrestrial Water Balance: Setup and First Results. Nutrient flows and balances at the field and farm scale: Exploring effects of land-use strategies and access to resources. A review of the usefulness of relative bulk density values in studies of soil structure and compaction. Regional nitrogen budgets and riverine N & P fluxes for the drainages to the North Atlantic Ocean: Natural and human influences. Field assessment of nutrient balance under intensive rice-farming systems, and its effects on the sustainability of rice production in Java Island, Indonesia. A study on the influence of climate upon nitrogen and organic matter content of soil. The potential impact of veterinary and human therapeutic agents in manure and biosolids on plants grown on arable land: a review. The vertical distribution of soil organic carbon and its relation to climate and vegetation. State experiences with emerging contaminants recommendations for Federal Action. Policies drain the North China Plain: agricultural policy and ground water depletion in Luancheng County, 19492000. Nutrient flows in small-scale peri-urban vegetable farming systems in Southeast Asia-A case study in Hanoi. Separating the effects of trees on crops: the case of Faidherbia albida and millet in Niger. The temperature dependence of soil organic matter decomposition, and the effect of global warming on soil organic storage. Will changes in soil organic carbon act as a positive or negative feedback on global warming? The evaluation of agricultural machines field trafficking intensity for different soil tillage technologies. Global terrestrial carbon storage and uncertainties in its temperature sensitivity examined with a simple model. Soil Processes are not influenced by the functional complexity of soil decomposer food webs under disturbance. Acid sulphate soil-landscape relationships in the Pearl River Delta, southern China. Untangling the confusion around land carbon science and climate change mitigation policy. Global distribution of atmospheric phosphorus sources, concentrations and deposition rates, and anthropogenic impacts. Chemical and biological processes leading to the neutralisation of acidity in soil incubated with litter materials. Estimating Sahelian and East African soil moisture using the Normalized Difference Vegetation Index. Geographic distribution of crop areas, yields, physiological types and net primary production in the year 2000. The role of African dust in the formation of Quaternary soils on Mallorca, Spain and implications for the genesis of Red Mediterranean soils. Plant nutrient balances in the Asian and Pacific region- the consequences for agricultural production.
The Jackson Laboratory Handbook on Genetically Standardized Mice Chapter 2: Some Basic Genetics about the Mouse 11 2 impotence male quality 100mg kamagra chewable. The vocabulary of genetic architecture the genetic architecture of a phenotype refers to the specific genes and alleles-and their interactions-that influence the expression of the phenotype erectile dysfunction with ms kamagra chewable 100 mg. Much of biomedical genetics is concerned with elucidating the genetic architecture of heritable traits erectile dysfunction cause of divorce discount kamagra chewable 100mg mastercard. Following are definitions and comparisons of terms used when defining the genetic architecture of a phenotype erectile dysfunction viagra dosage kamagra chewable 100mg. Terminology Basic terms used throughout the book include the following: genome genotype the genetic makeup of an organism as a whole, represented by a full set of chromosomes. Depending on context, the allelic composition of · a single gene in an individual, · multiple genes that affect a single trait in an individual, or · all the genes of an organism. A physical characteristic determined by a genotype and its interaction with the environment. By convention, a trait or a locus is considered polymorphic when the most common version or allele occurs at a frequency of less than 95%. This definition contrasts with "monomorphic," which refers to a trait or a locus with little or no variation within a defined population. Terms used to describe specific types of alleles include the following: wild-type allele mutant allele variant allele the most common allele of a gene within a population. An allele of a gene that appears less frequently than the wild-type allele, but at greater than 1% frequency in the population. If the frequency of a mutant allele increases in a population, it may be called a variant. The relationship between the alleles at a specific locus is described by the following: heterozygous homozygous hemizygous Having two different alleles at a locus. Having only one allele at a locus, such as an allele on the unpaired Chr X of a male or an unpaired transgene. When, for a designated population, all alleles for a gene or a locus are identical, the gene or locus is said to be "fixed. The expression level of the phenotype in heterozygotes is intermediate between the expression level of the phenotype in homozygotes for one allele and homozygotes for the alternate allele. The Jackson Laboratory Handbook on Genetically Standardized Mice 12 Section I: Introduction Most of the terms defined on the previous page refer to single genes or loci, or to traits (phenotypes) that are determined primarily by a single gene. Simple trait Complex trait Quantitative trait A trait for which the genetic variance is due primarily to allelic variation at a single locus. Polygenic influences can be additive (the effect of the genotype at each locus is independent of the genotypes at other loci) or interactive (the influence of the genotype at one locus is altered by the genotype at another locus) or both. The result of an interaction of two or more loci on the expression of a phenotype. A given gene may have only one known allele, in which case the terms are effectively interchangeable. Or, a given gene may be polymorphic, with two or more known alleles, in which case the terms gene and allele refer to different things-for example, the gene "leptin" (Lep); the alleles "leptin; obese 2 Jackson" (Lepob-2J), "leptin; obese" (Lepob), and the wild-type allele "leptin; wild-type" (Lep+). The widespread practice of informally naming a gene after the deviant phenotype produced by a mutation of the gene leads to occasional misunderstandings, even among geneticists. To say that an inbred strain does not have the "gene" for some disease phenotype because it does not express the disease is almost always incorrect (except where deletions are involved). The practice of calling a mutant allele a "gene" has become entrenched because of its convenience, and to simplify public communication, but it should be avoided in all scientific communications. Scientific communication is also not well served when investigators continue to use purely phenotypic descriptors (originally used to name mutations) after the gene itself is identified. For example, once a missense mutation in the carboxypeptidase E (Cpe) gene was shown to be the molecular basis for the "fat" mutation, the correct nomenclature for the mutation became Cpefat rather than "fat. Mendel was unaware of our concept of genotypes when he introduced the terms "dominant" and "recessive" to describe the relationship between the phenotypes of traits he studied. Yet, for the sake of convenience, we commonly refer to a "dominant" or "recessive" allele as the allele that produces a dominant or recessive phenotype. This shorthand is generally clear, except in cases where the gene is pleiotropic, i. The Jackson Laboratory Handbook on Genetically Standardized Mice Chapter 2: Some Basic Genetics about the Mouse 13 the 2008 Wikipedia provides an example of how multiple modes of inheritance can apply to a single allele. The allele that produces the sickle cell trait in red blood cells is caused by a base pair substitution in the beta-globin gene that replaces a glutamine with a valine. When only one of the two copies of the beta-globin gene is the mutant allele, resistance to malaria is conferred. Furthermore, the phenotype of blood cell sickling is co-dominant-it occurs when only one copy of the mutant allele is present, but it is more severe when both copies are the mutant allele. Thus, the same allele can display different modes of inheritance if the gene is pleiotropic (has multiple effects), even though each of the associated phenotypes has only one mode of inheritance. Dominance refers to a relationship of two traits that are controlled by the same locus. For many phenotypes that involve complex inheritance, dominance often gets confused with "masking epistatis. Among laboratory strains, at least five genes have common variants that alter coat color. One of these, Tyr (tyrosinase), governs the influence of the other genes on coat color because its activity is required to produce melanin, the pigment responsible for coat and skin color. When Tyr is inactive, melanin is not produced, and albinism results, no matter which alleles are at the other coat color genes. The albino trait is sometimes, incorrectly, said to be dominant over other coat color phenotypes. But because both copies of the Tyr gene must be inactive for albinism to result, the albino trait is recessive. Thus, albinism is a recessive trait that masks the expression of other coat color genes; it is not dominant over other coat color phenotypes. Often the terms "locus" and "gene" are used interchangeably; however, they do have different meanings. A locus is a segment of a chromosome that is demonstrated, by mapping, to contain at least one genetic modification that influences a trait. Although naming a locus for a specific trait (for example, a hyperlipidemia locus) does not mean the gene is known, once a locus is named, often the putative gene that influences the trait is referred to by the same name. On the other hand, numerous genes that were historically identified as loci before the specific gene was known may still be referred to as "loci. We now know that the albino phenotype results when the gene tyrosinase (Tyr) is inactivated. There is no need to continue to use the less precise term "albino locus" to refer to the gene; however, the practice continues due to traditional usage. Thus, although "gene" and "locus" have precise, and different, definitions, common usage often mixes the terms. Segregation refers to the separation, in the parent, of two heterozygous alleles into different gametes (and therefore, into different offspring) during meiosis. When geneticists refer to segregation of a phenotype in a cross, they mean that the phenotype appears in some, but not all, offspring because the genotype is not fixed. When a population is said to be segregating, it means that the line is not fully inbred and that one or more loci are not fixed. It is worth noting that variable expression of a phenotype is not sufficient evidence to claim that the phenotype is segregating. For example, all genes affecting the phenotype may be fixed, but the phenotype may display incomplete penetrance; i. The Jackson Laboratory Handbook on Genetically Standardized Mice 14 Section I: Introduction 2. Complex genetic regulation and the myth of the Mendelian trait When Mendel started his studies of inheritance, he specifically chose to study only binary traits-traits with only two alternatives, such as purple or white flowers. Today, we use the term "Mendelian trait" when referring to binary traits that appear to be controlled by a single locus. The idea that some phenotypes may be determined by a single gene is an oversimplification. But to simplify the study of a trait, researchers often create experimental conditions so that a single locus accounts for almost all of the genetically determined variance of a phenotype within their study population. An example of how this shorthand can create confusion is when a variant or mutant allele for a "Mendelian" trait is transferred to a different genetic background, as when creating a congenic strain.
Because of this impotence caused by anxiety discount kamagra chewable 100 mg without a prescription, toxicity can result if mice are fed autoclavable feed that has not been autoclaved erectile dysfunction treatment can herbal remedies help purchase kamagra chewable 100 mg on line. The degree of the effect varies with the specific ingredients and formula of feed erectile dysfunction adderall kamagra chewable 100mg online. Hardness tests on autoclaved food can identify any that is too hard for mice to eat prostate cancer erectile dysfunction statistics purchase 100mg kamagra chewable with mastercard. Collets, which are made by extrusion and have a honeycombed structure, are less susceptible to hardness problems. The Jackson Laboratory Handbook on Genetically Standardized Mice Chapter 10: Food and Water-Nutritional and Health Implications 221 Another issue with autoclaving is the clumping of food during the sterilizing process. Coatings such as silica dioxide or calcium bentonite have been used in the past to minimize clumping. Although these coatings are considered to be inert because they do not alter the normal pathology of research animals, the potential exists for interference with specific end points in research, and Tobin et al. Irradiation Irradiation is the process of exposing feed to radiation for the purpose of destroying microorganisms. Although irradiation is produced from a radioactive source, no radioactivity is transferred to the irradiated feed. Gamma irradiation is the most commonly used form of irradiation for diet decontamination. Irradiation at doses less than 10 kGy (radicidation or radurization) is equivalent to pasteurization. A minimum dose of 21 kGy is sufficient to kill most bacteria, molds and fungi, and is considered a sterilizing dose, although killing Clostridium and Bacillus spores may require doses above 30 kGy. Doses of at least 30 kGy may be necessary to inactivate some viruses (Baldelli, 1967). Because the radiation dose will vary throughout the product due to load pattern, density of the product, and thickness of the load, the dose is usually stated as the minimum received by the load (typically, at the center of the load). Colors may change somewhat with exposure to light and also vary among label manufacturers, so labels and color keys should be checked carefully. From the standpoint of nutrition, irradiation at doses typically used for rodent diets (2025 kGy for barrier facilities) has no effect on protein bioavailability (Ford, 1979; Eggum, 1979) and losses of most vitamins are less than 20 percent (Ford, 1979; Isler and Brubacher, 1999). Because the effects of irradiation are transmitted by the production of free radicals, the main concern for damage to the diet is the free radical-induced oxidation of fats, producing peroxides. Ford (1979) reported a six- to eight-fold increase in peroxide values in a high fat diet irradiated at 25 kGy; the increase was reduced to three- to four-fold by irradiating under a vacuum (in the absence of oxygen). Keep in mind that, although irradiated feed is free from pathogens, by the time the feed reaches its destination, outside packaging might not be. Comparison of decontamination methods Each decontamination method has advantages and disadvantages. For larger operations, where the expense of the autoclaving equipment and operating expertise is already assumed for other needs, autoclaving will be the most cost effective. Autoclaving also may be necessary where lipid peroxides in the diet may be a particular concern. And it has the additional advantage of on-site decontamination, so that contamination during transport is of minimal concern. Irradiated diets provide more consistent protein quality and levels of nutrients, and they are a uniform hardness, but they are more expensive. Irradiated diets are typically preferred for small barrier colonies or isolators where large autoclaves are unavailable. Pasteurization may be preferred over sterilization when a more consistent dietary protein quality or vitamin level is necessary, but neither pasteurization or sterilization by autoclaving provides the consistency of irradiation (Tobin et al. On-site storage of feed the two most important factors affecting food during storage are temperature and humidity. Natural-ingredient diets are typically stored at room temperature (22 C), and shelf lives are calculated on that basis. Because the rate of biological processes typically doubles with each temperature increase of 10 C, reducing the storage temperature to 12 C would reduce the rate of vitamin destruction and the oxidation of fats by half, thus doubling the shelf life. Because, compared to yeast or bacteria, mold starts growing at a lower relative humidity (about 80%), it will be the first microorganism to appear in stored food that is exposed to moisture. For storage guidelines, the National Research Council (1996) recommends a maximum exposure of 23 C and 70% relative humidity with a continuous exposure of less than 21 C and 60% relative humidity. It is important to heed storage conditions and the "use by" date recommended by the supplier. Nutritional composition of feed and requirements for healthy mice To produce research results that are unambiguous regarding the health of the animals, any diet you consider should be designed specifically for laboratory rodents. Nutrients can be divided into five broad categories: protein, fat, available carbohydrates, fiber, and essential nutrients. Essential nutrients, which include essential fatty acids, essential amino acids, vitamins and minerals, are listed in Table 10. Essential amino acids: · Arginine (may not be essential for adult mice) · Histidine · Isoleucine · Leucine · Valine · Threonine · Lysine · Methionine · Phenylalanine · Tryptophan Essential fatty acids: · Linoleic · " linolenic Macroelements: · Calcium · Phosphorus · Magnesium · Potassium · Sodium · Chloride · Sulfur Trace elements: · Iron · Zinc · Manganese · Copper · Selenium · Iodine Vitamins: · A (retinol) · Vitamin D3 (cholecalciferol) · Vitamin E (tocopherols) · Vitamin K3 (menadione) · Vitamin B1 (thiamine) · Vitamin B2 (riboflavin) · Available niacin · Vitamin B6 (pyridoxine) · Panthothenate · Vitamin B12 (cobalamin) · Available biotin · Folate · Choline Ultratrace chemicals, which are not yet established as essential but may be required, include arsenic, boron, chromium, cobalt, fluoride, lithium, molybdenum, nickel, silicon, tin, vanadium. The Jackson Laboratory Handbook on Genetically Standardized Mice Chapter 10: Food and Water-Nutritional and Health Implications 223 10. Protein Nutritional requirements for protein differ for the three classical physiological states: reproduction (including lactation), growth, and maintenance. In fact, diets with higher protein percentages (24%, for example), may be sub-optimal (Knapka et al. In most mouse colonies in the United States, commercial diets used for breeding, growth, and maintenance are about 18% protein. Growth A maximal growth rate to mature body weight typically is achieved on diets containing at least 1316% protein. Growth rate immediately after weaning may be higher on 18% protein diets, compared to 14%, which may reflect an interaction between the stress of weaning and dietary composition. Catch-up growth occurs on the diets with 1416% protein, and subsequent growth to mature body weight continues at the same rate with diets that range in protein composition from 1318% (reviewed in Tobin et al. Maintenance the few estimates of maintenance requirements for dietary protein in mice indicate that a 5% protein diet, with good quality protein, is sufficient to sustain adult body weight (Tobin et al. In fact, in adults, restriction of protein to 4% (casein), compared with 26%, typically increased lifespan for multiple strains of mice (Leto et al. In rats, high protein diets are associated with kidney damage; in mice, however, a comparable association of dietary protein and kidney damage has not been reported (Tobin et al. Fat and essential fatty acids For growth and maintenance of most strains, diets of 46% fat weight/weight (w/w) are generally appropriate (Knapka et al. For breeding, strain variation exists for the optimal dietary fat content, which ranges from 412%. General guidelines for dietary fat content do not exist specifically for poorly reproducing strains, and optimal amounts should be determined by each researcher. Linoleic acid is a precursor to arachadonic acid and other omega-6 fatty acids, and arachadonic acid can substitute in the absence of dietary linoleic acid. For example, about four times more lard, compared to soya or corn oil, is needed to satisfy the requirement for linoleic acid. Carbohydrates and fiber Complex carbohydrates provide the predominant energy source in natural diets. Crude fiber is the indigestible material remaining after a defatted feed sample is successively boiled in mild acid and then base, which digests proteins and starches and removes the amino acids and soluble carbohydrates. Total carbohydrate value overestimates the amount of carbohydrate available for metabolism because it includes insoluble (crude) fiber. Typically, the amount (in percent by weight) of crude protein, crude fat, and crude fiber will be provided as the proximate analysis with each bag of feed. Ash Ash is the inorganic material that remains after burning a feed sample at a minimum of 525° C for 1218 hours, depending on the temperature. Ash is composed of minerals; it is used in proximate analysis as a rough measure of the amount of minerals in a feed sample. Although the optimal amount of total protein differs for reproduction, growth, and maintenance, available information indicates that the relative amounts of each essential amino acid remain about the same for all three physiological states (Tobin et al.
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