bluuebunny/crossref_metadata_2025 huggingface dataset:
Transgenic overexpression of neuromedin U promotes leanness and hypophagia in mice
Authors: Kowalski T J , Spar B D , Markowitz L , Maguire M , Golovko A , Yang S , Farley C , Cook J A , Tetzloff G , Hoos L , Del Vecchio R A , Kazdoba T M , McCool M F , Hwa J J , Hyde L A , Davis H , Vassileva G , Hedrick J A , Gustafson E L
Published: April 2005

Recent work has shown that neuromedin U (NmU), a peptide initially identified as a smooth muscle contractor, may play a role in regulating food intake and energy homeostasis. To further evaluate this putative function, we measured food intake, body weight, energy expenditure and glucose homeostasis in transgenic mice that ubiquitously overexpress murine proNmU. NmU transgenic mice were lighter and had less somatic and liver fat, were hypophagic, and had improved insulin sensitivity as judged by an intraperitoneal insulin tolerance test. Transgenic mice had higher levels of hypothalamic NPY, POMC and MCH mRNA. There was no difference in O2 consumption between genotypes; however, NmU transgenic mice displayed a modest increase in respiratory quotient during food deprivation and refeeding. There were no behavioral disturbances in the NmU transgenic mice that could account for the results (e.g. changes in locomotor activity). When placed on a high-fat diet, transgenic mice remained lighter than wild-type mice and ate less, but gained weight at a rate similar to wild-type mice. Despite the increased weight gain with high-fat feeding, glucose tolerance was significantly improved in the transgenic mice. These findings support the hypothesized role of NmU as an endogenous anorexigenic peptide.
Growth factor-induced signaling of the pancreatic epithelium
Authors: Kayali A G , Stotland A , Gunst K V , Kritzik M , Liu G , Dabernat S , Zhang Y-Q , Wu W , Sarvetnick N
Published: April 2005

Activated signaling proteins regulate diverse processes, including the differentiation of the pancreatic islet cells during ontogeny. Here we uncover the in vivo phosphorylation status of major growth factor-activated signaling proteins in normal adult mice and during pancreatic islet regeneration. We report elevated phospho-mitogen-activated protein kinase (phospho-MAPK), phospho-c-Jun-NH2-terminal kinase (phospho-JNK), and phospho-p38 MAPK expression during pancreatic regeneration. Immunoblotting experiments demonstrated elevated phosphorylation of p52 Src-homology/collagen (SHC) in the ductal network as well, substantiating the activation of this pathway. Furthermore, protein kinase B (PKB/Akt), a key signaling protein in the anti-apoptotic pathway, was phosphorylated to a greater extent in the ductal network from regenerating pancreas. We observed fibroblast growht factor (FGF)10 and platelet-derived growth factor (PDGF)AA expression in embryonic as well as regenerating adult pancreas. Epidermal growth factor (EGF) and PDGFAA stimulated MAPK and Akt phosphorylation, while FGF10 stimulated MAPK but not Akt phosphorylation in a time-dependent manner in freshly isolated cells from the adult ductal network. These data suggest that a heightened level of expression and stimulation of key signaling proteins underlie the expansion and differentiation processes that support pancreatic ontogeny and regeneration.
Dexamethasone suppresses Smad3 pathway in osteoblastic cells
Authors: Iu Mei-Fway , Kaji Hiroshi , Sowa Hideaki , Naito Junko , Sugimoto Toshitsugu , Chihara Kazuo
Published: April 2005

Central in the pathogenesis of glucocorticoid (GC)-induced osteoporosis is the effects of GC on bone formation. However, the mechanism of GC-inhibited bone formation is not well known. Transforming growth factor (TGF)-β is most abundant in bone matrix compared with other tissues, and we have recently proposed that Smad3, a TGF-β signaling molecule, is important for promoting bone formation. However, no reports have been available about the effects of GC on Smad3 in osteoblasts. In the present study, we investigated whether dexamethasone (Dex), an active GC analog, would affect the expression and activity of Smad3 in mouse osteoblastic MC3T3-E1 and rat osteoblastic UMR-106 cells. Dex significantly suppressed Smad3-stimulated alkaline phosphatase (ALP) activity, although it did not affect TGF-β-inhibited ALP activity in MC3T3-E1 cells. Moreover, pretreatment with Dex suppressed TGF-β-enhanced expression of type I collagen in MC3T3-E1 and UMR-106 cells. In the luciferase assay using p3TP-Lux with a Smad3-specific response element, Dex significantly suppressed the transcriptional activity induced by TGF-β as well as Smad3. However, Dex did not affect the expression of Smad3 in these cells at both mRNA and protein levels. In conclusion, the present study indicates that Dex inhibits ALP activity and type I collagen expression, presumably by suppressing Smad3-induced transcriptional activity but not by modulating Smad3 expression in osteoblastic cells.
Nongenomic effect of thyroid hormone on free-radical production in human polymorphonuclear leukocytes
Authors: Mezosi E , Szabo J , Nagy E V , Borbely A , Varga E , Paragh G , Varga Z
Published: April 2005

Over the past few years increasing evidence has suggested the nongenomic effects of thyroid hormone, such as the activation of the signal transduction pathways and the activation of nuclear factor-κB by the induction of oxidative stress. The present study was undertaken to investigate the effect of thyroid hormone on human polymorphonuclear leukocytes (PMNLs) which are known as important sources of reactive oxygen species in the circulation. The production of superoxide anion (O2−) and the activity of myeloperoxidase were determined in the presence and absence of several inhibitors of the signalling pathway. l-Thyroxine (T4) l-3,5,3′-tri-iodothyronine (T3) and l-3,5-di-iodothyronine (T2) stimulated O2− production in PMNLs in a dose-dependent manner within a few minutes of addition to cells. Thyroid hormone-stimulated O2− production was partially inhibited by pertussis toxin, an inhibitor of GTP-binding G protein, and was completely abolished by the protein kinase C inhibitors calphostin C and Ro-32–0432, and by a calcium chelator (BAPTA; bis-(o-aminophenoxy)ethane-N,N,N′,N′-tetra-acetic acid). Thyroid hormone stimulated myeloperoxidase activity and induced 125I− incorporation into PMNLs. Furthermore, thyroid hormone pre-incubation enhanced O2− production for n-formyl-methionyl-leucyl- phenylalanine (FMLP) stimulation. In conclusion, novel nongenomic actions of thyroid hormone, the induction of superoxide anion production and the stimulation of myeloperoxidase activity in PMNLs were demonstrated. The induction of O2− production requires calcium and is mediated by a pertussis toxin-sensitive G protein via stimulation of protein kinase C(s). These results suggest the existence of a membrane-bound binding site for thyroid hormone in PMNLs and a physiological role for thyroid hormone in the cellular defence mechanisms by stimulating free-radical production.
Thyroid status and nitric oxide in rat arterial vessels
Authors: McAllister R M , Albarracin I , Price E M , Smith T K , Turk J R , Wyatt K D
Published: April 2005

Thyroid disease has profound effects on cardiovascular function. Hypo- and hyperthyroidism, for example, are associated with reduced and increased maximal endothelium-dependent vasodilation respectively. We therefore hypothesized that the capacity for vascular nitric oxide (NO) formation is decreased in hypothyroidism and increased in hyperthyroidism. To test this hypothesis, rats were made hypothyroid (HYPO) with propylthiouracil or hyperthyroid (HYPER) with triiodothyronine over 3–4 months. Compared with euthyroid control rats (EUT), HYPO exhibited blunted growth and lower citrate synthase activity in the soleus muscle; HYPER exhibited left ventricular hypertrophy and higher citrate synthase activity in the soleus muscle (P<0.05 for all effects). The capacity for NO formation was determined in aortic extracts by formation of [3H]l-citrulline from [3H]l-arginine, i.e. NO synthase (NOS) activity. Thyroid status modulated NOS activity (EUT, 36.8 ± 5.5 fmol/h per mg protein; HYPO, 26.0 ± 7.9; HYPER, 64.6 ± 12.7; P<0.05, HYPER vs HYPO). Expression of endothelial and neural isoforms of NOS was modulated by thyroid status in a parallel fashion. Capacity for responding to NO was also determined via measuring cGMP concentration in aortae incubated with sodium nitroprusside. Stimulated cGMP formation was also modulated by thyroid status (EUT, 73.0 ± 20.2 pmol/mg protein; HYPO, 152.4 ± 48.7; HYPER, 10.4 ± 2.6; P<0.05, HYPER vs HYPO). These data indicate that thyroid status alters capacities for both formation of and responding to NO. The former finding may contribute to previous findings concerning vascular function in thyroid disease states.
Substitution of the cysteine 438 residue in the cytoplasmic tail of the glucagon-like peptide-1 receptor alters signal transduction activity
Authors: Vázquez Patricia , Roncero Isabel , Blázquez Enrique , Alvarez Elvira
Published: April 2005

Several G-protein-coupled receptors contain cysteine residues in the C-terminal tail that may modulate receptor function. In this work we analysed the substitution of Cys438 by alanine in the glucagon-like peptide-1 (GLP-1) receptor (GLPR), which led to a threefold decrease in cAMP production, although endocytosis and cellular redistribution of GLP-1 receptor agonist-induced processes were unaffected. Additionally, cysteine residues in the C-terminal tail of several G-protein-coupled receptors were found to act as substrates for palmitoylation, which might modify the access of protein kinases to this region. His-tagged GLP-1 receptors incorporated 3H-palmitate. Nevertheless, substitution of Cys438 prevented the incorporation of palmitate. Accordingly, we also investigated the effect of substitution of the consensus sequence by protein kinase C (PKC) Ser431/432 in both wild-type and Ala438 GLP-1 receptors. Substitution of Ser431/432 by alanine did not modify the ability of wild-type receptors to stimulate adenylate cyclase or endocytosis and recycling processes. By contrast, the substitution of Ser431/432 by alanine in the receptor containing Ala438 increased the ability to stimulate adenylate cyclase. All types of receptors were mainly internalised through coated pits. Thus, cysteine 438 in the cytoplasmic tail of the GLP-1 receptor would regulate its interaction with G-proteins and the stimulation of adenylyl cyclase. Palmitoylation of this residue might control the access of PKC to Ser431/432.
Production of recombinant porcine IGF-binding protein-5 and its effect on proliferation of porcine embryonic myoblast cultures in the presence and absence of IGF-I and Long-R3-IGF-I
Authors: Pampusch M S , Xi G , Kamanga-Sollo E , Loseth K J , Hathaway M R , Dayton W R , White M E
Published: April 2005

IGF-binding protein-5 (IGFBP-5) is produced by porcine embryonic myogenic cell (PEMC) cultures and is secreted into the medium. IGFBP-5 may play some role in myogenesis and/or in changes in myogenic cell proliferation that accompany differentiation. IGFBP-5 reportedly may either suppress or stimulate proliferation or differentiation of cultured cells depending on cell type and culture conditions. Additionally, IGFBP-5 has been shown to possess both IGF-dependent and IGF-independent actions in some cell types. The goal of this study was to produce recombinant porcine IGFBP-5 (rpIGFBP-5) and assess its IGF-I-dependent and IGF-I-independent actions on the proliferation of PEMCs. To accomplish this, we have expressed porcine IGFBP-5 in the baculovirus system, purified and characterized the expressed rpIGFBP-5 and produced an anti-porcine IGFBP-5 antibody that neutralizes the biological activity of porcine IGFBP-5. rpIGFBP-5, purified to 98% homogeneity using nickel affinity chromatography and IGF-I affinity chromatography, suppressed IGF-I-stimulated proliferation of PEMCs in a concentration-dependent manner (P>0.05). rpIGFBP-5 also suppressed Long-R3-IGF-I-stimulated proliferation of PEMCs (P>0.05), even in the presence of significant molar excess of Long-R3-IGF-I compared with rpIGFBP-5, demonstrating the IGF-independent activity that rpIGFBP-5 possesses in PEMCs, since Long-R3-IGF-I is an IGF analog that has very low affinity for the IGFBPs but retains its ability to bind to the type I IGF receptor and thereby can stimulate proliferation. The anti-rpIGFBP-5 IgY produced against rpIGFBP-5 specifically recognized native porcine IGFBP-5 in PEMC media that also contained porcine IGFBP-2, -3, and -4. This antibody is capable of neutralizing the effects of both rpIGFBP-5 and endogenously produced porcine IGFBP-5 on PEMCs as well as detecting IGFBP-5 in Western blots. The production of rpIGFBP-5 and a neutralizing antibody to porcine IGFBP-5 provides a powerful tool to investigate the role of IGFBP-5 in porcine myogenic cell proliferation and differentiation. The data provided here demonstrated that IGFBP-5 has the potential to affect proliferation of PEMCs during critical periods of in vitro muscle cell development and therefore may impact the capacity for ultimate postnatal muscle mass development in vivo.
Thyroid hormone export from cells: contribution of P-glycoprotein
Authors: Mitchell A M , Tom M , Mortimer R H
Published: April 2005

Verapamil inhibits tri-iodothyronine (T3) efflux from several cell types, suggesting the involvement of multidrug resistance-associated (MDR) proteins in T3 transport. The direct involvement of P-glycoprotein (P-gp) has not, however, been investigated. We compared the transport of 125I-T3 in MDCKII cells that had been transfected with mdr1 cDNA (MDCKII-MDR) versus wild-type MDCKII cells (MDCKII), and examined the effect of conventional (verapamil and nitrendipine) and specific MDR inhibitors (VX 853 and VX 710) on 125I-T3 efflux. We confirmed by Western blotting the enhanced expression of P-gp in MDCKII-MDR cells. The calculated rate of 125I-T3 efflux from MDCKII-MDR cells (around 0.30/min) was increased twofold compared with MDCKII cells (around 0.15/min). Overall, cellular accumulation of 125I-T3 was reduced by 26% in MDCKII-MDR cells compared with MDCKII cells, probably reflecting enhanced export of T3 from MDCKII-MDR cells rather than reduced cellular uptake, as P-gp typically exports substances from cells. Verapamil lowered the rate of 125I-T3 efflux from both MDCKII and MDCKII-MDR cells by 42% and 66% respectively, while nitrendipine reduced 125I-T3 efflux rate by 36% and 48% respectively, suggesting that both substances inhibited other cellular T3 transporters in addition to P-gp. The specific MDR inhibitors VX 853 and VX 710 had no effect of 125I-T3 efflux rate from wild-type MDCKII cells but reduced 125I-T3 export in MDCKII-MDR cells by 50% and 53% respectively. These results have provided the first direct evidence that P-gp exports thyroid hormone from cells.
Akt Mediates Mechanical Strain-Induced Collagen Production by Mesangial Cells
Authors: Krepinsky Joan C. , Li Yanxia , Chang Yanfei , Liu Lieqi , Peng Fangfang , Wu Dongcheng , Tang Damu , Scholey James , Ingram Alistair J.
Published: April 2005

Increased glomerular hydrostatic pressure is an important determinant of glomerulosclerosis and can be modeled by

in vitro

exposure of mesangial cells to cyclic mechanical strain. Stretched mesangial cells increase extracellular matrix protein production, the hallmark of glomerulosclerosis. Recent data indicate that the serine/threonine kinase Akt may be involved in matrix modulation. Thus, Akt activation and matrix synthesis in stretched mesangial cells were studied. Exposure of mesangial cells to 1 Hz cyclic strain led to prompt Akt activation, which was biphasic to 24 h. Activation was dependent on signaling through phosphatidylinositol-3-kinase and required EGF receptor transactivation. Inhibition of signaling through the PDGF receptor, Src kinase, or cytoskeletal disruption failed to prevent strain-induced Akt activation. Collagen type 1A1 transcript expression, promoter activation, and protein secretion were increased by stretch at 24 h and were dependent on phosphatidylinositol-3 kinase. Overexpression of dominant-negative Akt inhibited strain-induced collagen 1A1 production. Conversely, overexpression of constitutively active Akt led to increased collagen 1A1 upregulation and secretion. Finally, Akt activation was observed in the glomeruli of remnant rat kidneys, a model marked by increased intraglomerular pressure. The authors conclude that mechanical strain induces Akt activation in mesangial cells through a mechanism requiring phosphatidylinositol-3-kinase and EGF receptor transactivation. Type 1 collagen production is dependent on Akt and can be induced by Akt overexpression. Akt activation is observed in remnant kidneys

in vivo

. Thus, the role of Akt in progression of chronic hemodynamic glomerular disease is worthy of further exploration.
Nitrification
Authors: Tarkalson David D.
Published: April 2005

Nitrification is the biologically facilitated oxidation of ammonium (NH
4
+
) to nitrate (NO
3
−
). The process of nitrification is performed by ammonium and nitrite (NO
2
−
) oxidizing bacteria found in soil and waters. In soil and water, ammonium is supplied through decomposition of organic matter by microbes and/or anthropogenic or natural additions of inorganic nitrogen sources containing ammonia (NH
3
), urea, or ammonium. Nitrification consists of two independent microbially facilitated reactions. In the first reaction,
ammonium
oxidizers oxidize ammonium to nitrite, and in the second reaction,
nitrite
oxidizers oxidize nitrite to nitrate.
Skimmed Groundwater
Authors: Asghar Muhammad Nadeem
Published: April 2005

In several unconfined aquifers under irrigated agricultural areas, the groundwater system consists of a saturated porous medium containing miscible fluids (fresh groundwater and saline groundwater). The native groundwater is deep and saline because of the marine origin of the hydrogeologic formation. However, fresh groundwater lenses from deep percolation of the extensive water conveyance and distribution system, as well as from irrigation and rainfall, overlie this native saline groundwater.

The thickness of these fresh groundwater lenses varies from a few meters to more than 100 meters.

Farmers are using this skimmed groundwater to fill the gap between the supply and demand of surface water in the conjunctive water use environment of the Indus Basin of Pakistan.
Groundwater Assessment Using Soil Sampling Techniques
Authors: Jacobs James A.
Published: April 2005

Groundwater assessment for environmental projects involves significant soil sampling to evaluate hydrologic and lithologic conditions. Soil samples in environmental investigations are typically collected at a minimum of every one to two meters and at changes of lithology or obvious signs of contamination, based on soil staining or discoloration of the soil or in the case of volatile organic compounds, organic vapor readings. Continuous coring is recommended for a minimum of at least one soil boring per site to characterize the subsurface adequately.
Soil Water Issues
Authors: Roberts Eliot C.
Published: April 2005

Landscape plants and turfgrass can eliminate erosion and conserve water most effectively by considering many variables in the makeup of the landscape. These variables include the sizes of mineral components of soil, the components of the root zone, soil moisture capacity, soil texture, soil pH, the soil's biodegradable capacity, and its mulching capacity. All these factors are explained in this entry.
Tile Drainage
Authors: Reed Tara
Published: April 2005

Tile (or relief) drains are porous pipes buried approximately 1 m beneath the surface of the soil. These pipes drain excess water from the land into nearby water bodies, most typically cisterns, open ditches, or streams. The most common use of tile drainage is to improve agricultural production by draining excess moisture from the plant root zone and allowing cultivation normally saturated soils. Subsurface tile drainage also lowers the water table and reduces soil salinity. Many of the world's productive agricultural areas, including 25% of the cropland in the United States, require artificial drainage. The area drained by subsurface drainage systems in the United States has increased since 1900 from less than 5 to almost 30 million hectares.
Xeriscape
Authors: Welsh Douglas F.
Published: April 2005

Much attention and controversy have surrounded the xeriscape concept of landscaping since its inception in 1981. The proper definition of xeriscape is “quality landscaping that conserves water and protects the environment.” Above all things, it must be a quality design that balances the lawn area, shrub and flower plantings, and the hardscape (i.e., decks, patios and sidewalks). Landscapes composed of rocks or plastic flowers alone are not xeriscapes. Xeriscapes are in tune with the environment; therefore, xeriscape applies to the desert in southwestern United States as well as the semitropical southeast.
Crop Evapotranspiration
Authors: Todorovic Mladen
Published: April 2005

Crop evapotranspiration is a physical process in which water passes from the liquid to the gaseous state while moving from the soil to the atmosphere. It refers to both evaporation from soil and vegetative surfaces and transpiration from plants. These two processes are considered together because they occur simultaneously in nature, and it is difficult to separate them when measured or estimated.

Crop evapotranspiration refers to the water losses from a cropped field, and this term is frequently used in irrigation scheduling and irrigation water management.

Crop evapotranspiration is affected by weather factors (radiation, air temperature, humidity, and wind speed), crop parameters (crop type, variety, and development stage), and local environmental and management conditions (soil salinity, application of fertilizers, tillage practices, planting density, presence of diseases and pests, windbreaks, irrigation practices, presence of groundwater and impermeable soil horizons, etc.). Accordingly, it is possible to distinguish between crop evapotranspiration under standard (optimal) conditions and crop evapotranspiration under nonstandard conditions. Standard conditions refer to disease‐free, well‐fertilized crops, grown in large fields, under optimal water supply, and achieving full production for the given climatic conditions. Nonstandard conditions are defined as those that differ from standard conditions.
Crop evapotranspiration under standard conditions
is usually denoted as ET
c
, and
crop evapotranspiration under nonstandard conditions
is marked as ET
c_adj
or ET
c_corr
, where the suffixes “
adj
” and “
corr
” refer to “adjusted” and “corrected,” respectively. Standard conditions concur with the optimal conditions of well‐managed irrigation fields, so, crop evapotranspiration under nonstandard conditions is always lower than or equal to crop evapotranspiration under standard conditions. Therefore,

urn:x-wiley:9780471478447:media:aw57:xm1

where
K

s

is the reduction coefficient (
K

s

 < 1) that accounts for the difference between standard and nonstandard conditions.
Crop Water Requirements
Authors: Todorovic Mladen
Published: April 2005

Crop water requirements (CWR) refer to the amount of water required to compensate for evapotranspiration losses from a cropped field during a specified period of time. Crop water requirements are expressed usually in mm/day, mm/month, or mm/season, and they are used for management purposes in estimating irrigation water requirements, irrigation scheduling, and water delivery scheduling.
Bottled Water
Authors: Hordon Robert M.
Published: April 2005

The rising consumption in the United States is attributed to an increasingly effective advertising campaign that touts bottled water as a safer and better tasting alternative to tap water. Packaging labels that show massive glaciers and springs in alpine settings have also helped

The presumed reason for drinking mineral water and more recently bottled water is for the purported therapeutic effects and associated health benefits. Using mineral waters as a form of therapy was discussed by the ancient Egyptians and Greeks. Based on legend, the thermal springs of Bath, England, date to 800B.C.Hannibal's army (and elephants) was reputed to have refreshed itself in the pools of Vergeze in southern France in 218B.C.while enroute to attack Rome. Later on, the spring waters at Vergeze became known as the source of Perrier water. The mineral waters from 12 springs at Vichy, France, date back to Roman times. Spring water from Fiuggi near Rome, Italy, was used by Michaelangelo. Another Italian luminary from the fifteenth century, Leonardo da Vinci, used the mineral waters from the three deep springs (396 m; 1300 ft) at San Pellegrino. Famous spas and watering holes, such as Hot Springs in Arkansas and Saratoga Springs in New York and many others in Europe, developed near mineral springs during the late 1800s and early 1900s

Bottled water can be grouped into the following several categories depending upon the nature of the water and its source.

Nonsparkling Water this includes spring water, artesian water, mineral water, and purified water. Domestic production of this type of water in the United States made up more than 95% of the bottled water market in 2002.
Storage Coefficient
Authors: Uliana Matthew M.
Published: April 2005

A coefficient is a mathematical quantity that relates two or more variables in an equation describing some physical process. In equations describing the flow of fluids in a porous medium (e.g., groundwater in an aquifer), the
storage coefficient
is the quantity that relates the change in fluid potential (i.e., hydraulic head) in the aquifer to the change in the amount of water stored in the aquifer at a given point. In practical terms, the storage coefficient tells us the volume of water that can be removed from an aquifer for a given drop in hydraulic head.

There are three storage coefficients used in groundwater flow equations (the units of each are given in [brackets] following each definition):

Specific Storage
(
S

s

) is the volume of water removed from a unit volume of a confined aquifer for a unit drop in hydraulic head [L
−1
].

Storativity
(
S
) is the volume of water removed from a unit area of an aquifer for a unit drop in hydraulic head; in confined aquifers, it is equal to the specific storage times the thickness of the aquifer, in unconfined aquifers, it is equal to the specific storage times the thickness of the aquifer plus the
specific yield
[−].

Specific Yield
(
S

y

) is the volume of water removed from a unit volume of an unconfined aquifer for a unit drop in water level; this quantity is also defined as the volume of water that will drain by gravity from a saturated unit volume of an aquifer and is equivalent to the effective porosity [−].
Summary of Isotopes in Contaminant Hydrogeology
Authors: Adelana Segun
Published: April 2005

The word contaminant is a general term to describe dissolved constituents, nonaqueous phase liquids (NAPLs), or industrial solvents which, when added to water as a result of human activities, impair groundwater quality. To an important extent, the complexity of a groundwater contamination problem can be determined by whether or not NAPLs are present. Obviously, contaminants related to anthropogenic activities are one of the major threats facing groundwater resources today. Groundwater contamination can have a significant impact on the present and future use of groundwater resources as a source of drinking water for an increasing population living in cities and rural areas.
Vulnerability Mapping of Groundwater Resources
Authors: Harter Thomas
Published: April 2005

Groundwater vulnerability is a measure of the likelihood that pollution or contamination at the land surface reaches a production aquifer. It is a measure of the “degree of insulation” that natural and man‐made factors provide to keep pollution away from groundwater. The term was first used in Europe in the 1960s. In defining groundwater vulnerability, a number of issues must be examined and clarified; all refer to these two questions: vulnerabilityof what?and vulnerabilityto whatExact definitions of groundwater vulnerability have therefore varied.

In principle, all groundwater is vulnerable to human activity; no groundwater is completely isolated from the aboveground environment. The degree of vulnerability depends on environmental conditions, on how we define groundwater and the part of groundwater in which we are interested in (hence the question, “vulnerabilityof what?”), and on the timescale of interest. In addition, it depends on whether or not a vulnerability measure is intended to account also for the presence and type of pollutants (hence, “vulnerabilityto what?”).
Water Contamination by Low Level Organic Waste Compounds in the Hydrologic System
Authors: Jacobs James A. , Parker Timothy K.
Published: April 2005

Laboratory methods have improved dramatically during the past decade with much lower detection levels enabling some interesting results of human impact on the condition of the hydrologic system. Low levels of organic contaminants are present in surface and groundwaters throughout the nation.
Water‐Jetting Drilling Technologies for Well Installation and
In Situ
Remediation of Hydrocarbons, Solvents, and Metals
Authors: Jacobs James A.
Published: April 2005

Well jetting is particularly suited to unconsolidated sediments such as sandy riverbeds or riverbanks, where water is generally found close to the surface (1 to 5 meters). The jetting technique, which generally does not penetrate more than 10 meters, can be used to drive a pipe and filter into the sandy riverbed of a dry river or wadi, so that subsurface water, close to the surface, can be pumped from below the surface. The jet of water is pushed from a tank through a pump and into a PVC or steel rod, which makes the sand fluid and allows the pipe to slide into the subsurface. On some floodplains, it is possible to jet through more than 30 meters of silt before reaching an underlying sandy aquifer. Small‐diameter jetted wells, called “washbores” by local farmers, are used worldwide to irrigate crops during the dry season.
Detecting Modern Groundwaters with
85
Kr
Authors: Divine Craig E. , Thyne Geoffrey
Published: April 2005

Since the 1950s, anthropogenic contributions of
85
Kr to the atmosphere (primarily the result of nuclear weapons testing and nuclear fuel rod reprocessing) have completely overwhelmed natural background concentrations.

The relatively simple behavior of the atmospheric concentration history permits estimating exact recharge dates to approximately 1960 by measuring the amount of
85
Kr activity in groundwater and accounting for radioactive decay. If dispersion is negligible, an age can be estimated by plotting the measured
85
Kr activity in groundwater samples back to an intercept point on the atmospheric
85
Kr activity curve. Alternatively, a decay‐corrected
85
Kr activity curve can be plotted for the sample collection date directly relating measured activity to an apparent groundwater age. For the
85
Kr method, the “clock” begins at the seasonal high water table because it is assumed that the
85
Kr concentration in the groundwater is in equilibrium with soil gas and the atmosphere.

A primary advantage of
85
Kr is that it is chemically inert in groundwater and is therefore affected only by the hydraulic properties of the aquifer and radioactive decay. Furthermore, age calculations do not require recharge temperature and krypton solubility information because the
85
Kr activity is normalized to the total
85
Kr present. This also implies that errors from excess air trapped in the aquifer or sample loss are negligible. However, because of the high current
85
Kr activity in the atmosphere, care must be taken to prevent sample contamination during well installation and sample collection. Note that the
85
Kr method may overestimate the groundwater age for deep‐water tables (greater than 10 meters) due to a time lag through the unsaturated zone.
Geothermal Water
Authors: Priyadarshi Nitish
Published: April 2005

From earliest times, hot geothermal water or geothermal springs have been used for bathing and cooking. The first technological success in using geothermal energy was in Italy in 1904 where the worlds first geothermally driven electrical plant was opened and operated. Today, applications of low‐ and moderate‐temperature (100 to 300°F) geothermal waters have expanded enormously to include heating large tracts of homes and buildings (district heating), heating greenhouses for growing vegetables and flowers, fish farming (aquaculture), drying foods and lumber, and many other uses. In the United States alone, there are 17 district heating systems, 38 greenhouse complexes, 28 fish farms, 12 industrial plants, and 218 spas that use geothermal waters to provide heat. The district heating system in Boise, Idaho, has been operating since the 1890s and continues to provide heat today. In Iceland, most of the homes and other buildings are connected to geothermal district heating systems, and in the Paris basin in France, many homes are heated by bringing geothermal water to the surface. Geothermal greenhouses are prominent in Italy and in the western United States.

Worldwide, there are about 12,000 thermal megawatts of installed direct uses of geothermal fluids in nearly 30 countries, replacing the combustion of fossil fuels equivalent to burning 830 million gallons of oil or 4.4 million tons of coal per year. This illustrates the trend of countries switching to alternative energy sources such as geothermal energy.

Geothermal water discharges from numerous springs located mostly in mountainous or plateau areas. The springs are connected by faults to deeply buried reservoirs that contain geothermal water, which moves upward along the fault zones to discharge at the land surface. Much geothermal water discharges as hot springs that flow steadily instead of erupting at intervals.
Groundwater and Vadose Zone Hydrology
Authors: Dannwolf Uwe
Published: April 2005

The vadose zone is the geologic media between the land surface and the regional water table.

The vadose zone includes the weathered soil horizon and the unconsolidated sediments and rocks below. The capillary fringe separates the water saturated zone from the unsaturated zone. The water saturated zone is often referred to as an aquifer if it allows significant amounts of water to be transmitted. Several processes take place in the vadose zone.

The processes, which influence the vadose zone and the recharge to groundwater include

precipitation,

evapotranspiration,

surface water runoff, and

infiltration and groundwater recharge.
Groundwater Remediation:In SituPassive Methods
Authors: Jacobs James A.
Published: April 2005

Passivein situremediation technologies (PIRT) use a variety of physical, chemical, or biological processes that act without significant human intervention in the subsurface to reduce the mass, toxicity, mobility, volume, or concentration of contaminants in soil or groundwater. Passive remediation uses the natural movement of water to disperse treatment chemicals or to move contaminated groundwater through a treatment zone.
Groundwater Contamination from Runoff
Authors: Priyadarshi Nitish
Published: April 2005

Not too long ago, urban runoff was considered an insignificant contributor to groundwater contamination. Urban runoff is now recognized as a significant source of contamination in water. Effluents from urban areas contain large concentration of oils, greases, nutrients, heavy metals, and detergents. Detergents that are soluble can pass through the soil and pollute groundwater. Raw sewage dumped in shallow soakpits and seepage from polluted lakes, ponds, and streams also pollute groundwater. Rainfall could pick up substantial contaminants from dust and air and join the aquifer below. The infiltration of liquids containing toxic pollutants may cause pollution in sandy soils and well waters.
Groundwater Quality
Authors: Moore John E.
Published: April 2005

The value of groundwater lies in its widespread occurrence and availability and also its consistent good quality. Groundwater, on the whole, is cleaner than most surface water and maintains a nearly uniform temperature.

As groundwater moves through the subsurface, physical, chemical, and biological processes interact to change its original quality. The earth materials through which groundwater moves act as natural filters to screen out some bacteria and some impurities from the water. Groundwater is usually clear and colorless and of excellent sanitary quality, making it drinkable directly as withdrawn. This does not mean, however, that groundwater is completely free of impurities. In fact, all groundwater contains some dissolved minerals.
Groundwater Sampling with Passive Diffusion Samplers
Authors: Divine Craig E.
Published: April 2005

Passive diffusion‐based sampling methods have been used to monitor environmental contaminants, particularly trace metals and certain lipophilic compounds including polychlorinated biphenyls (PCBs), polynuclear aromatic hydrocarbons (PAHs), and pesticides, for many years. In particular, dosimeter‐type and semipermeable membrane devices (SPMDs) are commonly used in limnology, oceanography, and ecotoxicology for evaluating ultralow concentrations and potential bioavailability of contaminants. These types of samplers are most frequently used for sampling sediment porewater and surface water (i.e., rivers, estuaries, harbors) and have occasionally been used for groundwater characterization in contaminant toxicology studies. These types of sampling devices are composed of a “trapping” phase, such as hexane, activated carbon, or triolein (a prominent fish lipid), contained within a semipermeable membrane (such as dialysis‐type cellulose or a synthetic polymer). Upon deployment, contaminants diffuse through the membrane and are subsequently retained in the trapping phase until analysis. After the SPMD is removed, the contaminants must typically be extracted from the trapping phase before analysis. A significant disadvantage with SPMDs and dosimeter‐type devices for groundwater sampling is that back‐calculation to actual
in situ
aqueous concentrations may not be straightforward due to nonlinear and/or nonequilibrium sorption behavior of the trapping phase.
Groundwater Sampling Techniques for Environmental Projects
Authors: Jacobs James A.
Published: April 2005

Groundwater sampling techniques are important for accurate project results and understanding aquifers whether the project is sampling a groundwater monitoring well as part of an environmental assessment or regular sampling of a potable water supply well.

Groundwater sampling techniques are important for accurate project results and understanding aquifers whether the project is sampling a groundwater monitoring well as part of an environmental assessment or regular sampling of a potable water supply well.

Groundwater samples are collected for a variety of reasons. Groundwater can be collected as a “grab” sample or from a monitoring well.

A “grab” groundwater sample is collected without the use of a fully installed groundwater monitoring well. Methods include using a bailer or jar to collect groundwater from an excavation or trench made with a backhoe or excavator. Other “grab” samples can be collected using a drilling rig wherein a sampler is drilled or pushed to the target depth and the sampler is pushed a bit further into the aquifer.
Hot Springs
Authors: Moore John E.
Published: April 2005

A spring is a source of water that flows naturally from an aquifer or soil onto the land or into a body of surface water. Its occurrence depends on the nature and relationship of rocks (especially permeable and impermeable strata), on the position of the water table, and on topography.

Springs are generally classified as gravity springs and artesian springs. Thermal springs are typically considered a type of artesian spring. The vast majority of springs are gravity springs. Gravity springs are created by water that moves downgradient (downhill) and emerges at the surface. Two gravity springs, contact and fault springs are shown in Fig. 2. Artesian (nongravitational) springs occur when the potentiometric level of the groundwater system is above the land surface and water flows at the land surface under pressure either at the aquifer outcrop or from fractures or faults.
Hydraulic Conductivity/Transmissibility
Authors: Dielman Steven A.
Published: April 2005

Hydraulic conductivity is a fundamental parameter that governs the flow of liquids such as groundwater through aquifers and other porous media. Specifically, hydraulic conductivity is a quantitative measure of the capacity of a geologic formation or other porous media to transmit a specific fluid. It is determined by the characteristics of both the porous medium and the fluid of interest.

Transmissibility (or transmissivity) is a property closely related to hydraulic conductivity that describes the capacity of a specific water‐bearing unit of a given thickness, such as an aquifer, to transmit water. Transmissibility is most simply defined as the effective hydraulic conductivity of an aquifer or other water‐bearing unit multiplied by the thickness of that unit.
Hydraulic Head
Authors: Uliana Matthew M.
Published: April 2005

Hydraulic head
is defined as the fluid energy per unit weight at a given point in a fluid system (like a pipe filled with flowing water or an aquifer). In simple, everyday terms, we can conceptualize (and measure) hydraulic head as an elevation—more specifically, the elevation to which water rises in a manometer, in a pressurized water pipe or in a piezometer.

Water elevations is a manifestation of the fluid energy in a groundwater system, and measuring a water elevation in a piezometer is really a measurement of the energy in the fluid at a certain point in a groundwater system.
Infiltration/Capacity/Rates
Authors: Holden Joseph
Published: April 2005

Infiltration is the process of water entry into the surface of a soil. It involves surface water entry, transmission through the soil, and depletion of the soil water storage capacity. Surface water entry is influenced by surface vegetation cover, soil texture, soil porosity, soil structure (e.g., cracks, surface crusting), and compaction. Land management can influence all of these parameters and therefore influence infiltration.

The infiltration rate is the volume of water passing into the soil per unit area per unit time and therefore has dimensions of velocity (e.g., m s
−1
; mm h
−1
). The infiltration rate is often measured using an infiltrometer and is one of the most easily and frequently measured soil water processes. Despite the units of velocity, the values of infiltration rate are actually volume fluxes expressed as volume flux density and therefore do not indicate the effective velocity of vertical water movement in the soil.

The maximum rate at which water soaks into or is absorbed by the soil is the infiltration capacity.
Artesian Water
Authors: Commander David P.
Published: April 2005

Artesian water is groundwater that flows freely at the surface from an artesian bore or well. The name artesian comes from the flowing wells constructed in the twelfth century at the Carthusian monastery near Lilliers in the northeastern French province of Artois.

The artesian condition is, however, an accident of topography, not necessarily a property of the water, the bore, or the aquifer. For this reason, it is preferable now to use the term ‘confined’ to refer to the aquifer. ‘Confined’ implies the presence of a low permeability confining bed above the confined aquifer, which allows a positive (above ground) hydraulic head to be maintained. Rarely, flowing water can be obtained from an unconfined aquifer without a confining bed, provided there is a sufficient upward head gradient.

Artesian water is common in sedimentary basins, where there are extensive aquifers overlain by confining beds. The classic artesian basin is shaped like a saucer; the aquifer crops out around the elevated margins of the basin, where it can be recharged by rainfall or stream flow. The cities of London and Paris lie at the centers of their basins and were among the first cities to exploit artesian water on a large scale. The Great Artesian Basin in eastern Australia is one of the largest examples; it is 1500 km across. However, artesian conditions can occur in other geological formations.
Innovative Contaminated Groundwater Remediation Technologies
Authors: Boving Thomas B.
Published: April 2005

The development of improved methods for remediating of contaminated aquifers has become a major environmental priority. Many innovative remediation technologies have emerged that promise fast and cost‐effective cleanup of contaminated ground water. According to, there are two general types of new technologies, those that destroy or immobilize contaminants
in situ
(e.g., chemical oxidation, chemical reductive dehalogenation, cometabolic and other bioremediation processes) and those that bring the contaminant mass to the surface for treatment or disposal (e.g., enhanced‐flushing technologies, thermal treatment).
Land Use Impacts on Groundwater Quality
Authors: Trojan Michael D.
Published: April 2005

The manner in which humans use land has important consequences for groundwater quality. Using land for waste disposal, recreation, agriculture, residential development, and industry releases different types and quantities of chemicals to the environment. These chemicals often end up in shallow groundwater, where they may impair water quality.

Groundwater impacts from point sources, such as landfills and hazardous waste sites, are well understood. Impacts from “routine” land use, such as residential, commercial, industrial, or agricultural use, are not fully understood or readily apparent. Sources of chemicals from these land uses are called nonpoint or areawide sources. Examples include fertilized urban lawns or all feedlots in an area. This discussion focuses on water quality impacts in shallow groundwater resulting from routine land use.
Organic Compounds in Groundwater
Authors: Boving Thomas B.
Published: April 2005

Virtually all natural waters contain at least some amounts of organic compounds. However, as human impact on the environment increases, the concentration of organic compounds, such as solvents or petroleum products, in the hydrosphere has increased in many places. Consequently, many aquifers experience a degradation of groundwater quality, and there is strong concern how to protect this valuable natural resource effectively from further contamination.

Organic compounds in groundwater can be of natural or anthropogenic origin. Naturally occurring organic compounds in terrestrial water include carbohydrates (sugars and cellulose), lipids (neutral fats), and proteins. The building blocks of proteins are amino acids, whereas functional proteins that act as biological catalysts are enzymes. Proteins are biopolymers that can form complexes with other organic compounds. Such compounds include tannins, which are phenolic compounds that occur naturally in bark, wood, leaves, or roots of many plants. The presence of elevated tannin levels in water results in a yellowish‐brown discoloration. The parameter, dissolved organic carbon (DOC), is a commonly used measure for the concentration of organic compounds in aqueous solution. DOC is the fraction of total organic carbon (TOC is all carbon atoms covalently bonded in organic molecules) in water that passes through a 0.45 micron pore‐diameter filter. Typical DOC concentrations for ground water range from a few micrograms to several 10 mg per liter and more. DOC concentrations depend on various factors, such as climate, soil and vegetation coverage, and land use.
Overdraft
Authors: Moore John E.
Published: April 2005

Groundwater mining (overdraft) occurs when there is a deliberate or inadvertent extraction of groundwater at a rate so in excess of replenishment that groundwater levels decline persistently and threaten exhaustion of the supply or at least a decline of pumping levels to uneconomic depths.