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Sensitive outcomes of surveys are plagued by wave nonresponse and measurement error (classification error for categorical outcomes). These types of error can lead to biased estimates and erroneous conclusions if they are not understood and addressed. The National Crime Victimization Survey (NCVS) is a nationally representative rotating panel survey with seven waves measuring property and violent crime victimization. Because not all crime is reported to the police, there is no gold standard measure of whether a respondent was victimized. For panel data, Markov Latent Class Analysis (MLCA) is a model-based approach that uses response patterns across interview waves to estimate false positive and false negative classification probabilities typically applied to complete data.This article uses Full Information Maximum Likelihood (FIML) to include respondents with partial information in MLCA. The impact of including partial respondents in the MLCA is assessed for reduction of bias in the estimates, model specification differences, and variability in classification error estimates by comparing results from complete case and FIML MLCA models. The goal is to determine the potential of FIML to improve MLCA estimates of classification error. While we apply this process to the NCVS, the approach developed is general and can be applied to any panel survey.

Sensitive outcomes of surveys are plagued by wave nonresponse and measurement error (classification error for categorical outcomes). These types of error can lead to biased estimates and erroneous conclusions if they are not understood and addressed. The National Crime Victimization Survey (NCVS) is a nationally representative rotating panel survey with seven waves measuring property and violent crime victimization. Because not all crime is reported to the police, there is no gold standard measure of whether a respondent was victimized. For panel data, Markov Latent Class Analysis (MLCA) is a model-based approach that uses response patterns across interview waves to estimate false positive and false negative classification probabilities typically applied to complete data.

The acute effect of metabolic acidosis on SO42−secretion by the marine teleost renal proximal tubule was examined. Metabolic acidosis was mimicked in primary cultures of winter flounder renal proximal tubule epithelium (fPTCs) mounted in Ussing chambers by reducing interstitial pH to 7.1 (normally 7.7). fPTCs with metabolic acidosis secreted SO42−at a net rate that was 40% higher than in paired isohydric controls (pH 7.7 on interstitium). The stimulation was completely blocked by the carbonic anhydrase inhibitor methazolamide (100 μM). Although Na+/H+exchange (NHE) isoforms 1, 2, and 3 were identified in fPTCs by immunoblotting, administering EIPA (20 μM) to the interstitial and luminal bath solutions had no effect on net SO42−secretion by fPTCs with a normal interstitial pH of 7.7. However, EIPA (20 μM) blocked most of the stimulation caused by acidosis when applied to the lumen but not interstitium, demonstrating that induction of brush-border NHE activity is important. In the intact flounder, serum pH dropped 0.4 pH units (pH 7.7 to 7.3, at 2–3 h) when environmental pH was lowered from 7.8 to ∼4.3. Whereas serum [SO42−] was not altered by acidosis, renal tubular SO42−secretion rate was elevated 200%. Thus metabolic acidosis strongly stimulates renal sulfate excretion most likely by a direct effect on active renal proximal tubule SO42−secretion. This stimulation appears to be dependent on inducible brush-border NHE activity.

The current models for branchial acid excretion in fishes include Na+/H+ exchange and the electrogenic excretion of H+ via H+‐ATPase. The predominant route of acid excretion in some freshwater fishes is thought to be via the H+‐ATPase/Na+ channel system. The euryhaline Fundulus heteroclitus may not fit this profile even when adapted to freshwater (FW). We hypothesize that the Na+/H+ exchanger (NHE) in this species may play a predominant role in acid‐base regulation for both marine and FW adapted animals. Acidosis induced by ambient hypercapnia (1% CO2 in air), resulted in an increase in net H+ excretion to the water in F. heteroclitus pre‐adapted to FW, brackish (isoosmotic; BW) and seawater (SW). Both FW and SW adapted mummichogs were tested for NHE protein expression using mammalian NHE antibodies, and we identified NHE‐like immunoreactive proteins in gill membrane preparations from both groups. Hypercapnia induced a ∼three‐fold elevation in gill NHE2‐like protein in FW animals but SW adapted fish showed inconsistent NHE3‐like protein expression. There was no change in NHE‐1 levels in FW fish. In contrast, SW animals demonstrated a significant increase in both NHE1 and NHE3‐like proteins following hypercapnia but limited expression of the NHE2 protein. We hypothesize that different isoforms of NHE may be preferentially expressed depending on the salinity to which the animals are adapted. Net H+ transfers during acidosis may be driven, at least in part by the action of these transporters. J. Exp. Zool. 303A:464–475, 2005. © 2005 Wiley‐Liss, Inc.

As adults, anadromous lampreys migrate from seawater into freshwater rivers, where they require branchial ion (NaCl) absorption for osmoregulation. In teleosts and elasmobranchs, pharmological, immunohistochemical, and molecular data support roles for Na+/K+‐ATPase (NPPase), carbonic anhydrase II (CAII), and vacuolar H+‐ATPase (V‐ATPase) in two different models of branchial ion absorption. To our knowledge, these transport‐related proteins have not been studied in adult freshwater lampreys, and therefore it is not known if they are expressed, or have similar functions, in lampreys. The purpose of this study was to localize NPPase, CAII, and V‐ATPase in the gills of adult freshwater lampreys and determine if any of these transport‐related proteins are expressed in the same cells. Heterologous antibodies were used to localize the three proteins in gill tissue from pouched lamprey (Geotria australis). Immunoreactivity (IR) for all three proteins occurred between, and at the base of, lamellae in cells that match previous descriptions of mitochondrion‐rich‐cells (MRCs). NPPase‐IR was always on the basolateral side of cells that did not stain for CAII or V‐ATPase. In contrast, CAII‐IR was always on the apical side of cells that also contained diffuse V‐ATPase‐IR. Therefore, we have identified two types of MRC in adult freshwater lamprey gills based on immunohistochemical staining for three transport proteins. A model of ion transport, based on our results, is proposed for adult freshwater lampreys. J. Exp. Zool. 301A:654–665, 2004. © 2004 Wiley‐Liss, Inc.

The mechanisms underlying acid–base transfers across the branchial epithelium of fishes have been studied for more than 70 years. These animals are able to compensate for changes to internal pH following a wide range of acid–base challenges, and the gill epithelium is the primary site of acid–base transfers to the water. This paper reviews recent molecular, immunohistochemical, and functional studies that have begun to define the protein transporters involved in the acid–base relevant ion transfers. Both Na⁺/H⁺ exchange (NHE) and vacuolar-type H⁺-ATPase transport H⁺ from the fish to the environment. While NHEs have been thought to carry out this function mainly in seawater-adapted animals, these proteins have now been localized to mitochondrial-rich cells in the gill epithelium of both fresh and saltwater-adapted fishes. NHEs have been found in the gill epithelium of elasmobranchs, teleosts, and an agnathan. In several species, apical isoforms (NHE2 and NHE3) appear to be up-regulated following acidosis. In freshwater teleosts, H⁺-ATPase drives H⁺ excretion and is indirectly coupled to Na⁺ uptake (via Na⁺ channels). It has been localized to respiratory pavement cells and chloride cells of the gill epithelium. In the marine elasmobranch, both branchial NHE and H⁺-ATPase have been identified, suggesting that a combination of these mechanisms may be utilized by marine elasmobranchs for acid–base regulation. An apically located Cl⁻/HCO3⁻ anion exchanger in chloride cells may be responsible for base excretion in fresh and seawater-adapted fishes. While only a few species have been examined to date, new molecular approaches applied to a wider range of fishes will continue to improve our understanding of the roles of the various gill membrane transport processes in acid–base balance. © 2002 Wiley-Liss, Inc.

The mechanisms underlying acid–base transfers across the branchial epithelium of fishes have been studied for more than 70 years. These animals are able to compensate for changes to internal pH following a wide range of acid–base challenges, and the gill epithelium is the primary site of acid–base transfers to the water. This paper reviews recent molecular, immunohistochemical, and functional studies that have begun to define the protein transporters involved in the acid–base relevant ion transfers. Both Na⁺/H⁺ exchange (NHE) and vacuolar-type H⁺-ATPase transport H⁺ from the fish to the environment. While NHEs have been thought to carry out this function mainly in seawater-adapted animals, these proteins have now been localized to mitochondrial-rich cells in the gill epithelium of both fresh and saltwater-adapted fishes. NHEs have been found in the gill epithelium of elasmobranchs, teleosts, and an agnathan. In several species, apical isoforms (NHE2 and NHE3) appear to be up-regulated following acidosis. In freshwater teleosts, H⁺-ATPase drives H⁺ excretion and is indirectly coupled to Na⁺ uptake (via Na⁺ channels). It has been localized to respiratory pavement cells and chloride cells of the gill epithelium. In the marine elasmobranch, both branchial NHE and H⁺-ATPase have been identified, suggesting that a combination of these mechanisms may be utilized by marine elasmobranchs for acid–base regulation. An apically located Cl⁻/HCO3⁻ anion exchanger in chloride cells may be responsible for base excretion in fresh and seawater-adapted fishes. While only a few species have been examined to date, new molecular approaches applied to a wider range of fishes will continue to improve our understanding of the roles of the various gill membrane transport processes in acid–base balance. © 2002 Wiley-Liss, Inc.

Individual autonomic postganglionic neurons are surrounded by pericellular baskets of preganglionic terminals that are easily identifiable with the light microscope. It has been assumed that the target cell of a pericellular basket of preganglionic terminals is the neuron at the centre of the basket. This assumption has enabled the connectivity of preganglionic neurons to be determined at the light microscopic level. However, if the preganglionic terminals in a pericellular basket make synapses with the dendrites of nearby, but functionally different, postganglionic neurons, then the conclusions of light microscopic studies are far less certain. We have used a serial section ultrastructural study to determine the target of the preganglionic pericellular basket in a situation where the apparent target cell is surrounded by neurons of dissimilar function. In the rat superior cervical ganglion, postganglionic neurons projecting to the iris were identified, using retrograde tracers, as single neurons (i.e., not in clusters). We have used immunohistochemistry to show that iris‐projecting neurons are surrounded by preganglionic nerve terminals containing calcitonin gene‐related peptide (CGRP). We have demonstrated that the pericellular basket of CGRP‐immunoreactive preganglionic terminals provides inputs only to the soma at the centre of the basket and not to the dendrites of surrounding neurons. This suggests that, in autonomic ganglia, light microscopic identification of the preganglionic terminal baskets is likely to be a reliable method for identifying the targets of subclasses of preganglionic neurons. J. Comp. Neurol. 412:606–616, 1999. © 1999 Wiley‐Liss, Inc.

Enzyme histochemistry and immunocytochemistry were used to determine the distribution of neurons in the snail Helix aspersa which exhibited nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase activity and/or immunoreactivity to nitric oxide synthase (NOS). NADPH diaphorase-positive cells and fibres were distributed extensively throughout the central and peripheral nervous system. NADPH diaphorase-positive fibres were present in all neuropil regions of the central and peripheral ganglia, in the major interganglionic connectives and in peripheral nerve roots. NADPH diaphorase-positive cell bodies were found consistently in the eyes, the lips, the tentacular ganglia and the procerebral lobes of the cerebral ganglia; staining of cell bodies elsewhere in the nervous system was capricious. The distribution of NOS-like immunoreactivity differed markedly from that of NADPH diaphorase activity. Small clusters of cells which exhibited NOS-like immunoreactivity were present in the cerebral and pedal ganglia; fibres which exhibited NOS-like immunoreactivity were present in restricted regions of the neuropil of the central ganglia. The disjunct distributions of NADPH diaphorase activity and NOS-like immunoreactivity in the neurvous system of Helix suggest that the properties of neuronal NOS in molluscs may differ sigificantly from those described previously for vertebrate animals.