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To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1523-1739.2009.01383.x Byline: DAVID L. PEARSON (*), COREY DEVIN ANDERSON ([dagger]), BRIAN R. MITCHELL ([double dagger]), MICHAEL S. ROSENBERG ([dagger]), RONALD NAVARRETE (s.), PAUL COOPMANS (**[dagger][dagger]) Keywords: bird community ecology; detectability; ecoinformatics; extinction; expert amateurs; occupancy modeling; professional biologists; species monitoring; tropical forest Abstract: Abstract: Informally gathered species lists are a potential source of data for conservation biology, but most remain unused because of questions of reliability and statistical issues. We applied two alternative analytical methods (contingency tests and occupancy modeling) to a 35-year data set (1973-2007) to test hypotheses about local bird extinction. We compiled data from bird lists collected by expert amateurs and professional scientists in a 2-km.sup.2 fragment of lowland tropical forest in coastal Ecuador. We tested the effects of the following on local extinction: trophic level, sociality, foraging specialization, light tolerance, geographical range area, and biogeographic source. First we assessed extinction on the basis of the number of years in which a species was not detected on the site and used contingency tests with each factor to compare the frequency of expected and observed extinction events among different species categories. Then we defined four multiyear periods that reflected different stages of deforestation and isolation of the study site and used occupancy modeling to test extinction hypotheses singly and in combination. Both types of analyses supported the biogeographic source hypothesis and the species-range hypothesis as causes of extinction; however, occupancy modeling indicated the model incorporating all factors except foraging specialization best fit the data. Abstract (Spanish): Comprobacion de Hipotesis sobre las Extinciones de Aves en Rio Palenque, Ecuador Mediante Listas Informales de Especies Resumen: Las listas de especies recabadas informalmente son una fuente potencial de datos para la biologia de la conservacion, pero la mayoria no son utilizadas por cuestiones de confiabilidad y temas estadisticos. Aplicamos dos metodos analiticos alternativos (pruebas de contingencia y modelos de ocupacion) a un conjunto de datos de 35 anos (1973-2007) para probar hipotesis sobre la extincion local de aves. Recopilamos los datos de listas de aves recabadas por amateurs expertos y por cientificos profesionales en un fragmento de 2 km.sup.2 de bosque tropical en la costa de Ecuador. Probamos los efectos de lo siguiente sobre la extincion local: nivel trofico, sociabilidad, especializacion de forrajeo, tolerancia a la luz, rango geografico y origen biogeografico. Primero evaluamos la extincion con base en el numero de anos en que la especie no fue detectada en el sitio y utilizamos pruebas de contingencia con cada factor para comparar la frecuencia de eventos de extincion esperada y observada en las diferentes categorias de especies. Posteriormente, definimos cuatro periodos multianuales que reflejaron diferentes etapas de deforestacion y aislamiento del sitio de estudio y utilizamos modelos de ocupacion para probar las hipotesis de extincion individual y combinadamente. Ambos tipos de analisis apoyaron las hipotesis del origen biogeografico y del rango geografico como causas de extincion; sin embargo, los modelos de ocupacion indicaron que el modelo que incorporo todos los factores, excepto la especializacion de forrajeo, tuvo el mejor ajuste a los datos. Author Affiliation: (*)School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, U.S.A., emaildpearson@asu.edu ([dagger])Center for Evolutionary Functional Genomics, The Biodesign Institute, P.O. Box 875301, Arizona State University, Tempe, AZ 85287-5301, U.S.A. ([double dagger])Northeast Temperate Inventory and Monitoring Network, National Park Service, 54 Elm Street, Woodstock, VT 05091-1023, U.S.A. (s.)Fundacion Wong, Av. Carlos Arosemena Km 2.5, Guayaquil, Ecuador (**)Mindo Cloud Forest Foundation, Condominio Fuente de Piedra 12, San Ignacio N30-50, Quito, Ecuador Article History: Paper submitted September 30, 2008; revised manuscript accepted July 20, 2009.

This study was undertaken to determine whether combined elastic and free weight resistance (CR) provides different strength and power adaptations than free weight resistance (FWR) training alone. Forty-four young (age 20 [+ or -] 1 years), resistance-trained (4 [+ or -] 2 years' experience) subjects were recruited from men's basketball and wrestling teams and women's basketball and hockey teams at Cornell University. Subjects were stratified according to team, then randomly assigned to the control (C; n = 21) or experimental group (E; n = 23). Before and after 7 weeks of resistance training, subjects were tested for lean body mass, 1 repetition maximum back squat and bench press, and peak and average power. Both C and E groups performed identical workouts except that E used CR (i.e., elastic resistance) for the back squat and bench press, whereas the C group used FWR alone. CR was performed using an elastic bungee cord attached to a standard barbell loaded with plates. Elastic tension was accounted for in an attempt to equalize the total work done by each group. Statistical analyses revealed significant (P < 0.05) between-group differences after training. Compared with C, improvement for E was nearly three times greater for back squat (16.47 [+ or -] 5.67 vs. 6.84 [+ or -] 4.42 kg increase), two times greater for bench press (6.68 [+ or -] 3.41 vs. 3.34 [+ or -] 2.67 kg increase), and nearly three times greater for average power (68.55 [+ or -] 84.35 vs. 23.66 [+ or -] 40.56 watt increase). Training with CR may be better than FWR alone for developing lower and upper body strength, and lower body power in resistance-trained individuals. Long-term effects are unclear, but CR training makes a meaningful contribution in the short term to performance adaptations of experienced athletes. KEY WORDS variable resistance, physical training, bungee cords, rubber bands

KCNH2 (hERG1) encodes the [alpha]-subunit proteins for the rapidly activating delayed rectifier [K.sup.+] current ([I.sub.Kr]), a major [K.sup.+] current for cardiac myocyte repolarization. In isolated myocytes [I.sub.Kr] frequently is small in amplitude or absent, yet KCNH2 channels and [I.sub.Kr] are targets for drug block or mutations to cause long QT syndrome. We hypothesized that KCNH2 channels and [I.sub.Kr] are uniquely sensitive to enzymatic damage. To test this hypothesis, we studied heterologously expressed [K.sup.+], [Na.sup.+], and L-type [Ca.sup.2+] channels, and in ventricular myoctyes [I.sub.Kr], slowly activating delayed rectifier [K.sup.+] current ([I.sub.Ks]), and inward rectifier [K.sup.+] current ([I.sub.1]), by using electrophysiological and biochemical methods. 1) Specific exogenous serine proteases (protease XIV, XXIV, or proteinase K) selectively degraded KCNH2 current ([I.sub.KCNH2]) and its mature channel protein without damaging cell integrity and with minimal effects on the other channel currents; 2) immature KCNH2 channel protein remained intact; 3) smaller molecular mass KCNH2 degradation products appeared; 4) protease XXIV selectively abolished [I.sub.Kr]; and 5) reculturing HEK-293 cells after protease exposure resulted in the gradual recovery of [I.sub.KCNH2] and its mature channel protein over several hours. Thus the channel protein for [I.sub.KCNH2] and [I.sub.Kr] is uniquely sensitive to proteolysis. Analysis of the degradation products suggests selective proteolysis within the S5-pore extracellular linker, which is structurally unique among Kv channels. These data provide 1) a new mechanism to account for low [I.sub.Kr] density in some isolated myocytes, 2) evidence that most complexly glycosylated KCNH2 channel protein is in the plasma membrane, and 3) new insight into the rate of biogenesis of KCNH2 channel protein within cells. rapidly activating delayed rectifier potassium current; enzymes; myocyte isolation

Mutations in the human ether-a-go-go-related gene (HERG) cause long QT syndrome. We previously showed that the HERG N470D mutation expressed as homotetrameric channels causes a protein trafficking defect, and this can be corrected by the HERG channel blocking drug E-4031. The N470D mutant also has been reported to cause dominant negative suppression of HERG current when coexpressed with wild-type channel subunits. The aims of this study were 1) to investigate the molecular mechanism responsible for the dominant negative effect of the N470D mutant coexpressed with wild-type subunits and 2) to test whether the trafficking defective heteromeric channels could be pharmacologically rescued by E-4031. Using a combination of immunoprecipitation and Western blot methods, we showed that N470D mutant and wild-type HERG subunits were physically associated in the endoplasmic reticulum as heteromeric channels. The coassembly resulted in the retention of both wild-type and N470D subunits in the endoplasmic reticulum. Culturing cells in E-4031 increased the cell surface expression of these channels, although with an altered electrophysiological phenotype. These results suggest that the dominant negative effect of the N470D wild-type coassembled channels is caused by retention of heteromeric channels in the endoplasmic reticulum and that the trafficking defect of these channels can be corrected by specific pharmacological strategies. ion channels; arrhythmia; protein trafficking; patch clamp

Molecular and functional characterization of common polymorphisms in HERG (KCNH2) potassium channels. Am J Physiol Heart Circ Physiol 286: H2434-H2441. 2004. First published February 19, 2004; 10.1152/ajpheart.00891.2003.--Long QT syndrome (LQTS) is a cardiac repolarization disorder that can lead to arrhythmias and sudden death. Chromosome 7-linked inherited LQTS (LQT2) is caused by mutations in human ether-a-go-go-related gene (HERG; KCNH2), whereas drug-induced LQTS is caused primarily by HERG channel block. Many common polymorphisms are functionally silent and have been traditionally regarded as benign and without physiological consequence. However, the identification of common nonsynonymous single nucleotide polymorphisms (nSNPs; i.e., amino-acid coding variants) with functional phenotypes in the SCN5A N[a.sup.+] channel and MiRP1 [K.sup.+] channel [beta]-subunit have challenged this viewpoint. In this report, we test the hypothesis that common missense HERG polymorphisms alter channel physiology. Comprehensive mutational analysis of HERG was performed on genomic DNA derived from a population-based cohort of sudden infant death syndrome and two reference allele cohorts derived from 100 African American and 100 Caucasian individuals. Amino acid-encoding variants were considered common polymorphisms if they were present in at least two of the three study cohorts with an allelic frequency >0.5%. Four nSNPs were identified: K897T, P967L, R1047L, and Q1068R. Wild-type (WT) and polymorphic channels were heterologously expressed in human embryonic kidney cells, and biochemical and voltage-clamp techniques were used to characterize their functional properties. All channel types were processed similarly, but several electrophysiological differences were identified: 1) K897T current density was lower than the other polymorphic channels; 2) K897T channels activated at more negative potentials than WT and R1047L; 3) K897T and Q1068R channels inactivated and recovered from inactivation faster than WT, P967L, and R1047L channels; and 4) K897T channels showed subtle differences compared with WT channels when stimulated with an action potential waveform. In contrast to K897T and Q1068R channels, P967L and R 1047L channels were electrophysiologically indistinguishable from WT channels. All HERG channels had similar sensitivity to block by cisapride. Therefore, some HERG polymorphic channels are electrophysiologically different from WT channels. ion channels; genetics; long QT syndrome; arrhythmia; sudden death

Role of glycosylation in cell surface expression and stability of HERG potassium channels. Am J Physiol Heart Circ Physiol 283: H77-H84, 2002. First published March 7, 2002; 10.1152/ajpheart.00008. 2002.--The human ether-a-go-go-related gene (HERG) encodes the pore-forming subunit of the rapidly activating delayed rectifier potassium channel in the heart. We previously showed that HERG channel protein is modified by N-linked glycosylation. HERG protein sequence contains two extracellular consensus sites for N-linked glycosylation (N598, N629). In this study, we used the approaches of site-directed mutagenesis and biochemical modification to inhibit N-linked glycosylation and studied the role of glycosylation in the cell surface expression and turnover of HERG channels. Our results show that N598 is the only site for N-linked glycosylation and that glycosylation is not required for the cell surface expression of functional HERG channels. In contrast, N629 is not used for glycosylation, but mutation of this site (N629Q) causes a protein trafficking defect, which results in its intracellular retention. Pulse-chase experiments show that the turnover rate of nonglycosylated HERG channel is faster than that of the glycosylated form, suggesting that N-linked glycosylation plays an important role in HERG channel stability. heart; arrhythmia; ion channels; mutations; patch clamp

Several mutations in the human ether-a-go-go-related gene (HERG of KCNH2)-encoded [K.sup.+] channel disrupt intracellular ion channel transport (trafficking) and cause long QT syndrome (LQT2). Compared with WT HERG, trafficking-defective LQT2 channels have a phenotype of minimal of absent complex glycosylation and poor surface membrane expression. We report a novel HERG mutation in the sixth transmembrane segment (F640V) in a family with a history of sudden death, syncope, and long QT syndrome. Heterologous expression of F640V showed a trafficking-defective phenotype, and this phenotype was corrected by a 24-h incubation in the HERG channel blocker E4031(10 mM). We then tested the hypothesis that mutating the putative drug-binding domain at position Y652 would alter the effect of E4031. In a WT background, the Y652C mutation did not alter the WT glycosylation pattern but reduced [I.sub.HERG] (WT = 108 [+ or -] 20pA/pF, n = 9; Y652C 31 [+ or -] 8pA/pF, n = 6), presumably by altering channel function. Y652C [I.sub.HERG] also was less sensitive than WT to E4031(100 nM) block; [I.sub.HERG] WT = 17 + 1% (n = 5) and Y652C = 78 [+ or -] 3% (n = 3). We next tested the double mutation F640V-Y652C. In contrast to F640V, F640V-Y652C was complexly glycosylated; confocal microscopy confirmed cell surface expression; and [I.sub.HERG] was increased (F640V = 8 [+ or -] 1 pA/pF, n = 13; F640V-Y652C = 22 [+ or -] 2 pA/pF, n = 10) to a level similar to Y652C alone. We also tested the trafficking-defective G601S mutation and obtained similar findings; G601S-Y652C was complexly glycosylated and [I.sub.HERG] density was comparable to that of Y652C alone (G601S = 39 [+ or -] 8 pA/pF, n = 6; G601S-Y652C = 25 [+ or -] 7 pA/pF, n = 5). E4031 (10 [micro]M) incubation (24 h) did not alter the glycosylation pattern or [I.sub.HERG] in F640V-Y652C of G601S-Y652C. We conclude that mutagenic modification of the inner pore can restore the processing of several trafficking-defective LQT2 channel proteins. (Supported in part by RO1 HL60723 to Craig T. January and F32 HL071476-01 to Brian Delisle.)