bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular analysis of the A322D mutation in the GABAA receptor α1‐subunit causing juvenile myoclonic epilepsy
Authors: Krampfl Klaus , Maljevic Snezana , Cossette Patrick , Ziegler Elke , Rouleau Guy A. , Lerche Holger , Bufler Johannes 
Published: July 2005

AbstractJuvenile myoclonic epilepsy (JME) belongs to the most common forms of hereditary epilepsy, the idiopathic generalized epilepsies. Although the mode of inheritance is usually complex, mutations in single genes have been shown to cause the disease in some families with autosomal dominant inheritance. The first mutation in a multigeneration JME family has been recently found in the α1‐subunit of the GABAA receptor (GABRA1), predicting the single amino acid substitution A322D. We further characterized the functional consequences of this mutation by coexpressing α1‐, β2‐ and γ2‐subunits in human embryonic kidney (HEK293) cells. By using an ultrafast application system, mutant receptors have shown reduced macroscopic current amplitudes at saturating GABA concentrations and a highly reduced affinity to GABA compared to the wild‐type (WT). Dose–response curves for current amplitudes, activation kinetics, and GABA‐dependent desensitization parameters showed a parallel shift towards 30‐ to 40‐fold higher GABA concentrations. Both deactivation and resensitization kinetics were considerably accelerated in mutant channels. In addition, mutant receptors labelled with enhanced green fluorescent protein (EGFP) were not integrated in the cell membrane, in contrast to WT receptors. Therefore, the A322D mutation leads to a severe loss‐of‐function of the human GABAA receptor by several mechanisms, including reduced surface expression, reduced GABA‐sensitivity, and accelerated deactivation. These molecular defects could decrease and shorten the resulting inhibitory postsynaptic currents (IPSCs) in vivo, which can induce a hyperexcitability of the postsynaptic membrane and explain the occurrence of epileptic seizures.
Immunoautoradiographic analysis of NMDA receptor subunits and associated postsynaptic density proteins in the brain of dyskinetic MPTP‐treated common marmosets
Authors: Hurley M. J. , Jackson M. J. , Smith L. A. , Rose S. , Jenner P. 
Published: July 2005

Abstractl‐3,4‐dihydroxyphenylalanine methyl ester (l‐DOPA)‐induced dyskinesia in Parkinson's disease may result from aberrant glutamatergic stimulation of the striatum due to synaptic plasticity in the motor cortex or striatum as a consequence of adaptation of striatal output pathways. This might result from changes in NMDA receptor subunit or NMDA receptor associated postsynaptic density (PSD) scaffold protein expression. Using immunoautoradiography the expression levels of NR1 and NR2B subunits of the NMDA receptor and the postsynaptic density scaffold proteins, PSD‐95, PSD‐93, and neurofilament light (NFL) were examined in normal common marmosets (Callithrix jacchus) and 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐lesioned animals that exhibited high or low levels ofl‐DOPA‐induced dyskinesia. Brains from MPTP‐lesioned animals that were not primed forl‐DOPA‐induced dyskinesia were not included in this study. No alterations in the NR1 NMDA receptor subunit were observed. The NR2B NMDA receptor subunit was increased in caudal caudate nucleus and putamen, hippocampus, cingulate motor area (CMA), supplementary motor area (SMA) and dorsal primary motor cortex (dMI) of highly dyskinetic MPTP‐lesioned marmosets, but not in animals with low levels of dyskinesia. PSD‐93 was decreased in the globus pallidus of marmosets with high and low levels of dyskinesia and increased in the CMA, SMA and dMI of highly dyskinetic marmosets. PSD‐95 was increased in the SMA of highly dyskinetic marmosets, but not in animals with low dyskinesia. NFL expression was elevated in the SMA and dorsal and ventral MI of highly dyskinetic marmosets. These results suggest thatl‐DOPA treatment of MPTP‐lesioned marmosets can affect glutamatergic systems and indicate that altered NMDA receptor function may relate to dyskinesia.
Chemically induced long‐term potentiation increases the number of perforated and complex postsynaptic densities but does not alter dendritic spine volume in CA1 of adult mouse hippocampal slices
Authors: Stewart M. G. , Medvedev N. I. , Popov V. I. , Schoepfer R. , Davies H. A. , Murphy K. , Dallérac G. M , Kraev I. V. , Rodríguez J. J. 
Published: July 2005

AbstractExamination of the morphological correlates of long‐term potentiation (LTP) in the hippocampus requires the analysis of both the presynaptic and postsynaptic elements. However, ultrastructural measurements of synapses and dendritic spines following LTP induced via tetanic stimulation presents the difficulty that not all synapses examined are necessarily activated. To overcome this limitation, and to ensure that a very large proportion of the synapses and spines examined have been potentiated, we induced LTP in acute hippocampal slices of adult mice by addition of tetraethylammonium (TEA) to a modified CSF containing an elevated concentration of Ca2+ and no Mg+. Quantitative electron microscope morphometric analyses and three‐dimensional (3‐D) reconstructions of both dendritic spines and postsynaptic densities (PSDs) in CA1 stratum radiatum were made on serial ultrathin sections. One hour after chemical LTP induction the proportion of macular (unperforated) synapses decreased (50%) whilst the number of synapses with simple perforated and complex PSDs (nonmacular) increased significantly (17%), without significant changes in volume and surface area of the PSD. In addition, the surface area of mushroom spines increased significantly (13%) whilst there were no volume differences in either mushroom or thin spines, or in surface area of thin spines. CA1 stratum radiatum contained multiple‐synapse en passant axons as well as multiple‐synapse spines, which were unaffected by chemical LTP. Our results suggest that chemical LTP induces active dendritic spine remodelling and correlates with a change in the weight and strength of synaptic transmission as shown by the increase in the proportion of nonmacular synapses.
Sensitization of the reinforcing effects of self‐administered cocaine in rats: effects of dose and intravenous injection speed
Authors: Liu Yu , Roberts David C. S. , Morgan Drake 
Published: July 2005

AbstractSpeed of drug onset is assumed to be an important determinant of the abuse liability of a drug. Studies in human and non‐human primates suggest that the subjective and reinforcing effects of cocaine can be influenced by route of administration and/or speed of intravenous injection. Sensitization to the reinforcing effects of cocaine was studied in rats and the effects of various injection durations (i.e. speed of injection) on the development of sensitization was examined using a progressive ratio schedule. In addition, the effects of cocaine dose on sensitization and the effects of injection duration on the acute reinforcing effects of cocaine were examined. The initial study demonstrated that the development of sensitization (i.e. progressive increases in breakpoints) was dose‐dependent. A robust sensitization of the reinforcing effects of cocaine was replicated in animals receiving cocaine at the highest rate (i.e. shortest duration; 5 s), but not in animals receiving the same dose over 25 or 50 s. Subsequent testing revealed that injection duration did not have profound effects on the acute reinforcing effects of cocaine (assessed by breakpoints or rate of responding on a fixed ratio schedule). These findings are similar to recent studies demonstrating that the development of sensitization, but not the acute responsivity, to cocaine's locomotor‐activating effects are influenced by rate of intravenous injection. Taking these findings together, we hypothesize that the process of drug addiction involves both the acute reinforcing effects and the development of sensitization.
Processes and components participating in the generation of intrinsic optical signal changes in vitro
Authors: Buchheim Katharina , Wessel Ole , Siegmund Herbert , Schuchmann Sebastian , Meierkord Hartmut 
Published: July 2005

AbstractImaging of intrinsic optical signals has become an important tool in the neurosciences. To better understand processes underlying changes in intrinsic optical signals, we studied electrical stimulation at varying strengths in hippocampal slices of adult Wistar rats. Following serial stimulation we observed an increase in light transmittance in all tested slices. During antidromic stimulation at minimum stimulation strength the increase in light transmittance was 75 ± 8% (P < 0.05), and during orthodromic minimum stimulation 19.6 ± 5.6% (P < 0.001) in the stratum pyramidale of the CA1‐region. During orthodromic stimulation no significant difference between submaximum, maximum and supramaximum stimulation was found, indicating saturation. In contrast, submaximum antidromic stimulation yielded 56.2 ± 12% (P < 0.05) of maximum stimulation strength, indicating recruitment. In a further set of experiments serial stimulation was carried out under glial blockade with fluoroacetate (FAC) or blockage of mitochondrial function. Amplitude and slope of the intrinsic optical signal significantly decreased in the presence of FAC (amplitude: 36 ± 6%, P < 0.01; slope: 37 ± 11% as compared with baseline conditions, P < 0.05). This suggests a glial participation in signal generation. Rotenone, an inhibitor of mitochondrial complex I, yielded decreased amplitudes of the intrinsic optical signal (27 ± 7% after 40 min, P < 0.01). Our data indicate that the intrinsic optical signal change reflects type and strength of neuronal activation and point to glia and mitochondria as important participants in signal generation.
Recognition and avoidance of insecticide‐treated Scots Pine (Pinus sylvestris) by Hylobius abietis (Coleoptera: Curculionidae): implications for pest management strategies
Authors: Rose D. , Leather S. R. , Matthews G. A. 
Published: July 2005

Abstract  1 The feeding preferences of Hylobius abietis (L.) were studied in a series of choice and no‐choice trials for insecticide‐treated food, time‐to‐death studies and arena trials.2 Treatment of Scots Pine twigs with a pyrethroid insecticide, lambda‐cyhalothrin, was compared with twigs treated with imidacloprid, a neonicotinoid.3 Clear avoidance of insecticide‐treated food sources, with strong evidence of selection for untreated food sources, was shown.4 In addition, it took up to 3 weeks for H. abietis to die from insecticide poisoning when fed on treated food and, during this time, it was potentially capable of finding new untreated food sources.
Modelling temperature‐dependent development and survival of Otiorhynchus sulcatus (Coleoptera: Curculionidae)
Authors: Son Youngsoo , Lewis Edwin E. 
Published: July 2005

Abstract  1 We conducted a laboratory experiment to quantify the stage‐specific effects of temperature on development time and survival of Otiorhynchus sulcatus (Fabricius) (Coleoptera: Curculionidae), a serious economic pest of horticultural crops. Quantification of the relationship between stage development and temperature is required to predict seasonal occurrence of particular life stages and to optimize the timing of monitoring and control tactics.2 Temperature‐dependent survival rate was quantified using an extreme value function and showed a skewed bell shape, due to the vulnerability of the insect to high temperature in all stages.3 The development times of O. sulcatus decreased with increasing temperature up to 27 °C for eggs and 24 °C for larvae and pupae. The nonlinear relationship between development rate and temperature was described using the Logan model, and enabled us to estimate the optimum temperature for development.4 The inherent variation of development time was estimated from the cumulative frequency of stage emergence, which was modelled using the cumulative Weibull function.5 The stage emergence model, which simulated the transition from one stage to the next in relation to temperature and cohort age, was constructed by incorporating stage‐specific survival and development rate submodels with the Weibull model of stage frequency.6 Our results show a difference in optimal temperature regime among developmental stages of O. sulcatus.
Response of Neoseiulus fallacis Garmen and Galendromus occidentalis Nesbitt (Acari: Phytoseiidae) to Tetranychus urticae Koch (Acari: Tetranychidae)‐Damaged Hop Humulus lupulus (L.) (Urticales: Cannabaceae)
Authors: Gardiner M. M. , Eigenbrode S. D. , Cervantes D. E. , Barbour J. D. 
Published: July 2005

Abstract  1 The response of Neoseiulus fallacis Garmen and Galendromus occidentalis (Acari: Phytoseiidae) to Tetranychus urticae Koch (Acari: Tetranychidae)‐damaged and undamaged hop, Humulus lupulus (L.), plants was tested using a Y‐tube olfactometer.2 Neoseiulus fallacis but not G. occidentalis was attracted to volatiles from T. urticae‐damaged hop plants when paired with undamaged plants.3 The response of N. fallacis to these volatiles was stronger for plants severed at the soil surface than for intact plants.4 There was no difference in the response of N. fallacis to severed or intact hop plants that had no spider mite damage, indicating that artificial wounding by severing alone does not elicit the production of attractive volatiles detectable to N. fallacis. These results are consistent with the existence of cross‐talk between signalling pathways initiated by feeding damage and artificial wounding that result in elevated levels of predator‐attracting volatiles.
Cultural variations in children's coping behaviour, TV viewing time, and family functioning
Authors: Chen J.‐L. , Kennedy C. 
Published: July 2005

Aim:  To examine children's coping behaviour, TV viewing hours and family functioning in four ethnic groups and factors related to children's coping behaviour.Methods:  This study was part of two larger research projects investigating children's health behaviours in the United States and Taiwan. Fifty‐six White American children of European ancestry, 66 Mexican American children, 68 Chinese American children and 95 native Taiwanese children were included in the analysis. Standardized instruments were used to measure coping strategies, children's TV viewing hours and family functioning.Results:  There were significant differences in the types of stressor that children of different ethnicity reported. Similarities and differences were found in the four ethnic groups regarding the top five most frequently used and most effective coping strategies. Multiple regressions identified two variables that contributed significantly to the variance in the frequency of children's coping strategies – ethnicity and poorer behaviour control in the family. Ethnicity was the only variable found to contribute to the variance in coping effectiveness. Significant differences were found in the number of hours children spent watching TV.Conclusions:  Findings suggest that children of different ethnicity utilized different types of coping strategies and ethnicity is one of the important factors related to children's coping behaviour. These findings provide evidence for nurses to assess children's coping behaviour and TV viewing and provide children with healthier alternatives.
Jordanian nurses’ attitudes toward older patients in acute care settings
Authors: Hweidi I. M. , Al‐Hassan M. A. 
Published: July 2005

Purpose:  To identify and describe Jordanian nurses’ attitudes toward older patients in acute care settings. The effects of socio‐demographics and nursing work characteristics on nurses’ attitudes were also examined.Method:  Descriptive correlational design was used. Kogan's (1961) Attitudes Toward Old People Scale was administered to a total population of Jordanian nurses (n = 200) working in selected units in acute care settings of three public hospitals in northern Jordan. Nurses’ attitudes were described by using descriptive statistics. anova and Pearson correlation were used to examine the effects of selected socio‐demographic details and work characteristics on nurses’ attitudes.Results:  Jordanian nurses who participated in this study had marginally positive attitudes toward older patients in acute care settings. Years of clinical experience correlated significantly with their attitudes. Male nurses had significantly more positive attitudes than their female counterparts. Surgical nurses also demonstrated significantly more positive attitudes than those working in medical units.Conclusion:  Although positive attitudes emerged towards older people, it was also apparent that efforts should be made to enhance them further so that quality care is delivered to this population. In addition, Jordanian nurse educators should put a greater focus on issues related to the care of the older person in their nursing curriculum.
The Economics of Managing Infectious Wildlife Disease
Authors: Horan Richard D. , Wolf Christopher A. 
Published: July 2005

AbstractWe use a two‐state linear control model to examine the socially optimal management of disease in a valuable wildlife population when diseased animals cannot be harvested selectively. The two control variables are nonselective harvests and supplemental feeding of wildlife, where feeding increases both in situ productivity and disease prevalence. We derive a double singular solution which depends on the initial state and does not require bang‐bang controls. The case of bovine tuberculosis among Michigan white‐tailed deer is analyzed. In the base model, the disease is optimally maintained at low levels, with intermittent investments (via feeding) in deer productivity.
Do Intra‐Household Effects Generate the Food Stamp Cash‐Out Puzzle?
Authors: Breunig Robert , Dasgupta Indraneel 
Published: July 2005

AbstractPrevious empirical studies have noted the higher marginal propensity to consume food out of food stamps in the United States, compared to that out of cash income. Analyzing data from U.S. Food Stamp Program participants, we find evidence that this discrepancy may be driven primarily by the behavior of multiple‐adult households. Single‐adult households show no evidence of any discrepancy. Thus, our results suggest that food stamp and cash income (welfare or market) may have very different impact on the intra‐household allocation process, and that this is reflected empirically in the cash‐out puzzle.
Information Exchange and Strategic Behavior in Supply Chains: Application to the Food Sector
Authors: Mohtadi Hamid , Kinsey Jean D. 
Published: July 2005

AbstractInformation technology (IT) facilitates information exchange between retailers and suppliers. Based on evidence from food industry, information strategies under uncertainty are analyzed, using game theory. Some key results are under certain conditions, retailers withhold valuable sales data from suppliers even if this means less supply coordination; a revealed equilibrium exists where suppliers learn retailers' market data despite retailers' withholding of such data; this leads either to full information convergence or, surprisingly, incomplete information convergence with some informational asymmetry left; retailers with greater market power and numerous suppliers are more inclined to share, rather than to withhold, information.
The Diffusion of New Agricultural Technologies: The Case of Crossbred‐Cow Technology in Tanzania
Authors: Abdulai Awudu , Huffman Wallace E. 
Published: July 2005

AbstractThe recent literature on agricultural technology adoption shows that diffusion of new technologies varies significantly across space and time. Furthermore, puzzles exist about why some seemingly profitable technologies are not adopted, especially in livestock production. We employ a hazard or duration function to explain diffusion of crossbred‐cow technology in a unique sample of Tanzania farmers. A farmer's adoption of crossbred technology depends positively on the proximity of his farm to other users, on his schooling, and on his access to credit and contact with extension agents.
Consistent Estimation of Censored Demand Systems Using Panel Data
Authors: Meyerhoefer Chad D. , Ranney Christine K. , Sahn David E. 
Published: July 2005

AbstractWe derive a joint continuous/censored commodity demand system for panel data applications. Unobserved heterogeneity is controlled for using a correlated random effects specification and a generalized method of moments framework used to estimate the model. While relatively small differences in elasticity estimates are found between a flexible random effects specification and one that restricts the random effect coefficient to be time invariant, larger differences are observed when comparing the flexible model to a pooled cross‐sectional estimator. The results suggest the limited ability of such estimators to control for preference heterogeneity and unit‐value endogeneity leads to parameter bias.
The Costs and Returns of Agricultural Credit Delivery
Authors: Gloy Brent A. , Gunderson Michael A. , LaDue Eddy L. 
Published: July 2005

AbstractBorrower‐level data from 963 agricultural lending relationships are used to examine how several factors influence the costs and returns of extending agricultural credit. The results provide estimates of the costs and returns of agricultural lending and the extent to which these costs and returns are influenced by factors such as loan volume, lender/borrower relationship factors, and contract terms. The findings indicate that economies of size exist in agricultural credit delivery and that lenders pass most of these benefits on to borrowers through lower interest rates. In addition, the impacts of lender/borrower relationship factors were relatively small.
Selling at the Farmgate or Traveling to Market
Authors: Fafchamps Marcel , Hill Ruth Vargas 
Published: July 2005

AbstractUsing detailed survey data from Uganda, this article examines whether coffee producers sell to itinerant traders or directly to markets, where they can get a higher price but must incur a transport cost. We find that selling to the market is more likely when the quantity sold is large and the market is close by. Wealthy farmers are less likely to sell to the market, possibly because the shadow value of their time is higher. But if they have a large quantity of coffee for sale, they are more likely to sell it to the market. They are also more likely to travel to a distant market. These findings are consistent with their better ability to pay for public transportation. We find no evidence that the decision to sell at the farmgate is driven by a self‐control motive.
Time to Burn: Modeling Wildland Arson as an Autoregressive Crime Function
Authors: Prestemon Jeffrey P. , Butry David T. 
Published: July 2005

AbstractSix Poisson autoregressive models of orderp[PAR(p)] of daily wildland arson ignition counts are estimated for five locations in Florida (1994–2001). In addition, a fixed effects time‐series Poisson model of annual arson counts is estimated for all Florida counties (1995–2001). PAR(p) model estimates reveal highly significant arson ignition autocorrelation, lasting up to eleven days, in addition to seasonality and links to law enforcement, wildland management, historical fire, and weather. The annual fixed effects model replicates many findings of the daily models but also detects the influence of wages and poverty on arson, in ways expected from theory. All findings support an economic model of crime.