Bennett Model Research Articles

Dissolved Organic Nitrogen in Mediterranean Ecosystems

Dissolved organic nitrogen (DON) in soils has recently gained increasing interest because it may be both a direct N source for plants and the dominant available N form in nutrient-poor soils, however, its prevalence in Mediterranean ecosystems remains unclear. The aims of this study were to i) estimate soil DON in a wide set of Mediterranean ecosystems and compare this levels with those for other ecosystems; ii) describe temporal changes in DON and dissolved inorganic nitrogen (DIN) forms (NH + 4 and NO − 3), and characterize spatial heterogeneity within plant communities; and iii) study the relative proportion of soil DON and DIN forms as a test of Schimel and Bennett's hypothesis that the prevalence of different N forms follows a gradient of nutrient availability. The study was carried out in eleven plant communities chosen to represent a wide spectrum of Mediterranean vegetation types, ranging from early to late successional status. DON concentrations in the studied Mediterranean plant communities (0–18.2 mg N kg −1) were consistently lower than those found in the literature for other ecosystems. We found high temporal and spatial variability in soil DON for all plant communities. As predicted by the Schimel and Bennett model for nutrient-poor ecosystems, DON dominance over ammonium and nitrate was observed for most plant communities in winter and spring soil samples. However, mineral-N dominated over DON in summer and autumn. Thus, soil water content may have an important effect on DON versus mineral N dominance in Mediterranean ecosystems.

Depolymerization and mineralization rates at 12 Mediterranean sites with varying soil N availability. A test for the Schimel and Bennett model

It has been suggested that the relative abundance of soil nitrogen forms should change along an N availability gradient. This model was originally described at a biome scale, and few studies have tested it at other scales. Moreover, none of them has examined whether changes in the relative rates of ammonification, nitrification and depolymerization rates also occurs. Our goal was to test whether these N transformation rates change along an N availability gradient which is likely to exist between forest, shrubs and grasses. We used three N availability indexes (total K2SO4-extractable N, ion exchange membrane N and the sum of N mineralization and depolymerization rates). Depolymerization dominated over mineralization in the two poorest plant communities, while ammonification and nitrification rates dominated in intermediate and nutrient rich plant communities respectively. These results confirm that the Schimel and Bennett model can be applied at a regional scale, and that N availability may be modulating not only the dominant N form, but also the relative abundance of a particular N transformation rate.

A Study of Sponsor Fit in a Sponsorship Context of a Sport Event in Japan

The purpose of this study was to replicate the applicability of the Gwinner and Bennett model (2008) which examined the effects of brand cohesiveness and sport identification on sponsor fit in a sponsorship in a Japan context. This study analyzed also focusing on the impact of sponsor fit on two important consumer behavioral outcome; attitude toward sponsors and purchase intentions. The data were collected from 537 spectators at the HP JAPAN WOMEN'S OPEN TENNIS 2009 in Osaka. The results of study indicate that brand cohesiveness and sport identification also have strong impacts on the sponsor fit at the event. Findings also support our hypotheses that sponsor fit has a positive influence on consumers purchase intentions through the attitude toward sponsor. It can be concluded that the Gwinner and Bennett model is applicable to the sponsorship in a Japanese context.

Anti-nociceptive synergism of morphine and gabapentin in neuropathic pain induced by chronic constriction injury

In order to detect an anti-nociceptive interaction between morphine and gabapentin, the anti-allodynic and anti-hyperalgesic effects of these drugs, administered either separately or in combination, were determined using the von Frey and acetone tests in a rat model of neuropathic pain (Bennett model). Morphine and gabapentin individually induced moderate attenuation of mechanical hyperalgesia, whereas the morphine and gabapentin combination completely decreased hyperalgesia. Morphine showed its maximal effect at 30 min post-injection in the acetone test; however, this effect gradually returned to the baseline value. Gabapentin did not produce an anti-allodynic effect, whereas the morphine and gabapentin combination completely decreased allodynia behavior at 30 min post-injection, an effect that persisted until 120 min. The area under the curve (AUC) of the anti-allodynic or anti-hyperalgesic effects produced by the combinations were significantly greater than the theoretical sum of effects produced by each drug alone or similar to the theoretical sum. The analysis of the effect, expressed as the AUC of the time course, supports the hypothesis that the combination of these drugs is useful in neuropathic pain therapy.

Characterization of packed beds of plant materials processed by supercritical fluid extraction

The particle size distributions of crushed plant materials obtained using different types of comminuting machines were analysed. The Rosin–Rammler–Bennett model was used, as an appropriate description for these data. Some characteristics of raw materials and packed columns were determined using different simple measuring methods (sieving, air pycnometry, traditional solvent Soxhlet-extraction). Furthermore, simple empirical equations were used to determine as many other parameters (density, viscosity, solubility, diffusion coefficient, mass transfer coefficient in the fluid phase) as possible. The usage of data was demonstrated by modelling the supercritical fluid extraction (SFE) of corn germ, pumpkin seed, calendula and paprika. The suitability of Sovová’s model for description the extraction curves was proven. A comparison of measured data to model predictions showed that extraction yields and concentration profiles in packed columns may be evaluated by using the same model parameters.

Semi-mechanistic Pharmacokinetic/Pharmacodynamic Modelling of the Antinociceptive Response in the Presence of Competitive Antagonism: The Interaction Between Tramadol and its Active Metabolite on μ-Opioid Agonism and Monoamine Reuptake Inhibition, in the Rat

To establish a semi-mechanistic pharmacokinetic/pharmacodynamic (pk/pd) model for racemic tramadol (T) integrating all the components with a significant contribution to T effects in rats, using cold allodynia in the Bennett model of neuropathic pain. Male Sprague-Dawley rats (n=53) were randomly allocated in six groups receiving saline, racemic T (5 mg/kg), RR-T (5 mg/kg), SS-T (5 mg/kg), RR-O-demethyltramadol [RR-M1 (1 mg/kg)] or SS-M1 (30 mg/kg) in two h intravenous infusion. The mu-opioid effects of RR-M1 (E(RR-M1)) were described with an effect compartment model. Contribution to analgesic response of RR-T resulted negligible. The monoamine re-uptake inhibition effects (ESS-M1,T) were modelled as an indirect response model incorporating a competitive interaction between SS-T and SS-M1. ERR-M1 and ESS-M1,T were finally considered as a two independent stimuli converging into a single and common antinoceptive stimulus. The estimates of the steady-state plasma concentrations eliciting half of maximum response for RR-M1, SS-T, and SS-M1 were 20.2, 230, and 869 ng/ml, respectively. RR-M1 is the main active component, but SS-T having a significant contribution. Cold allodynia in the Bennett model has proven an adequate experimental set up to develop complex pk/pd models in analgesia involving different mechanisms of action.

Teaching Sensitivity to Cultural Difference in the First‐Year Foreign Language Classroom

Abstract: This article summarizes teacher action research for the teaching of subjective culture in the foreign language classroom. It begins with a literature review, followed by a description of Milton J. Bennett's Developmental Model of Intercultural Sensitivity (Bennett, 1993), the theoretical paradigm upon which classroom activities and experiments were based. Bennett's model is compared and contrasted with other approaches to teaching culture, its strengths and weaknesses are discussed, and suggestions for implementing the model are presented. The article then summarizes efforts to mobilize the theory at the elementary French level, describes various culture‐teaching strategies, and presents the results of evaluations of the effectiveness of the strategies using the Intercultural Development Inventory. Final remarks concern the goals of the culture component in the foreign language curriculum and suggestions for next steps in research.

The Journey Toward Intercultural Sensitivity

This paper reports on the use of Milton Bennett's Developmental Model of Intercultural Sensitivity (DMIS) to analyze logs that were submitted by mental health service providers who participated in an intensive training program on intercultural competency. Program participants wrote eight monthly reflective logs about cultural experiences that occurred between training sessions. The categories of intercultural sensitivity described in the DMIS were used as the basis for coding log entries. The findings over the 10-month training period show that the development of intercultural sensitivity is, for the most part, a non-linear process in which one makes intermittent reversions to earlier levels and moves forward in spurts. After offering examples of non-linear and linear patterns in the logs, the paper discusses possible explanations for the findings and the challenges of coding according to the Bennett Model. Implications for intercultural competency education and training programs and their evaluation are proposed.

Effect of a graded single constriction of the rat sciatic nerve on pain behavior and expression of immunoreactive NPY and NPY Y1 receptor in DRG neurons and spinal cord

In the present study, the rat sciatic nerve was constricted to varying degrees using only one ligature with a very thin polyethylene sheath placed between nerve and ligature thread. Complete nerve transection was studied for comparison. With a 40–80% constriction of the nerve we observed allodynia to a similar extent as in the so-called Bennett model based on four loose ligatures. We also monitored changes in the expression of neuropeptide Y (NPY) and the NPY Y1 receptor (Y1R) in the lumbar 4–5 dorsal root ganglia (DRG) and dorsal horn and found upregulation of NPY and downregulation of the Y1R in DRG neurons after injury. These results indicate that similar peptide and receptor changes occur in this model as after axotomy and in other nerve injury models, although the immunohistochemical and behavioral changes seem to be dependent on the degree of constriction of the nerve. Thus, it seems relevant to monitor the degree of constriction when evaluating pain and other post-injury events. The possibility that some of the changes in NPY-ergic neurotransmission are related to the generation of allodynia is discussed; as well as the possibility to use this mononeuropathic model based on a single ligature nerve constriction (SLNC) as a complementary approach to other widely used pain models.

The Determinants of Reporting Farm Crime in Australia

Crime victimization surveys are an important means of examining unreported crimes. A study of property‐related victimization on farms in Australia found that although the problem was widespread and frequently involved serious financial and personal losses for farmers, there was considerable underreporting of crimes to police. Bennett and Wiegand's (1984) model of crime reporting was employed to analyze those factors that influenced farmers’ propensity to report crimes, whether they be incident‐specific, individual‐specific or environment‐specific factors. The analyses found that the nature of the farming environment clearly affects farmers’ decisions to report crimes. The study highlights the need for more research into the unique, costly and little understood nature of agricultural crime.

Differential activation of C1 complement components in rat spinal cord after sciatic nerve injury

Neuroimmune interactions are discussed to drive neuropathic pain. We used the Bennett model to correlate pain and cellular expression profiles of the complement factors C1q and C1q‐associated serine proteases C1r/C1s in lumbar spinal cord. At 2 days C1q mRNA levels increased ipsilateral to the lesion, and peaked at 8 days when allodynia and severe walking problems were present. During regeneration walking problems disappeared together with C1q mRNA levels. C1q biosynthesis was restricted to microglia. Surprisingly, C1s/C1r biosynthesis was not increased after injury suggesting a role for C1q different from classical complement activation. Sustained C1q expression in spinal microglia after lesion in conjunction with pain behavior indicates that microglial C1q may be causally involved in the development and maintenance of neuropathic pain.Acknowledgements: Supported by BMBF01GG9818, SFB297, DFGWE910/8‐3, KBN3P05C00623.

Magnetism of amorphous FeB in the Bennett model

We investigate magnetic properties of amorphous clusters, containing 10 4 atoms of two kinds: magnetic and nonmagnetic. Atoms are represented as hard spheres. The clusters are obtained with the sequential deposition algorithm. The ratio of radii of two kinds of spheres is chosen as to reproduce the density of FeB amorphous alloy. Then, calculated spectra of the Fe–Fe radial correlation functions also agree with experimental data. The magnetization is obtained within the Ising model. We reproduce the experimental thermal dependence of spontaneous magnetization of Fe 80B 20. This gives information on the Slater–Néel curve and allows to calculate the Arrott plots. We observe also a direct proportionality between the paramagnetic spin–spin correlation function and the Slater–Néel curve.

Assessing Instructor Cultural Competence in the Classroom: An Instrument and a Development Process

The ability to manage diversity effectively is important not only in organizations but also in the classroom. This article describes an instrument for assessing instructor cultural competence and the process used to develop the instrument. Using the critical incident technique, the authors developed a situational questionnaire that assesses behavioral intentions in response to classroom diversity incidents. Responses are scored using the Bennett model of cultural competence. The authors discuss ways in which the instrument can be adapted by instructors interested in assessing and improving their own cultural competence.

A Novel Analgesic Compound OT-7100 Attenuates Nociceptive Responses in Animal Models of Inflammatory and Neuropathic Hyperalgesia: A Possible Involvement of Adenosinergic Anti-nociception

We studied the effects of OT-7100 (5-n-butyl-7-(3,4,5-trimethoxybenzoylamino)pyrazolo [1,5-a]pyrimidine), a novel analgesic compound, on the inhibitory action of adenosine on the contraction of guinea pig ileum and investigated the effects of OT-7100 on the nociceptive responses in animal models of inflammatory and peripheral neuropathic hyperalgesia and decreases spinal c-Fos expression. OT-7100 at 0.3 - 3 μ M significantly enhanced the inhibitory effect of adenosine on the contraction of guinea pig ileum. The efficacy of OT-7100 (1, 3 or 10 mg /kg, p.o.) on hyperalgesia induced by yeast or substance P and in the Bennett model was significantly suppressed by coadministration of the adenosine A1 antagonist DPCPX (0.01 or 0.1 pmol/animal, i.t.), while OT-7100 without DPCPX significantly increased the nociceptive threshold in each rat model. OT-7100 (3, 10 and 30 mg /kg per day, p.o.) significantly inhibited the mechanical nociceptive threshold in the injured paw in the Chung model. OT-7100 (30 mg /kg, p.o.) significantly decreased the number of Fos-LI neurons in the spinal dorsal horn in the Bennett model. These finding suggest that OT-7100 inhibits hyperalgesia in these animal models possibly by enhancing adenosinergic neurotransmission in the dorsal horn, although we still lack direct evidence for it.

Effect of aging on the substance P receptor, NK–1, in the spinal cord of rats with peripheral nerve injury

Substance P (SP) levels in the spinal cords of very old rats are less than the levels in younger rats (Bergman et al., 1996). After injury to a peripheral nerve in young rats, immunoreactivity (ir) to the SP receptor, NK–1 (neurokinin-1), increases in the spinal cord ipsilateral to the injury and the increases are correlated with the development of thermal hyperalgesia (Goff et al., 1998). Thus we postulated that aged rats might display an increased sensitivity to thermal stimulation before peripheral nerve injury and that they might respond differently to injury than do younger rats. To test this hypothesis, we used the Bennett and Xie model (1988) of chronic constriction injury (CCI) to the sciatic nerve to induce a neuropathic pain condition. We investigated the effect of age on changes in NK-1 ir in superficial layers of the dorsal horn and on numbers of NK ir cells in deeper laminae at the L4-L5 levels of the spinal cord after CCI. NK-1 receptors were tagged immunohistochemically and their distribution quantified by use of computer-assisted image analysis. NK-1 ir changes were related to alterations in thermal and tactile sensitivity that developed after CCI in young, mature and aged (4-6, 14-16, and 24-26 months) Fischer F344 BNF1 hybrid rats. No differences in thermal or tactile sensitivity of young and aged rats were seen in the absence of nerve injury. After injury, aged rats developed thermal hyperalgesia and tactile allodynia more slowly than did the younger rats. NK-1 receptor ir and numbers of NK-1 ir cells in the dorsal horn increased with time post-injury in all three groups. NK-1 ir increases were correlated with the development of thermal hyperalgesia in those rats that displayed hyperalgesia. However, some rats developed an increased threshold to thermal stimuli (analgesia) and that also was correlated with increases in NK-1 ir. Thus NK-1 ir extent, while correlated with thermal sensitivity in the absence of injury, is not a specific marker for disturbances in one particular sensory modality; rather it increases with peripheral nerve injury per se.

The analgesic potential of intraventricular polymer-encapsulated adrenal chromaffin cells in a rodent model of chronic neuropathic pain.

Adrenal chromaffin cells reportedly produce analgesic effects when implanted in the periaqueductal gray and the intrathecal space near the spinal cord. Chromaffin cells implanted in the cerebral ventricles may also produce analgesic effects, and the availability of the cerebral ventricles as a potential implant site could be advantageous for some patients. In fact, some of the first patients were implanted in the intraventricular site, even though the analgesic potential of that site had never been demonstrated. The present study was conducted to assess the analgesic potential of intraventricular, polymer-encapsulated calf adrenal chromaffin cells in the Bennett model. Sciatic nerve ligations produced substantial, long-lasting pain-related behaviors. However, there was no evidence that polymer-encapsulated adrenal chromaffin cells implanted in the cerebral ventricles produce analgesic effects in this model of chronic neuropathic pain.

The analgesic potential of intraventricular polymer-encapsulated adrenal chromaffin cells in a rodent model of chronic neuropathic pain.

Adrenal chromaffin cells reportedly produce analgesic effects when implanted in the periaqueductal gray and the intrathecal space near the spinal cord. Chromaffin cells implanted in the cerebral ventricles may also produce analgesic effects, and the availability of the cerebral ventricles as a potential implant site could be advantageous for some patients. In fact, some of the first patients were implanted in the intraventricular site, even though the analgesic potential of that site had never been demonstrated. The present study was conducted to assess the analgesic potential of intraventricular, polymer-encapsulated calf adrenal chromaffin cells in the Bennett model. Sciatic nerve ligations produced substantial, long-lasting pain-related behaviors. However, there was no evidence that polymer-encapsulated adrenal chromaffin cells implanted in the cerebral ventricles produce analgesic effects in this model of chronic neuropathic pain.

Regulation of galanin and neuropeptide Y in dorsal root ganglia and dorsal horn in rat mononeuropathic models: possible relation to tactile hypersensitivity

The expression of galanin and neuropeptide Y in rat lumbar 5 (L5) dorsal root ganglia and dorsal horn (L4–5) was studied after four types of peripheral nerve injury using immunohistochemistry and in situ hybridization. The possible correlation between these two peptides and tactile allodynia-like behaviour was analysed as well. The models employed were the Gazelius (photochemical lesion) and Seltzer and Bennett (constriction lesions) models, as well as complete sciatic nerve transection (axotomy). Two weeks after surgery, the Gazelius model rats more frequently displayed a greater tactile allodynia than the rats from the Seltzer and Bennett models. Tactile allodynia was not observed in any of the axotomized rats. A marked increase in the number of galanin-immunoreactive and galanin messenger RNA-positive neuron profiles was observed in ipsilateral dorsal root ganglia in all types of models. The increase in allodynic rats (Gazelius, Seltzer and Bennett models) was less pronounced than that after axotomy. In addition, in the Bennett model the number of galanin-immunoreactive neurons was significantly lower in allodynic rats as compared to non-allodynic rats, and the same tendency, but less obvious was found in the Seltzer model. Furthermore, an increase in galanin-immunoreactive fibres was found in the superficial laminae of the ipsilateral dorsal horn in all lesion models, especially in lamina II. A dramatic increase in the number of neuropeptide Y and neuropeptide Y messenger RNA-positive neuron profiles was also found in the ipsilateral dorsal root ganglia in all models, but no significant difference was found in peptide levels between allodynic and non-allodynic rats in any of the models. The present results suggest that the levels of endogenous galanin may play a role in whether or not allodynia develops in the Bennett model.

The Novel Analgesic Compound OT-7100 (5-n-Butyl-7-(3,4,5-trimethoxybenzoylamino)pyrazolo [1,5-a] pyrimidine) Attenuates Mechanical Nociceptive Responses in Animal Models of Acute and Peripheral Neuropathic Hyperalgesia

We investigated the effects of OT-7100, a novel analgesic compound (5-n-butyl-7-(3,4,5-trimethoxybenzoylamino)pyrazolo[1,5-a]pyrimidine), on prostaglandin E2 biosynthesis in vitro, acute hyperalgesia induced by yeast and substance P in rats and hyperalgesia in rats with a chronic constriction injury to the sciatic nerve (Bennett model), which is a model for peripheral neuropathic pain. OT-7100 did not inhibit prostaglandin E2 biosynthesis at 10−8-10−4 M. Single oral doses of 3 and 10 mg/kg OT-7100 were effective on the hyperalgesia induced by yeast. Single oral doses of 0.1, 0.3, 1 and 3 mg/kg OT-7100 were effective on the hyperalgesia induced by substance P in which indomethacin had no effect. Repeated oral administration of OT-7100 (10 and 30 mg/kg) was effective in normalizing the mechanical nociceptive threshold in the injured paw without affecting the nociceptive threshold in the uninjured paw in the Bennett model. Indomethacin had no effect in this model. While amitriptyline (10 and 30 mg/kg) and clonazepam (3 and 10 mg/kg) significantly normalized the nociceptive threshold in the injured paw, they also increased the nociceptive threshold in the uninjured paw. These results suggest that OT-7100 is a new type of analgesic with the effect of normalizing the nociceptive threshold in peripheral neuropathic hyperalgesia.

Roughness of the porous silicon dissolution interface

We present a study of the fluctuations in the dissolution front observed during the formation of porous silicon, leading finally to layer thickness inhomogeneities. Two types of fluctuations were revealed, one at the millimeter scale (waviness) and the other one at the micrometer scale (roughness). Root mean square amplitudes are comparable. In both cases fluctuations of the dissolution velocity can be invoked and we discuss their dependence on the current density and viscosity of the solution. The large scale fluctuations are attributed to planar resistivity fluctuations in the wafer. The second type of fluctuation displays a typical spatial periodicity comparable to the wavelength of the light so that a statistical characterization can be performed by optical measurements. The Davies–Bennett model quantitatively describes the induced light scattering. Remarkably, these fluctuations increase linearly with the layer thickness up to a critical value where a saturation regime is observed. In order to explain this behavior, we show the importance of the initial surface state of the wafer and of the porous medium.