SINGLE-POINT VERSUS TIME-INTENSITY SENSORY MEASUREMENTS: AN INFORMATIONAL ENTROPY ANALYSIS1

Single-point sensory response measurement techniques such as magnitude estimation and category scaling only contain a limited amount of information. Time-intensity (T-I) data collection techniques provide much more information, addressing rate-related and duration aspects as well as intensity quantification. A theoretical analysis and comparison of single-point and T-I responses is presented from an informational (Shannon) entropy content viewpoint. The analysis is based on a hypothetical T-I response curve and a hypothetical series of single-point measurements attempting to approximate the T-I curve. Assuming a 15 s sensory event the associated T-I response of a single parameter is shown to contain a significantly greater amount of potential information storage capacity relative to the single-point or a small series of single-point measurements attempting to generate temporal behavior. Theoretically, the T-I response also displays greater quantities of a parameter called information density. Finally, it may be hypothesized that T-I techniques can be shown to be more efficient in terms of rate of information acquisition.     

Immunoelectron microscopic localization of thiolases, beta-oxidation enzymes of an n-alkane-utilizable yeast, Candida tropicalis.

The location of acetoacetyl-CoA thiolase (T-I) and 3-ketoacyl-CoA thiolase (T-III), enzymes of the fatty acid beta-oxidation system, was studied in n-alkane-grown Candida tropicalis cells by immunoelectron microscopy using a post-embedding method with colloidal gold conjugated IgG. The deposition of gold particles for T-I was detected in the microbodies and cytoplasm and that of gold particles for T-III specifically in the microbodies. The double labeling technique confirmed that T-I and T-III occurred concurrently in a microbody and T-I also in cytoplasm. These results were consistent with the biochemical data based on subcellular fractionation and indicated that the yeast beta-oxidation system operates efficiently only in the microbodies.     

Tumor necrosis factor-alpha stimulates proliferation of rat ovarian theca-interstitial cells.

Tumor necrosis factor-alpha (TNF-alpha) is a potent modulator of ovarian function, affecting steroidogenesis of both granulosa and theca-interstitial (T-I) cells. Women with polycystic ovary syndrome (PCOS) have increased levels of serum TNF-alpha. The present study evaluated the effects of TNF-alpha on T-I cell proliferation. Purified rat T-I cells were cultured for 48 h with or without TNF-alpha (0.001-1 nM), insulin-like growth factor I (IGF-I; 10 nM), and/or insulin (10 nM). Proliferation was measured by [(3)H]thymidine incorporation assay and by counting the steroidogenically active (stained positive for 3beta-hydroxysteroid dehydrogenase; 3beta-HSD) and inactive (3beta-HSD negative) cells. TNF-alpha stimulated thymidine incorporation in a dose-dependent fashion (up to 3.2-fold; P < 0.01). Insulin and IGF-I stimulated T-I proliferation (respectively, by up to 2.4- and 3.1-fold; P < 0.001). TNF-alpha potentiated effects of insulin and IGF-I in a dose-dependent and additive fashion (up to 6.7-fold; P < 0.001). TNF-alpha (1 nM) increased total cell count (by 80%, P < 0.05) and the proportion of 3beta-HSD-positive cells (by 19%, P < 0.05). Flow cytometry DNA analysis revealed that TNF-alpha (1 nM) increased the proliferative index by up to 16% (P = 0.05). The present findings demonstrate that TNF-alpha stimulates mitotic activity of T-I cells by increasing the proportion of actively dividing cells and preferentially increasing the number of steroidogenically active cells. The effects of TNF-alpha appear to be independent of those induced by insulin and IGF-I. We postulate that TNF-alpha may play a pathophysiologic role in disorders of the T-I compartment, such as PCOS.     

Activin stimulates proliferation of rat ovarian thecal-interstitial cells

There is growing evidence that the function of ovarian theca-interstitial (T-I) cells may be modulated by paracrine actions of activin, inhibin, and follistatin. Furthermore, either dysregulation, dysfunction, or both, of these peptides may play a role in conditions associated with T-I hyperplasia, such as polycystic ovary syndrome (PCOS) and hyperthecosis. This study was designed to evaluate the role of activin, inhibin, and follistatin in the modulation of T-I cell proliferation. Interaction of these peptides with insulin-like growth factor-I (IGF-I), a known stimulator of T-I cell proliferation, was also assessed. Purified rat T-I cells were cultured for 48 h in chemically defined media and with or without activin (3-30 ng/ml), inhibin (3-30 ng/ml), follistatin (100 ng/ml), and/or IGF-I (10 nM). T-I cell proliferation was assessed using radiolabeled thymidine incorporation assay. Activin alone stimulated proliferation of T-I cells in a dose-dependent fashion (by up to 320% above control; P < 0.001), whereas inhibin alone or follistatin alone had no significant effect. Inhibin had also no effect on activin-induced proliferation. Follistatin significantly reduced the stimulatory effects of activin and decreased proliferation by up to 46% (P < 0.01) below the level attained in the presence of activin alone. IGF-I (10 nM), at a dose producing a near-maximal effect, increased proliferation by 175% above control (P < 0.001); insulin (10 nM) increased proliferation by 52% above control (P < 0.03). A combination of IGF-I (10 nM) and activin (30 ng/ml) resulted in a 1090% increase of proliferation above control (P < 0.001); this stimulatory effect was significantly greater than that achieved in the presence of either activin alone or IGF-I alone (P < 0.001). Similarly, a combination of insulin (10 nM) and activin (30 ng/ml) increased proliferation by 506% above control levels. Flow cytometry evaluation revealed that activin increased the proportion of actively dividing cells (in S or G2/M phase of the cell cycle) by 42% (P < 0.02), whereas IGF-I had no effect on the proportion of actively dividing cells. The present findings indicate that an activin-follistatin system may be involved in the regulation of the size of ovarian thecal-stromal compartment. In view of the synergy between activin and IGF-I, and the difference in the effects on the cell cycle distribution, stimulation of T-I proliferation by these agents is likely to be mediated via separate transduction pathways. Excess activin or insufficient follistatin may contribute to T-I hyperplasia.     

A complex relationship among chemical concentration, detection threshold, and suprathreshold intensity of bitter compounds

Detection thresholds and psychophysical curves were established for caffeine, quinine-HCl (QHCl), and propylthiouracil (PROP) in a sample of 33 subjects (28 female mean age 24 +/- 4). The mean detection threshold (+/-standard error) for caffeine, QHCl, and PROP was 1.2 +/- 0.12, 0.0083 +/- 0.001, and 0.088 +/- 0.07 mM, respectively. Pearson product-moment analysis revealed no significant correlations between detection thresholds of the compounds. Psychophysical curves were constructed for each bitter compound over 6 concentrations. There were significant correlations between incremental points of the individual psychophysical curves for QHCl and PROP. Regarding caffeine, there was a specific concentration (6 mM) below and above which the incremental steps in bitterness were correlated. Between compounds, analysis of psychophysical curves revealed no correlations with PROP, but there were significant correlations between the bitterness of caffeine and QHCl at higher concentrations on the psychophysical curve (P<0.05). Correlation analysis of detection threshold and suprathreshold intensity within a compound revealed a significant correlation between PROP threshold and suprathreshold intensity (r=0.46-0.4, P<0.05), a significant negative correlation for QHCl (r=-0.33 to -0.4, P<0.05), and no correlation for caffeine. The results suggest a complex relationship between chemical concentration, detection threshold, and suprathreshold intensity.     

POTENCY OF SWEETNESS OF ASPARTAME, D-TRYPTOPHAN AND THAUMATIN EVALUATED BY SINGLE VALUE AND TIME-INTENSITY MEASUREMENTS

Perceived sweetness of sucrose, aspartame, D-tryptophan and thaumatin in a sour, citric acid background was analyzed in terms of the potency of these compounds relative to sucrose-water combinations. Potencies of the sweeteners were determined from (1) maximum intensity using single value and time-intensity (T-I) measurements and (2) average intensity calculated as the ratio of area under the T-I curve and total perceived time. Stevens' law was applied to sweet responses, either in static or dynamic conditions. It was found that the exponent of the concentration-response function reflected the relative capacity of a compound to sweeten a given food and stressed differences of potency among sweeteners. Aspartame, D-tryptophan and thaumatin exhibited a decrease in sweetness potency relative to sucrose as sweetness increased from 10 to 100% of the full scale of response. Across the entire sweetness range, thaumatin showed the greatest potency but its long persistence time led to differentiate this intense sweetener from the other sweeteners evaluated.     

Reduction of T-kininogen messenger RNA levels by dexamethasone in the adjuvant-treated rat

When inflammation is induced in rats following injection of Freund's complete adjuvant, steady state levels of T-I and T-II kininogen mRNAs increase markedly as do plasma levels of T-I and T-II kininogens. When rats are additionally treated with dexamethasone, T-I and T-II steady state mRNA levels and plasma levels of T-kininogens are reduced. The results suggest that dexamethasone may affect the magnitude of T-kininogen gene induction caused by inflammation.     

TEMPORAL STUDY OF SUCROSE AND FRUCTOSE RELATIVE SWEETNESS

Time-Intensity (T-I) and Gustatory Reaction Time (GRT) methodologies were used to study the relative sweetness of sucrose and fructose at 25C. Eleven panelists evaluated nine concentrations (5 to 45%, w/v) of sucrose and fructose by T-I and seven parameters were determined. Higher values were obtained for fructose at 25, 30 and 35% for Maximum Intensity; at 35, 40 and 45% for the Area Under the Curve; at 40 and 45% for Time to decline the Intensity to half of its maximum value and at 45% for Rate of Increase. Ten subjects evaluated seven concentrations (3 to 15%, w/v) of sucrose and fructose by the GRT procedure. Fructose had shorter GRT than sucrose at 3 and 4.5%. Thus, fructose at 25, 30 and 35%, has a more intense and at 40% more persistent sweetness than sucrose and is detected earlier than sucrose at concentrations near gustatory threshold.     

基于抚育间伐效应的落叶松人工林直径分布动态模拟

基于黑龙江省孟家岗林场长白落叶松人工林5块固定样地(其中1块为对照样地,4块为抚育间伐样地,断面积强度为3.7%~49.7%)1974—2014年(林龄为19～59 a)复测的31次胸径数据,采用三参数Weibull分布函数拟合5块样地各年份直径分布,研究了直径分布曲线随林龄的动态变化规律,并分析了抚育间伐对林分直径分布曲线及Weibull分布参数的动态影响.构建了基于抚育间伐效应的Weibull分布参数预测的联立方程组模型,分别采用三阶段最小二乘法及度量误差法估计了模型的参数.结果表明: 未间伐林分(对照)直径分布曲线随林龄增加由“高峰狭窄”(林木直径分布集中)状态逐渐向“低峰宽广”(林木直径分布分散)状态过渡;抚育间伐后,林木直径分布曲线均较抚育间伐前右偏加剧,峰度变高,径阶变窄,对称性下降;间伐强度越大,伐除的中小径阶树木越多,直径分布曲线较间伐前左侧截尾明显,峰度增高,径阶分布范围变小.低强度抚育间伐使得参数a值变大,b值变小,对参数c的影响不明显;高强度抚育间伐使得参数a的增量变大,b值变小,参数c值变小.参数预测联立方程组模型的拟合结果表明,参数b的预测模型拟合效果最好,R²>0.98;参数c预测模型拟合效果稍差,但R²>0.91;三阶段最小二乘法拟合结果与度量误差联立方程组方法区别不大,两种方法检验结果均较好,模型精度都>97%,拟合效率均>0.92.所建立的模型能够较好地模拟抚育间伐效应下落叶松人工林直径分布动态变化,为科学合理经营森林提供了依据.     

TEMPORAL ASPECTS OF HEDONIC RESPONSES1

Continuous measurement of degree of liking for chocolate milk varying in milkfat (0–36%) showed significant fluctuations over the 80 s test period. For 17 judges, samples with intermediate fat levels received maximum liking 20–30 s after placement in the mouth then declined to neutral (neither like nor dislike). The nonfat sample gave a flat, neutral response across time while the 36% fat sample was initially neutral, reached maximum dislike at approximately 20 s then gradually returned to neutral. For 5 judges, increasing degree of liking was expressed for increasing fat levels. For both groups, maximum and minimum time-intensity (T-I) measurements correlated significantly with results from conventional hedonic scaling on a 20-cm line. Degree of liking was unaffected by swallowing or expectorating samples by either T-I or scaling. Thus, similar to perceived intensity, hedonic responses are not static, but show systematic changes during tasting, i.e., from the time the sample is placed into the mouth, through expectoration (or swallowing) until a steady (usually neutral) state is reached.     

Correlation between the different therapeutic properties of Chinese medicinal herbs and delayed luminescence

In the practice and principle of Chinese medicine, herbal materials are classified according to their therapeutic properties. ‘Cold’ and ‘heat’ are the most important classes of Chinese medicinal herbs according to the theory of traditional Chinese medicine (TCM). In this work, delayed luminescence (DL) was measured for different samples of Chinese medicinal herbs using a sensitive photon multiplier detection system. A comparison of DL parameters, including mean intensity and statistic entropy, was undertaken to discriminate between the ‘cold’ and ‘heat’ properties of Chinese medicinal herbs. The results suggest that there are significant differences in mean intensity and statistic entropy and using this method combined with statistical analysis may provide novel parameters for the characterization of Chinese medicinal herbs in relation to their energetic properties. Copyright © 2015 John Wiley & Sons, Ltd.     

GUSTATORY REACTION TIME AND TIME INTENSITY MEASUREMENTS OF TREHALOSE AND SUCROSE SOLUTIONS AND THEIR MIXTURES

Dynamic sweetness perception of commercial food grade trehalose, sucrose solutions and their mixtures were studied for a wide range of concentrations. For gustatory reaction time (GRT), concentrations ranged from 2.3 to 13.8% for sucrose and up to 23.0% for trehalose. For time intensity (T-I) sucrose or trehalose solutions (concentration range 2.3–36.8%) and their combinations (23.0 and 36.8% total solids) were analyzed. Trehalose had bigger GRT along the studied range. Both sugars presented similar values for persistence and times of plateau and to maximum intensity, while a significant difference was observed in intensity and GRT at equal concentrations. Trehalose had longer persistence than sucrose in equi -sweet solutions. Overall sweetness profile of some sucrose solutions (i.e., 29.9% sucrose solution and 0.6 sucrose/trehalose ratio mixture at 36.8% total solids) were perceived as similar to mixtures of sucrose/trehalose or single trehalose solutions, which suggests the possibility of sugar replacement without completely modifying sweetness perception.

PRACTICAL APPLICATIONS

It has been suggested that trehalose may be a potential substitute for sucrose and other sugars used in food formulation because, although its chemical structure is very similar to that of sucrose, it is more stable at low pH and high temperatures. It is not involved in caramelization and does not participate in Maillard reaction with amino acids/proteins. In order to fully establish the potential of trehalose as a functional replacement of sucrose we have determined the sweetness dynamic profile (gustatory reaction time and time-intensity curves) of trehalose solutions and sucrose/trehalose solutions; this aspect is needed for adequately replacing (partially or totally) sucrose in food systems.     

Pregnancy rate in peripuberal beef heifers following treatment with syncro-mate-B and gonadotropin releasing-hormone

A study was conducted to evaluate the effectiveness of treatment with Syncro-Mate-B (SMB) and gonadotropin releasing-hormone (GnRH) on inducing a fertile estrus and/or ovulation in peripuberal beef heifers. Two hundred and twenty-three, 13 to 15 month peripuberal beef heifers, primarily of Angus or Simmental breeding, were alternately allotted by weight and age within breed to a non-treated control group (C) and three groups which received the SMB treatment regime. Treated groups differed in that one group was inseminated approximately 12 hr after detected in estrus (T) while two other groups were inseminated at a fixed time after implant removal (T-G-I42, T-I48). Heifers in group T-G-I42 received 125 mug GnRH at 30 hr, and were inseminated 42 hr after implant removal. The remaining group of SMB-treated heifers received no additional hormone therapy but were inseminated 48 hr after implant removal (T-I48). Age had no significant effect on estrous response or pregnancy rate nor were there significant age by weight interactions on these parameters. Weight was a significant source of variation on interval from start of breeding to pregnancy (P<.01) and the effect on interval to estrus approached statistical significance (P<.0.9). In control heifers, increased weight had a positive effect on estrous response during the first 21 days of breeding (P<.05). Conversely, weight had no effect on estrous response during the 5-day synchronized period in heifers treated with SMB and observed for estrus (group T). Cumulative estrous response in control heifers was 10, 47, 48 and 55% in 5, 21, 27 and 45 days of breeding, respectively. Cumulative estrous response in SMB-treated heifers obsrved for estrus (group T) was 88, 91, 91 and 91% in 5, 21, 27 and 45 days of breeding, respectively. Pregnancy rate after 5 days of breeding was 9, 27, 18 and 30% for heifers in groups C, T, T-G-I42 and T-I48, respectively. Pregnancy rate after 21 days of breeding for heirfers in groups C, T, T-G-I42 and T-I48, respectively, was 33, 38, 21 and 41%; after 27 days of breeding was 36, 43, 40 and 48%; after 45 days of breeding was 48, 61, 51 and 69% and after the total 88-day breeding season was 59, 68, 71 and 72%. While a large percentage of peripuberal beef heifers with adequate age but insufficient weight were induced into estrus with the SMB treatment, pregnancy rates were low. Timed insemination programs with or without GnRH do not appear to be effective in improving pregnancy response in non-cyclic beef heifers.     

Glucose concentration determination by means of fluorescence emission spectra of soluble and insoluble glucose oxidase: some useful indications for optical fibre-based sensors

By using soluble and insoluble glucose oxidase, the changes in intrinsic emission fluorescence in the visible spectral region were studied as a function of glucose concentration. Insoluble glucose oxidase (GOD) was obtained by entrapment in a gelatine membrane or by covalent attachment on an agarose membrane grafted with hexamethylendiamine. The intensity of the fluorescence emission peak at 520 nm or the value of the integral fluorescence area from 480 to 580 nm were taken as physical parameters representative of the glucose concentration during the enzyme reaction. By using these parameters, linear calibration curves for glucose concentration were obtained. The extension of the calibration curve and the sensitivity of the adopted systems were found to be dependent on the enzyme state (free or immobilized) and on the immobilization method. In particular, it was found that the extent of the linear range of the calibration curves is increased of one order of magnitude when the glucose oxidase is immobilized, while the sensitivity of the measure is decreased of one order of magnitude by the immobilization process. Measures carried out by using the integral fluorescence area resulted more sensitive than those obtained with the peak size. Useful indications for the construction of optical fibre-based sensors were drawn from the reported results.     

Determination of initial electron parameters by means of Monte Carlo simulations for the Siemens Artiste Linac 6 MV photon beam

AimIn this study, we investigated initial electron parameters of Siemens Artiste Linac with 6 MV photon beam using the Monte Carlo method.BackgroundIt is essential to define all the characteristics of initial electrons hitting the target, i.e. mean energy and full width of half maximum (FWHM) of the spatial distribution intensity, which is needed to run Monte Carlo simulations. The Monte Carlo is the most accurate method for simulation of radiotherapy treatments.Materials and methodsLinac head geometry was modeled using the BEAMnrc code. The phase space files were used as input file to DOSXYZnrc simulation to determine the dose distribution in a water phantom. We obtained percent depth dose curves and the lateral dose profile. All the results were obtained at 100 cm of SSD and for a 10 × 10 cm² field.ResultsWe concluded that there existed a good conformity between Monte Carlo simulation and measurement data when we used electron mean energy of 6.3 MeV and 0.30 cm FWHM value as initial parameters. We observed that FWHM values had very little effect on PDD and we found that the electron mean energy and FWHM values affected the lateral dose profile. However, these effects are between tolerance values.ConclusionsThe initial parameters especially depend on components of a linac head. The phase space file which was obtained from Monte Carlo Simulation for a linac can be used as calculation of scattering, MLC leakage, to compare dose distribution on patients and in various studies.     

An improved method for measuring perceived intensity/time relationships in human taste and smell

A method has been improved for recording and processing perceivedintensity/time curves constructed from panel results. A slide-wirepotentiometer, coupled to a microcomputer, is used to storethe data recorded, which are subsequently treated to eliminateend-effects caused by use of the potentiometer. The data arethen averaged according to their statistical distributions intime and intensity directions. This averaging procedure givesa panel curve in which the three main parameters – themaximum perceived intensity, the time of maximum perceived intensity(t_max) and the time after which the flavour is no longer perceived– are averages of all the corresponding individual scores.Results show that a stronger stimulus is perceived longer andmore intensely, but with the same t_maxvalue.     

Identification and characterization of two functional domains in cytochrome P-450BM-3, a catalytically self-sufficient monooxygenase induced by barbiturates in Bacillus megaterium

In a previous publication (Narhi, L. O. and Fulco, A. J. (1986) J. Biol. Chem. 261, 7160-7169) we described the characterization of a soluble 119,000-dalton P-450 cytochrome (P-450BM-3) that was induced by barbiturates in Bacillus megaterium. This single polypeptide contained 1 mol each of FAD and FMN/mol of heme and, in the presence of NADPH and O2, catalyzed the oxygenation of long-chain fatty acids without the aid of any other protein. We have now utilized limited trypsin proteolysis in the presence of substrate to cleave P-450BM-3 into two polypeptides (domains) of about 66,000 and 55,000 daltons. The 66-kDa domain contains both FAD and FMN but no heme, reduces cytochrome c in the presence of NADPH, and is derived from the C-terminal portion of P-450BM-3. The 55-kDa domain is actually a mixture of three discrete peptides (T-I, T-II, and T-III) separable by high performance liquid chromatography. All three contain heme and show a P-450 absorption peak in the presence of CO and dithionite. The major component, T-I (Mr = 55 kDa), binds fatty acid substrate and has an N-terminal amino acid sequence identical to that of intact P-450BM-3, an indication that this domain constitutes the N-terminal portion of the 119-kDa protein. T-II (54 kDa) is the same as T-I except that it is missing the first nine N-terminal amino acids and does not bind substrate. T-III (Mr = 53.5 kDa) has lost the first 15 N-terminal residues and does not bind substrate. Since trypsin digestion of P-450BM-3 carried out in the absence of substrate yields T-II and T-III but no T-I, it appears that 1 or more residues of the first nine N-terminal amino acids of this protein are intimately involved in substrate binding. Although both the heme- and flavin-containing tryptic peptides retain their original half-reactions, fatty acid monooxygenase activity cannot be reconstituted after proteolysis, and the two domains, once separated, show no affinity for each other. In most respects, the reductase domain of P-450BM-3 more closely resembles the mammalian microsomal P-450 reductases than it does any known bacterial protein.     

Survey of Zoonotic Trematode Metacercariae in Fish from Water systems of Geum-gang (River) in Republic of Korea

The infection status of zoonotic trematode metacercariae (ZTM) was surveyed in freshwater fishes from the water systems of Geum-gang (River) in the Republic of Korea (Korea). A total of 1,161 freshwater fishes from 6 local sites of Geum-gang were examined with the artificial digestion method for 4 years (2012–2015). Clonorchis sinensis metacercariae were detected in 122 (37.2%) out of 328 fishes in the positive fish species from 4 surveyed areas, and their mean intensity was 43 per fish infected. Metagonimus spp. metacercariae were found in 432 (51.7%) out of 835 fishes in the positive fish species from all 6 surveyed areas, and their mean intensity was 30 per fish infected. Centrocestus armatus metacercariae were detected in 285 (75.0%) out of 380 fishes in the positive fish species from 6 surveyed areas, and their mean intensity was 2,100 per fish infected. Echinostoma spp. metacercariae were found in 56 (19.7%) out of 284 fishes in the positive fish species from 5 surveyed areas, and their mean intensity was 10 per fish infected. Clinostomum complanatum metacercariae were detected in 98 (57.3%) out of 171 fishes in the positive fish species from only 2 surveyed areas, and their mean intensity was 11 per fish infected. Conclusively, the endemicity of ZTM is not so high in fishes from water systems of Geum-gang in Korea although it is more or less different by fish species, surveyed areas and ZTM species.