On the convergence of the no response test

The no response test is a new scheme in inverse problems for partial differential equations which was recently proposed in [D. R. Luke and R. Potthast, SIAM J. Appl. Math., 63 (2003), pp. 1292–1312] in the framework of inverse acoustic scattering problems. The main idea of the scheme is to construct special probing waves which are small on some test domain. Then the response for these waves is constructed. If the response is small, the unknown object is assumed to be a subset of the test domain. The response is constructed from one, several, or many particular solutions of the problem under consideration. In this paper, we investigate the convergence of the no response test for the reconstruction information about inclusions D from the Cauchy values of solutions to the Helmholtz equation on an outer surface $\partial\Omega$ with $\overline{D} \subset \Omega$. We show that the one‐wave no response test provides a criterion to test the analytic extensibility of a field. In particular, we investigate the construction of approximations for the set of singular points $N(u)$ of the total fields u from one given pair of Cauchy data. Thus, the no response test solves a particular version of the classical Cauchy problem. Also, if an infinite number of fields is given, we prove that a multifield version of the no response test reconstructs the unknown inclusion D. This is the first convergence analysis which could be achieved for the no response test.

Unification of the probe and singular sources methods for the inverse boundary value problem by the no-response test

In this article, we use the no-response test idea, introduced in Luke and Potthast (2003) and Potthast (Preprint) and the inverse obstacle problem, to identify the interface of the discontinuity of the coefficient gamma of the equation del (.) gamma(x)del + c(x) with piecewise regular gamma and bounded function c(x). We use infinitely many Cauchy data as measurement and give a reconstructive method to localize the interface. We will base this multiwave version of the no-response test on two different proofs. The first one contains a pointwise estimate as used by the singular sources method. The second one is built on an energy (or an integral) estimate which is the basis of the probe method. As a conclusion of this, the probe and the singular sources methods are equivalent regarding their convergence and the no-response test can be seen as a unified framework for these methods. As a further contribution, we provide a formula to reconstruct the values of the jump of gamma(x), x is an element of partial derivative D at the boundary. A second consequence of this formula is that the blow-up rate of the indicator functions of the probe and singular sources methods at the interface is given by the order of the singularity of the fundamental solution.

Application of an auditory steady-state response test to evaluate the attenuation of hearing protection devices

This research aims to present a new method to get real attenuation of hearing protection devices, with good reproducibility and a small standard deviation, without relying on skills and cooperation individual. Thus the authors performed tests in 10 individuals without protection and after with two kinds of ear protections (ear plug and ear muffs), to get the threshold limit value in each of the 3 stages. For this, the research used an electrophysical exam, normally used in speech therapy, named ASSR (auditory steady-state response). The principle of this exam is put on individual’s head 3 electrodes, to capture electrical signs directly in auditory nerve. In summary, the authors presented the final results. The method proposed by ANSI (American National Standards Institute) indicated an attenuation of 27.6 dB for ear plugs, while the value found in this work was 16 dB; and for ear muffs, the ANSI method indicated 29.8 dB while the value found here was 28.5 dB.

Effects of six carbohydrate sources on diet digestibility and postprandial glucose and insulin responses in cats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Métodos para estudo das respostas metabólicas de cães e gatos a diferentes alimentos

Durante o processo de assimilação e uso dos alimentos, diferentes respostas metabólicas podem ser desenvolvidas pelo organismo dos animais. Estas respostas são fruto da integração de mecanismos complexos, que envolvem os sistemas neuro-endócrino e o funcionamento dos órgãos, sendo influenciadas pela dieta, espécie animal, idade, condição fisiológica e composição corporal. Este trabalho enfoca a importância fisiológica e os métodos de estudo das respostas pós-prandiais aos carboidratos, bem como as alterações fisiológicas conseqüentes ao balanço eletrolítico da dieta. A quantidade, estrutura química e processamento industrial do amido determinam boa parte da resposta pós-prandial de glicose e insulina de cães. em gatos, outros mecanismos parecem ser mais importantes, como a ingestão de aminoácidos. A fibra alimentar também altera a resposta pós-prandial ao alimento, devendo ser consideradas sua quantidade, solubilidade e fermentabilidade no desenvolvimento das dietas. Os métodos de estudo destas respostas incluem avaliação das respostas glicêmica e insulínca pós-prandiais, teste endovenoso de tolerância à glicose e à arginina. O clâmp euglicêmico apresenta-se também como ferramenta de estudo, no entanto revela informações mais relacionadas ao animal do que à dieta. A compreensão do conjunto de alterações metabólicas aos carboidratos é importante no estudo do controle da saciedade, composição corporal e inúmeras doenças degenerativas e endócrinas. A concentração e relação entre os macro-elementos da dieta (Na, Cl, K, P, Ca, Mg e S) e dos aminoácidos sulfurados (metionina, cistina e taurina) interferem em inúmeras funções orgânicas, como a cardiovascular, neuromuscular, metabolismo ósseo, renal e pulmonar, refletindo-se no equilíbrio hidro-eletrolítico e ácido-básico orgânicos. de importância prática para cães e gatos encontram-se a relação destes nutrientes com cardiopatias, nefropatias, osteodistrofias e urolitíases. A relação entre os macro-elementos é estabelecida em mmol/kg de matéria seca da dieta, calculando-se seu balanço cátion-ânion (excesso de bases ou ânions dietéticos não determinados). Suas repostas orgânicas são medidas, dentre outros métodos, pela hemogasimetria, balanço hídrico, mensuração do volume dos espaços extracelular e vascular, supersaturação e pH urinários.

Growth and nutrient utilization of Murray cod Maccullochella peelii peelii (Mitchell) fingerlings fed diets with varying levels of soybean meal and blood meal

The Australian native freshwater fish Murray cod, Maccullochella peelii pellii (Mitchell), currently supports a fledgling inland aquaculture industry, which is thought to have considerable growth potential. The aim of this study was to evaluate the suitability of two alternate protein sources [blood meal (BM) and defatted soybean meal (SBM)] as substitutes for fish meal at various levels of inclusion in diets for juvenile Murray cod. The growth performance of juvenile Murray cod in response to nine isonitrogenous and isocalorific diets (50% protein, 14% lipid, 20.2 kJ g⁻¹) consisting of a control diet in which protein was supplied from fish meal, and test diets in which the fish meal protein was substituted at levels of 8%, 16%, 24%, and 32% with BM or SBM was evaluated from a 70-day growth experiment. The per cent apparent dry matter (% ADC_dm) and percentage protein digestibility (% ADC_p) of the test diets were also determined using Cr₂O₃ as a marker. Survival in all the SBM dietary treatments was high but that of fish on the BM dietary treatments was significantly (P < 0.05) lower than in all the other dietary treatments. Specific growth rate (% day−1) of Murray cod fed SBM incorporated diets ranged from 1.63 ± 0.06 to 1.78 ± 0.10 and even at the highest level tested (32% of the dietary protein from SBM) was not significantly different (P > 0.05) from the fish fed the control diet (1.65 ± 0.09). Feed conversion ratios of the SBM dietary treatments ranged from 1.36 ± 0.08 to 1.45 ± 0.07. The protein efficiency ratios and protein conversion efficiencies of Murray cod in the soybean meal treatments were also good and for a majority of the SBM diets were better than those for the control diet. Per cent ADC_dm and ADC_p of the SBM diets tested ranged from 70.6 ± 1.46 to 72.3 ± 1.81% and 88.6 ± 0.57 to 90.3 ± 0.17%, respectively, and was not significantly different (P > 0.05) from the control diet (% ADC_dm 74.3 ± 1.63; % ADC_p 91.3 ± 0.55). The reasons for significantly poor survival and growth of Murray cod reared on BM incorporated diets, and relatively poor digestibility of these diets are discussed. The study shows that for Murray cod diets in which fish meal protein is substituted up to 32% performance or carcass composition is not compromised.

Blood-clotting response tests for resistance to diphacinone and chlorophacinone in the Norway rat (Rattus norvegicus Berk.)

Resistance baselines were obtained for the first generation anticoagulant rodenticides chlorophacinone and diphacinone using laboratory, caesarian-derived Norway rats (Rattus norvegicus) as the susceptible strain and the blood clotting response test method. The ED99 estimates for a quantal response were: chlorophacinone, males 0.86 mg kg−1, females 1.03 mg kg−1; diphacinone, males 1.26 mg kg−1, females 1.60 mg kg−1. The dose-response data also showed that chlorophacinone was significantly (p<0.0001) more potent than diphacinone for both male and female rats, and that male rats were more susceptible than females to both compounds (p<0.002). The ED99 doses were then given to groups of five male and five female rats of the Welsh and Hampshire warfarin-resistant strains. Twenty-four hours later, prothrombin times were slightly elevated in both strains but all the animals were classified as resistant to the two compounds, indicating cross-resistance from warfarin to diphacinone and chlorophacinone. When rats of the two resistant strains were fed for six consecutive days on baits containing either diphacinone or chlorophacinone, many animals survived, indicating that their resistance might enable them to survive treatments with these compounds in the field.

A reduction of CETP activity, not an increase, is associated with modestly impaired postprandial lipemia and increased HDL-Cholesterol in adult asymptomatic women

Background: The relationship between CETP and postprandial hyperlipemia is still unclear. We verified the effects of varying activities of plasma CETP on postprandial lipemia and precocious atherosclerosis in asymptomatic adult women. Methods: Twenty-eight women, selected from a healthy population sample (n = 148) were classified according to three CETP levels, all statistically different: CETP deficiency (CETPd <= 4.5%, n = 8), high activity (CETPi >= 23.8, n = 6) and controls (CTL, CETP >= 4.6% and <= 23.7%, n = 14). After a 12 h fast they underwent an oral fat tolerance test (40 g of fat/m(2) of body surface area) for 8 hours. TG, TG-rich-lipoproteins (TRL), cholesterol and TRL-TG measurements (AUC, AUIC, AR, RR and late peaks) and comparisons were performed on all time points. Lipases and phospholipids transfer protein (PLTP) were determined. Correlation between carotid atherosclerosis (c-IMT) and postprandial parameters was determined. CETP TaqIB and I405V and ApoE-epsilon 3/epsilon 2/epsilon 4 polymorphisms were examined. To elucidate the regulation of increased lipemia in CETPd a multiple linear regression analysis was performed. Results: In the CETPi and CTL groups, CETP activity was respectively 9 and 5.3 higher compared to the CETPd group. Concentrations of all HDL fractions and ApoA-I were higher in the CETPd group and clearance was delayed, as demonstrated by modified lipemia parameters (AUC, AUIC, RR, AR and late peaks and meal response patterns). LPL or HL deficiencies were not observed. No genetic determinants of CETP deficiency or of postprandial lipemia were found. Correlations with c-IMT in the CETPd group indicated postprandial pro-atherogenic associations. In CETPd the regression multivariate analysis (model A) showed that CETP was largely and negatively predicted by VLDL-C lipemia (R(2) = 92%) and much less by TG, LDL-C, ApoAI, phospholipids and non-HDL-C. CETP (model B) influenced mainly the increment in ApoB-100 containing lipoproteins (R(2) = 85% negatively) and phospholipids (R(2) = 13%), at the 6(th)h point. Conclusion: The moderate CETP deficiency phenotype included a paradoxically high HDL-C and its sub fractions (as earlier described), positive associations with c-IMT, a postprandial VLDL-C increment predicting negatively CETP activity and CETP activity regulating inversely the increment in ApoB100-containing lipoproteins. We hypothesize that the enrichment of TG content in triglyceride-rich ApoB-containing lipoproteins and in TG rich remnants increases lipoproteins` competition to active lipolysis sites, reducing their catabolism and resulting on postprandial lipemia with atherogenic consequences.

Effects of six carbohydrate sources on dog diet digestibility and post-prandial glucose and insulin response

The effects of six extruded diets with different starch sources (cassava flour, brewer's rice, corn, sorghum, peas or lentils) on dog total tract apparent digestibility and glycemic and insulinemic response were investigated. The experiment was carried out on thirty-six dogs with six dogs per diet in a completely randomized design. The diets containing brewer's rice and cassava flour presented the greatest digestibility of dry matter, organic matter and gross energy (p < 0.05), followed by corn and sorghum; pea and lentil diets had the lowest. Starch digestibility was greater than 98% in all diets and was greater for brewer's rice and cassava flour than for lentils and peas diets (p < 0.05). Dogs' immediate post-prandial glucose and insulin responses (AUC <= 30 min) were greater for brewer's rice, corn, and cassava flour diets (p < 0.05), and later meal responses (AUC >= 30 min) were greater for sorghum, lentil and pea diets (p < 0.05). Variations in diet digestibility and post-prandial response can be explained by differences in chemical composition of each starch source including fibre content and starch granule structure. The nutritional particularities of each starch ingredient can be explored through diet formulations designed to modulate glycemic response. However, more studies are required to support these.

Analisi della stabilità dei risultati dei test di risposta termica: prove in campo, confronto e analisi critica per diversi metodi di esecuzione e modellizzazione

Il Test di Risposta Termica (Thermal Response Test-TRT) (Mogenson,1983) è il test esistente con il più alto grado di accuratezza per la caratterizzazione del reservoir geotermico superficiale. Il test consiste in una simulazione in situ del funzionamento di un sistema a circuito chiuso di sfruttamento dell’energia geotermica, per un periodo limitato di tempo, attraverso l’iniezione o estrazione di calore a potenza costante all’interno del geo-scambiatore (Borehole Heat Exchanger-BHE). Dall’analisi della variazione delle temperature del fluido circolante, è possibile avere una stima delle proprietà termiche medie del volume del reservoir geotermico interessato dal test. Le grandezze principali per la caratterizzazione di un serbatoio geotermico sono la conduttività termica (λ), la capacità termica volumetrica (c), la temperatura indisturbata del suolo (Tg) e la resistenza termica del pozzo (Rb); la loro determinazione è necessaria per il corretto progettazione degli geo-scambiatori. I risultati del TRT sono tuttavia sensibili alle condizioni al contorno spazio-temporali quali ad es.: variazione della temperatura del terreno, movimento d’acqua di falda, condizioni metereologiche, eventi stagionali, ecc. Questo lavoro vuole: i) introdurre uno studio sui problemi di caratterizzazione del reservoir geotermico superficiale, in particolare analizzando l’effetto che il movimento d’acqua di falda ha sui parametri termici; ii) analizzare la sensitività dei risultati del test alle variabilità dei parametri caratteristici del funzionamento delle attrezzature. Parte del lavoro della mia tesi è stata svolta in azienda per un periodo di 4 mesi presso la “Groenholland Geo Energy systems” che ha sede ad Amsterdam in Olanda. Tre diversi esperimenti sono stati realizzati sullo stesso sito (stratigrafia nota del terreno: argilla, sabbia fine e sabbia grossa) usando una sonda profonda 30 metri e diversi pozzi per l’estrazione d’acqua e per monitorare gli effetti in prossimità del geo scambiatore. I risultati degli esperimenti sono stati molto diversi tra di loro, non solo in termini di dati registrati (temperature del fluido termovettore), ma in termini dei valori dei parametri ottenuti elaborando i dati. In particolare non è sufficiente adottare il modello classico della sorgente lineare infinita (Infinite Line Source Solution- ILS) (Ingersoll and Plass, 1948), il quale descrive il trasferimento di calore per conduzione in un mezzo omogeneo indefinito a temperatura costante. Infatti, lo scambio di calore avviene anche tramite convezione causata dal movimento d’acqua di falda, non identificabile mediante gli approcci classici tipo CUSUM test (Cumulative Sum test) (Brown e altri,1975) Lo studio della tesi vuole dare un quadro di riferimento per correlare la variabilità dei risultati con la variabilità delle condizioni al contorno. L’analisi integra le metodologie classiche (ILS) con un approccio geostatistico utile a comprendere i fenomeni e fluttuazioni che caratterizzano il test. Lo studio delle principali variabili e parametri del test, quali temperatura in ingresso e uscita del fluido termovettore, portata del fluido e potenza iniettata o estratta, è stato sviluppato mediante: il variogramma temporale, ovvero la semivarianza dell’accrescimento, che esprime il tipo di autocorrelazione temporale della variabile in esame; la covarianza incrociata temporale, ovvero la covarianza fra due variabili del sistema, che ne definisce quantitativamente il grado di correlazione in funzionamento del loro sfasamento temporale. L’approccio geostatistico proposto considera la temperatura del fluido Tf come una funzione aleatoria (FA) non stazionaria nel tempo (Chiles, 1999), il cui trend è formalmente definito, ma deve essere identificato numericamente. Si considera quindi un classico modello a residuo; in cui la FA è modellizzata come la somma di un termine deterministico, la media (il valore atteso) m(t),coincidente col modello descritto dalla teoria della sorgente lineare infinità, e di un termine aleatorio, la fluttuazione, Y(t). Le variabili portata e potenza sono invece considerate delle funzioni aleatorie stazionarie nel tempo, ovvero a media costante. Da questo studio di Tesi si sono raggiunte delle conclusioni molto importanti per lo studio del TRT: Confronto tra gli esperimenti in estrazione di calore, con e senza movimento d’acqua di falda: si studia l’effetto indotto dalla falda sul TRT. E’ possibile caratterizzare quantitativamente l’incremento della conducibilità termica equivalente legata a fenomeni convettivi dovuti al movimento d’acqua di falda. Inoltre, i variogrammi sperimentali evidenziano periodicità simili nei due casi e legate al funzionamento della pompa di calore e della componentistica associata ed alla circolazione del fluido termovettore all’interno della sonda. Tuttavia, la componente advettiva ha un effetto di smorzamento sulle piccole periodicità dei variogrammi, ma di aumento dell’ampiezza delle periodicità maggiori a causa del funzionamento della pompa di calore che deve fornire maggiore energia al sistema per bilanciare le dispersioni dovute al movimento d’acqua di falda. Confronto fra estrazione ed iniezione di calore, con movimento d’acqua di falda: si studia la significatività dei risultati nei due casi. L’analisi delle variografie evidenzia significative differenze nella struttura dei variogrammi sperimentali. In particolare, nel test con iniezione di calore i variogrammi sperimentali delle temperature hanno valori sistematicamente inferiori, circostanza che assicura una migliore precisione nella stima dei parametri termici. Quindi eseguire il TRT in iniezione di calore risulta più preciso. Dall’analisi dei variogrammi sperimentali delle singole variabili quali temperatura del fluido in ingresso e uscita all’interno del geoscambiatore è stato confermato il fenomeno di smorzamento delle oscillazioni da parte del terreno. Dall’analisi delle singole variabili del test (temperature, potenza, portata) è stata confermata l’indipendenza temporale fra portate e temperature. Ciò è evidenziato dalle diverse strutture dei variogrammi diretti e dalle covarianze incrociate prossime a zero. Mediante correlogrami è stato dimostrato la possibilità di calcolare il tempo impiegato dal fluido termovettore per circolare all’interno della sonda. L’analisi geostatistica ha permesso quindi di studiare in dettaglio la sensitività dei risultati del TRT alle diverse condizioni al contorno, quelle legate al reservoir e quelle legate al funzionamento delle attrezzature

Bestimmung thermischer Untergrundparameter in Erdwärmesondenfeldern und Evaluierung tiefenaufgelöster Thermal-Response-Tests durch thermohydraulische Modellierungen

Die oberflächennahe Geothermie leistet im Bereich der Nutzung regenerativer Wärme einen wichtigen Beitrag zum Klima- und Umweltschutz. Um die technische Nutzung oberflächennaher Geothermie zu optimieren, ist die Kenntnis der Beschaffenheit des geologischen Untergrundes ausschlaggebend. Die vorliegende Dissertation befasst sich mit der Bestimmung verschiedener Untergrundparameter an einem Erdwärmesondenfeld. Es wurden Untersuchungen zur Bestimmung der Wärmeleitfähigkeit wie der enhanced Thermal Response Test (eTRT), sowie eine Untergrund-Temperaturüberwachung im ersten Betriebsjahr durchgeführt. Die Überwachung zeigte keine gegenseitige Beeinflussung einzelner Sonden. Ein Vergleich zwischen dem geplanten und dem tatsächlichem Wärmebedarf des ersten Betriebsjahres ergab eine Abweichung von ca. 35%. Dies zeigt, dass die Nutzungsparameter der Anlage deren Effizienz maßgeblich beeinflussen können. Der am Beispielobjekt praktisch durchgeführte eTRT wurde mittels numerischer Modellierung auf seine Reproduzierbarkeit hin überprüft. Bei einem rein konduktiven Wärmetransport im Untergrund betrug die maximale Abweichung der Messung selbst unter ungünstigen Bedingungen lediglich ca. 6% vom zu erwartenden Wert. Die Detektion von grundwasserdurchflossenen Schichten ist in den Modellen ebenfalls gut abbildbar. Problematisch bleibt die hohe Abhängigkeit des Tests von einer konstanten Wärmezufuhr. Lediglich die Bestimmung der Wärmeleitfähigkeit über das Relaxationsverhalten des Untergrundes liefert bei Wärmeeintragsschwankungen hinreichend genaue Ergebnisse. Die mathematische Nachbearbeitung von fehlerhaften Temperaturkurven bietet einen Einstiegspunkt für weiterführende Forschung.

Dietary carbohydrate source affects glucose concentrations, insulin secretion, and food intake in overweight cats

This study was undertaken to assess the impact of dietary carbohydrate source on food intake, body composition, glucose tolerance, insulin sensitivity, and glucose and insulin concentrations in overweight and obese cats with reduced insulin sensitivity. Sixteen overweight and obese cats were divided into two groups and randomly allocated one of two extruded diets formulated to contain similar starch content (33%) from different cereal sources (sorghum and corn versus rice). Meal response, glucose tolerance and insulin sensitivity tests were performed before and after a 6-week weight-maintenance phase and after an additional 8-week free-access feeding phase. Dual energy x-ray absorptiometry (DEXA)-derived body composition was determined in each cat before the study and after each test phase. Food intake was measured daily and body weight measured twice weekly for the duration of the study. When compared with the sorghum/corn-based diet, cats fed the rice-based diet consumed more energy and gained more weight in response to free-access feeding. Cats fed the rice-based diet also tended to have higher glucose concentrations and insulin secretion in response to a glucose load or a test meal. We conclude that a sorghum and corn blend is a superior carbohydrate source than rice for overweight cats with glucose intolerance and reduced insulin sensitivity. Such a diet may help to minimize overeating and additional weight gain, and may also reduce the risk of developing type 2 diabetes mellitus. (C) 2004 Elsevier Inc. All rights reserved.