bluuebunny/crossref_metadata_2025 huggingface dataset:
Temel Bileşenler Analizi Kullanılarak Fındık Bahçesi Toprak Özelliklerine Farklı Sulama Yönetimlerinin Etkilerinin Değerlendirilmesi
Authors: EREN Ediphan , KÜÇÜK Edip Erhan , İÇ Serkan , SAĞLAM Mustafa
Published: February 2024

İklime en duyarlı meyve türlerinden birisi olan ve yetişmesi için belirli iklim koşullarına gereksinim duyan fındık, genel olarak ortalama yıllık yağış miktarının 800-1000 mm arasında olduğu belirli bir kuzey enlemde yetiştirilmektedir. Fındık, ayrıca yarı kurak ve kurak iklim bölgelerinde yetiştirildiğinde veya yetiştirildiği bölgenin yağış rejiminde düzensizlikler meydana geldiğinde sulamaya gereksinim duyabilmektedir. Mevcut çalışma, Samsun ili Terme ilçesinde kurulmuş bir fındık bahçesinde toprak özellikleri üzerine dört farklı sulama suyu düzeyinin (Kontrol, % 70 sulama, % 100 sulama, %130 sulama) etkilerinin araştırılması amacıyla yürütülmüştür. Çalışmadaki değişkenlik kaynaklarının (sulama suyu yönetimi ve toprak örnekleme derinliği) etkileri iki yönlü varyans analizi ile değerlendirilmiştir. Ayrıca sulama suyu yönetimleri ve toprak örnekleme derinliklerinin kombine etkileri, temel bileşenler analizi ile incelenmiştir. Elde edilen sonuçlar, çalışma alanı toprak özellikleri üzerine en yüksek etkileri ortaya koyan uygulamanın %70 sulama suyu yönetimi olduğunu göstermiştir. Kontrol ve %130 sulama suyu uygulamaları ise en düşük istatistiksel etkileri ortaya koyan sulama yönetimleri olmuşlardır. Çalışmada elde edilen sonuçlar sonrasında %70 sulama suyu düzeyi uygulamasının, çalışmanın yürütüldüğü fındık bahçesi toprak özelliklerinin gelişimi için en uygun sulama yönetimi olduğu önerilmiştir.
Comparative Analysis of Genetic and Greedy Algorithm for Optimal Drone Flight Route Planning in Agriculture
Authors: ÖNLER Eray
Published: February 2024

In this study, the performance of the Genetic Algorithm (GA) in optimizing the agricultural drone flight route was compared with the Greedy Algorithm, revealing that GA produce routes that are, on average, 17.44 % more efficient. This efficiency, measured over 500 generations in a static field model, suggests substantial potential for saving resources and time in agricultural operations. Despite the effectiveness of the GA, its computational intensity limits real-time field applications, but offers advantages in offline route planning for pre-mapped areas. A t-test between flight lengths created by the algorithms highlighted a significant difference, with a p-value of approximately 7.18×10−9, indicating the GA's superior performance. Future research should aim to bridge the gap between the simplified binary field model used in simulations and the complexities of real-world agricultural landscapes to improve the practical deployment of GAs in drone route optimization.
Investigation of the Phenological and Climate Indices of Some Table and Wine Grapes and Their Growing Status in the Samsun-Bafra Plain (Türkiye)
Authors: KARABEKTAŞOĞLU Şinasi , KÖSE Bülent , SVYANTEK Andrej
Published: February 2024

The aim of this study was to determine the viticultural potential of Bafra plain based on viticulture climate indices. Bafra district was classified as warm-temperate according to Winkler and Huglin indices. The Winkler index (WI) 1969.0, Huglin index (HI) 2184.4 °C units, Branas Heliothermic Index (BHI) 4.5, and Branas Hydrothermal Index (HYI) 3423.6 were obtained for the Bafra region. Annual sunshine duration was calculated as 2295.5 hours, while sunshine duration during the growing period was 1715.0 hours. Considering the HYI value being somewhat high, this combined with the high air humidity in the summer months shows an increased risk of fungal diseases. The bud burst occurred in the second week of April and flowering occurred in the first week of June in all cultivars. The earliest veraison initiated with early ripening ‘Early Sweet’ and ‘Trakya İlkeren’ cultivars and the latest veraison was in ‘Ugni Blanc’ and ‘Red Globe’. The earliest ripening was determined in ‘Early Sweet’ with 937.7 GDD, and the latest ripening was determined in the ‘Ugni Blanc’ cultivar as 1729.2 GDD. The period from bud burst to maturity was 110 days in ‘Early Sweet’ and 170 days in the ‘Ugni Blanc’. Sites selected with high altitude, areas that slope slightly to the south sides, low humidity, and far from sea areas are suitable for early and mid-season ripening grape cultivars. The high humidity in the summer and heavy rain in the fall season increase fungal disease risks in the Bafra region.
Determining consumers’ willingness to pay in view of extrinsic attributes of Erzurum Stuffed-Kadayif with Protected Geographical Indication
Authors: GÜLER Tuba , TOPCU Yavuz
Published: February 2024

The aim of the study is to determine consumers’ willingness to pay (WTP) in view of the brand types and food retailers simulations from the product profiles based on the intrinsic and extrinsic attributes of Erzurum Stuffed-kadayif profiles with Protected Geographical Indication, and then to create the marketing strategies for each consumer segment. In order to reach to these goals, the main material composed of the primary data obtained from consumers consuming Erzurum Stuffed-kadayif in Erzurum Province. Based on the data, k-means cluster analysis was firstly used to segment heterogeneous consumer masses according to their consumption frequencies, and choice-based CA model was secondly applied to calculate the total utilities for each consumer segment and then to measure consumers’ WTP for Erzurum Stuffed-kadayif profile simulations. The results of the study highlighted that the light and heavy users’ WTPs with higher premium prices for the local brands and manufacturer outlets calculated as 48.0% and 28.2%, and 40.8% and 26.5% respectively, but the medium users’ WTPs with high premium prices for each product attribute found as 14.5%. Focused on such consumer-oriented attitudes, the market actors should position Erzurum Stuffed-kadayif with local retailer brands sold from the higher premium prices at the manufacturer stores for the light and heavy users, but it should be implemented the product differentiation strategies under the intrinsic and extrinsic food attributes for the medium users.
Fiscal policy and economic growth in the short and long run: a literature review
Authors: Poylov Nikita Aleksandrovich
Published: February 2024

The purpose of this paper is to establish the main channels of fiscal policy impact on economic growth and to identify problems or missing aspects in the analysis. The paper summarizes the impact of fiscal policy on economic growth in the long-run and short-run on the basis of extensive (82 sources) literature analysis. The paper analyzes the results of theoretical and empirical studies. The paper pays attention to the comparison of empirical results for poor and rich countries, as the optimal fiscal policy may differ significantly from country to country. On the theoretical side, the paper mainly focuses on endogenous growth models, but also touches on overlapping generations and Solow models. Special attention is paid to the estimation of fiscal multipliers. Through a broad view, the paper touches upon the main instruments of fiscal policy and their impact on economic growth both in the short run and in the long run. The author's contribution is in overview of a wide body of literature on fiscal policy, which helps to identify the main problems in analyzing the impact of fiscal policy. Fiscal policy can have short- and long-term effects on economic growth through changing the incentives of economic agents, through reducing transaction costs between them, and through influencing expectations. However, the main body of empirical literature examines the impact of fiscal policy on economic growth in developed countries. This poses a challenge for fiscal policy in developing countries, as recommendations derived from the experience of developed countries are often suboptimal for developing countries. The article also points out the significant problems associated with empirical analysis of the performance of fiscal policy even in developed countries.
An efficient calculation method for particle transport problems based on neural network
Authors: Ma Rui-Yao , Wang Xin , Li Shu , Yong Heng , Shangguan Dan-Hua ,   Institute of Applied Physics and Computational Mathematics, Beijing 100094, China,   CAEP Software Center for High Performance Numerical Simulation, Beijing 100088, China
Published: February 2024

Monte Carlo (MC) method is a powerful tool for solving particle transport problems. However, it is extremely time-consuming to obtain results that meet the specified statistical error requirements, especially for large-scale refined models. This paper focuses on improving the computational efficiency of neutron transport simulations. Specifically, this study presents a novel method of efficiently calculating neutron fixed source problems, which has many applications. This type of particle transport problem aims at obtaining a fixed target tally corresponding to different source distributions for fixed geometry and material. First, an efficient simulation is achieved by treating the source distribution as the input to a neural network, with the estimated target tally as the output. This neural network is trained with data from MC simulations of diverse source distributions, ensuring its reusability. Second, since the data acquisition is time consuming, the importance principle of MC method is utilized to efficiently generate training data. This method has been tested on several benchmark models. The relative errors resulting from neural networks are less than 5% and the times needed to obtain these results are negligible compared with those for original Monte Carlo simulations. In conclusion, in this work we propose a method to train neural networks, with MC simulation results containing importance data and we also use this network to accelerate the computation of neutron fixed source problems.
Physical activity level and physical fitness in subjects with chronic musculoskeletal pain: a cross-sectional study
Authors: Rojas Gabriel , Orozco-Chavez Ignacio
Published: February 2024

Background

Low physical activity (PA) levels and low physical fitness (PF) have been reported in subjects with temporality-based chronic pain; however, it is unknown whether there are differences in subjects with nociplastic pain (NP) compared with subjects with non-nociplastic pain (NNP).

Objective

The aim was to compare the levels of PA and PF in patients with chronic, nociplastic, and non-nociplastic musculoskeletal pain.

Methods

This is an analytical, cross-sectional study. The sample comprised 30 patients receiving ambulatory physiotherapy treatment. Pain was classified as NP or NNP according to the International Association for the Study of Pain categorization system. The PA level was measured with the International Physical Activity Questionnaire–Short Form, and the PF level was measured with the hand grip strength test (HGS) to assess upper limb strength, the five Repetition Sit-to-Stand Test (5R-SRTS) to assess lower limb strength and power, and the YMCA 3 Min Step Test (YMCA-3MST) to estimate peak VO2. The results were compared with independent samples t-tests (with p < 0.05 considered significant). Cohen’s d was calculated to determine the effect size.

Results

The NP group reported a significantly lower PA level than the NNP group, specifically the vigorous PA (p = 0.0009), moderate PA (p = 0.0002), and total PA (p = 0.005) dimensions. The NP group also showed significantly lower 5R-STS (p = 0.000) and HGS (p = 0.002) results compared with the NNP group. There were no significant differences in the YMCA-3MST between the NP and NNP groups (p = 0.635).

Conclusion

It is possible that the neurophysiological and neuromuscular changes related to NP are associated with a reduced ability to perform vigorous PA. Clinicians should identify the presence of NP comorbidities in conjunction with the diagnosis when establishing the therapeutic goals.
Gestão de estoque em uma indústria de fitas de borda: evidências por meio de estudo de caso
Authors: Silva Joyce Aparecida Passos , Fioravante Igor Alexandre , Ribeiro Rosinei Batista , Luciano Érik Leonel , Melo Rosenil Honorato de , Souza Adriano José Sorbile de
Published: February 2024

A gestão eficaz de estoque é crucial para o sucesso empresarial em um cenário competitivo. Nesse contexto, a empresa em foco enfrenta desafios relacionados à gestão de estoque, especificamente ligados a divergências entre o estoque físico e as informações registradas no sistema. Essas discrepâncias surgem de erros de contagem, problemas de registro e outras fontes, sendo agravadas pela gestão inadequada, dificultando a localização de produtos. A falta de controle preciso do estoque pode causar atrasos nas entregas e prejuízos financeiros. Isso motivou uma pesquisa para investigar suas causas e propor soluções eficazes. O método utilizado é o estudo bibliográfico para embasamento teórico e o estudo de caso, permitindo uma análise minuciosa da situação. Com o auxílio das ferramentas da qualidade, foram identificados pontos crucias que interferiam diretamente no controle eficaz do estoque.  Foram propostas algumas medidas de correção e preventivas para que esse problema forre solucionado e não voltasse a ocorrer. Com a implementação da proposta obteve-se o aumento de 3% da acuracidade no estoque e espera-se que este projeto possa beneficiar outras empresas que enfrentam desafios semelhantes.
Analysis of Soil Health Card awareness and Constraints among Farmers in Vidarbha Region
Authors: Lade Ashish Homraj , Ingle Sagar Nandulal , Gawali Kevin , Gadge Priya
Published: February 2024

This study is conducted to assess the awareness levels of farmers regarding the Soil Health Card and identify the constraints they encountered in utilizing its information in the Vidarbha region of Maharashtra state. The research was conducted in Chandrapur district, specifically in the talukas of Warora, Bhadravati, Jivti, and Rajura. Three villages were selected from each taluka and ten respondents were selected from each village, resulting in a total of 120 purposively selected respondents for the study. Data collection involved personal interviews using a structured interview schedule. The findings revealed that slightly over half of the respondents (54.17%) had a moderate level of awareness about the Soil Health Card, while a quarter of the farmers (25.00%) had low awareness, and just over twenty per cent (20.83%) had a high level of awareness. The study also examined the distribution of respondents based on the constraints they faced and their efforts to overcome these challenges. These findings contribute to our understanding of the awareness and constraints faced by farmers in effectively utilizing the information from the Soil Health Card, highlighting the need for targeted interventions and support to improve its implementation in the region.
Designing a Learning Model with a Contextual Teaching Learning Approach Based on the Flipped Classroom to Improve Science Understanding
Authors: Nasrah  , Malago Jasruddin , Saman Abdul
Published: February 2024

This research aims to describe a learning model design with a Contextual Teaching Learning (CTL) approach based on the Flipped Classroom to increase the understanding of science concepts. The research is categorized as qualitative research with descriptive analysis. Data were obtained from literature studies, documentation, and expert opinions related to the design of learning models. Several theories that support the design of learning models with a CTL approach based on the Flipped Classroom to improve understanding of science concepts were studied. The result of this research is a learning model design named Contextual Flipped Group Classroom (CFGC), which has the syntax of Networked Learning, Active Inquiry, Student Empowerment, Reflective Practice, and Authentic Assessment.
The Influence of Demographic Factors of Nigerian Dentists on their Satisfaction with Duration of Orthodontic Treatment and Knowledge of Accelerated Orthodontics
Authors: Orikpete Mariam , Okino Benjamin O. , Ututu Chinyere , Okino Chikamaram O. , Isiekwe Ikenna Gerald , Onyeaso Chukwudi O.
Published: February 2024

Background: The duration of orthodontic treatment and the knowledge of accelerated orthodontics are very important to the dental practitioner but there are limited information on the relationship between their satisfaction with duration of orthodontic treatment and knowledge of accelerated orthodontics.

Aim: To assess the associations between the demographics of the Nigerian dental practitioners and their satisfactions with the duration of orthodontic treatment and their knowledge of accelerated orthodontics.

Materials and Methods: Electronic and physical methods of surveying the Nigerian dental practitioners were carried out between January and June 2023. The contents of the questionnaire involving satisfaction with duration of orthodontic treatment and the knowledge of accelerated orthodontics were analysed for associations with the participants’ demographics, using the IBM SPSS version 25. Descriptive statistics, the ANOVA and independent t-test were used with the significance level set at P < .05.

Results: No statistically significant associations were found between the dentists’ satisfaction with duration of orthodontic treatment and their age, gender and years of practice as dentists (P > .05). Also, no statistically significant associations were found between the dentists’ knowledge of the methods of accelerated orthodontics and age (P > .05). Statistically significant associations were found between the male gender and knowledge of administration of biological substances and piezocision, while the highest number of methods of accelerated orthodontics was statistically significantly associated with the years of practice of dentistry (P < .05).

Conclusion: Although no significant associations were found between the participants’ demographics and satisfaction with duration of orthodontic treatment, gender gave significant associations with knowledge of two methods of accelerated orthodontics, while years of practice of dentistry revealed the most significant associations with knowledge of accelerated orthodontics.
A Review on the Nutritional Value of Some Leafy Vegetables used in India
Authors: Kumar Akhilesh , Pringchinoramarak  , Mishra Saket , Ekka Shashi Kant , Kujur Reena , Lakra Johnson
Published: February 2024

This review explores the nutritional profiles of leafy vegetables commonly used in Indian cuisine, emphasizing their significance in promoting human health and well-being. Leafy greens play a pivotal role in traditional Indian diets, contributing essential vitamins, minerals, and antioxidants. The low calorific value of leafy vegetables makes them ideal for human weight balance. The good nutrition profile of leafy vegetables are beneficial in reducing the risk of major diseases such as cardiovascular and cancer. Anti nutritional factors are chemical compounds in plant tissues, which deter the absorption of nutrients in humans. From all the findings it was suggested that consumption of leafy vegetables fulfills the nutrition reqiurements and avoid from malnutrition.
Phytochemical Screening and Evaluation of the Larvicidal Activities of Three Organic Extracts Derived from the Leaves of Cassia sieberiana to Control Anopheles gambiae, the Vector of Malaria
Authors: Kébé Mamadou , Diouf El Hadji Gorgui , Ndour Mamadou Latyr , Faye Adama , Sarr Abdou , Ndior Talibouya , Camara Ndeye Bineta , Ngom Mamadou , Sarr Baboucar , Sène Aboubacry
Published: February 2024

Senegal is one of the African countries where malaria remains a major public health problem. In the fight against mosquitoes, the vector of this disease, the significant accumulation of active ingredients in ecosystems treated with synthetic insecticides poses an increased environmental problem linked to the very high persistence time.

The aim of this study is to propose an alternative method of vector control using natural products of plant origin.

Three organic extracts (cyclohexanic, chloroformic and methanolic) from the leaves of Cassia sieberiana were tested by contact on mosquito larvae of the genus Anopheles gambiae. Four doses of each extract were prepared and monitored over 48 hours.

The families of chemical compounds in the various organic extracts are identified using coloring and precipitation tests.

The results obtained show a variable sensitivity of the larvae, reflected in low to very high mortality rates when moving from one extract to another. The chloroform extract was the most effective, with a mortality rate of just under 90% after 48 hours' exposure.

Phytochemical screening reveals that this plant is rich in secondary metabolites such as polyphenols and alkaloids, which could explain its larvicidal activity.
Phyto-Extract-Based Weed Management in Organic Sweet Corn: A Comparative Analysis
Authors: Emmiganur Kiran , Matiwade, P. S.  , Sanadi Ummesalma , Goudra Shivanand , Shivashankar, K.
Published: February 2024

A field experiment was conducted during kharif 2020 and 2021 to study the weed management in organic sweet corn through phyto-extracts at the Main Agricultural Research Station, University of Agriculture Sciences, Dharwad, Karnataka. The experiment with randomized complete block design (RCBD) was laid out with fifteen treatments, comprises of four Phyto extracts of 30% concentration (Parthenium hysterophorus, Cassia sericea, Lantana camara and Prosopis juliflora) in combinations with directed spray of respective extract at pre-emergence, 20, 40 DAS fb one inter cultivation at 40 DAS fb hand weeding and another three treatments namely T13: inter-cultivation at 20 and 40 DAS fb one hand weeding at 20 DAS, T14: weedy check and T15: weed free check.   The pooled data of the experiment indicated that, inter-cultivation at 20 and 40 DAS and one hand weeding at 20 DAS recorded significantly higher the fresh cob yield (180.26 q ha-1), fresh fodder yield (341.66 q ha-1), net returns (Rs. 2,45,049 ha-1) and B:C ratio (4.16) with higher WCE as compared to other treatments. Among different phyto-extract treatments with time of application, directed spray of Parthenium hysterophorus at 30% leaf extract at 20 DAS and one inter-cultivation at 40 DAS followed by hand weeding recorded significantly higher the fresh cob yield (159.15 q ha-1), fresh fodder yield (315.13 q ha-1), net returns (Rs. 2,07,914 ha-1) and B:C ratio (3.66) with the higher WCE 80.40 and 68.76 per cent at 60 DAS and at harvest, respectively as compared to other phyto-extract treatments.
Evaluation of Different Gerbera Varieties for Vegetative Growth under Protected Environment
Authors: Raveena  , Malik Arvind , Dalal R. P. S. , Sharma Vikas Kumar , Divya
Published: February 2024

The vegetative growth of gerbera varieties (Szogun, Kormoran, Salsa and Feliks) was studied at Agri-Tourism Centre, CCS Haryana Agricultural University, Hisar during the year 2019-20 under different growing conditions. Among the varieties Szogan recorded maximum plant spread (74.95 cm) and leaf length (37.38 cm). Whereas, Salsa showed maximum number of leaves per plant (21.47), plant height (32.73 cm) and leaf width (14.68). While, comparing growing conditions plants grown under polyhouse produced maximum plant spread (68.55 cm), number of leaves (22.67), leaf length (35.85 cm) and leaf width (13.68 cm), whereas, maximum plant height (30.11 cm) was recorded in plants grown under shade net followed by polyhouse (29.08 cm).
Breeding for Bacterial Wilt Disease Resistance in Brinjal
Authors: Pandiyaraj P. , Singh T. H. , Pandav Ajay Kumar , Sreegayathri E. , Das Arindam , Mudhalvan S. , Jeyaprabha J.
Published: February 2024

Brinjal is a warm–season vegetable that belongs to the Solanaceae family. Among the biotic stresses of brinjal, bacterial wilt is a major disease caused by a soil-borne bacterium, Ralstonia solanacearum. Both cultural and chemical disease control methods are not effective due to the wide host range and prolonged spore survival periods in soil. In recent past, the use of resistant varieties and hybrids are recognized as the effective method to control bacterial wilt disease. Information on genetics of resistance to bacterial wilt disease is of prime importance for improvement of varieties and hybrids in brinjal. The bacterial wilt resistance response and resistance mechanisms are strictly based on the environmental conditions and cultivars. In traditional crop improvement methods, the development of varieties and hybrids is expensive and time consuming. The discovery of molecular marker systems increases the speed and precision for developing of varieties and hybrids with desired agronomic traits.
Isolation, Characterization, and Selection of Bacterial Endophytes from Soybean (Glycine max) Nodules and Roots in Some Soils of Cameroon for Promoting Growth of Forage Legume Plants
Authors: Bahdjolbe Marcelin , Sontsa-Donhoung Alain-Martial , Abdouraman Hawaou , Wade Abel , Tobolbaï Richard , Okiobe Simon Thierry , Nwaga Dieudonne
Published: February 2024

Aim: The present study aimed to isolate, characterize and select the most effective bacterial endophytes to enhance soybean growth, biomass, and yield.
Methodology: Seven soil samples were collected from the rhizosphere of forage legumes in fields across three agroecological zones of Cameroon. Bacterial endophytes were isolated from soybean roots and nodules and cultured on nutrient agar. The isolates were screened for the tolerance tests, extracellular enzymatic activity, P-solubilization activity, and IAA production. The best isolates were selected using a two-factor block factorial design. Each treatment was replicated six times.
Results: A total of 85 bacterial endophytes were isolated. Characterization results of 22 preselected isolates revealed an optimal growth temperature of 37°C and a pH range between 6 and 7. Furthermore, the 22 isolates solubilized inorganic phosphate, 7 produced IAA, and 8 exhibited amylase activity. PCR analysis of the nifH and nodC genes showed that the isolates possessed the nifH gene as a nitrogen fixation marker and the nodC gene as a nodulation marker. The findings show that, out of the 22 bacterial endophyte isolates, NTT1 and BOSH9 were the most effective in increasing plant height by 26.74% and 31.78%, respectively. Additionally, they resulted in an increase in biomass of 94.24% to 120.48% and an increase of 71.59% to 76.70% in grain yield compared to control treatment.
Conclusion: The selected isolates significantly enhance plant growth, increase biomass, and improve soybean grain yield. However, their potential use as biofertilizers in agriculture will require further investigation under real field conditions.
Sulfatasen: Struktur, Mechanismus, biologische Aktivität, Inhibition, Anwendung in Synthesen
Authors: Hanson Sarah R. , Best Michael D. , Wong Chi‐Huey
Published: October 2004

Sulfatasen – d. h. Sulfatester spaltende Enzyme – spielen eine entscheidende Rolle bei der Regulierung von Sulfatierungszuständen, die über die Funktion vieler physiologischer Moleküle entscheiden. Die Substrate der Sulfatasen reichen von kleinen cytosolischen Steroiden wie dem Östrogensulfat bis hin zu komplexen Kohlenhydraten auf Zelloberflächen, etwa den Glycosaminoglycanen. Die Umwandlung dieser Moleküle wurde mit wichtigen zellulären Funktionen in Verbindung gebracht, z. B. mit der Hormonregulation, dem zellulären Abbau und der Modulation von Signalisierungsprozessen. Sulfatasen hängen mit dem Ausbruch etlicher pathophysiologischer Erscheinungen zusammen, etwa mit hormonabhängigen Krebsformen. Bis heute sind zwar zahlreiche Sulfatasen identifiziert worden, die Aufklärung des weitreichenden Spektrums ihrer biologischen Aktivitäten befindet sich aber erst am Anfang. Dieser Aufsatz gibt einen Überblick über den derzeitigen Wissensstand zu den Strukturen, Mechanismen und der Inhibition von Sulfatasen.
Neue Terrasse Dresden
Authors: Fink Roland , Jentzsch Klaus‐Jürgen , Mathes Donald , Schäfer Christian , Wörzberger Ralf
Published: October 2004

Die Vedouten Canalettos dokumentieren, daß sich die Stadt Dresden trotz verheerender Zerstörungen durch den 2. Weltkrieg ihre einzigartige, unverwechselbare Silhouette bewahrt hat. Sie wird durch bedeutende Bauten aus verschiedenen Epochen entlang der Brühlschen Terrasse mit den anliegenden Gebäuden und der Semperoper mit dem sich anschließenden Landtagsneubau begrenzt. Das Kongreßzentrum schließt die Charakteristika der Stadtsilhouette mit seiner modernen Architektursprache in beeindruckender Weise ab.

Der Beitrag soll die ingenieurtechnischen Leistungen an diesem Gebäude verdeutlichen. Dazu werden sowohl die Konstruktion des Gebäudes, seine Gründung und die Probleme der unmittelbaren Flußnähe vorgestellt, als auch Lösungen für die weitgespannte und unterspannte geneigte Decke der Säle in fugenloser Bauweise erläutert. Weitere Schwerpunkte sind das Schwingungsverhalten unter der Erregersituation von Menschenansammlungen, die Verformungsbegrenzung und der Brandschutz.
Neufassung der Empfehlung Nr. 1 des Arbeitskreises “Versuchstechnik Fels” der Deutschen Gesellschaft für Geotechnik e. V.: Einaxiale Druckversuche an zylindrischen Gesteinsprüfkörpern
Authors: Mutschler Thomas
Published: October 2004

Der Arbeitskreis AK 3.3 “Versuchstechnik Fels” der Deutschen Gesellschaft für Geotechnik e. V. erarbeitet Empfehlungen für felsmechanische Laborversuche und Feldversuche sowie Messungen im Gebirge und an Bauwerken. Die vorliegende Neufassung der Empfehlung Nr. 1 behandelt den einaxialen Druckversuch an Gesteinsprüfkörpern und berücksichtigt die Weiterentwicklungen der Prüfmaschinen‐ und Versuchstechnik seit der gleichnamigen Empfehlung Nr. 1 von 1979. Es werden die Anforderungen an die Prüfeinrichtung und die Prüfkörper sowie die Vorgehensweisen für die Durchführung und Auswertung von einaxialen Druckversuchen festgelegt. Wesentliche Neuerungen bestehen in Optionen, die es ermöglichen, das Verformungsverhalten im Vorbruch‐Bereich in reversible (elastische) und irreversible (anelastische) Anteile zu trennen und das Nachbruch‐Verhalten zu erfassen. Die häufigsten Anwendungsfälle werden mit 12 Standard‐Versuchsoptionen abgedeckt.
Cellular stiffness response to external deformation: Tensional homeostasis in a single fibroblast
Authors: Mizutani Takeomi , Haga Hisashi , Kawabata Kazushige
Published: October 2004

Stiffness responses of fibroblasts were measured by scanning probe microscopy, following elongation or compression by deformation of an elastic substrate by 8%. The cellular stiffness, reflecting intracellular tension acting along stress fibers, decreased or increased instantly in response to the elongating or compressing stimuli, respectively. After this rapid change, the fibroblasts gradually recovered to their initial stiffness during the following 2 h, and then stabilized. The cells did not show conspicuous changes in shape after the 8% deformation during the SPM measurements. Fluorescence examination for GFP‐actin demonstrated that the structure of the stress fibers was not altered noticeably by this small degree of deformation. Treatment with Y‐27632, to inhibit myosin phosphorylation and abrogate cellular contractility, eliminated the change in stiffness after the mechanical elongation. These results indicate that fibroblasts possess a mechanism that regulates intracellular tension along stress fibers to maintain the cellular stiffness in a constant equilibrium state. Cell Motil. Cytoskeleton 59:242–248, 2004. © 2004 Wiley‐Liss, Inc.
Boundary layers for cellular flows at high Péclet numbers
Authors: Novikov Alexei , Papanicolaou George , Ryzhik Lenya
Published: October 2004

We analyze the behavior of solutions of steady advection‐diffusion problems in bounded domains with prescribed Dirichlet data when the Péclet number Pe ≫ 1 is large. We show that the solution converges to a constant in each flow cell outside a boundary layer of width O(ϵ1/2), ϵ = Pe−1, around the flow separatrices. We construct an ϵ‐dependent approximate “water pipe problem” purely inside the boundary layer that provides a good approximation of the solution of the full problem but has ϵ‐independent computational cost. We also define an asymptotic problem on the graph of streamline separatrices and show that solution of the water pipe problem itself may be approximated by an asymptotic, ϵ‐independent problem on this graph. Finally, we show that the Dirichlet‐to‐Neumann map of the water pipe problem approximates the Dirichlet‐to‐Neumann map of the separatrix problem with an error independent of the flow outside the boundary layers. © 2004 Wiley Periodicals, Inc.
Probing Ligand–Protein Recognition with Sum‐Frequency Generation Spectroscopy: The Avidin–Biocytin Case
Authors: Dreesen Laurent , Sartenaer Yannick , Humbert Christophe , Mani Alaa A. , Méthivier Christophe , Pradier Claire‐Marie , Thiry Paul A. , Peremans André
Published: October 2004

Infrared/visible sum‐frequency generation (SFG) spectroscopy is used to study the recognition of a protein (avidin) by a derived vitamin (biocytin) adsorbed on a calcium fluoride substrate. The specificity of the process is tested by replacing avidin with bovine serum albumin or presaturated avidin. The SFG spectroscopy shows drastic modifications in the CH and NH spectral ranges only upon exposure of the biocytin film to avidin. The comparison of the SFG data with Fourier transform infrared reflection absorption spectra (FT‐IRRAS) in the same spectral ranges illustrates the advantages of nonlinear spectroscopy for studying and detecting recognition between biomolecules.
Reaction of Mercury(0) with the I2 Adduct of Tetraphenyldithioimidodiphosphinic Acid (SPPh2)2NH (HL) − Crystal Structures of [Hg(HL)I2] and HgL2
Authors: Aragoni M. Carla , Arca Massimiliano , Carrea M. Bonaria , Demartin Francesco , Devillanova Francesco A. , Garau Alessandra , Isaia Francesco , Lippolis Vito , Verani G.
Published: October 2004

The complex [Hg(HL)I2] (1) has been synthesised by reacting liquid Hg(0) in Et2O under mild reaction conditions with the I2 adduct of HL, HL·I2, while HgL2 (2) has been obtained from the reaction of compound 1 with HL in CH3CN. A single‐crystal X‐ray investigation of 1 shows four independent molecules in the asymmetric unit, each of which contains an HgII ion coordinated to two iodine atoms and two sulfur atoms of one bidentate neutral ligand in a distorted tetrahedral coordination geometry. Compound 2 consists of two anionic ligands coordinated to an HgII ion, which again displays a distorted tetrahedral coordination sphere. The reaction of 2 with HI (55 wt.‐% in water) affords [Hg(HL)2](I)2 (3). Compounds 1, 2, and 3 have been characterised by FT‐IR and 31P NMR spectroscopy. Density functional calculations suggest that compound 3 should feature a distorted tetrahedral coordination around the metal centre, with unequal Hg−S bond lengths. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Triiron Complex Containing the Carboxylate‐Free {Fe3(μ3‐O)}7+ Core and Distorted Pentagonal‐Bipyramidal Metal Centres
Authors: Sreerama Subramanya Gupta , Pal Samudranil
Published: October 2004

The reaction of Fe(ClO4)3·6H2O, 1,2‐bis(biacetylmonoximeimino)ethane (H2bamen) and triethylamine (1:1:2 mol ratio) in methanol affords a trinuclear complex with the formula [Fe3(μ3‐O)(μ3‐bamen)3]ClO4·2H2O. The structure of the complex cation in this species shows a symmetric planar central {Fe3(μ3‐O)}7+ unit coordinated to three N4O2 donor bridging (via oximate groups) ligands (bamen2−). The N4O3 coordination sphere around each metal centre is very close to pentagonal‐bipyramidal. Four N atoms of one bamen2− and the oxo group satisfy five coordination sites and form a pentagonal plane around the metal ion. The axial sites are occupied by two oximato O atoms from the other two bamen2− ligands. Thus, in addition to the μ3‐oxo group, two oximate groups provide two additional bridges between each pair of metal centres. In the crystal lattice, the water molecules exist as hydrogen‐bonded dimers and these water dimers together with the perchlorate ions form a hydrogen‐bond‐supported helix. The complex cations form a chain via C−H···O interactions involving a methyl group and a metal‐coordinated oximato O atom. The helix of {(H2O)2ClO4−} units and the chain of [Fe3O(bamen)3]+ cations are connected by O−H···O interactions which involve a water molecule and a second oximato O atom. In its cyclic voltammogram, the complex displays metal‐centred oxidation as well as reduction responses. Variable‐temperature magnetic susceptibility measurements revealed the presence of an antiferromagnetic interaction [J = −41.0(2) cm−1] between the FeIII centres in this complex. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Kinetic Study on the Reactions of Azolato‐Bridged Dinuclear Platinum(II) Complexes with Guanosine 5′‐Monophosphate
Authors: Komeda Seiji , Yamane Hirotoshi , Chikuma Masahiko , Reedijk Jan
Published: October 2004

By using 1H NMR spectroscopy the reactions of [{cis‐Pt(NH3)2}2(µ‐OH)(µ‐pz)](NO3)2 (1), [{cis‐Pt(NH3)2}2(µ‐OH)(µ‐1,2,3‐ta‐N1,N2)](NO3)2 (2) and [{cis‐Pt(R,R‐dach)}2(µ‐OH)(µ‐pz)](NO3)2 (3) with guanosine 5′‐monophosphate (GMP) were monitored spectroscopically in 0.1 M phosphate D2O solutions at three different pD values (5.4, 6.9, 8.4). From the investigations some kinetic information was obtained. The reaction rate for all these complexes become higher when the pD decreases. In addition, for the reactions performed in unbuffered solutions (pD 8.2), the reactivity of all the complexes for GMP was found to increase dramatically. The 1:2 reaction products were characterized by 1H, 195Pt, and 31P NMR spectroscopy. Reactions of 2 with GMP include an unusual ligand‐binding isomerization, resulting from the Pt atom migration along the 1,2,3‐triazolato ring. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Electrochemical detector based on sol‐gel‐derived carbon composite material for capillary electrophoresis microchips
Authors: Sun Xiuhua , Yan Jilin , Yang Xiurong , Wang Erkang
Published: October 2004

An on‐chip disk electrode based on sol‐gel‐derived carbon composite material could be easily and reproducibly fabricated. Unlike other carbon‐based electrodes reported previously, this detector is rigid, convenient to fabricate, and amenable to chemical modifications. Based on the stable and reproducible characters of this detector, a copper particle‐modified detector was developed for the detection of carbohydrates which extends the application of the carbon‐based electrode. In our experiments, the performance of the new integrated detector for rapid on‐chip measurement of epinephrine and glucose was illustrated. Experimental procedures including the fabrication of this detector, the configuration of separation channel outlet and electrode verge, and the performance characteristics of this new electrochemical detector were investigated.
Chemical analysis of raw, dry‐roasted, and honey‐roasted licorice by capillary electrophoresis
Authors: Sung Michael W. , Li Paul C. H.
Published: October 2004

In herbal medicine, licorice is usually processed using a roasting procedure which might modify the chemical compositions in licorice. To test this hypothesis, licorice root samples were roasted under various conditions (with or without honey) and subsequently extracted by refluxing with 95% ethanol. The analysis of chemical compositions of licorice root extracts was achieved by capillary electrophoresis. The running buffer has been optimized to be 50 mM sodium tetraborate (pH 9.01) containing 5 mM β‐cyclodextrin. Thermal decomposition of glycyrrhizin, which was a major ingredient in licorice, was first studied in detail, indicating the conversion of glycyrrhizin to glycyrrhetinic acid. The licorice extracts were then analyzed to indicate the above thermal conversion did occur in the licorice samples. This finding may shed some light on understanding the differences in the therapeutic values of raw versus roasted licorice in herbal medicine.
Direct automatic determination of biogenic amines in wine by flow injection‐capillary electrophoresis‐mass spectrometry
Authors: Santos Bricio , Simonet Bartolomé M. , Ríos Angel , Valcárcel Miguel
Published: October 2004

A capillary electrophoresis‐electrospray mass spectrometry (CE‐ESI‐MS) method for the separation and determination of nine biogenic amines is proposed. Operational variables, such as the voltage, temperature, sheath liquid composition, flow‐rate, and MS parameters, were optimized. Samples are injected in the hydrodynamic mode into a 75 cm×50 μm ID coated capillary and separated by using 25 mM citric acid at pH 2.0. Heptylamine is used as internal standard. The experimental setup includes a flow manifold coupled to the CE system for automatic insertion of samples into the CE vials. The proposed method allows amines to be determined with limits of detection from 0.018 to 0.09 μg·mL‐1 and relative standard deviation (RSD) values from 2.4% to 5.0% (except 6.8% for histamine). The method was successfully used to determine biogenic amines in red and white wines.
Catching protein antigens by antibody affinity electrophoresis
Authors: Lee Bao‐Shiang , Gupta Shalini , Krisnanchettier Sangeeth , Lateef Syed S.
Published: October 2004

A new kind of affinity electrophoresis called antibody affinity electrophoresis is a technique used to capture protein antigens based on their interactions with specific monoclonal or polyclonal antibodies incorporated in the polyacrylamide gel. Polyclonal anti‐glutathione‐S‐transferase (anti‐GST), monoclonal anti‐bovine serum albumin (anti‐BSA), and polyclonal anti‐human α‐lactalbumin are embedded in distinct areas of a 7.5% native polyacrylamide gel. Some of the embedded antibodies get covalently and/or noncovalently incorporated into the gel matrix network. Under electrophoresis conditions, these antibodies do not show significant electrophoretic mobility, as compared to their specific protein antigen analytes. We observed that electrophoretic migration of GST, BSA, and protein G ceases when they encounter anti‐GST, anti‐BSA, and immunoglobulin G, respectively.
Determination of some acidic drugs in surface and sewage treatment plant waters by capillary electrophoresis‐electrospray ionization‐mass spectrometry
Authors: Macià Alba , Borrull Francesc , Calull Marta , Aguilar Carme
Published: October 2004

We describe an analytical method involving solid‐phase extraction (SPE) and capillary zone electrophoresis‐electrospray ionization‐mass spectrometry (CZE‐ESI‐MS) for determining some pharmaceutical compounds – naproxen, clofibric acid and bezafibrate – in real water samples. The electrospray parameters were optimized to maximize sensitivity. When a mixed aqueous‐organic solvent and CZE‐ESI‐MS were used to analyze these drugs in water samples, the capillary was coated with hexadimethrin bromide (HDB) to permanently reverse the EOF. The method was developed from off‐line SPE‐CZE‐MS and was validated with surface water. The detection limits were 100 ng·L‐1 for all analytes. The method was applied to analyze water samples from the influent and effluent of a sewage treatment plant. A liquid‐liquid extraction step was required before SPE, and the compounds studied were found, some of them between detection and quantification limits.
Electrophoretic separation of amyloid β peptides in plasma
Authors: Lewczuk Piotr , Esselmann Hermann , Bibl Mirko , Paul Sabine , Svitek Jana , Miertschischk Johannes , Meyrer Robert , Smirnov Alexandr , Maler Juan Manuel , Klein Christian , Otto Markus , Bleich Stefan , Sperling Wolfgang , Kornhuber Johannes , Rüther Eckhard , Wiltfang Jens
Published: October 2004

In this prospective study, for the first time we have separated and quantified amyloid β (Aβ) peptides in the plasma of patients with Alzheimer's disease (AD, n = 8) and age‐ and environment‐matched healthy controls (n = 9) with urea‐based Aβ‐sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE)/immunoblot. In addition to the Aβ peptides 1–37/38/39/40/42, which we recently identified as regular constituents of human cerebrospinal fluid (CSF), we have observed a novel electrophoretic band migrating slightly cathodically to Aβ1–42. Since a standard peptide with the amino acid sequence Aβ2–40 migrates in the same position, we hypothesize that this plasma‐specific band may correspond to Aβ2–40. The concentration of Aβ peptides in the plasma has been approximately 100‐fold lower compared to the CSF. Interestingly, the concentration of the two shortest peptides and the longest one of these considered here (i.e., Aβ1–37/38/42) have increased significantly when the samples have been frozen at –80°C before immunoprecipitation, while the ‘middle‐length' peptides (i.e., Aβ1–39/40) have not been affected by this procedure. We have not observed significant differences of the Aβ peptides concentrations between AD and control subjects. Our method can be used to investigate the significance of plasma Aβ peptides in neurodegenerative disorders, and to monitor the efficiency of drugs with β/γ‐secretase inhibitory potency.
Quantitative measurement of collagen methylation by capillary electrophoresis
Authors: Zhang Jing , Wei Hong‐Ping , Quek Chai‐Hoon , Chia Ser‐Mien , Yu Hanry
Published: October 2004

Collagen methylation has been exploited in various applications involving living cells. We have observed correlation between the collagen methylation with the rate of cell proliferation in three‐dimensional (3‐D) microenvironment. To quantify the degree of collagen methylation, we have developed a capillary zone electrophoresis method. Using a polyvinyl alcohol‐coated fused‐silica capillary and UV detection at 200 nm, we have optimized pH and separated the native collagen into three major bands in phosphate buffer (50 mM, pH 2.5) with 0.05% hydroxypropylmethylcellulose. Under these conditions, the methylated collagens were separated into four major bands, which changed with different methylation reaction conditions. We propose an index to quantify the degree of collagen methylation that also correlates with their effects on cell proliferation.
High‐speed DNA sequencing by tube‐based capillary electrophoresis
Authors: Sakai Tomoyuki , Sonehara Tsuyoshi , Goda Chifumi , Kohara Yoshinobu , Anazawa Takashi
Published: October 2004

We assessed the feasibility of high‐speed DNA sequencing by tube‐based capillary electrophoresis (TCE) with electrokinetic sample injections. We developed a water‐circulated TCE system to control the capillary temperature precisely. Using this system and a ready‐made sieving matrix at 50°C, single‐stranded DNA size marker fragments were separated at various pairs of the electric field strength, E, of 128–480 V/cm and the capillary effective length, L, of 100–360 mm. Assuming the read length (RL) is the fragment size at which the peak width equals the peak interval per base in obtained electropherograms, we estimated the values of RL (E, L), the RL at the pair (E, L). The points in ELz‐space, (E, L, RL(E, L)), form a curved surface expressed by z = RL(E, L). Analyzing the contour lines of this curved surface, we determined the pairs of E and L providing target RLs of 300–500 bases within a minimum time. At a pair optimized for a 500‐base RL (330 V/cm, 200 mm), one‐color sequencing fragments were successfully separated up to 529 bases within 9.6 min. These results demonstrate that high‐speed DNA sequencing comparable with that obtained by microfabricated chip‐based capillary electrophoresis (MCE) can be achieved with TCE, which is more suitable in automation than MCE.