bluuebunny/crossref_metadata_2025 huggingface dataset:
Polytene chromosomes of Chironomidae (Diptera) as a bioassay of trace-metal-induced genome instability
Authors: Michailova Paraskeva Vladimirova , Sella Gabriella , Petrova Ninel
Published: October 2012

Chironomids are a ubiquitous group of aquatic insects that are very sensitive to environmental stress. Due to the presence of polytene (‘giant’) salivary gland chromosomes, it is possible to define the genome response of several Chironomid species to various stress agents. The aim of this study was to assess the genotoxic changes in populations of widely distributed chironomid species from aquatic basins in Bulgaria, Italy, Russia, U.K. and Poland, which were exposed to high concentrations of trace metals. We analyzed the structural and functional alterations of polytene chromosomes of the salivary glands of larvae belonging to three different cytocomplexes of the genus Chironomus (“thummi”, “lacunarius”, “pseudothummi”), and genera Glyptotendipes and Kiefferulus. Somatic structural chromosome rearrangements (para- and pericentric heterozygous inversions, deletions, deficiencies and amplifications) were used to estimate a Somatic index (S) for each population. The highest S indexes were detected in Chironomus riparius populations from locations with high concentrations of trace metals in the sediment. Each species showed specific genome responses to stress agents which we discussed in the light of the specific DNA structures and cytogenetic characteristics of the species. In larvae from polluted sediments two key structures of the salivary gland chromosomes (Balbiani Rings and Nucleolar Organizer) sharply reduced their activity to levels below those observed under non-polluted conditions. It is concluded that polytene chromosomes can be used as tools for evaluating the genotoxicity of the aquatic environment. Structural and functional chromosome alterations provide cost-effective early-warning signals of genotoxic concentrations of environmental pollutants.doi: 10.5324/fn.v31i0.1355.Published online: 17 October 2012.
New species of Paratanytarsus Thienemann & Bause 1913 (Diptera: Chironomidae) from the Mediterranean Region (Corsica, southern France and Lebanon)
Authors: Moubayed-Breil Joel , Ashe Patrick , Langton Peter H
Published: October 2012

Three new species of Paratanytarsus are described, from Corsica, southern France and Lebanon, based on the adult males and associated pupal exuviae. These descriptions increase the number of western Palaearctic species in the genus to 23. The pupal exuviae of the new species resemble those of P. bituberculatus (Edwards). Main diagnostic characters as well as additional illustrations of P. bituberculatus are also presented. Characters are given for distinguishing the adult males and the pupal exuviae from other related species. A key to the adult males and pupal exuviae of the described species is provided.doi: 10.5324/fn.v31i0.1372.Published online: 17 October 2012.
Rheotanytarsus dactylophoreus, a new mountain species from streams in the Eastern Pyrenees and Corsica (Diptera: Chironomidae)
Authors: Moubayed-Breil Joel , Langton Peter H , Ashe Patrick
Published: October 2012

The description of Rheotanytarsus dactylophoreus sp. nov. is based on adult males, pharate males and pupal exuviae collected in low and middle mountain streams located in the Eastern Pyrenees and Corsica is presented. The most distinctive character in the adult male is the unusually long, finger-like, digitus and in the pupal exuviae is the thoracic horn which is spinulate laterally (extending from swollen base into tapered apical half). The distribution of R. dactylophoreus sp. nov. indicates that this pyreneocorsican species is a Tyrrhenian faunal element which spread westwards to mountain streams of the Eastern Pyrenees perhaps during the repeated waves of migration from the Paleocene (Montian) till the late Miocene.doi: 10.5324/fn.v31i0.1375.Published online: 17 October 2012.
Time-Efficiency of Sorting Chironomidae Surface-Floating Pupal Exuviae Samples from Urban Trout Streams in Northeast Minnesota, USA
Authors: Anderson Alyssa M , Ferrington Leonard C
Published: October 2012

Collections of Chironomidae surface-floating pupal exuviae (SFPE) provide an effective means of assessing water quality in streams. Although not widely used in the United States, the technique is not new and has been shown to be more cost-efficient than traditional dip-net sampling techniques in organically enriched stream in an urban landscape. The intent of this research was to document the efficiency of sorting SFPE samples relative to dip-net samples in trout streams with catchments varying in amount of urbanization and differences in impervious surface. Samples of both SFPE and dip-nets were collected from 17 sample sites located on 12 trout streams in Duluth, MN, USA. We quantified time needed to sort subsamples of 100 macroinvertebrates from dip-net samples, and less than or greater than 100 chironomid exuviae from SFPE samples. For larger samples of SFPE, the time required to subsample up to 300 exuviae was also recorded. The average time to sort subsamples of 100 specimens was 22.5 minutes for SFPE samples, compared to 32.7 minutes for 100 macroinvertebrates in dip-net samples. Average time to sort up to 300 exuviae was 37.7 minutes. These results indicate that sorting SFPE samples is more time-efficient than traditional dip-net techniques in trout streams with varying catchment characteristics.doi: 10.5324/fn.v31i0.1380.Published online: 17 October 2012.
A review of Tsudayusurika Sasa, 1985 (Diptera: Chironomidae, Orthocladiinae), with the description of a new species
Authors: Yamamoto Masaru , Yamamoto Nao
Published: October 2012

Tsudayusurika Sasa, 1985 is reviewed based on material from Taiwan and Japan. This orthocladiine genus is characterized by having a female antenna with 10 flagellomeres and large and rhombic cerci. The male antenna has 13 flagellomeres and the anal point is transparent, short and prominently wide. Tsudayusurika fudosecunda Sasa, the type species of the genus, and T. multiannulata (Tokunaga) are redescribed. A new species, T. suginoi, from Okinawa Island is described and figured as male and female. Kuroyonyusurika Sasa, 1996 is presented as a new junior synonym of Tsudayusurika and the type species K. kuroheius is transferred to this genus and redescribed. Tsudayusurika cladochaita Wang and T. yufunivea (Sasa et Suzuki) are removed from Tsudayusurika and tentatively placed in Bryophaenocladius. doi: 10.5324/fn.v31i0.1401. Published online: 17 October 2012.
Chironomidae of semiaquatic lake shore habitats in the Karelian Isthmus (northwestern Russia)
Authors: Przhiboro Andrey , Paasivirta Lauri
Published: October 2012

Shores of lentic waters are poorly studied as habitats of Chironomidae. We investigated floating shore marsh surrounding the lakes Bol’shoe Rakovoe (Äyräpäänjärvi or Eteläjärvi) and Okhotnich’e (Muolaanlampi), shallow mesotrophic wetlands in the Karelian Isthmus. Our research aimed to identify species structure of immature chironomid assemblages in this peculiar habitat and to provide their quantitative assessment. Five sites of the water margin zone (a 20-m part of floating marsh adjoining the lake littoral) were studied using two techniques, quantitative samples taken with a grab-net and laboratory rearings of adults from substrata. Thirty-two samples were taken in July and October; 2970 emerging chironomid adults were identified. Nineteen species were found, 3 of Tanypodinae, 10 of Orthocladiinae and 6 of Chironominae. Tavastia yggdrasilia, Thienemanniella minuscula and Polypedilum trigonus are first recorded from Russia, and 8 more species, from NW Russia. Orthocladiinae accounted for over 99% emerging adults, with 3 species predominant and numerous on all sites, Paraphaenocladius impensus, Limnophyes minimus and L. natalensis. Species structure is discussed and compared with the data on similar habitats. Chironomid larvae were most numerous macroinvertebrates. Mean abundance of chironomid immatures varied from 1246 to 32060 ind./m2, mean biomass, 0.104 to 3.591 g(wet weight)/m2, depending on site and season. In July, Chironomidae comprised 3-15% of Diptera biomass and 1-5% of macroinvertebrates biomass; in October, 13-49% and 7-20%, respectively.doi: 10.5324/fn.v31i0.1410.Published online: 17 October 2012.
Phenotypic and genetic variation within the Cricotopus sylvestris species-group (Diptera, Chironomidae), across a Nearctic - Palaearctic gradient
Authors: Gresens Susan , Stur Elisabeth , Ekrem Torbjorn
Published: October 2012

Intraspecific variation sometimes obscures species boundaries and makes identification of certain Chironomidae difficult. This is true for many species in the genus Cricotopus. We used DNA barcode data and multivariate statistical analyses to investigate which phenotypic characters in populations of the Cricotopus sylvestris species-group are useful for species identification. Specimens collected across a broad latitudinal range from the Southwest United States through subarctic Canada to northern Norway formed nine distinct barcode clusters. Body size of adult flies decreased by 51% from the northern to southernmost populations. Meristic characters in wings and legs were strongly related to overall body size, and related morphometric ratios were not species specific. Antennal ratio increased significantly with body size, thus limiting its value in species delimitation. Non-metric ordinations of setal and coloration pattern data were characteristic for most species in the sylvestris-group. DNA barcode data worked well in separating morphologically different populations, except for the case of C. (I.) sylvestris and C. (I.) trifasciatus, which were distinguished by ordination of color pattern, but not by barcoding data. These two species appeared closely related, and we conclude that sequence data from neutral nuclear markers will be necessary to determine if these are genetically distinct species, or whether there is merely a high level of environmental plasticity in pigmentation within this geographically widespread barcode cluster.doi: 10.5324/fn.v31i0.1417.Published online: 17 October 2012.
Critical Analysis of Esophageal Multichannel Intraluminal Impedance Monitoring 20 Years Later
Authors: Herbella Fernando A. M.
Published: October 2012

Multichannel intraluminal impedance (MII) for the evaluation of esophageal diseases was created in 1991 trying to solve previous limitations of esophageal function test. MII-pH is able to determine the physical characteristics of the refluxate (liquid, gas, or mixed) and nonacidic GER. MII-manometry can determine the presence of bolus and its relation with peristalsis. This paper makes a critical analysis of the clinical applications of MII 20 years after its creation. Literature review shows that MII made great contributions for the understanding of esophageal physiology; however, direct clinical applications are few. MII-pH was expected to identify patients with normal acid reflux and abnormal nonacidic reflux. These patients are rarely found off therapy, that is, nonacidic reflux parallels acid reflux. Furthermore, the significance of isolated nonacidic reflux is unclear. Contradictory MII-manometry and conventional manometry findings lack better understanding and clinical implication as well as the real significance of bolus transit.
Rheumatological Findings in Candidates for Valvular Heart Surgery
Authors: Owlia Mohammad Bagher , Mirhosseini Seyed Jalil , Naderi Nafiseh , Mostafavi Pour Manshadi Seyed Mohammad Yousof , Ali Hassan Sayegh Sadegh
Published: October 2012

Background and Objectives. Valvular heart diseases are among the frequent causes of cardiac surgery. Some patients have a well-known rheumatic condition. Heart valves are fragile connective tissues which are vulnerable to any systemic autoimmune diseases. This study was designed to evaluate the frequency of rheumatological background in patients candidate for valvular heart surgery in Afshar Cardiovascular Center, Yazd, Iran. Methods. One hundred and twenty (120) patients candidate for valvular heart surgery were selected for this study. Careful history and physical examination were undertaken from rheumatological stand points. The most sensitive screening serologic tests were also assayed. Results. The result of this study showed that 53.3% were male and 46.6% were female with mean age of years old. 45.8% of the patients had history of nonmechanical joint disease, 14.2% had history of rheumatological conditions in their family, and 30% had history of constitutional symptoms. 29.8% had positive joint dysfunction findings in their physical examination while 25.8% had anemia of chronic disease. Positive Rheumatoid factor (RF), anticyclic citrullinated peptide (CCP, ACPA), C-reactive protein (CRP), antinuclear antibody (ANA), abnormal urine and elevated erythrocyte sedimentation rate (ESR) were 34, 2.5, 26.7, 4.2, 5, and 36.7%, respectively. Antineutrophil cytoplasmic antibody (ANCA) and antiphospholipid (APL) were positive in a few cases. Conclusion. The findings of this study show immunologic bases for most patients with valvular heart diseases candidate for surgery. Undifferentiated connective tissue diseases may play an important role in the pathophysiology of valvular damage.
Association between Taste Sensitivity and Self-Reported and Objective Measures of Salt Intake among Hypertensive and Normotensive Individuals
Authors: Piovesana Paula de Moura , Sampaio Karina de Lemos , Gallani Maria Cecília B. J.
Published: October 2012

This study investigated the gustatory threshold for salt and its relationship with dietary salt intake among hypertensive (n=54) and normotensive (n=54) subjects. Salt intake was evaluated through 24-hour urinary sodium excretion and self-reported measures (discretionary salt, Sodium- Food Frequence Questionnaire (Na-FFQ), and 24-hour recall). Detection and recognition thresholds were higher among hypertensive subjects, as well as the total sodium intake. Detection and recognition thresholds were positively related to discretionary salt and total intake of the group as whole. Hypertensive and normotensive subjects presented positive correlations between taste sensitivity and the different measures of salt intake. To conclude, a positive correlation exists between taste threshold and salt intake and both seem to be higher among hypertensive subjects. The combined use of methods of self-report and assessment of taste thresholds can be useful in health promotion and rehabilitation programs, by screening subjects at higher risk of elevated salt intake and the critical dietary behaviors to be targeted as well to evaluate the result of targeted interventions.
Meta-Analysis of the Hemodynamic Properties of Antihypertensive Medications
Authors: Iftikhar Imran Hasan , Blankfield Robert P. , Hassan Nauman , Tisch Daniel
Published: October 2012

Background. While all antihypertensive medications lower blood pressure, hemodynamic properties of various classes of antihypertensive medications may differ.
Objective. To perform a meta-analysis to compare the hemodynamic properties of different classes of antihypertensive medications.
Methods. Studies involving the treatment of hypertension using the effect of ACEIs, β-blockers, CCBs and thiazide diuretics on plasma volume (PV), cardiac output (CO) or stroke volume (SV) were searched using online databases prior to May 2011. Studies had to be written in the English language, studying human subjects with a single pharmacological agent (monotherapy), and with a minimum duration of 4 weeks.
Results. Seventy-five (75) studies that enrolled a total of 1522 subjects were included. All four antihypertensive classes lowered blood pressure. β-blockers decreased heart rate; the other classes had no effect upon heart rate. ACEIs increased PV; the other classes had no effect upon PV. β-blockers and thiazide diuretics decreased CO while ACEIs and CCBs had no effect upon CO. β-blockers and CCBs increased SV, thiazide diuretics decreased SV, and ACEIs did not change SV. Conclusion. In the treatment of uncomplicated hypertension, the various classes of antihypertensive medications differ from each other in terms of their non-blood pressure lowering hemodynamic properties.
Comprender la movilidad en la Unión Europea ampliada: discursos de los inmigrantes rumanos en España
Authors: Marcus Silvia
Published: October 2012

El artículo analiza el proceso de comprensión de movilidad de los ciudadanosrumanos en España. El trabajo plantea tres niveles de análisis que responden atres preguntas de investigación: cómo negocian los inmigrantes su movilidad,cuáles son sus experiencias de movilidad y cómo comprenden su proceso demovilidad. Para la realización del estudio se utilizó el método cualitativo de lasentrevistas en profundidad llevadas a cabo, tanto en origen como en destino.Los niveles de análisis se organizaron de la siguiente manera: la negociaciónse vincula a consideraciones de tipo práctico; las experiencias de movilidadvienen acompañadas por el retorno parcial, y la comprensión del procesomigratorio se refl eja en el sentido de lugar e identidad fl exible. Los niveles deanálisis interactúan y ayudan a buscar formas de asimilar la movilidad y lacreación del ciudadano móvil en el entramado europeo.
Experiencia y rearticulación identitaria en mujeres españolas convertidas al Islam
Authors: Madonia Salvatore
Published: October 2012

Este artículo analiza la capacidad de rearticulación y redefiniciónidentitaria desarrollada por parte de mujeres convertidas al Islam. La adopción de una perspectiva teórica comprometida con los feminismos contemporáneos permite superar los límites conceptuales de algunos estudios sobre las conversiones. Unos estudios que, dentro de la tradición funcionalista, focalizan el análisis en un genérico «objeto» mujer que relega a mero epifenómeno sus capacidades interpretativas subjetivamente desarrolladas. Sin embargo, la atención a algunos«sujetos» mujeres conversas permite describir la performatividad y la originalidad desplegadas en la construcción de sus identidades religiosas. La conversión se muestra por tanto como un proceso complejo, múltiple y continuo que supone una progresiva construcción de sentido en un contexto sociocultural, el europeo, en el cual no existetodavía una visión determinada del ser musulmana.
Valores postmaterialistas y aprendizaje político adulto. El cambio de valores intracohorte en Europa Occidental
Authors: Tormos Raül
Published: October 2012

La investigación sobre estabilidad y cambio de valores tiende asubrayar la importancia de los efectos generacionales, siendo la teoríadel postmaterialismo de Inglehart un ejemplo de ello. En su teoría, lasexperiencias formativas confi guran los valores de cada cohorte deedad, y el cambio social tiene lugar de forma gradual mediante elreemplazo generacional. En este artículo se analizan datos de encuestasque abarcan un período de tiempo más amplio que el que utilizóInglehart para sacar sus conclusiones. Aplicando técnicas de seriestemporales se identifi can cambios relevantes en cada generación a lolargo del tiempo. Se demuestra que ha tenido lugar un importanteproceso de aprendizaje adulto en el ámbito de los valores postmaterialistas,obviado en la literatura empírica. Contradiciendo a Inglehart, seconcluye que los efectos del período no son sólo de carácter menor ycortoplacista, sino que toman la forma de una tendencia sistemática detipo intracohorte. Esta tendencia se vincula a la creciente prosperidadeconómica europea de las últimas décadas.
First Records of Potamic Leech Fauna of Eastern Siberia, Russia
Authors: Kaygorodova Irina A. , Dzyuba Elena V. , Sorokovikova Natalya V.
Published: October 2012

We studied the fauna of leech and leech-like species inhabiting main water streams of Eastern Siberia and its tributaries, which are attributed to Lake Baikal basin and Lena River basin. Here we present their list for the first time. This study was mainly aimed for free-living parasitic and carnivorous leeches whereas piscine parasites were not included specially. In total, the potamic leech fauna of Eastern Siberia includes 12 described species belonging to 10 genera. Representatives of three unidentified species of two genera Erpobdella and Barbronia have been also recorded.
Varieties and the Issue of Standards: How Should English be Taught in a Global Community?
Authors: Florendo Maria Rosario Y.
Published: October 2012

As language policies for basic and tertiary education in the Philippines vacillate between the preservation, promotion and use of first and native languages of students and the enhancement of English as a Second Language, language teachers are put in a dilemma. While sound language theories dictate that it is more productive to teach content courses in the students’ native tongue, the Department of Education’s language policy says otherwise. Further, while English language courses are still taught with emphasis on structure and form with Standard British or American English as models, outside, the native Philippine Variety of English is actually used. Although many young Filipinos today are raised speaking English as their first language, the variety too that they actually learn is native. The Philippines has also been a popular destination for other Asians who want to learn English (EFL). Learning from Filipino teachers would eventually result to the further spread, not of the Inner Circle variety, but the Philippine Variety of English. Thus, there is a need to reevaluate how English is actually taught and re-assess the standards of evaluation of students’ performance. Keywords - Teaching English, Standards, Models, Varieties/Variations, Multilingua l
Attitude of A-Level Medicine (ALM) Students towards Learning the Mathematical Subjects
Authors: Mahad Nor Faradilah , Abdullah Fathiah , Kadir Siti Aisyah Abdul
Published: October 2012

This research is conducted to study the attitude of A-level Medicine (ALM) students towards learning the Mathematical subjects and there are two research questions in the study. Firstly, what is the attitude of ALM students towards learning the Mathematical subjects? Secondly, is there any difference between male students’ attitude and female students’ attitude towards learning the Mathematical subjects? The sampling method used in this research is random sampling. The researchers selected the survey method as the research design and one set of questionnaires consisted of 30 items as the instruments. Some 95 respondents consist of 37 male students and 58 female students of ALM programmed of International Education College (INTEC) were chosen randomly. The researchers used the 5 point Liker Scale in order to determine the attitude of the ALM students towards learning the Mathematical subjects. The data were analyzed by using mean test, one sample t-test and independent t-test by using SPSS version 20 software. The finding showed that the students have positive attitude towards learning the Mathematical subjects and there is difference between male students’ attitude and female students’ attitude towards learning the Mathematical subjects. The finding showed that female students have more positive attitude than the male students. Keyword - Attitude, Mathematics, A-level, Education, International Education College.
Grammar in the Language Classroom: A Case Study of Teachers’ Attitudes and their Actual Behaviour in the Class
Authors: Azimi Mozhgan
Published: October 2012

The purpose of this paper was to explore the language teachers’ attitudes towards teaching English grammar. In addition, this study compared the teachers’ beliefs and their actual behaviors in the class. The “Action Theory” was chosen regarding this issue. It was investigated if there was any compatibility between their beliefs and practice or not and in case of incompatibility, the subjects were aware of it or not. This paper also tried to explore the reasons of this incompatibility as well as to find out the factors that influenced the teachers’ actual behaviors in the class. The present study is a case study done in a semi-government language center in Mashhad, Iran. Three female language teachers were selected as subjects for this research. To identify the language teachers’ attitudes towards teaching English grammar, a series of observations was done. And also, some interviews with three English teachers were planned to make known their attitudes towards teaching grammar. The Constant Comparative Method (CCM) was used to analyze the data obtained from observations and interviews. The findings of this study revealed that sometimes there was no compatibility between beliefs and actual behaviors. Most of the time, teachers were not aware of this incompatibility.   Keywords - Attitudes, Grammar, Belief, Behavior, Action Theory and Compatibility
The Development of Local Content-based Science Curriculum for Madrasah Tsanawiyah (Islamic Middle School) in Yogyakarta, Indonesia
Authors: Suprihatiningrum Jamil
Published: October 2012

Indonesia has been implementing a basically competencybased curriculum which provides a large room for local potentials to be incorporated into the curriculum. This paper aims at describing the process of developing and implementing local content-based science curriculum, by using the case of the embedment of salakpondoh into the Islamic middle school science curriculum. The development of the curriculum followed the 4-D model of the research based development, i.e. Define, Design, Development, and Disseminate. The Define phase was conducted through a thorough analysis of the national curriculum, local potentials as well as the characteristics of students and school environment. The Design phase was characterized by the development of the prototype of the curriculum. The prototype of the curriculum was then reviewed by 6 middle school science teachers from 3 types of middle schools in the district. The revised version of the curriculum was then implemented in the Public Madrasah Tsanawiyah(PMTs) of Pakem, Sleman, Yogyakarta. The result of this study shows that the prototype of the curriculum was given a good score by the teachers. It also was implemented in the PMTsand can increase the learning outcome of students well and also improve the cooperative skills.   Keywords - local content, salakpondoh, science curriculum, learning model, prototype, research and development
Evaluating Service Encounters: The Effects of Employee Responses on Service Failure and Recovery
Authors: Tan Tiffany Adelaine G.
Published: October 2012

Service failure could still happen in spite of management efforts to prevent it. Earlier studies have shown that a service failure can still end up satisfying customers through the efforts of the frontline employees. This empirical study investigates how the performance of the frontline employees affects customer satisfaction after a service recovery, specifically, customer’s propensity to recommend the service firm. The primary purpose of the study is to determine whether the same dimensions that affect perceived service quality (namely, reliability, assurance, responsiveness, empathy and tangibility) of a service performance also applies to service recovery performance evaluation. Using confirmatory factor analysis on the items of SERVPERF, results showed that a customer who was satisfied with the service employee’s performance on the recovery process will most probably recommend the service firm to others even after a service failure. The results also indicate that while the service quality items are all significantly different from zero, only the reliability and assurance dimensions meaningfully affect the customer’s satisfaction during the recovery process. It seems that, for this study, not all of the dimensions in the SERVPERF survey that affect perceived service quality of a service performance also apply to service recovery evaluation.   Keywords - service failure, service recovery, frontline employees, assurance, Philippines
Time-Domain Microwave Breast Cancer Detection: Extensive System Testing with Phantoms
Authors: Porter Emily , Santorelli Adam , Coates Mark , Popović Milica
Published: October 2012

Early detection of breast cancer is known to be a key factor in the successful treatment of the disease. Here, we present a detection technique complementary to the currently used modalities (primarily mammography, ultrasound and magnetic resonance imaging). Our time-domain breast cancer detection system transmits microwave-range pulses into the breast and records the scattering off of the breast in order to detect malignancies. This method is made possible by an intrinsic contrast in the dielectric parameters, specifically the relative permittivity and conductivity, of the healthy and malignant breast tissues over the microwave frequency range. The long-term goal of our work is to develop a system that can be used periodically to monitor for unusual changes in breast tissues; for instance, healthy breasts would be scanned, and follow-up scans at regular intervals would detect any small changes in breast tissue composition that could indicate the presence of a malignant growth. At that point, the patient would be referred to see a doctor for further investigation of the abnormal results. Such a system would compare each new scan with previous ones to determine the level of tissue changes, and would be used by patients at home. We report feasibility and performance tests for our initial system, conducted with breast phantoms made up of tissue-mimicking materials (unique skin, fat, gland and tumor mixtures). We initiated the system testing with simple homogeneous phantoms, consisting solely of adipose tissue. Then, we extended our tests to cases of increasing complexity by adding a skin layer and varying percentages of glandular structures and tumor sizes. In order to optimize the experimental system, we performed tests with multiple antenna arrangements, tumor sizes and locations. This work shows that there are specific antenna arrangements that are advantageous for tumor detection and demonstrates the capabilities of our time-domain microwave breast tumor detection system.
Effects of Alignment of Adjustable Collimator on Dosimetric Parameters of a Telecobalt Machine
Authors: Sahani G. , Sharma S. D. , Sharma P. K. Dash , Sharma D. N. , Hussain S. A.
Published: October 2012

The objectives of this study was to investigate the most appropriate hinge point for the alignment of adjustable collimators/trimmer bars in a telecobalt machine for obtaining acceptable dosimetric parameters of a telecobalt machine. Variations of relative output of the telecobalt machine with selection of different hinge points were also investigated. MCNP code was used for the present the study. A water phantom of dimension 50 × 50 × 40 cm3 having voxels each of volume 0.72 cm3 was used in our study for generating beam profiles and depth dose curves. When hinge points are selected at the periphery of the source bottom and the source top, flatness, symmetry and penumbra were found to be well within the recommended tolerance limits whereas values are far beyond with the hinge points selected at the centre of source bottom or the source top. Moreover, it was observed that the relative output of a telecobalt machine with hinge points at centre of the source bottom and the source top are appreciably lower than that of at periphery of source bottom particularly for smaller field sizes. This effect is due to the blockage of the part of the source volume in the radiation field. Therefore, hinge point for the alignment of adjustable collimators/trimmer bars should be selected either at periphery of source bottom or the source top for obtaining clinically acceptable flatness, symmetry and penumbra. However, selecting hinge point at the periphery of the source bottom for the alignment of the adjustable collimators/trimmer bars would be more appropriate as height of the source will vary depending on activity of the source used in the source capsule for given specific activity.
Simultaneous Integrated Boost in Breast Conserving Radiotherapy: Is Replanning Necessary following Tumor Bed Change?
Authors: Yang ZhaoZhi , Chen JiaYi , Xie Jiang , Zhu ChuanYing , Pan ZiQiang , Yu XiaoLi , Mei Xin , Fu XiaoLong , Guo XiaoMao
Published: October 2012

Tumor bed (TB) change is often seen during the whole breast irradiation (WBI) in early breast cancer patients. The aims of this study were to evaluate change in seroma volume on repeat CTs and to explore whether replanning is necessary in breast conserving radiotherapy (RT) using the intensity modulated radiotherapy (IMRT) with simultaneous integrated boost (SIB). Thirty patients underwent WBI with 84 CT scans (24 with 3 CTs (CT1, CT2 and CT3) and 6 without CT3) during the 6 weeks of RT were reviewed. TB and other target volumes on all CTs were delineated and compared. IMRT-SIB treatment plans with 50.68 Gy to the whole breast and 64.4 Gy to the boost in 28 fractions were constructed in the CT1. Replan and hybrid plan (without replanning) in the CT2 were reproduced. Dosimetric differences between the replans and hybrid plans were also compared. The mean TB volumes for CT1, CT2 and CT3 were 42.1 cm3, 20.1 cm3, 17.0 cm3, respectively. The mean TB volume reduction was 40.5% from the CT1 to CT2 and 4.3% from the CT2 to CT3. The difference of TB volumes between the CT1 and CT2 was statistically significance ( p < 0.001), but not significant between the CT2 and CT3 ( p = 1.000). For all patients, target coverage remained adequate with either hybrid plans or replans. However, replanning can significantly decrease the whole breast mean dose (35.2 vs. 35.6 Gy, p = 0.026) and breast volume outside the boost receiving 95% of the boost prescribed dose (39.5 vs. 68.2 cm3, p < 0.001). In summary, boost volume could irradiate adequately after the significance shrinkage of tumor bed with the fractionated schedule of IMRT-SIB, but replanning on a second CT could avoid the undesired high dose irradiated breast_tissue outside boost.
The Unintended and Anticompetitive Consequences of Laws to Control Health Care Costs
Authors: Chen Lanhee J.
Published: June 2024

This JAMA Forum discusses the effects of certificate of need laws, certificates of public advantage laws, and restrictions on physician-owned hospitals under the Affordable Care Act on hospital expansion and renovation and health care costs.
Biomarkers of Cellular Senescence and Aging: Current State‐of‐the‐Art, Challenges and Future Perspectives
Authors: Muthamil Subramanian , Kim Hyun‐Yong , Jang Hyun‐Jun , Lyu Ji‐Hyo , Shin Ung Cheol , Go Younghoon , Park Seong‐Hoon , Lee Hee Gu , Park Jun Hong
Published: June 2024

Population aging has increased the global prevalence of aging‐related diseases, including cancer, sarcopenia, neurological disease, arthritis, and heart disease. Understanding aging, a fundamental biological process, has led to breakthroughs in several fields. Cellular senescence, evinced by flattened cell bodies, vacuole formation, and cytoplasmic granules, ubiquitously plays crucial roles in tissue remodeling, embryogenesis, and wound repair as well as in cancer therapy and aging. The lack of universal biomarkers for detecting and quantifying senescent cells, in vitro and in vivo, constitutes a major limitation. The applications and limitations of major senescence biomarkers, including senescence‐associated β‐galactosidase staining, telomere shortening, cell‐cycle arrest, DNA methylation, and senescence‐associated secreted phenotypes are discussed. Furthermore, explore senotherapeutic approaches for aging‐associated diseases and cancer. In addition to the conventional biomarkers, this review highlighted the in vitro, in vivo, and disease models used for aging studies. Further, technologies from the current decade including multi‐omics and computational methods used in the fields of senescence and aging are also discussed in this review. Understanding aging‐associated biological processes by using cellular senescence biomarkers can enable therapeutic innovation and interventions to improve the quality of life of older adults.
Fluoride Substitution: Quantifying Surface Hydroxyls of Metal Oxides with Fluoride Ions
Authors: Lau Kinran , Zerebecki Swen , Pielsticker Lukas , Hetaba Walid , Dhaka Kapil , Exner Kai S. , Reichenberger Sven , Barcikowski Stephan
Published: June 2024

Surface hydroxyls (OH) are crucial for heterogeneous catalysis in water. However, they are commonly characterized at solid–gas interfaces (e.g., FTIR, XPS, TGA), which may not represent the surface in aqueous environments. Here, the surface OH of five catalytically relevant oxides (Al2O3, ZrO2, TiO2, Fe2O3, Co3O4) are quantified by substituting them with F− ions at pH 3–10, where the surface fluoride (F) density is evaluated by XPS using the geometry factor for spherical particles. These results show that the surface F density peaks at around pH 4 across all oxides, but decreases at more basic pH due to increased OH− competition. Generally, oxides more abundant in surface OH can also accommodate more surface F, establishing F− ions as effective probes. While terminal F are likely the preferential substitution product, bridging F also appear to form at lower pH levels. Furthermore, fluoride substitution is applied to a series of Co3O4 gradually enriched with defects using pulsed laser defect engineering in liquid (PUDEL). This approach reveals a linear correlation between laser processing and surface OH density, which aligns with a previously observed improvement in OER activity, and is supported by additional DFT calculations here. This work will stimulate further studies adopting fluoride substitution to better understand the relationship between surface chemistry and catalytic processes in aqueous environments.
A Cryopreservation Strategy for Myoblast Storage in Paper‐Based Scaffolds for Inter‐Laboratory Studies of Skeletal Muscle Health
Authors: Rjaibi Saifedine T. , Jacques Erik , Ni Jiaru , Xu Bin , Kouthouridis Sonya , Sitolle Julie , Lad Heta , Gulati Nitya , Li Nancy T. , Ahn Henry , Ginsberg Howard J. , Zhang Boyang , Grand Fabien Le , Gilbert Penney M. , McGuigan Alison P.
Published: June 2024

3D tissue‐engineered models are poised to facilitate understanding of skeletal muscle pathophysiology and identify novel therapeutic agents to improve muscle health. Adopting these culture models within the broader biology community is a challenge as many models involve complex methodologies and significant investments of time and resources to optimize manufacturing protocols. To alleviate this barrier, a protocol with commercially available reagents is developed to cryopreserve myoblasts in a 96‐well compatible format that allows tissues to be transferred to users without expertise in 2D or 3D skeletal muscle cell culture. This report validates that myoblasts encapsulated in a hydrogel and cryopreserved in paper‐based scaffolds maintain cell viability, differentiation, and function via acetylcholine‐induced transient calcium responses. Furthermore, successful shipping of myoblasts cryopreserved in paper‐based scaffolds to intra‐provincial and international collaborators is demonstrated who successfully thaw, culture, and use the 3D muscle tissues. Finally, the application of this method is confirmed for studying muscle endogenous repair by seeding freshly isolated skeletal muscle stem cells to cryopreserved then differentiated and injured tissues, demonstrating expected responses to a known stimulator of muscle stem cell self‐renewal, p38α/β MAPKi. Altogether, the 3D myoblast cryopreservation protocol offers broadened access of a complex skeletal muscle tissue model to the research community.
Recrystallization Strategy for Efficient Preparation of Metal Halide Single Crystals with High‐Quality
Authors: Yun Xiangyan , Zhou Bo , Hu Hanlin , Zhong Haizhe , Xu Denghui , Li Henan , Shi Yumeng
Published: June 2024

Large size high‐quality perovskite single‐crystals are highly desirable for investigating their fundamental materials properties and realizing state of the art electronic/optoelectronic device performance. Herein, a novel single‐crystal growth method is reported by recrystallization of perovskites in oversaturated solutions. Perovskite single crystals including both organic–inorganic hybrid metal halides and their all‐inorganic counterparts can be obtained in large amounts by this method. All of the synthesized perovskite single crystals exhibit large crystal sizes (centimeter level) and exceptional light emission properties. Meanwhile, the single‐crystal growth can be well controlled and the solvent can be reused for cycles of single‐crystal growth, which sheds light on the preparation of perovskite materials in a way of green chemistry. In addition, thermodynamic growth principles for the single‐crystal growth are proposed, providing a universal approval for metal halide single‐crystal synthesis.
Alzheimer's disease biomarker burden in primary motor cortices is associated with poorer dexterity performance
Authors: Gupta Lily , Ma Yue , Kohli Akshay , Yang Kao Lee , Oh Jennifer M. , Betthauser Tobey J. , Chin Nathaniel A. , Okonkwo Ozioma C. , Pasquesi Mary‐Elizabeth , Nair Veena , Prabhakaran Vivek , Li Shi‐Jiang , Bendlin Barbara
Published: June 2024

INTRODUCTION

Motor function has correlated with longevity and functionality; however, there is limited research on those with Alzheimer's disease (AD). We studied the association between motor functionality and AD pathology in primary motor and medial temporal cortices.

METHODS

A total of 206 participants with a clinical diagnosis of cognitively healthy, AD, or mild cognitive impairment (MCI) underwent imaging and motor assessment. Linear regressions and analyses of variance were applied to test the prediction from AD imaging biomarkers to motor performance and the diagnosis group differences in motor performance.

RESULTS

Increased neurodegeneration was associated with worsening dexterity and lower walking speed, and increased amyloid and tau were associated with worsening dexterity. AD and MCI participants had lower motor performance than the cognitively healthy participants.

DISCUSSION

Increased AD pathology is associated with worsening dexterity performance. The decline in dexterity in those with AD pathology may offer an opportunity for non‐pharmacological therapy intervention.

Highlights

Noted worsening dexterity performance was associated with greater Alzheimer's disease (AD) pathology (tau, amyloid beta, and neurodegeneration) in primary motor cortices.

Similarly, increased neurodegeneration and tau pathology in parahippocampal, hippocampal, and entorhinal cortices is associated with worsening dexterity performance.

Motor performance declined in those with clinical and preclinical AD among an array of motor assessments.
Neighborhood racial income inequality and cognitive health
Authors: Zahodne Laura B. , Sol Ketlyne , Scambray Kiana , Lee Ji Hyun , Palms Jordan D. , Morris Emily P. , Taylor Lauren , Ku Vivian , Lesniak Mary , Melendez Robert , Elliott Michael R. , Clarke Philippa J.
Published: June 2024

INTRODUCTION

Neighborhood socioeconomic status (SES) has been linked to dementia, but the distribution of SES within a neighborhood may also matter.

METHODS

Data from 460 (47% Black, 46% White) older adults from the Michigan Cognitive Aging Project were linked to census tract–level data from the National Neighborhood Data Archive (NaNDA). Neighborhood SES included two composites reflecting disadvantage and affluence. Neighborhood racial income inequality was the ratio of median incomes for White versus Black residents. Generalized estimating equations examined associations between neighborhood factors and cognitive domains.

RESULTS

Neighborhood racial income inequality was uniquely associated with worse cognitive health, and these associations did not differ by participant race. Neighborhood disadvantage was only associated with worse cognitive health among Black participants.

DISCUSSION

Both the level and racial distribution of SES within a neighborhood may be relevant for dementia risk. Racial differences in the level and impact of neighborhood SES contribute to dementia inequalities.

Highlights

Black participants lived in neighborhoods with lower socioeconomic status (SES) than White participants, on average.

Neighborhood SES and racial income inequality were associated with worse cognition.

Effects of neighborhood racial income inequality did not differ across racial groups.

Effects of neighborhood SES were only evident among Black participants.
The ketamine metabolite (2R,6R)‐hydroxynorketamine rescues hippocampal mRNA translation, synaptic plasticity and memory in mouse models of Alzheimer's disease
Authors: Ribeiro Felipe C. , Cozachenco Danielle , Argyrousi Elentina K. , Staniszewski Agnieszka , Wiebe Shane , Calixtro Joao D. , Soares‐Neto Rubens , Al‐Chami Aycheh , Sayegh Fatema El , Bermudez Sara , Arsenault Emily , Cossenza Marcelo , Lacaille Jean‐Claude , Nader Karim , Sun Hongyu , De Felice Fernanda G. , Lourenco Mychael V. , Arancio Ottavio , Aguilar‐Valles Argel , Sonenberg Nahum , Ferreira Sergio T.
Published: June 2024

INTRODUCTION

Impaired brain protein synthesis, synaptic plasticity, and memory are major hallmarks of Alzheimer's disease (AD). The ketamine metabolite (2R,6R)‐hydroxynorketamine (HNK) has been shown to modulate protein synthesis, but its effects on memory in AD models remain elusive.

METHODS

We investigated the effects of HNK on hippocampal protein synthesis, long‐term potentiation (LTP), and memory in AD mouse models.

RESULTS

HNK activated extracellular signal‐regulated kinase 1/2 (ERK1/2), mechanistic target of rapamycin (mTOR), and p70S6 kinase 1 (S6K1)/ribosomal protein S6 signaling pathways. Treatment with HNK rescued hippocampal LTP and memory deficits in amyloid‐β oligomers (AβO)‐infused mice in an ERK1/2‐dependent manner. Treatment with HNK further corrected aberrant transcription, LTP and memory in aged APP/PS1 mice.

DISCUSSION

Our findings demonstrate that HNK induces signaling and transcriptional responses that correct synaptic and memory deficits in AD mice. These results raise the prospect that HNK could serve as a therapeutic approach in AD.

Highlights

The ketamine metabolite HNK activates hippocampal ERK/mTOR/S6 signaling pathways.

HNK corrects hippocampal synaptic and memory defects in two mouse models of AD.

Rescue of synaptic and memory impairments by HNK depends on ERK signaling.

HNK corrects aberrant transcriptional signatures in APP/PS1 mice.
Comparative morphological, thermal, and mechanical characteristics of doped bentonite and dolomite natural clay fillers into high‐density polyethylene
Authors: Mahmoud Mohamed E. , Khalifa Mohammed A. , Youssef Mahues R. , El‐Sharkawy Rehab M.
Published: June 2024

Organic–inorganic composites have attracted great interest, due to their remarkable impact, causing improvements in the mechanical properties of polymers when compared with their pure forms. Hence, this study has been attempted to investigate and compare the various properties of high‐density polyethylene (HDPE), separately doped with two different types of clay minerals using melt‐mixing and compression‐molding techniques. The fourier transform infrared spectroscopy (FT‐IR), x‐ray diffraction (XRD), and scanning electron microscope (SEM) were used to characterize the structural and morphological properties of the resulting composites, while, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were employed to characterize their thermal properties. Morphological investigations indicated homogeneous dispersion of both clay materials in the HDPE matrix. Moreover, an investigation was conducted on the mechanical properties of composites, including elastic modulus, yield stress, tensile strain at break, tensile strain at yield, tensile stress at break, and ultimate tensile strength. According to the mechanical data, adding 6.0 wt% of bentonite or dolomite to HDPE led to an increase in the elastic modulus up to 125% and 116% increments, respectively. An increase in the filler content in the composite from 2.0 to 8.0 wt% resulted in a slight decrease in tensile stress at break, yield stress, tensile strain at break, and tensile strain at yield.