bluuebunny/crossref_metadata_2025 huggingface dataset:
Central Endocannabinoid Signaling Regulates Hepatic Glucose Production and Systemic Lipolysis
Authors: O’Hare James D. , Zieliński Elizabeth , Cheng Bob , Scherer Thomas , Buettner Christoph
Published: March 2011

OBJECTIVE

The endocannabinoid (EC) system has been implicated as an important regulator of energy homeostasis. In obesity and type 2 diabetes, EC tone is elevated in peripheral tissues including liver, muscle, fat, and also centrally, particularly in the hypothalamus. Cannabinoid receptor type 1 (CB1) blockade with the centrally and peripherally acting rimonabant induces weight loss and improves glucose homeostasis while also causing psychiatric adverse effects. The relative contributions of peripheral versus central EC signaling on glucose homeostasis remain to be elucidated. The aim of this study was to test whether the central EC system regulates systemic glucose fluxes.

RESEARCH DESIGN AND METHODS

We determined glucose and lipid fluxes in male Sprague-Dawley rats during intracerebroventricular infusions of either WIN55,212-2 (WIN) or arachidonoyl-2'-chloroethylamide (ACEA) while controlling circulating insulin and glucose levels through hyperinsulinemic, euglycemic clamp studies. Conversely, we fed rats a high-fat diet for 3 days and then blocked central EC signaling with an intracerebroventricular infusion of rimonabant while assessing glucose fluxes during a clamp.

RESULTS

Central CB1 activation is sufficient to impair glucose homeostasis. Either WIN or ACEA infusions acutely impaired insulin action in both liver and adipose tissue. Conversely, in a model of overfeeding-induced insulin resistance, CB1 antagonism restored hepatic insulin sensitivity.

CONCLUSIONS

Thus central EC tone plays an important role in regulating hepatic and adipose tissue insulin action. These results indicate that peripherally restricted CB1 antagonists, which may lack psychiatric side effects, are also likely to be less effective than brain-permeable CB1 antagonists in ameliorating insulin resistance.
Glucose- and Hormone-Induced cAMP Oscillations in α- and β-Cells Within Intact Pancreatic Islets
Authors: Tian Geng , Sandler Stellan , Gylfe Erik , Tengholm Anders
Published: March 2011

OBJECTIVE

cAMP is a critical messenger for insulin and glucagon secretion from pancreatic β- and α-cells, respectively. Dispersed β-cells show cAMP oscillations, but the signaling kinetics in cells within intact islets of Langerhans is unknown.

RESEARCH DESIGN AND METHODS

The subplasma-membrane cAMP concentration ([cAMP]pm) was recorded in α- and β-cells in the mantle of intact mouse pancreatic islets using total internal reflection microscopy and a fluorescent translocation biosensor. Cell identification was based on the opposite effects of adrenaline on cAMP in α- and β-cells.

RESULTS

In islets exposed to 3 mmol/L glucose, [cAMP]pm was low and stable. Glucagon and glucagon-like peptide-1(7-36)-amide (GLP-1) induced dose-dependent elevation of [cAMP]pm, often with oscillations synchronized among β-cells. Whereas glucagon also induced [cAMP]pm oscillations in most α-cells, <20% of the α-cells responded to GLP-1. Elevation of the glucose concentration to 11–30 mmol/L in the absence of hormones induced slow [cAMP]pm oscillations in both α- and β-cells. These cAMP oscillations were coordinated with those of the cytoplasmic Ca2+ concentration ([Ca2+]i) in the β-cells but not caused by the changes in [Ca2+]i. The transmembrane adenylyl cyclase (AC) inhibitor 2′5′-dideoxyadenosine suppressed the glucose- and hormone-induced [cAMP]pm elevations, whereas the preferential inhibitors of soluble AC, KH7, and 1,3,5(10)-estratrien-2,3,17-β-triol perturbed cell metabolism and lacked effect, respectively.

CONCLUSIONS

Oscillatory [cAMP]pm signaling in secretagogue-stimulated β-cells is maintained within intact islets and depends on transmembrane AC activity. The discovery of glucose- and glucagon-induced [cAMP]pm oscillations in α-cells indicates the involvement of cAMP in the regulation of pulsatile glucagon secretion.
Cohort Study of Pioglitazone and Cancer Incidence in Patients With Diabetes
Authors: Ferrara Assiamira , Lewis James D. , Quesenberry Charles P. , Peng Tiffany , Strom Brian L. , Van Den Eeden Stephen K. , Ehrlich Samantha F. , Habel Laurel A.
Published: March 2011

OBJECTIVE

To explore whether treatment with pioglitazone was associated with risk of incident cancer at the 10 most common sites (prostate, female breast, lung/bronchus, endometrial, colon, non-Hodgkin lymphoma [NHL], pancreas, kidney/renal pelvis, rectal, and melanoma).

RESEARCH DESIGN AND METHODS

A cohort study of 252,467 patients aged ≥40 years from the Kaiser Permanente Northern California Diabetes Registry was conducted. All prescriptions for diabetes medications were identified by pharmacy records. Cox proportional hazards models were used to examine the association between risk of incident cancer and ever use, duration, dose, and time since initiation of pioglitazone (modeled as time-dependent variables).

RESULTS

In models adjusted for age, sex, year of cohort entry, race/ethnicity, income, smoking, glycemic control, diabetes duration, creatinine levels, congestive heart failure, and use of other diabetes medications, the hazard ratio (HR) for each cancer associated with ever use of pioglitazone ranged from 0.7 to 1.3, with all 95% CIs including 1.0. There was a suggestion of an increased risk of melanoma (HR 1.3 [95% CI 0.9–2.0]) and NHL (1.3 [1.0–1.8]) and a decreased risk of kidney/renal pelvis cancers (0.7 [0.4–1.1]) associated with ever use of pioglitazone. These associations were unaltered with increasing dose, duration, or time since first use.

CONCLUSIONS

We found no clear evidence of an association between use of pioglitazone and risk of the incident cancers examined. Because the maximum duration of follow-up was fewer than 6 years after the initiation of pioglitazone, longer-term studies are needed.
Analysis on genetic contribution of some traits to seed yield in rapeseed by additive-dominance genetic method of mixed model
Authors: Sabaghnia N. , Dehghani H. , Alizadeh B. , Mohghaddam M.
Published: March 2011

Analysis on genetic contribution of some traits to seed yield in rapeseed by additive-dominance genetic method of mixed model

A genetic model is developed with additive, dominance and genotype x environment interaction effects for the progeny from a diallel mating design. To uncover the genetic contributions of some traits of rapeseed to seed yield and find indicator traits for indirect selection, multivariable conditional analysis was conducted based on this method. Therefore, an experiment was conducted to estimate genetic parameters using a half diallel of nine international rapeseed cultivars. The 36 Fl hybrids, the parents and four additional cultivars were planted in the breeding nurseries in 2008 and 2009. Several traits including number of pods per plant (NPP), pod length (LP), height of the first pod (HFP), height of the first lateral branch (HFB), stem diameter (SD), days of flowering period (FP), days to physiological maturity (DPM) and seed yield were recorded. The genetic variance component (VDxY) was significant for all the studied traits but the genetic variance component (VA) was significant for NPP, HFB, HFP, DPM and SY traits and the genetic variance component (VD) was significant for HFB, HFP, LP and FP traits. There was significant positive phenotypic correlation (rA) between seed yield with NPP and HFP and there was significant positive dominance x year interaction correlation (rDxY) between seed yield with NPP and DPM while there was significant negative dominance x year interaction correlation (rDxY) between seed yield with HFB, LP and FP. There were significantly positive additive effects of SY for two parents Orient and Talaye. Finally according to additive-dominance genetic model and conditional genetic effects, the genotypes Talaye proved good general combiner for seed yield improvement and crosses 4 × 8 (Orient × Talaye), 7 × 8 (Opera × Talaye) were found the best specific combiner for all the studied traits.
SETHI: The Flying Lab
Authors: Bruyant Jean-Paul , Dreuillet Philippe , du Plessis Olivier , Oriot Héléne , Dubois-Fernandez Pascale , Cantalloube Hubert
Published: March 2011

SETHI: The Flying Lab

This paper presents the new-generation test bench SETHI, developed by ONERA, the French Aerospace Lab. SETHI is a medium range platform dedicated to environmental, scientific and security applications. The first part of this paper describes the system architecture, the development state and the future capabilities. A set of recent significant results are presented: these results cover various applications, such as high spatial resolution imaging, change detection between two acquisitions, biomass measurement in the rain forest, bistatic imaging and innovative measurements, such as air-to-air imaging or circular imaging.
Multisensor Tracking of Marine Targets - Decentralized Fusion of Kalman and Neural Filters
Authors: Stateczny Andrzej , Kazimierski Witold
Published: March 2011

Multisensor Tracking of Marine Targets - Decentralized Fusion of Kalman and Neural Filters

This paper presents an algorithm of multisensor decentralized data fusion for radar tracking of maritime targets. The fusion is performed in the space of Kalman Filter and is done by finding weighted average of single state estimates provided be each of the sensors. The sensors use numerical or neural filters for tracking. The article presents two tracking methods - Kalman Filter and General Regression Neural Network, together with the fusion algorithm. The structural and measurement models of moving target are determined. Two approaches for data fusion are stated - centralized and decentralized - and the latter is thoroughly examined. Further, the discussion on main fusing process problems in complex radar systems is presented. This includes coordinates transformation, track association and measurements synchronization. The results of numerical experiment simulating tracking and fusion process are highlighted. The article is ended with a summary of the issues pointed out during the research.
Nonuniform Spatial Sampling in a Ground-Based Noise SAR
Authors: Maślikowski Łukasz , Misiurewicz Jacek
Published: March 2011

Nonuniform Spatial Sampling in a Ground-Based Noise SAR

The paper presents an idea of nonuniform spatial sampling applied to a noise synthetic aperture radar. In certain cases it is desirable to limit the number of spatial (along-track) domain samples acquired in a SAR radar because of external constraints on sampling frequency or on the overall number of samples - e.g. in order to economy on time or power consumed. Lowering number of samples taken may, however, lead to spatial aliasing and incorrect reconstruction of the image. Nonuniform sampling allows to reduce the aliasing effect and reconstruct the image better. This technique can be applied with standard reconstruction methods, but it works best together with Compressive Sensing reconstruction algorithms. The idea will be verified with an experimental noise SAR built at ISE PW.
Application of Digital Control Techniques for Satellite Medium Power DC-DC Converters
Authors: Skup Konrad , Grudziński Paweł , Orleański Piotr
Published: March 2011

Application of Digital Control Techniques for Satellite Medium Power DC-DC Converters

The objective of this paper is to present a work concerning a digital control loop system for satellite medium power DC-DC converters that is done in Space Research Centre. The whole control process of a described power converter is based on a high speed digital signal processing. The paper presents a development of a FPGA digital controller for voltage and current mode stabilization that was implemented using VHDL. The described controllers are based on a classical digital PID controller. The converter used for testing is a 200 kHz, 750W buck converter with 50V/15A output. A high resolution digital PWM approach is presented. Additionally a simple and effective solution of filtering of an analog-to-digital converter output is presented.
Bistatic Noise SAR Experiment with a Non-Cooperative Illuminator
Authors: Maślikowski Łukasz , Kulpa Krzysztof
Published: March 2011

Bistatic Noise SAR Experiment with a Non-Cooperative Illuminator

The paper describes the results of a conception-stage experiment with a ground-based bistatic noise SAR (Synthetic Aperture Radar) demonstrator. Its aim was to research the ability of a simple Commercial-Off-The-Shelf (COTS) build system to provide a bistatic SAR image using non-cooperative illuminator. The noise signal used in the experiment is similar to a signal used in many transmission systems such as DVB-T that can be employed in passive bistatic radars. The paper presents the system setup, details of the measurement campaign, signal processing and the results of SAR imaging.
A Short Range Synthetic Aperture Imaging Radar with Rotating Antenna
Authors: Ali Faiza , Urban Alexander , Vossiek Martin
Published: March 2011

A Short Range Synthetic Aperture Imaging Radar with Rotating Antenna

The design of a short range synthetic aperture imaging radar is introduced in this paper. A radar hologram is acquired using a small omnidirectional antenna that is mounted on a rotating platform. After each turn of the platform a high resolution 360° 2D image is reconstructed; a rotating window function optimizes the reconstructed image function to get the best image focus for detecting both weak and strong scatterers. The rotating window function depends on the target direction and is executed for each image point and each target direction. The size of the synthetic aperture - and thus the lateral resolution of the imaging system - is determined by the diameter of the circular antenna trajectory. In contrast to common radar scanner concepts that utilize highly directional and thus bulky antennas, the proposed scanner concept has the advantage of using a small, lightweight omni-directional antenna. The developed radar system is much more compact and the scanning mechanics are significantly simplified. Furthermore, an omni-directional antenna offers very straightforward options for powering the radar on the rotation platform. Measurement results obtained with a 24 GHz FMCW short range radar sensor illustrate the performance of the proposed SAR imaging method.
27 dBm Microwave Amplifiers with Adaptive Matching Networks
Authors: Rosolowski Dawid , Wojtasiak Wojciech , Gryglewski Daniel
Published: March 2011

27 dBm Microwave Amplifiers with Adaptive Matching Networks

The paper describes adaptive amplifier design with varactors and pin diodes as regulators of matching networks. As examples the two amplifiers with SHF-0189 HFET transistor and different matching sections were designed and manufactured. The output power level of 27 dBm and gain higher than 13 dB within L and S-band have been achieved. The amplifier design methodology is based on the small-signal approach and DC characteristics of transistors and regulators. Amplifier adaptivity allows us to remotely control the chosen parameters such as: frequency range, output power level, gain and etc.
A Computer-controlled System of High-power Microwave Sources
Authors: Korpas Przemysław , Gryglewski Daniel , Wojtasiak Wojciech , Gwarek Wojciech
Published: March 2011

A Computer-controlled System of High-power Microwave Sources

The paper presents the design and hardware implementation of a computer controlled system composed of up to four high-power microwave sources. Each source provides up to 200 W of continuous wave power. Frequency of each source is stabilized within ±0.5 ppm of the nominal frequency adjustable within 2.35 ÷ 2.6 GHz range. All four sources can be synchronized to the same frequency with computer-controlled phase shift between the signals generated by each of them. The paper concentrates on the choice of components for such a system and the properties of the realized hardware implementation.
Modulation-Mode Assignment for SVD-assisted Downlink Multiuser MIMO Transmission Schemes with Iterative Detection
Authors: Ahrens Andreas , Benavente-Peces César
Published: March 2011

Modulation-Mode Assignment for SVD-assisted Downlink Multiuser MIMO Transmission Schemes with Iterative Detection

Since the capacity of multiple-input multiple-output (MIMO) systems increases linearly with the minimum number of antennas at both, the transmitter as well as the receiver side, MIMO systems have attracted a lot of attention for both frequency and non-frequency selective channels and reached a state of maturity. By contrast, MIMO-aided multiple-user systems require substantial further research. In comparison to zero-forcing (ZF) multiuser transmission techniques, where all users are treated jointly, the investigated singular value decomposition (SVD) assisted DL multiuser MIMO solution takes the individual user's channel characteristics into account. In analogy to bit-interleaved coded irregular modulation, we introduce a MIMO-BICM scheme, where different user-specific signal constellations and mapping arrangement were used within a single codeword. Extrinsic information transfer (EXIT) charts are used for analyzing and optimizing the convergence behaviour of the iterative demapping and decoding. Our results show that in order to achieve the best bit-error rate, not necessarily all user-specific MIMO layers have to be activated.
Information-Seeking Behaviors of First-Semester Veterinary Students: A Preliminary Report
Authors: Weiner Sharon A. , Stephens Gretchen , Nour Abdelfattah Y.M.
Published: March 2011

Although emphasis in veterinary education is increasingly being placed on the ability to find, use, and communicate information, studies on the information behaviors of veterinary students or professionals are few. Improved knowledge in this area will provide valuable information for course and curriculum planning and the design of information resources. This article describes a survey of the information-seeking behaviors of first-semester veterinary students at Purdue University. A survey was administered as the first phase of a progressive semester-long assignment for a first semester DVM course in systemic mammalian physiology. The survey probed for understanding of the scientific literature and its use for course assignments and continuing learning. The survey results showed that students beginning the program tended to use Google for coursework, although some also used the resources found through the Purdue libraries' Web sites. On entering veterinary school, they became aware of specific information resources in veterinary medicine. They used a small number of accepted criteria to evaluate the Web site quality. This study confirms the findings of studies of information-seeking behaviors of undergraduate students. Further studies are needed to examine whether those behaviors change as students learn about specialized veterinary resources that are designed to address clinical needs as they progress through their training.
The Informatics Imperative in Veterinary Medicine: Collaboration across Disciplines
Authors: Johnson Layne M. , Ames Trevor R. , Jacko Julie A. , Watson Linda A.
Published: March 2011

Information and data management are essential to support the collaborative and interdisciplinary pursuits of an academic veterinary medicine enterprise, ranging from research conducted by individual investigators, education processes, clinical care, and outreach to administration and management. Informatics is an academic discipline that focuses on the creation, management, storage, retrieval, and use of information and data and how technology can be applied to improve access to and use of these resources. In this article, we discuss the challenges in integrating informatics across a large academic enterprise from a veterinary medicine point of view. As a case study, we describe an example program of informatics at the University of Minnesota designed to support interdisciplinary collaboration.
Optimism, Self-Esteem, and Social Support as Mediators of the Relationships among Workload, Stress, and Well-Being in Veterinary Students
Authors: Gardner Dianne H. , Parkinson Tim J.
Published: March 2011

Optimism, self-esteem, satisfaction with social support, and coping strategies were examined in relation to study-related subjective workload, stress, and life satisfaction. Questionnaires were distributed to students in the second, third, and fourth years of the five-year BVSc program at Massey University. One hundred fifty usable responses were received. Most respondents were female. Students with more optimism and self-esteem were less stressed than those who were more pessimistic or lower in self-esteem. Students who reported having heavy subjective workloads were more stressed, whereas students with higher self-esteem experienced more well-being. Men and women did not differ on any of the study variables, and there were no differences between students in different years of study. Recommendations include retaining initiatives to build well-being that are already in place. Support resources exist within the university, but students are often reluctant to seek help, so staff need to continue to identify students in need of additional help who might benefit from referral to a health practitioner. Where practicable, support service providers may be able to contribute actively to teaching. As well as helping students build effective social and coping strategies, this approach will provide students with additional information about the services that are available. Students may not see workshops on interpersonal skills or stress management as relevant unless they are linked to their immediate concerns.
Analysis of Short-Answer Question Styles versus Gender in Pre-Clinical Veterinary Education
Authors: Foster Neil
Published: March 2011

One large study in medical education has reported that the choice of question format (or question content) could introduce a gender bias, with men outperforming women on questions with a true–false component or that required knowledge of anatomy or physiology. The purpose of our study was to ascertain whether this finding is also true in veterinary medical education. Two veterinary student cohorts were analyzed across four different modules over a three-year period (804 questions in total). The results of the study show that the women's and men's performance did not differ in any of the question types analyzed across any module or year. When students' (both women and men) overall average performance on different question types was compared with their performance on standard multiple-choice questions (MCQs), performance levels increased when students were asked to answer MCQs that contained an image-based prop (IMCQ) such as a photograph, X-ray image, or diagram. In contrast, students' performance was consistently lower when answering assertion–reason questions (ARQs), and this performance could not be explained by the demographic makeup of the two cohorts analyzed. When comparing standard MCQs with MCQs that contained a true–false question stem, no specific trend in the data could be determined. In conclusion, this study suggests that the short-answer question style does not bias against one gender in veterinary medical education, but that overall students do perform differently according to question type and, in particular, less well when ARQs are used in examinations.
Can Teaching Veterinary and Animal-Science Students about Animal Welfare Affect Their Attitude toward Animals and Human-Related Empathy?
Authors: Hazel Susan J. , Signal Tania D. , Taylor Nicola
Published: March 2011

Attitudes toward animals are important in influencing how animals are treated. Few studies have investigated attitudes toward animals in veterinary or animal-science students, and no studies have compared attitudes to animals before and after a course teaching animal welfare and ethics. In this study, students enrolled in veterinary (first-year) or animal-science (first- and third-year) programs completed a questionnaire on attitudes toward different categories of animals before and after the course. Higher attitude scores suggest a person more concerned about how an animal is treated. Normally distributed data were compared using parametric statistics, and non-normally distributed data were compared using non-parametric tests, with significance p<.05. Attitudes toward pets (45.5–47.6) were higher than those toward pests (34.2–38.4) or profit animals (30.3–32.1). Attitude scores increased from before to after the course in the veterinary cohort on the Pest (36.9 vs. 38.4, respectively, n=27, p<.05) and Profit (30.3 vs. 32.1, respectively, n=28, p<.05) subscales, but not in the animal-science cohorts. Attitude scores in all categories were higher for women than for men. Currently having an animal was associated with higher pet scores (46.8 vs. 43.8, ns=120 and 13, respectively, p<.05), and having an animal as a child was associated with higher profit scores (31.0 vs. 26.6, ns=129 and 8, respectively, p<.05). Students electing to work with livestock had lower scores on the Pest and Profit subscales, and students wanting to work with wildlife had significantly higher scores on the Pest and Profit subscales. This study demonstrates attitudinal changes after an animal-welfare course, with significant increases in veterinary but not animal-science students.
150th Anniversary of Veterinary Education and the Veterinary Profession in North America: Part 2, 1940–1970
Authors: Smith Donald F.
Published: March 2011

This article is the second in a series of four to be published in the Journal of Veterinary Medical Education (JVME). These articles are abridged versions of six lectures that make up an elective course on the history of the veterinary profession in North America offered at Cornell University's College of Veterinary Medicine to students in all four years of the program. The course is built in part on a series of biographies and interviews captured in a collection at http://www.vet.cornell.edu/legacy , and complemented by a growing collection of historical and public policy blogs at http://www.veterinarylegacy.blogsite.com . This article describes the development of the veterinary profession from 1940 to 1970, with particular emphasis on World War II, the Land Grant colleges established in the mid- and late 1940s, women in veterinary medicine (1910–1970), and African-Americans (ca. 1890–1945). Though the article is somewhat Cornell-centric because the lectures were presented to Cornell students at their home institution, many events are representative of the broader American experience.
RNA interference and its role in the inhibition and cure of HIV/AIDS
Authors: Mahfuz Istiak , Mandal Abul
Published: March 2011

The HIV/AIDS epidemic kills about 2.1 million people around the world every year. Unfortunately, until now attempts to control and diminish further spread of the disorder have resulted in very limited success. Although highly active antiretroviral therapy (HAART) is now available as a treatment option, the rate of its success is limited because of drug resistance. In this context, a more efficient treatment is very much necessary to fight with this fatal disease. The RNA interference (RNAi) can be employed as one of the powerful methods for treatment of the disease as it can effectively silence gene expression in a sequence specific manner. The RNAi-mediated treatment is therefore a promising substitution for therapy of the global epidemic HIV/AIDS in the future. The main objective of this review is to focus on an in-depth analysis of RNAi and the principles underlying RNAi treatment, and it’s also describes the molecular mechanisms of HIV infection, current treatment facilities available to patients as well as therapeutic applications of RNAi along with their limitations as to why the options are inadequate to give a safe and sound cure of HIV/AIDS.Key words: HIV/AIDS; RNA interference; treatments; limitationsDOI: 10.3329/jles.v5i0.7341J. Life Earth Sci., Vol. 5: 1-10, 2010
Changes in wetlands in Dhaka City: Trends and physico-environmental consequences
Authors: Islam Md Shahidul , Rahman Md Rejaur , Shahabuddin AKM , Ahmed Raquib
Published: March 2011

There existed a large number of water bodies including rivers, Khals, lakes and low-lying areas in Dhaka, a thickly populated City and capital of the country. The water bodies played important roles on the natural environment of the City including its drainage system. Due to various natural and human induced reasons, the wetlands of the City have been shrinking with the passage of time. This study makes an attempt to identify the urban wetlands, emphasizing on the extent of their changes and subsequent impacts on physical environment of the area. For ascertaining the land-use pattern of the City, this study uses topographical map (Toposheet of 1960) and satellite images (Landsat TM, 1988 and ALOS VNIR, 2008). It also uses remote sensing and GIS based software (e.g. Arc GIS, Erdas Imagine) for this purpose. Statistical analysis has been carried out in order to process and analyze the data. The study observes that the wetlands of Dhaka city are changing very quickly. In 1960, the total area of water bodies and lowlands were 2952.02 and 13527.58 ha, respectively. Whereas in 1988, the total area of the same decreased to 2103.62 and 12717.73 ha, respectively. This deteriorated further, occupying an area of 1990.71 ha in 2008 which indicates that the lowlands continued to decrease. Thus the water bodies and lowlands decreased by 32.57% and 52.58%, respectively during 1960 and 2008. This changing trend of wetlands makes the drainage system of Dhaka City vulnerable, creating water logging problems and their consequences. Land filling and encroachment were recognized to be the main reasons for changing wetlands in the City. Key words: Wetlands; wetland changes; water logging; environment DOI: 10.3329/jles.v5i0.7348 J. Life Earth Sci., Vol. 5: 37-42, 2010
Factors of economic transformation in sub-urban areas of Rajshahi City, Bangladesh
Authors: Rahman Md Mizanoor
Published: March 2011

Urbanization of Bangladesh is developed by the natural growth of city, sub-urban growth, sub-urban transformation to urban area, and attaining new urban centers. Accordingly, growth of major urban centers depends on natural growth of city, suburban growth, sub-urban transformation and change in development level of sub-urban areas. As a result, the economy of those areas changes over time and the changes are controlled by a number of factors that playing increasingly dominated roles on the urban as well as national economy of Bangladesh. In the research an attempt has been made to identify the factors that have been influencing the economic transformation, the consequences of transformation in the area, and adopted governmental policies and programmes to develop them. Necessary data and information have collected from both primary and secondary sources for the study, and to analysis and represent of collected data quantitative analysis and mapping techniques have been applied. The research findings indicate that the change in economic setting of those areas in term of occupation, income, expenditure, land use, agricultural practices, infrastructure and facilities and so on is dependent on a set of factors such as distance, market demand, growth center, land availability and land value, employment opportunity, facilities and governmental development policies and programmes. Key words: Economic transformation; factors of economic transformation; sub-urban areas DOI: 10.3329/jles.v5i0.7350 J. Life Earth Sci., Vol. 5: 47-55, 2010
Egg quality traits of indigenous, exotic and crossbred chickens (Gallus domesticus L.) in Rajshahi, Bangladesh
Authors: Islam M Saiful , Dutta Ripon Kumar
Published: March 2011

This study was aimed at investigating the external and internal egg quality traits along with their correlation values of an indigenous (Deshi), three exotics (Cobb 500 of Broiler, Fayoumi, and RIR) and a crossbred (Sonali derived from RIR?× Fayoumi?) chicken breeds available in Rajshahi. From a total of 50 eggs (5 breeds × 10 replicates each), the external quality traits such as gross egg weight (EW), egg length (L), egg width (W), egg volume (EV), shell weight (SW), shell ratio (SR) and egg shape index (ESI), and the internal quality traits like yolk weight (YW), albumen weight (AW), yolk ratio (YR) and albumin ratio (AR) were determined. Results showed that highly significant differences exist for both external and internal egg quality traits between the genetic groups of chicken (P<0.001). Even though RIR showed the highest EW and EV and Fayoumi had the lowest for both traits, AR was in the sequence of Cobb 500 > RIR> Indigenous> Fayoumi> Sonali. Phenotypic correlations among the egg quality traits revealed that EV was not significantly correlated with EW except for Sonali (P<0.001). The association between EW and ESI was negative in all the chickens except Sonali. However, EW was significantly correlated with the AW in RIR (P<0.001), Cobb 500 (P<0.01) and Sonali (P<0.01). Moreover, the EW was significantly correlated with YW only in Fayoumi and RIR (P<0.05). In view of the cholesterol, fat and antioxidant contents of the hen’s egg, a higher AR is healthier than a higher YR. The present findings therefore suggest that Cobb 500, RIR and Indigenous eggs are healthier than Fayoumi and Sonali eggs that contain higher YR. Key words: Egg quality traits; phenotypic correlation; Indigenous; exotic and crossbred chickens DOI: 10.3329/jles.v5i0.7352 J. Life Earth Sci., Vol. 5: 63-67, 2010
Within group and between group comparisons of political and apolitical voters of Bangladesh with personality dimension of authoritarianism
Authors: Ziauddin Syed Md
Published: March 2011

The study attempted to measure authoritarianism, as related to political-apolitical group composition, male-female gender recognition and urban-rural residential background of the subjects. Kool's (1980) authoritarian scale was used. A total of 320 subjects were equally divided into political and apolitical groups. Thus a 2×2×2 factorial design involving 2 levels of group composition (political vs. apolitical), 2 levels of gender (male vs. female) and 2 levels of residential background (urban vs. rural) was used. Results were analyzed using t-tests on the scores of authoritarian scale. Although no significant difference was obtained between political and apolitical groups (N=160), within-group comparisons revealed that urban females of political affiliation were more authoritarian than the urban males, rural males and rural females (N=40 for each). Again urban females of apolitical group were found more authoritarian than urban males, rural males and rural females (N=40 for each). A comparison between groups of political and apolitical subjects revealed that urban females of political group were more authoritarian than rural males and rural females of apolitical groups (N=40 for each). On the other hand, urban females of apolitical group were found more authoritarian than urban males, rural males and rural females of political affiliation. Irrespective of gender, political urban subjects were more authoritarian than apolitical rural subjects (N=80) while apolitical urban subjects were more authoritarian than political rural subjects (N=80). Key words: Political and apolitical voters; authoritarianism; personality dimension; Kool's authoritarian scale DOI: 10.3329/jles.v5i0.7353 J. Life Earth Sci., Vol. 5: 69-73, 2010
Psychophysical health in relation to the environmental noise perception of younger versus older groups of people in Dhaka City
Authors: Saifuddin Kazi , Shahinuzzaman Md , Muhammad Noor , Quader Mohammad Abdul
Published: March 2011

Auditory perception towards environmental noise was tested individually in 510 graduate and undergraduate student participants (18-28 yrs) who were experienced in habitually noisy-living areas. A 15-item questionnaire was developed to measure the auditory perception and the responses were evaluated by 10 teachers of Psychology living and working in Dhaka City. Another 33-item ‘Burns Anxiety Inventory’ questionnaire for the assessment of psychophysical health was used for the same participants. Results showed that increased level of negative perception towards environmental noise maintain a significant linear relation with the degradation of psychophysical health (P<0.01). Another study similar to the above one was performed in which age factor was tested as a parameter. The results of the second study on 345 older participants (55-65 yrs) showed a significant improvement of psychophysical health (P<0.05), though the respondents have had negative perception towards environmental noise. The inverse results of these two studies have been interpreted by assuming a threshold function (λ) between the two age groups, where λ represented a psychophysical antibody against the effects of environmental noise perception. Key words: Psychophysical health; environmental noise perception; psychophysical antibody DOI: 10.3329/jles.v5i0.7355 J. Life Earth Sci., Vol. 5: 81-84, 2010
Petrology of the metamorphic rocks (gravels) from Bhajanpur area in Panchagarh District, Bangladesh
Authors: Hossain Md Rahat , Hossain Ismail , Hossain ASM Zahid , Biswas Prodip Kumar
Published: March 2011

The present study deals with petrology of the detrital gravelly rocks from Bhajanpur area, Panchagarh, Bangladesh. The results of detailed petrography of gravelly rocks indicate the presence of quartz (monocrystalline and polycrystalline quartz), K-feldspar, plagioclase, chlorite, muscovite and biotite as major mineralogical compositions. Other minor minerals are garnet, kyanite, graphite and opaque minerals. Based on definitive mineral assemblages, blueschist and greenschist facies sequences are recognized. Correspondingly, index minerals provide chlorite zone, biotite zone, garnet zone, kyanite zone, and graphite zone. The P-T conditions of the studied rocks demonstrate the possible temperature ranges 300-550°C and pressure ranges 2-10 kbar. Most common varieties of metamorphic rocks in the study area are garnet mica schist, chlorite schist, gneiss and few quartzites. Characteristics of garnet mica schist and chlorite schist are equivalent with the lesser Himalayan metamorphic rock sequence in Sikkim area, whereas gneiss from Bhajanpur area has similar precursor as Darjeeling gneiss. Therefore, the sources of detrital metamorphic rocks in Bhajanpur area obviously come from the lesser Himalayan sequence in Sikkim and Darjeeling areas, India. Key words: Petrology; metamorphic rocks; gravels; P-T conditions; Panchagarh; lesser Himalayan sequence DOI: 10.3329/jles.v5i0.7357 J. Life Earth Sci., Vol. 5: 91-96, 2010
Report on a heronry at the Rajshahi University Campus
Authors: Reza AM Saleh , Hossain Mosharrof , Parween Selina
Published: March 2011

Key words: Heronry; cormorant; heron; egret; RU campus DOI: 10.3329/jles.v5i0.7358 J. Life Earth Sci., Vol. 5: 97-100, 2010
Effects of gender and education on social identity in Chakma tribal population in Bangladesh
Authors: Rahman AKM Rezanur
Published: March 2011

Key words: Social identity; gender; tribal culture; self-categorization; educationDOI: 10.3329/jles.v5i0.7359 J. Life Earth Sci., Vol. 5: 101-103, 2010
Delineating an Epigenetic Continuum for Initiation, Transformation and Progression to Breast Cancer
Authors: Chen Kang Mei , Stephen Josena K. , Raju Usha , Worsham Maria J.
Published: March 2011

Aberrant methylation of promoter CpG islands is a hallmark of human cancers and is an early event in carcinogenesis. We examined whether promoter hypermethylation contributes to the pathogenesis of benign breast lesions along a progression continuum to invasive breast cancer. The exploratory study cohort comprised 17 breast cancer patients with multiple benign and/or in situ lesions concurrently present with invasive carcinoma within a tumor biopsy. DNA from tumor tissue, normal breast epithelium when present, benign lesions (fibroadenoma, hyperplasia, papilloma, sclerosing adenosis, apocrine metaplasia, atypical lobular hyperplasia or atypical ductal hyperplasia), and in situ lesions of lobular carcinoma and ductal carcinoma were interrogated for promoter methylation status in 22 tumor suppressor genes using the multiplex ligation-dependent probe amplification assay (MS-MLPA). Methylation specific PCR was performed to confirm hypermethylation detected by MS-MLPA. Promoter methylation was detected in 11/22 tumor suppressor genes in 16/17 cases. Hypermethylation of RASSF1 was most frequent, present in 14/17 cases, followed by APC in 12/17, and GSTP1 in 9/17 cases with establishment of an epigenetic monocloncal progression continuum to invasive breast cancer. Hypermethylated promoter regions in normal breast epithelium, benign, and premalignant lesions within the same tumor biopsy implicate RASSF1, APC, GSTP1, TIMP3, CDKN2B, CDKN2A, ESR1, CDH13, RARB, CASP8, and TP73 as early events. DNA hypermethylation underlies the pathogenesis of step-wise transformation along a monoclonal continuum from normal to preneoplasia to invasive breast cancer.
The Role of Nrf2 and Cytoprotection in Regulating Chemotherapy Resistance of Human Leukemia Cells
Authors: Rushworth Stuart A. , MacEwan David J.
Published: March 2011

The Nrf2 anti-oxidant response element (ARE) pathway plays an important role in regulating cellular anti-oxidants. Under normal cellular conditions Nrf2 can be described as an anti-tumor molecule due to its induction of cytoprotective genes which protect cells from electrophile and oxidative damage. However in cancerous cells, Nrf2 takes on a pro-tumoral identity as the same cytoprotective genes can enhance resistance of those cancer cells to chemotherapeutic drugs. Such Nrf2-regulated cytoprotective genes include heme oxygenase-1 (HO-1), which has been shown to protect human leukemia cells from apoptotic signals. Moreover, a relationship between Nrf2 and the nuclear factor-κB (NF-κB) signaling pathway has been recently identified, and is now recognized as an important cross-talk mechanism by which Nrf2 can overcome apoptosis and provide cells with reduced sensitivity towards chemotherapeutic agents. In recent years a number of important research papers have highlighted the role of Nrf2 in providing protection against both current and new chemotherapeutic drugs in blood cancer. This review will provide a synopsis of these research papers with an aim to carefully consider if targeting Nrf2 in combination with current or new chemotherapeutics is a viable strategy in the more effective treatment of blood cancers.
Regulatory T Cells in Colorectal Cancer: From Biology to Prognostic Relevance
Authors: Mougiakakos Dimitrios
Published: March 2011

Regulatory T cells (Tregs) were initially described as "suppressive" lymphocytes in the 1980s. However, it took almost 20 years until the concept of Treg-mediated immune control in its present form was finally established. Tregs are obligatory for self-tolerance and defects within their population lead to severe autoimmune disorders. On the other hand Tregs may promote tolerance for tumor antigens and even hamper efforts to overcome it. Intratumoral and systemic accumulation of Tregs has been observed in various types of cancer and is often linked to worse disease course and outcome. Increase of circulating Tregs, as well as their presence in mesenteric lymph nodes and tumor tissue of patients with colorectal cancer de facto suggests a strong involvement of Tregs in the antitumor control. This review will focus on the Treg biology in view of colorectal cancer, means of Treg accumulation and the controversies regarding their prognostic significance. In addition, a concise overview will be given on how Tregs and their function can be targeted in cancer patients in order to bolster an inherent immune response and/or increase the efficacy of immunotherapeutic approaches.
Quantum Kolmogorov Complexity and Information-Disturbance Theorem
Authors: Miyadera Takayuki
Published: March 2011

In this paper, a representation of the information-disturbance theorem based on the quantum Kolmogorov complexity that was defined by P. Vit´anyi has been examined. In the quantum information theory, the information-disturbance relationship, which treats the trade-off relationship between information gain and its caused disturbance, is a fundamental result that is related to Heisenberg’s uncertainty principle. The problem was formulated in a cryptographic setting and the quantitative relationships between complexities have been derived.
Geometrical Conditions Indispensable for Muscle Contraction
Authors: Skubiszak Ludmila
Published: March 2011

Computer simulation has uncovered the geometrical conditions under which the vertebrate striated muscle sarcomere can contract. First, all thick filaments should have identical structure, namely: three myosin cross-bridges, building a crown, should be aligned at angles of 0°, 120°, 180°, and the successive crowns and the two filament halves should be turned around 120°. Second, all thick filaments should act simultaneously. Third, coordination in action of the myosin cross-bridges should exist, namely: the three cross-bridges of a crown should act simultaneously and the cross-bridge crowns axially 43 and 14.333 nm apart should act, respectively, simultaneously and with a phase shift. Fifth, six thin filaments surrounding the thick filament should be turned around 180° to each other in each sarcomere half. Sixth, thin filaments should be oppositely oriented in relation to the sarcomere middle. Finally, the structure of each of the thin filaments should change in consequence of strong interaction with myosin heads, namely: the axial distance and the angular alignment between neighboring actin monomers should be, respectively, 2.867 nm and 168° instead of 2.75 nm and 166.15°. These conditions ensure the stereo-specific interaction between actin and myosin and good agreement with the data gathered by electron microscopy and X-ray diffraction methods. The results suggest that the force is generated not only by the myosin cross-bridges but also by the thin filaments; the former acts by cyclical unwrapping and wrapping the thick filament backbone, and the latter byelongation.
Designing Data Protection Safeguards Ethically
Authors: Pagallo Ugo
Published: March 2011

Since the mid 1990s, lawmakers and scholars have worked on the idea of embedding data protection safeguards in information and communication technology (ICT) with the aim to access and control personal data in compliance with current regulatory frameworks. This effort has been strengthened by the capacities of computers to draw upon the tools of artificial intelligence (AI) and operations research. However, work on AI and the law entails crucial ethical issues concerning both values and modalities of design. On one hand, design choices might result in conflicts of values and, vice versa, values may affect design features. On the other hand, the modalities of design cannot only limit the impact of harm-generating behavior but also prevent such behavior from occurring via self-enforcement technologies. In order to address some of the most relevant issues of data protection today, the paper suggests we adopt a stricter, yet more effective version of “privacy by design.” The goal should be to reinforce people’s pre-existing autonomy, rather than having to build it from scratch.