bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Ca
2+
/Calcineurin-Regulated
cup
Gene Family in
Dictyostelium discoideum
and Its Possible Involvement in Development
Authors: Coukell Barrie , Li Yi , Moniakis John , Cameron Anne 
Published: February 2004

ABSTRACT

Changes in free intracellular Ca
2+
are thought to regulate several major processes during
Dictyostelium
development, including cell aggregation and cell type-specific gene expression, but the mechanisms involved are unclear. To learn more about Ca
2+
signaling and Ca
2+
homeostasis in this organism, we used suppression subtractive hybridization to identify genes up-regulated by high extracellular Ca
2+
. Unexpectedly, many of the genes identified belong to a novel gene family (termed
cup
) with seven members. In vegetative cells, the
cup
genes were up-regulated by high Ca
2+
but not by other ions or by heat, oxidative, or osmotic stress.
cup
induction by Ca
2+
was blocked completely by inhibitors of calcineurin and protein synthesis. In developing cells,
cup
expression was high during aggregation and late development but low during the slug stage. This pattern correlates closely with reported levels of free intracellular Ca
2+
during development. The
cup
gene products are highly homologous, acidic proteins possessing putative ricin domains. BLAST searches failed to reveal homologs in other organisms, but Western analyses suggested that Cup-like proteins might exist in certain other cellular slime mold species. Localization experiments indicated that Cup proteins are primarily cytoplasmic but become cell membrane-associated during Ca
2+
stress and cell aggregation. When
cup
expression was down-regulated by antisense RNA, the cells failed to aggregate. However, this developmental block was overcome by partially up-regulating
cup
expression. Together, these results suggest that the Cup proteins in
Dictyostelium
might play an important role in stabilizing and/or regulating the cell membrane during Ca
2+
stress and/or certain stages of development.
Flagellar Radial Spoke Protein 2 Is a Calmodulin Binding Protein Required for Motility in
Chlamydomonas reinhardtii
Authors: Yang Pinfen , Yang Chun , Sale Winfield S. 
Published: February 2004

ABSTRACT

Genetic and morphological studies have revealed that the radial spokes regulate ciliary and flagellar bending. Functional and biochemical analysis and the discovery of calmodulin in the radial spokes suggest that the regulatory mechanism involves control of axonemal protein phosphorylation and calcium binding to spoke proteins. To identify potential regulatory proteins in the radial spoke, in-gel kinase assays were performed on isolated axonemes and radial spoke fractions. The results indicated that radial spoke protein 2 (RSP2) can bind ATP and transfer phosphate in vitro.
RSP2
was cloned and mapped to the
PF24
locus, a gene required for motility. Sequencing revealed that
pf24
contains a point mutation converting the first ATG to ATA, resulting in only trace amounts of RSP2 and confirming the
RSP2
mapping. Surprisingly, the sequence does not include signature domains for conventional kinases, indicating that RSP2 may not perform as a protein kinase in vivo. However, the predicted RSP2 protein sequence contains Ca
2+
-dependent calmodulin binding motifs and a GAF domain, a domain found in diverse signaling proteins for binding small ligands including cyclic nucleotides. As predicted from the sequence, recombinant RSP2 binds calmodulin in a calcium-dependent manner. We postulate that RSP2 is a regulatory subunit of the radial spoke involved in localization of calmodulin for control of motility.
Potential research participants’ views regarding researcher and institutional financial conflicts of interest
Authors: Kim S Y H , Millard R W , Nisbet P , Cox C , Caine E D 
Published: February 2004

Background:Financial conflict of interest in clinical research is an area of active debate. While data exist on the perspectives and roles of academic institutions, investigators, industry sponsors, and scientific journals, little is known about the perspectives of potential research participants.Methods:The authors surveyed potential research participants over the internet, using the Harris Interactive Chronic Illness Database. A potential research participant was defined by: (1) self report of diagnosis by a health care professional and (2) willingness to participate in clinical trials. Email invitations were sent to 20 205 persons with coronary artery disease, breast cancer, or depression; a total of 6363 persons were screened; of these, 86% or 5478 met inclusion criteria and completed the survey. The outcome measures were respondents’ ratings on: importance of knowing conflict of interest information, whether its disclosure ought to be required, and its effect on willingness to participate—across seven widely discussed scenarios of financial conflicts of interest (ranging from commercial funding to equity ownership).Results:Majority responded that knowing conflict of interest information was “extremely” or “very” important; a larger majority felt financial conflicts of interest should be disclosed as part of informed consent (64% to 87%). In all seven scenarios, a majority was still willing to participate but in some scenarios a sizable minority would be wary of participation. Respondents were more wary of individual than institutional conflicts of interest. Illness group and sociodemographic factors had modest effects and did not affect the main trends.Conclusions:The prevailing practice of non-disclosure of financial conflicts of interest in clinical research appears contrary to the values of potential research participants.
Public attitudes towards the use of primary care patient record data in medical research without consent: a qualitative study
Authors: Robling M R , Hood K , Houston H , Pill R , Fay J , Evans H M 
Published: February 2004

Objectives:Recent legislative changes within the United Kingdom have stimulated professional debate about access to patient data within research. However, there is currently little awareness of public views about such research. The authors sought to explore attitudes of the public, and their lay representatives, towards the use of primary care medical record data for research when patient consent was not being sought.Methods:49 members of the public and four non-medical members of local community health councils in South Wales, UK gave their views on the value and acceptability of three current research scenarios, each describing access to data without patient consent.Results:Among focus group participants, awareness of research in primary care was low, and the appropriateness of general practitioners as researchers was questioned. There was general support for research but also concerns expressed about data collection without consent. These included lack of respect and patient control over the process. Unauthorised access to data by external agencies was a common fear. Current data collection practices, including population based disease registers elicited much anxiety. The key informants were equally critical of the scenarios and generally less accepting.Conclusions:This exploratory study has highlighted a number of areas of public concern when medical records are accessed for research without patient consent. Public acceptability regarding the use of medical records in research cannot simply be assumed. Further work is required to determine how widespread such views are and to inform those advising on confidentiality issues.
Non-therapeutic research with minors: how do chairpersons of German research ethics committees decide?: Figure 1
Authors: Lenk C , Radenbach K , Dahl M , Wiesemann C 
Published: February 2004

Objectives:Clinical trials in humans in Germany—as in many other countries—must be approved by local research ethics committees (RECs). The current study has been designed to document and evaluate decisions of chairpersons of RECs in the problematic field of non-therapeutic research with minors. The authors’ purpose was to examine whether non-therapeutic research was acceptable for chairpersons at all, and whether there was certainty on how to decide in research trials involving more than minimal risk.Design:In a questionnaire, REC chairpersons had to evaluate five different scenarios with (in parts) non-therapeutic research. The scenarios described realistic potential research projects with minors, involving increasing levels of risk for the research participants. The chairpersons had to decide whether the respective projects should be approved.Methods:A total of 49 German REC chairpersons were sent questionnaires; 29 questionnaires were returned. The main measurements were approval or rejection of research scenarios.Results:Chairpersons of German RECs generally tend to accept non-therapeutic research with minors if the apparent risk for the participating children is low. If the risk is clearly higher than “minimal”, the chairpersons’ decisions differ widely.Conclusion:The fact that there seem to be different attitudes of chairpersons to non-therapeutic research with minors is problematic from an ethical point of view. It suggests a general uncertainty about the standards of protection for minor research participants in Germany. Therefore, further ethical and legal regulation of non-therapeutic research with minors in Germany seems necessary.
Embryonic Cell Lines with Endothelial Potential: An In Vitro System for Studying Endothelial Differentiation
Authors: Yin Yijun , Que Jianwen , Teh Ming , Cao Wei Ping , El Oakley Reida Menshawe , Lim Sai-Kiang 
Published: February 2004

Objective—Endothelial differentiation is a fundamental process in angiogenesis and vasculogenesis with implications in development, normal physiology, and pathology. To better understand this process, an in vitro cellular system that recapitulates endothelial differentiation and is amenable to experimental manipulations is required.Methods and Results—Embryonic cell lines that differentiate exclusively into endothelial cells were derived from early mouse embryos using empirical but reproducible culture techniques without viral or chemical transformation. The cells were not pluripotent and expressed reduced levels ofOct 4andRex-1. They were non-tumorigenic with a population doubling time of ≈15 hours. When plated on matrigel, they readily differentiated to form patent tubular structures with diameters of 30 to 150 μm. The differentiated cells endocytosed acetylated low-density lipoprotein (LDL) and began to express endothelial-specific markers such as CD34, CD31, Flk-1, TIE2, P-selectin, Sca-1, and thy-1. They also expressed genes essential for differentiation and maintenance of endothelial lineages, eg, Flk-1, vascular endothelial growth factor (VEGF), and angiopoietin-1. When transplanted into animal models, these cells incorporated into host vasculature.Conclusions—These cell lines can undergo in vitro and in vivo endothelial differentiation that recapitulated known endothelial differentiation pathways. Therefore, they are ideal for establishing an in vitro cellular system to study endothelial differentiation.
Influence of incubation conditions on hatching success, embryo development and hatchling phenotype of common chameleon (Chamaeleo chamaeleon) eggs
Authors: Díaz-Paniagua  , Cuadrado  
Published: February 2004

AbstractChameleons lay flexible-shelled eggs that are affected by environmental characteristics during incubation. We incubated eggs of six clutches under four treatments using two different constant temperatures (25 and 29°C) and water potentials (-150 kPa and-600 kPa). Eggs gained mass in all treatments, especially under the wetter and warmer conditions. Temperature, not water potential, affected hatching rate, which was 100% under 25°C and 64% under 29°C. Development time was considered as the period during which eggs were incubated under both constant temperatures and differed between treatments, from an average length of 98.8 days in the wettest and warmest media to 144.2 days in the driest and coldest one. Differences in hatchling phenotype were mostly explained by clutch identity, although it was also affected by incubation treatments, with bigger and heavier hatchlings in colder treatments. Incubation conditions did not affect hatchling growth nor survival rates, but survivors were differentiated by their higher increase in egg mass during incubation. Los huevos de los camaleones tienen la cáscara flexible, estando influidos por las características del medio en que se encuentran. Se incubaron huevos de seis puestas en cuatro tratamientos, usando dos temperaturas de incubación constantes (25 y 29°C) y dos potenciales hídricos (-150 kPa y-600 kPa). Los huevos incrementaron de peso en todos los tratamientos, principalmente en los de condiciones más húmedas y cálidas. La tasa de eclosión resultó influida por el efecto de la temperatura, pero no por el del potencial hídrico. Eclosionó el 100% de los huevos incubados a 25°C y el 64% de los incubados a 29°C. Se apreciaron diferencias en la duración del desarrollo entre los huevos incubados en los distintos tratamientos, variando el promedio entre 98.8 días (en las condiciones más húmedas y cálidas) y 144.2 días (en el más seco y frío). Las diferencias apreciadas en el fenotipo de las crías se atribuyen principalmente a su origen materno, aunque también se apreciaron influencias de las condiciones de incubación, resultando crías de mayor tamaño y peso en los tratamientos de menor temperatura. Las condiciones de incubación no afectaron al crecimiento ni a la supervivencia de las crías, sobreviviendo las que procedían de huevos con mayor incremento de peso durante la incubación.
Aspects of population ecology of Testudo hermanni hermanni from Asinara Island, NW Sardinia (Italy, Western Mediterranean Sea): preliminary data
Authors: Zuffi Marco , Corti Claudia 
Published: February 2004

AbstractHermann's tortoise (Testudo hermanni Gmelin) of the Island of Asinara (NW Sardinia, Italy) has been studied during a period of four seasons. This population consisted of several individuals of large body size, some of them being amongst the largest known for this species. Bony shells of males were commonly found on this island, while the same was not true for female bony shells. Although wild boars (Sus scrofa) are potential large sized predators for tortoises, the analysis of carapace morphology did not reveal injuries signs due to bites. Male tortoises could die due to up-turning, as the result of male-male combats during the mating season, to possible hyperthermia when upturned, and to predation carried out by birds particularly when upturned. Estimated density was 4.88 individuals ha-1, which was similar to that of conspecifics from other areas studied so far.
Giant and long-lived? Age structure in Macroscincus coctei, an extinct skink from Cape Verde
Authors: Guarino Fabio , Andreone Franco 
Published: February 2004

AbstractThe age structure of the extinct giant Cape Verde skink Macroscincus coctei was studied using skeletochronology applied to 11 preserved males, 15 females, and one juvenile, collected at the end of the 19th century. Counts of lines of arrested growth (LAGs) indicated that in this species — which lived on islets with extreme natural conditions (e.g., hard aridity, lack of rainfall) — the maximum life span was estimated as 16 years for males and 12 years for females; the single juvenile was 4 years old. Although the sexes had similar mean ages, mean body length of males was significantly higher than that of females (283 versus 255 mm). There was no clear relationship between body length and estimated age, although the largest males were also the oldest. The analysis of LAGs revealed a sexual difference in growth rates, males reaching greater size earlier than females.
Aseasonal reproduction and high fecundity in the Cape grass lizard, Cordylus anguinus, in a fire-prone habitat
Authors: du Toit Annemarie , Mouton P. le Fras , Flemming Alexander 
Published: February 2004

AbstractWe investigated life history characters of the Cape grass lizard, Cordylus anguinus, and relate them to survival in the fire-prone habitat in which it occurs. Unlike in other cordylids, reproductive activity was found to be asynchronous among females, with vitellogenic and gravid females encountered virtually throughout the year. Aseasonal breeding will circumvent reduction or complete loss of reproductive effort for any given year due to fire. Female grass-lizards attain significantly larger body sizes than males. Clutch size ranged from three to seventeen and was positively correlated with snout-vent length. Maximum clutch size is more than three times that recorded for any other cordylid. We suggest that high fecundity will allow quick recruitment after a fire. To determine the reproductive cycle exhibited by males, testicular volume and seminiferous tubule diameter were measured, and spermatogenic activity assessed qualitatively, using Licht's classification system. Our data indicate that C. anguinus has a post-nuptial spermatogenic cycle. The species differs from other cordylids having a post-nuptial cycle, in that spermatogenesis already commences in spring.
Distribution of genetic variation and taxonomy of insular and mainland populations of the Italian wall lizard, Podarcis sicula
Authors: Capula Massimo , Ceccarelli Arianna 
Published: February 2004

AbstractThe genetic structure and heterogeneity of Podarcis sicula (Reptilia, Lacertidae) was studied in insular (Pontine Archipelago) and mainland (central and southern Italy) populations by means of allozyme electrophoresis at 20 presumptive gene loci. Genetic variability in the species is low and genetic subdivision is high. The highest values of percent polymorphism and heterozygosity were found in the samples from the southernmost part of Italy (Calabria). The insular samples from the Pontine Archipelago were characterized by loss of alleles and erosion of genetic variability. Population heterogeneity analysis carried out by the estimation of Wright's F-statistics demonstrated substantial genetic differentiation among populations. F-statistics and genetic distance data show that genetic variation is distributed into three population groups. The first group includes the genetically very similar populations from central Italy and the Pontine Archipelago, the second includes the populations from Campania (southern Italy), the third comprises the populations from the southernmost part of the Italian Peninsula (Calabria). Based on the results of the allozyme data, the systematic status of the subspecies of P. sicula occurring in the studied areas is discussed.
Seasonal and daily activity patterns of Vipera latastei in northern Portugal
Authors: Brito José 
Published: February 2004

AbstractThe annual and daily activity cycles of Vipera latastei were investigated in northern Portugal from 1999 to 2001, based on field observations, radio-tracking data and road killed snakes. Annual activity was extended from early March to late October, although some snakes were active during winter. Two annual peaks of activity were observed, a minor one in March-May and a major one in September-October. The daily activity pattern of vipers in spring and autumn was unimodal, whereas in summer they expanded their activity from early morning to late afternoon, and were also active at night. Activity and body exposure of adult males were correlated with meteorological variables. Females had shedding periods in June and July, whereas males shed their skin more frequently in June and August. Sperm was detected in the vas deferens of males in October to December. Females ovulated in June and new-born vipers were found from early August. Mating season is apparently restricted to autumn, and spring mating is either absent or very reduced.
Do Male Black-capped Chickadees Eavesdrop on Song Contests? A Multi-speaker Playback Experiment
Authors: Ratcliffe Laurene , Mennill Daniel 
Published: February 2004

AbstractWithin a network of communicating individuals, animals may gather information about the relative quality of conspecifics by eavesdropping on their signalling interactions. For territorial male songbirds, eavesdropping may be a low-cost, low-risk method for assessing the relative quality of the males around them. We used a three-speaker playback design to evaluate whether male black-capped chickadees (Poecile atricapillus) respond differently to two simulated countersinging intruders who differ only in relative features of their singing performance. We arranged three loudspeakers in an equilateral triangle at the center of playback subjects' territories. After luring males to the first loudspeaker by broadcasting non-song vocalizations, we played songs from the remaining loudspeakers to simulate a countersinging interaction between two male intruders. During the interactions, one simulated intruder consistently overlapped the songs of the other, a behaviour thought to be a signal of directed aggression in songbirds. Territorial male chickadees discriminated between the simulated intruders by preferentially approaching the loudspeaker broadcasting the overlapping signal, suggesting that males eavesdrop on other males' countersinging interactions. Male responses to playback support the idea that overlapping is a more threatening signal than being overlapped. Responses varied with the dominance status of the subject. High-ranking males approached the overlapping loudspeaker in 15 of 16 cases whereas low-ranking males approached the overlapping speaker in only 5 of 10 cases, suggesting that males of different quality may use different tactics for territorial defense.
East Timor: A Critique of the Model of Accountability for Serious Human Rights and International Humanitarian Law Violations
Authors: Othman Mohamed 
Published: February 2004

AbstractThe article examines the model of accountability for international humanitarian law violations committed in East Timor in 1999, in which the Security Council opted for parallel accountability,in East Timor and Indonesia. In the former, it is anchored on a 'mixed' judicial process, administered by 'Special Panels' of the Dili District Court composed of national and international judges. Although its legal framework is sound, and persons 'most responsible' have been indicted, the allocated resources were meager, desired full accountability overambitious, and most accused remain at large. In Indonesia, the ad hoc Human Rights Court's framework is laden withjurisdictional loopholes, and the conduct of prosecutions non-diligent, reflecting 'unwillingness or inability', genuinely to account. If that process had been under the ICC regime, it would have been a valid ground for seizure of jurisdiction by that court. The net result of the model is a misjoinder of human rights perpetrators.