bluuebunny/crossref_metadata_2025_split huggingface dataset:
CARBON STARS
Authors: Wallerstein George , Knapp Gillian R. 
Published: July 2002

▪ Abstract  Absolute magnitudes are estimated for carbon stars of various subtypes in the Hipparcos catalogue and as found in the Magellanic Clouds. Stellar radii fall within the limits of 2.4–4.7 AU. The chemical composition of carbon stars indicates that the C-N stars show nearly solar C/H, N/H, and 12C/13C ratios. This indicates that much of the C and N in our Galaxy came from mass-losing carbon stars. Special carbon stars such as the C-R, C-H, and dC stars are described. Mass loss from asymptotic giant branch carbon stars, at rates up to several × 10−5 M[Formula: see text] year−1, contributes about half of the total mass return to the interstellar medium. R stars do not lose mass and may be carbon-rich red giants. The mass loss rates for Miras are about 10 times higher than for SRb and Lb stars, whose properties are similar enough to show that they are likely to belong to the same population. The distribution of carbon star mass loss rates peaks at about 10−7 M[Formula: see text] year−1, close to the rate of growth of the core mass and demonstrative of the close relationship between mass loss and evolution. Infrared spectroscopy shows that dust mixtures can occur. Detached shells are seen around some stars; they appear to form on the time scales of the helium shell flashes and to be a normal occurrence in carbon star evolution.
O2-Sensing Mechanisms in Excitable Cells: Role of Plasma Membrane K+ Channels
Authors: Haddad Gabriel G. , Jiang Chun 
Published: July 2002

Although carotid chemosensitive glomus cells have been the most extensively studied from the vantage point of how cells sense the lack of O2, it is clear that all tissues sense O2 deprivation. In addition, all mammalian cells can trigger a cascade of events that, depending on the severity and duration of hypoxia-induced stress, can lead to permanent injury and death or to adaptation and survival. Crucial in this cascade, we believe, how the cascade is initiated, how O2 lack is detected by cells, and how these initial steps can activate further processes. In this chapter, we focus on the initial steps of O2 sensing in tissues most commonly studied, i.e. carotid glomus cells, central neurons, smooth muscle cells, and neuro-epithelial bodies of the airways. Recently it has become clear that plasma membranes of various tissues can sense the lack of O2, not only indirectly via alterations in the intracellular milieu (such as pH, Ca, ATP, etc), but also directly through an unknown mechanism that involves plasma-membrane K channels and possibly other membrane proteins. This latter mechanism is suspected to be totally independent of cytosolic changes because excised patches from plasma membranes were used in these experiments from carotid cells and neurons. There are a number of questions in this exciting area of research that pertain to the role of this plasma-membrane O2-sensing mechanism in the overall cell response, identification of all the important steps in O2 sensing, differences between O2-tolerant and O2-susceptible cells, and differences between acute and chronic cell responses to lack of O2.
When in Doubt, Do it Both Ways: Brain Evidence of the Simultaneous Activation of Conflicting Motor Responses in a Spatial Stroop Task
Authors: DeSoto M. Catherine , Fabiani Monica , Geary David C. , Gratton Gabriele 
Published: July 2002

Abstract
Response competition is often considered an important contributor to the delayed reaction to stimuli for which physical and semantic information are in conflict (“Stroop” effect). Response competition implies that brain areas associated with correct and incorrect responses (e.g., left and right motor cortices) should be simultaneously activated in conflict conditions. However, there is at present little direct evidence of this phenomenon, in part because of the paucity of brain imaging techniques that can independently monitor the time course of activation of adjacent brain areas, such as the motor areas. In the present study, we show that the event-related optical signal (EROS) can provide these types of data. The results confirm the prediction that conflict trials elicit simultaneous activation of both motor cortices, whereas nonconflict trials elicit brain activity only in the contralateral motor cortex. These data support a parallel view of the human information processing system.
Neural Basis of Endogenous and Exogenous Spatial Orienting: A Functional MRI Study
Authors: Rosen Allyson C. , Rao Stephen M. , Caffarra Paolo , Scaglioni Augusto , Bobholz Julie A. , Woodley Scott J. , Hammeke Thomas A. , Cunningham Joseph M. , Prieto Thomas E. , Binder Jeffrey R. 
Published: July 2002

Abstract
Whole-brain functional magnetic resonance imaging (MRI) was used to examine the neural substrates of internally (endogenous) and externally (exogenous) induced covert shifts of attention. Thirteen normal subjects performed three orienting conditions: endogenous (location of peripheral target predicted by a central arrow 80% of the time), exogenous (peripheral target preceded by a noninformative peripheral cue), and control (peripheral target preceded by noninformative central cue). Behavioral results indicated faster reaction times (RTs) for valid than for invalid trials for the endogenous condition but slower RTs for valid than for invalid trials for the exogenous condition (inhibition of return). The spatial extent and intensity of activation was greatest for the endogenous condition, consistent with the hypothesis that endogenous orienting is more effortful (less automatic) than exogenous orienting. Overall, we did not observe distinctly separable neural systems associated with the endogenous and exogenous orienting conditions. Both exogenous and endogenous orienting, but not the control condition, activated bilateral parietal and dorsal premotor regions, including the frontal eye fields. These results suggest a specific role for these regions in preparatory responding to peripheral stimuli. The right dorsolateral prefrontal cortex (BA 46) was activated selectively by the endogenous condition. This finding suggests that voluntary, but not reflexive, shifts of attention engage working memory systems.
Role of the Cerebellum in Tuning Anticipatory and Reactive Grip Force Responses
Authors: Serrien Deborah J. , Wiesendanger Mario 
Published: July 2002

Abstract
The aim of our study was to determine if load perturbations that could destabilize grasp control are adequately controlled by cerebellar patients. We examined patients with unilateral cerebellar lesions who had largely recovered from their initial symptoms and compared grip force regulation for the affected and unaffected hand during a drawer-opening task. Two experimental paradigms were included: (1) a brief load perturbation during a self-stopped drawer pull and (2) a loading impact when the drawer was pulled out to the mechanical stop. The results showed that when a self-stopped movement was perturbed during its trajectory, anticipatory grip force increase was smaller for the affected than for the unaffected hand, illustrating a disturbed gain control due to cerebellar dysfunction. When the mechanical stop arrested the movement, the amount of grip force did not differ significantly between the affected and unaffected side; however, both hands used different control strategies. Whereas the unaffected hand anticipated the load perturbation by a ramp-like increase of grip force toward the impending impact, the affected hand increased grip force at movement onset to a default level and maintained this value until the task was ended. In addition, the latency between impact and reactive peak in grip force was prolonged for the affected hand, suggesting a delayed cerebellar transmission of reactive responses. In conclusion, these findings demonstrate that the cerebellum is involved in anticipatory and reactive mechanisms dealing with load perturbations during goal-directed behavior.
Divergence in mitochondrial DNA of Near Eastern water frogs with special reference to the systematic status of Cypriote and Anatolian populations (Anura, Ranidae)
Authors: Ohst Torsten , Böhme Wolfgang , Schreiber Robert , Plötner Jörg 
Published: July 2002

AbstractWater frogs from Anatolia, Syria, Jordan, and central Asia (Turkmenistan, Uzbekistan, Kazakhstan) were compared on the basis of the complete mitochondrial (mt) ND3 gene (340 bp), two flanking mt t-RNA gene fragments (26 bp), and a 374 bp fragment of the mt 12S rRNA gene. A total of 27 haplotypes were found among the investigated individuals. Anatolian water frogs differed from Syrian and Jordanian Rana bedriagae by 2.2-3.4% of the analysed sites. The observed divergence (2.8-4.1%) between the Cypriote water frogs and frogs from the surrounding mainland (southern Turkey, west Syria) was in the same range as between R. bedriagae and European R. ridibunda (3.1-3.9%). These results suggest that neither the Cypriote nor the Anatolian water frogs represent R. bedriagae. Furthermore, maximum parsimony and neighbour-joining trees showed a clear subdivision of Asian water frogs into three Anatolian lineages, two central Asian lineages, a Cypriote lineage and the bedriagae lineage. In all trees the Cypriote lineage branches off first and a clade formed by two Anatolian lineages is placed as the sister group of water frogs from Turkmenistan and Uzbekistan, whereas the phylogenetic positions of R. bedriagae, the Ceyhan lineage, the Kazakhstan lineage and R. ridibunda remain unclear.
PARENTAL CARE AND PARENTAGE IN MONOGAMOUS GREAT SPOTTED WOODPECKERS (PICOIDES MAJOR) AND MIDDLE SPOTTED WOODPECKERS (PICOIDES MEDIUS)
Authors: Michalek Klaus , Winkler Hans 
Published: July 2002

Abstract
Paternal effort is high in some monogamous mating systems. Trivers' (1972) model predicts that high male investment in brood care should evolve only when males have a high certainty of paternity. For this study, we chose two woodpecker species: the great spotted woodpecker (Picoides major) and the middle spotted woodpecker (Picoides medius). Both species were socially monogamous despite a very high breeding density in the study area. We used DNA fingerprinting to determine whether these two species were also genetically monogamous. We found that in great spotted and middle spotted woodpeckers paternal effort was high. Multi-locus DNA-fingerprinting showed that its actual paternity was also very high. In P. major all 161 young from 36 broods and in P. medius all 61 young from 13 broods were sired by the male feeding at the nest hole. There were also no cases of intraspecific brood parasitism or quasi parasitism (P. major: 114 chicks from 24 broods; P.medius: 33 chicks from 8 broods). We further found no case of mate switching during the fertile period of the female. Great spotted and middle spotted woodpeckers are typical of a group of monogamous nonpasserine birds with high male investment in brood care having low frequencies of EPP. We did not find efficient paternity guards. High certainty of paternity may be explained by paternal care being essential for female reproductive success, as in many seabirds and birds of prey. Females rarely engage in extra-pair copulations probably because they are constrained by male care. Males in both species spend little effort in acquiring mates as well as in extrapair copulations. They expend their reproductive effort in defending territories and in parental care. Females compete intensely with members of their own sex for pair formation before the time of frequent copulation. Choosing and securing a high quality partner is the only possibility to achieve high reproductive success for both sexes.
VOCALIZATIONS AROUND THE TIME OF MILK EJECTION IN DOMESTIC PIGLETS: A RELIABLE INDICATOR OF THEIR CONDITION?
Authors: Illmann Gudrun , Špinka Marek , De Jonge Francien 
Published: July 2002

Abstract
In some nursings, piglets initiate nose contacts with their mother and emit typical 'croaking' vocalizations. We examined whether the croaking vocalizations reflect the condition of the piglets and whether the sows increase their maternal investments in response to those vocalizations. The following predictions were tested: (i) Piglets with lower weight gain should vocalize more than piglets with higher weight gain; (ii) piglets' milk intake is lower in those nursings in which they vocalize after milk ejection; (iii) piglets make more croaking vocalization in nursings which were preceded by longer intervals since the last nursing with milk ejection; (iv) sows permit longer post-ejection massage in nursings in which piglets vocalized immediately after milk ejection; (v) sows decrease the interval until the succeeding nursing after those nursings in which the piglets have vocalized. Hypotheses (i) and (ii) were investigated by controlling the inter-nursing intervals in 14 sows and recording the milk intake of individual piglets' over 24 hours during days 7 or 8 post partum (Experiment 1). Hypotheses (iii) to (v) were examined through analysing video recordings of undisturbed six h nursing sequences in 29 sows (Experiments 2 and 3). The majority of our predictions were not confirmed: piglets did not vocalize more (either before or after milk ejection) after longer intervals since last milk ejection; they did not vocalize more in nursing in which they received less milk; and it was not the piglets or the litter with a lower milk intake or lower weightgain that emitted more vocalization. Neither of our predictions regarding the influence of croaking vocalizations on maternal investment was confirmed. The vocalizations were in no way associated with the length of the following inter-nursing interval or with the permission of longer udder massage. To conclude, piglet croaking vocalizations during nursings are not reliable indicators of piglet condition and are not used by sows to adjust their maternal investment.
Racial Disparities in Receipt of Guideline-Concordant Care in Older Adults With Early Breast Cancer
Authors: Castillo Brenda S. , Boadi Taussia , Han Xiaoyan , Shulman Lawrence N. , Martei Yehoda M. 
Published: October 2024

ImportanceRacial disparities in receipt of guideline-concordant care (GCC) among older patients with potentially curable breast cancer are understudied.ObjectiveTo determine whether rates of GCC, time to treatment initiation, and all-cause mortality in stage I to III breast cancer differ by race among older adults.Design, Setting, and ParticipantsThis cohort study used data from the National Cancer Database and included patients aged 65 years and older with stage I to III breast cancer, diagnosed between 2010 and 2019. Data analysis was conducted between July 2022 to July 2023.ExposuresRace, defined as non-Hispanic Black or non-Hispanic White.Main Outcomes and MeasuresThe primary outcome was nonreceipt of GCC, defined using the National Comprehensive Cancer Network guidelines, and all-cause mortality. The secondary outcome was time to treatment initiation. Univariate and multivariate regression analysis were used to determine association between exposure and outcomes. Models for GCC and all-cause mortality included age, stage, receptor status, year of diagnosis, Charlson-Deyo comorbidity index, insurance, health care setting, and neighborhood-level educational attainment and median income.ResultsThe analytic cohort included 258 531 participants (mean [SD] age, 72.5 [6.0] years), with 25 174 participants who identified as non-Hispanic Black (9.7%) and 233 357 participants who identified as non-Hispanic White (90.3%), diagnosed between 2010 and 2017. A total of 4563 non-Hispanic Black participants (18.1%) and 35 374 non-Hispanic White participants (15.2%) did not receive GCC. Non-Hispanic Black race, compared with non-Hispanic White race, was associated with increased odds of not receiving GCC in the multivariate analysis (adjusted odds ratio [aOR], 1.13; 95% CI, 1.08-1.17; P &amp;lt; .001). Non-Hispanic Black race was associated with 26.1% increased risk of all-cause mortality in the univariate analysis, which decreased to 4.7%, after adjusting for GCC and clinical and sociodemographic factors (adjusted hazard ratio, 1.05; 95% CI, 1.01-1.08; P = .006). Non-Hispanic White race, compared with non-Hispanic Black race, was associated with increased odds of initiating treatment within 30 (OR, 1.65; 95% CI, 1.6-1.69), 60 (OR, 2.11; 95% CI, 2.04-2.18), and 90 (OR, 2.39; 95% CI, 2.27-2.51) days of diagnosis.Conclusions and RelevanceIn this cohort study, non-Hispanic Black race was associated with increased odds of not receiving GCC and less timely treatment initiation. Non-Hispanic Black race was associated with increased all-cause mortality, which was reduced after adjusting for GCC and clinical and sociodemographic factors. These findings suggest that optimizing timely receipt of GCC may represent a modifiable pathway to improving inferior survival outcomes among older non-Hispanic Black patients with breast cancer.
Pharmacologic Treatments for Dementia and the Risk of Developing Age-Related Macular Degeneration
Authors: Wang Jingya , Antza Christina , Lee Wen Hwa , Coker Jesse , Keane Pearse A. , Denniston Alastair K. , Nirantharakumar Krishnarajah , Adderley Nicola J. 
Published: October 2024

ImportanceAge-related macular degeneration (AMD) is the leading cause of blindness among people aged 50 years or older worldwide. There is a need for new strategies for the prevention and treatment of AMD. There is some limited evidence to suggest the possibility of a protective association of dementia medications with the development of some types of AMD, but the evidence is weak.ObjectiveTo investigate whether the dementia medications memantine and donepezil are associated with the risk of developing AMD.Design, Setting, and ParticipantsThree population-based cohort studies were performed using data from the Clinical Practice Research Datalink GOLD and Aurum databases from May 15, 2002, to June 21, 2022. Participants included individuals with dementia (vascular dementia, nonvascular dementia, or Alzheimer disease) aged 40 years or older. Statistical analysis was carried out between February and November 2023.ExposuresExposures were dementia medications. Cohort 1 compared patients prescribed donepezil with those prescribed rivastigmine or galantamine using the new-user design. Cohort 2 compared memantine with donepezil, rivastigmine, or galantamine using the prevalent new-user design. In a sensitivity analysis, cohort 3 compared memantine with rivastigmine or galantamine only.Main Outcomes and MeasuresNew diagnosis of AMD.ResultsThere were 132 846 individuals (mean [SD] age, 80.4 [7.6] years; 61.8% women; mean [SD] body mass index [BMI], 25.5 [4.6]) with a diagnosis of dementia included in cohort 1, 159 419 individuals (mean [SD] age, 81.2 [7.6] years; 59.7% women; mean [SD] body mass index [BMI], 25.6 [4.7]) with a diagnosis of dementia included in cohort 2, and 92 328 individuals with a diagnosis of dementia included in cohort 3 (mean [SD] age, 80.9 [7.7] years; 58.5% women; mean [SD] body mass index [BMI], 25.5 [4.7]). The adjusted hazard ratio (HR) for donepezil compared with rivastigmine or galantamine (cohort 1) was 0.95 (95% CI, 0.67-1.35). The adjusted HR for memantine compared with donepezil, rivastigmine, or galantamine (cohort 2) was 1.03 (95% CI, 0.83-1.27). The adjusted HR for memantine vs rivastigmine or galantamine only (cohort 3) was 1.24 (95% CI, 0.83-1.86).Conclusions and RelevanceThis cohort study of patients with dementia found no significant associations between memantine or donepezil compared with other dementia medications and the risk of development of AMD. Further research is recommended to examine any possible pathophysiological protective action of memantine and other dementia medications against the development of AMD.
Firearm Experiences, Behaviors, and Norms Among Rural Adolescents
Authors: Weybright Elizabeth H. , Terral Heather F. , Hall Ashley , Varrella Gary , Ellyson Alice M. , Schleimer Julia P. , Kuklinski Margaret R. , Dalve Kimberly , Gause Emma L. , Oesterle Sabrina , Rowhani-Rahbar Ali 
Published: October 2024

ImportanceRural adolescents are at high risk for firearm-related injury, yet most existing prevention efforts are informed by research conducted in urban areas. Despite the need to account for rural perspectives, few studies have investigated the unique social ecological context of firearms for rural adolescents or have directly engaged with rural adolescents to understand their views on firearm use.ObjectiveTo describe rural adolescents’ firearm behaviors and perceptions of firearm-related social norms within their communities, peer groups, and families.Design, Setting, and ParticipantsThis cross-sectional study used a convergent mixed-methods design and involved a community-based participatory research approach. Participants comprised 93 adolescents residing in rural Washington state and enrolled in a county or tribal reservation 4-H youth development program as an intermediate or senior age-level grouping (ie, aged 12-19 years). Adolescents completed a survey and participated in a semistructured focus group or interview between September 1, 2021, and September 30, 2022. Data were analyzed using descriptive and thematic analysis.Main Outcomes and MeasuresIndividual handgun behavior and peer, family, and community perceptions of firearm-related social norms.ResultsThe sample included 93 adolescents (mean [SD] age, 15.7 [1.7] years; 49 female participants [52.7%]). Approximately half of participants (52 [55.9%]) had carried a handgun at some point in their lives, with a mean (SD) age at first carry of 10.9 (3.1) years. Primary themes across quantitative and qualitative data focused on social norms (specifically, acceptable and unacceptable ways to engage with firearms, reasons for carrying firearms, and places to carry a firearm).Conclusions and RelevanceIn this cross-sectional study, rural adolescents in 4-H programs generally understood acceptable and unacceptable firearm carrying behaviors, which aligned with state laws. Findings provide context for rural adolescent behaviors such as carrying a firearm predominantly for prosocial reasons (hunting, recreation, and sport) and adult behavior such as carrying for protection of person and personal property. Understanding firearm-related social norms in rural communities holds implications for firearm injury prevention efforts, especially related to enhancing training, developing norms-based prevention approaches, and tailoring efforts to rural settings.