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1.
This paper examines a statistics debate among African American caregivers raising children with disabilities for insights
into the work of “African American mothering.” Using ethnographic, narrative and discourse analyses, we delineate the work
that African American mothers do—in and beyond this conversation—to cross ideological and epistemological boundaries around
race and disability. Their work entails choosing to be an “I” and, in some cases, actively resisting being seen as a “they”
and/or part of a collective “we” in order to chart alternative futures for themselves and their children. 相似文献
2.
Through the use of principal components analysis of the correlation matrix between excentricity quotients of intra- and inter-individual
transitions between pairs of the 22 most frequent behaviour elements of male and female gelada baboons observed in captivity,
the total variance could be described in terms of a low number of causal factors. In intra-individual sequences the five factors
requested of the analysis explain 74 per cent of the total variance. The following intra-individual groupings were found:
(I) “autostimulation”, (II) “intensive social” versus “groom”, (III) “male sexual”, (IV) “attack” versus “sexual presentation”,
and (V) “greeting” versus “threat”. In inter-individual transitions, the five factors explain 68 per cent of the variance.
The following communicative sets were found: (1) “female-sexual releasing”, (2) “greeting and approaching releasing” versus
“groom releasing”, (3) “austostimulation releasing” versus “male-sexual releasing”, (4) “fight releasing”, and (5) “conflict”.
Mimetic induction of same acts or acts within one particular intra-individual set was frequent. 相似文献
3.
We summarize the ethnographic literature illustrating that “abnormal birth” circumstances and “ill omens” operate as cues
to terminate parental investment. A review of the medical literature provides evidence to support our assertion that ill omens
serve as markers of biological conditions that will threaten the survival of infants. Daly and Wilson (1984) tested the prediction
that children of demonstrably poor phenotypic quality will be common victims of infanticide. We take this hypothesis one stage
further and argue that some children will be poor vehicles for parental investment yet are not of demonstrably poor quality
at birth. We conclude that when people dispose of infants due to “superstitious beliefs” they are pursuing an adaptive strategy
in eliminating infants who are poor vehicles for parental investment.
Catherine Hill lectures in biological anthropology/human sciences at Durham University’s University College, Stockton. She
trained in biological anthropology at University College, London. Her current research interests include human and nonhuman
primate socioecology and human resource ecology and development issues.
Helen Ball lectures in biological anthropology/human sciences at Durham University’s University College, Stockton. She trained
in biological anthropology at the University of Massachusetts at Amherst. Her current research interests include nonhuman
primate behavior and socioecology, reproductive biology, and evolutionary issues. 相似文献
4.
Overview This review considers the “tween twixt and twain” of hair cell physiology, specifically the signaling elements and membrane
conductances which underpin forward and reverse transduction at the input stage of hair cell function and neurotransmitter
release at the output stage. Other sections of this review series outline the advances which have been made in understanding
the molecular physiology of mechanoelectrical transduction and outer hair cell electromotility. Here we outline the contributions
of a considerable array of ion channels and receptor signaling pathways that define the biophysical status of the sensory
hair cells, contributing to hair cell development and subsequently defining the operational condition of the hair cells across
the broad dynamic range of physiological function. 相似文献
5.
P. G. Kostyuk 《Neurophysiology》1997,29(4-5):191-194
Calcium ions are the most universal intracellular messengers transmitting signals from the plasmalemma of excitable cells
to the intracellular structures and triggering or modulating in this way most cellular functions. The molecular mechanisms
responsible for injection of Ca ions into the cytoplasm during cellular activity and for producting transient elevations of
their cytoplasmic free level (calcium “transient,” or “signals”) have been a subject of extensive investigation in numerous
laboratories during last three decades. In a short review it is impossible to summarize the results obtained; two extensive
publications on this subject have appeared already from our laboratory [1, 2]. Therefore, here the main attention will be
paid to the most recent data from our laboratory concerning different aspects of the mechanisms forming calcium signals in
neuronal cells. 相似文献
6.
Curtis J. Richardson 《Wetlands Ecology and Management》2010,18(5):517-542
The Everglades is the largest subtropical wetland in the United States. Because of its size, floral and faunal diversity,
geological history and hydrological functions on the Florida landscape, the remaining Everglades are considered to be the
crown jewel of U.S. wetlands. It is also called a “sentinel wetland” to test our society’s resolve for ecosystem restoration.
Originally called Pa-hay-okee (“grassy lake”) by the American Indians, it was later popularized as the “river of grass” by
Marjory Stoneman Douglas. This metaphor unfortunately has led to a simplistic view of the complexities of the Everglades ecosystem
and how it functions on the landscape. Often incorrectly referred to as the “marsh” or “swamp,” the Everglades is a fen peatland
or alkaline mire. These are important distinctions when one considers how different marshes and swamps are from peatlands
in terms of their hydrologic controls, biogeochemistry, rate of peat development, plant and animal communities and-importantly-succession
patterns. This paper provides a brief review of the geological processes that led to the development of the Everglades, compares
historic and current hydrologic flow patterns, assesses nutrient conditions, presents information on vegetation communities
and succession patterns, and provides a new peatland classification of the Everglades system, which may help in the development
of a more appropriate restoration management framework. 相似文献
7.
S. V. Tillib 《Molecular Biology》2011,45(1):66-73
This short review provides an introduction to the rapidly developing field of generation and utilization of “camel nanoantibodies”
(or “nanobodies”). The term “nanoantibody” or “nanobody” was given to single-domain variable fragments of special type of
antibodies that naturally exist (in addition to classical types of antibodies) in blood of Camelidae family animals and in
some chondrichthyan fishes. The existence of very efficient technology of nanobody generation and some very useful characteristic
features promise a big potential for their use in immunobiotechnology and medicine. 相似文献
8.
Brada B 《Culture, medicine and psychiatry》2011,35(2):285-312
This essay argues that what makes “global health” “global” has more to do with configurations of space and time, and the claims
to expertise and moral stances these configurations make possible, than with the geographical distribution of medical experts
or the universal, if also uneven, distribution of threats to health. Drawing on a study of public–private partnerships supporting
Botswana’s HIV/AIDS treatment program, this essay demonstrates ethnographically the processes by which “global health” and
its quintessential spaces, namely “resource-limited” or “resource-poor settings,” are constituted, reinforced, and contested
in the context of medical education and medical practice in Botswana’s largest hospital. Using Silverstein’s work on orders
of indexicality, I argue that the terms of “global health” are best understood as chronotopic, and demonstrate how actors
orient themselves and others spatio-temporally, morally, and professionally by using or refuting those terms. I conclude by
arguing that taking “global health” on its own terms obscures the powerful forces by which it becomes intelligible. At stake
are the frames within which medical anthropologists understand their objects of study, as well as the potential for the spaces
of “global health” intervention to expand ever outward as American medical personnel attempt to calibrate their experiences
to their expectations. 相似文献
9.
Sharon E. Kingsland 《Journal of the history of biology》2009,42(2):289-324
In Landscapes and Labscapes Robert Kohler emphasized the separation between laboratory and field cultures and the creation of new “hybrid” or mixed practices
as field sciences matured in the early twentieth century. This article explores related changes in laboratory practices, especially
novel designs for the analysis of organism–environment relations in the mid-twentieth century. American ecologist Victor Shelford
argued in 1929 that technological improvements and indoor climate control should be applied to ecological laboratories, but
his recommendations were too ambitious for the time. In the postwar period Frits W. Went, plant physiologist at the California
Institute of Technology, created a new high-tech laboratory, dubbed a “phytotron”, in the hope that it would transform plant
sciences by allowing for unprecedented control of environmental variables. Went’s aspirations, the research conducted in his
laboratory, and its impact in initiating an international movement, are considered. Went’s laboratory can be seen as a “hybrid
culture” evolving in the laboratory, complementing and intersecting with some of the field practices that Kohler describes.
It was also a countercultural movement against the reductionist trends of molecular biology in the 1950s and 1960s. By considering
the history of the laboratory in relation to field sciences, we can explore how new funding sources and cross-disciplinary
relations affected the development of field sciences, especially in the postwar period. 相似文献
10.
Two successive hydroponic experiments were carried out to identify barley varieties tolerant to Cd toxicity via examining
Soil–Plant Analyses Development (SPAD) value, plant height, leaves and tillers per plant, root number and volume, and biomass
accumulation. The results showed that SPAD values (chlorophyll meter readings), plant height, leaf number, root number and
volume, and biomass accumulation of shoot/root were significantly reduced in the plants grown in 20 μM Cd nutrient solution
compared with control, and the uptake and translocation of Zn, Mn, and Cu was also strictly hindered. Furthermore, there was
a highly significant difference in the reduction in these growth parameters among varieties, and varieties “Weisuobuzhi” and
“Jipi 1” showed the least reduction both in the two experiments, suggesting their high tolerance to Cd toxicity, while “Dong
17” and “Suyinmai 2” with the greatest reduction and the toxicity symptoms appeared rapidly and severely, denoting as Cd-sensitive
varieties. Significant variety difference in Cd concentration was also found, with Weisuobuzhi containing the highest and
Jipi 1 the lowest Cd concentration in shoots. 相似文献
11.
Substitution of nitrilotriacetic acid (NTA) for polyphosphates in detergents has brought questions concerning its potential
toxicity and impact on trace metal distribution in the environment. A calculation based upon metal ligand equilibria, known
environmental concentrations of NTA following extensive detergent usage, and the presence of competitive metal-binding ligands
and trace elements demonstrates that NTA will be present almost completely as the calcium and magnesium chelates. An analogous
estimate of the speciation of NTA in various toxicity studies demonstrates that the onset of chronic toxicity in feeding studies
is coincident with the presence of significant concentrations of “free” NTA in the gastrointestinal tract. Massive doses of
NTA over long periods of time cause reproducible renal tumors in rats, but dosages of 7500 ppm administered indefinitely are
without measurable effect. 相似文献
12.
Dynamic role of “illite-like” clay minerals in temperate soils: facts and hypotheses 总被引:2,自引:0,他引:2
Analysis of new data and reinterpretation of published information for clay minerals found in temperate climate soil profiles
indicates that there is often a gradient of “illite-like” clay minerals with depth. We used the term “illite-like” because
these observations are based on X-Ray Diffractogram patterns and not on layer charge measurements which allow to define properly
illite. It appears that “illite-like” layers are concentrated in the upper, organic - rich portion of the soil profile both
under grassland and forest vegetation. “Illite-like” layer quantity seems directly related to soil potassium status. Indeed,
intensive agriculture practises without potassium fertilization reduce “illite-like” content in surface soils, whereas several
years of potassic fertilization without plant growth can increase “illite-like” content. The potassic soil clay mineral, illite,
is particularly important in that it can be the major source of readily available potassium for plants. Spatial and temporal
dynamics of clay minerals should be related to the potassium cycle. We propose that the frequently observed general trend
of increasing exchangeable potassium in the top soil can be correlated with an increase in “illite-like” in the clays and
that the decrease of potassium caused by intensive agricultural practices leads to “illite-like” layer destabilization. This
vision of “illite-like” layer as a potassium reservoir refueled by plants and emptied by intensive cropping renews the concept
of potassium availability and indicates a need to be discussed as well in natural ecosystems as in cultivated ecosystems. 相似文献
13.
A novel technique (“bioshrouding”) for safeguarding highly reactive sulfidic mineral tailings deposits is proposed. In this,
freshly milled wastes are colonised with ferric iron-reducing heterotrophic acidophilic bacteria that form biofilms on reactive
mineral surfaces, thereby preventing or minimising colonisation by iron sulfide-oxidising chemolithotrophs such as Acidithiobacillus ferrooxidans and Leptospirillum spp. Data from initial experiments showed that dissolution of pyrite could be reduced by between 57 and 75% by “bioshrouding”
the mineral with three different species of heterotrophic acidophiles (Acidiphilium, Acidocella and Acidobacterium spp.), under conditions that were conducive to microbial oxidative dissolution of the iron sulfide. 相似文献
14.
Vaghri Z Wong H Barr SI Chapman GE Hertzman C 《Biological trace element research》2011,143(3):1398-1412
Marginal zinc deficiency (MZD) exists in children of industrialized societies and impairs growth and development. MZD is believed
to be one of the most common deficiencies, even though there is no data available on its global prevalence. This is partly
because of the lack of sensitivity and specificity of serum zinc, the most commonly used biomarker of zinc status, to detect
MZD. In children, MZD is always accompanied by a decrease in hair zinc. This cross-sectional study was designed to explore
if there are any associations between some socio-demographic and behavioral variables with hair zinc status in an attempt
to understand the social determinants of MZD and the profile of at risk children. Our citywide survey (n = 719) indicated a mean hair zinc of 116 ± 43 μg/g with 17% below the cutoff. Logistic regression analysis indicated that
age, maternal education, number of adults at home, being described as “eating unhealthy”, and Child Behavior Questionnaire
scores of “activity level” as the significant predictors of hair zinc status. Our study provides important information on
the hair zinc status of Vancouver preschoolers and some factors in children and their environment associated with hair zinc,
which may help in better understanding of hair zinc as a biomarker of MZD. 相似文献
15.
Miles B. Markus 《Journal of the history of biology》2011,44(4):781-786
The term “hypnozoite” is derived from the Greek words hypnos (sleep) and zoon (animal). Hypnozoites are dormant forms in the life cycles of certain parasitic protozoa that belong to the Phylum Apicomplexa
(Sporozoa) and are best known for their probable association with latency and relapse in human malarial infections caused
by Plasmodium ovale and P. vivax. Consequently, the hypnozoite is of great biological and medical significance. This, in turn, makes the origin of the name
“hypnozoite” a subject of interest. Some “missing” history that is now placed on record (including a letter written by P.
C. C. Garnham, FRS) shows that Miles B. Markus coined the term “hypnozoite”. While a PhD student at Imperial College London,
he carried out research that led to the identification of an apparently dormant form of Cystoisospora (synonym: Isospora). In 1976, he speculated: “If sporozoites of Isospora can behave in this fashion, then those of related Sporozoa, like malaria parasites, may have the ability to survive in the
tissues in a similar way.” He adopted the term “hypnozoite” for malaria in 1978 when he wrote in a little-known journal that
this name would “… describe any dormant sporozoites or dormant, sporozoite-like stages in the life cycles of Plasmodium or other Haemosporina.” At that time, the existence of a hypnozoite form in the life cycle of Plasmodium was still a hypothetical notion. In 1980, however, Wojciech A. Krotoski published (together with several co-workers) details
concerning his actual discovery of malarial hypnozoites, an event of considerable importance. 相似文献
16.
I. N. Konareva 《Neurophysiology》2006,38(3):201-208
Modifications of different EEG rhythms induced by a single neurofeedback session (by the EEG characteristics) directed toward
an increase in the ratio of the spectral powers (SPs) of the α vs θ oscillations were compared with the psychological characteristics of the tested subjects (the group included 30 persons).
A generally accepted neurofeedback technique was used; the intensity of acoustic white noise served as the feedback signal.
EEG potentials were recorded from the C3 and C4 leads. Psychological testing was carried out using Eysenck’s (EPQ), Rusalov’s
(OST), and (16 PF) questionnaires. The directions of changes in the SPs of EEG frequency components were found to significantly
correlate with some individuality-related peculiarities of the tested subjects. The SP of the δ rhythm correlated with the
EPQ scale “neuroticism,” OST scale “social plasticity,” and 16 PF factors H (“parmia”), I (“premsia”), and Q3 (“self-control of behavior”). The SP of the θ component demonstrated correlations with the OST scales “ergisity,” “plasticity,”
and “social temp” and with 16 PF factors M (“autia”), Q4 (“frustration”), and Q1 (“exvia”). The SP of the α rhythm correlated with 16 PF factors Q3 (“self-control of behavior”), G (“strength of superEgo”), O (“hypothymia”), L (“protension”), and N (“shrewdness”). The SP
of the β rhythm correlated with the OST scale “emotionality,” while that of the γ rhythm showed correlations with the 16 PF
indices L (“protension”) and M (“autia”). Changes in the ratio of the α vs θ SPs correlated with the EPQ scale “neuroticism.” Thus, our data confirm the statement that a high individual variability
of the results of a single (first in the series) neurofeedback session is to a great extent related to peculiarities of the
individual psychological pattern of the subject.
Neirofiziologiya/Neurophysiology, Vol. 38, No. 3, pp. 239–247, May–June, 2006. 相似文献
17.
The intentional introduction of exotic species can increase the level of local biodiversity, enrich people’s material lives,
and bring significant social and economic benefits that are also the symbols of human progress. However, along with the frequent
intercourse among countries and regions, the frequency of uncontrolled crossregional migration of species is increased and
there is a lack of scientific management strategy for the intentional introduction of exotic species. Exotic species invasion,
which is behind habitat fragmentation, has become the second largest threatening factor to the maintenance of the global-scale
level of biological diversity. Exotic species invasion can destroy the structure of an ecosystem, disturb the economic life
of a society, and do harm to human health. In this paper, the authors review some of the ecological explanations for issues
such as “what causes or mechanisms have led to the successful invasion of exotic species”, including the “ideal weeds characteristics”,
“biodiversity resistance hypothesis”, “enemies release hypothesis”, “evolution of increased competitive ability hypothesis”,
“niche opportunity hypothesis”, and “novel weapon hypothesis”. The authors also analyze and evaluate the background and theoretical
basis of the hypotheses, providing explanations for some phenomena, as well as the deficiencies of these explanations. 相似文献
18.
The inheritance of resistance to Plum pox virus (PPV) has been studied in 1,178 apricot hybrids. Seven hundred and eighteen F1 hybrids, obtained from controlled crosses
between the susceptible Greek cultivar “Bebecou” and the resistant PPV cultivars of American origin (“Stark Early Orange,”
‘NJA2,” ‘Veecot,” “Sunglo,” “Harlayne,” and “Orangered”) were evaluated for resistance to the PPV-M (Marcus) strain, 8 years
after artificial inoculation. The inheritance of resistance to PPV has been additionally studied for the first time in a BC1 population of 95 apricot hybrids for four vegetative periods. Reaction of each hybrid to PPV-M was scored through visual
symptoms, indexing onto GF-305 and double-antibody sandwich enzyme-linked immunosorbent assay tests. Segregation within the
hybrids, determined by Chi-squared analysis, fits a 1:1 ratio (P ≤ 0.05) of the resistant vs susceptible, indicating that resistance to PPV is controlled by a single dominant gene locus
and that the above six resistant cultivars are heterozygous for the trait. Plants carrying this gene may initially develop
disease symptoms on leaves but eventually recover and no virus can be detected in leaves. Susceptible plants show similar
symptoms initially but remain symptomatic. Inheritance of resistance to PPV also has been studied in 365 F1 hybrids by crossing
the resistant cultivar “Stella” with the susceptible “Bebecou” and the resistant cultivars “Sunglo” and “NJA2,” for 8 years
after inoculation. The segregation ratio was 1:0 (resistant/susceptible) suggesting that “Stella” is homozygous for the resistance
trait. The purpose of this work was the enhancement of the knowledge of inheritance of resistance to PPV for the selection
of new cultivars. 相似文献
19.
Heat shock proteins HSP70 and GP96: structural insights 总被引:3,自引:0,他引:3
Facciponte JG Wang XY MacDonald IJ Park JE Arnouk H Grimm MJ Li Y Kim H Manjili MH Easton DP Subjeck JR 《Cancer immunology, immunotherapy : CII》2006,55(3):339-346
Several heat shock proteins (HSPs) act as potent adjuvants for eliciting anti-tumor immunity. HSP-based tumor vaccine strategies
have been highly successful in animal models and are undergoing testing in clinical trials. It is generally accepted that
HSPs, functioning as chaperones for tumor antigens, elicit tumor-specific adaptive immune responses. HSPs also appear to induce
innate immune responses in an antigen-independent fashion. Innate responses generated by HSPs may contribute to anti-tumor
immunity. Immunologically active chaperones with anti-tumor activity are referred to as “immunochaperones”. Here, we review
the studies that address the role of structural domains or regions of the immunochaperones HSP70 and GP96 that may be involved
in the induction of adaptive or innate immune responses.
This article forms part of the Symposium in Writing “Thermal stress-related modulation of tumor cell physiology and immune
responses”, edited by Elfriede Noessner. 相似文献
20.
Pedersen PL 《Journal of bioenergetics and biomembranes》2007,39(1):1-12
This introductory article to the review series entitled “The Cancer Cell’s Power Plants as Promising Therapeutic Targets”
is written while more than 20 million people suffer from cancer. It summarizes strategies to destroy or prevent cancers by
targeting their energy production factories, i.e., “power plants.” All nucleated animal/human cells have two types of power
plants, i.e., systems that make the “high energy” compound ATP from ADP and P
i
. One type is “glycolysis,” the other the “mitochondria.” In contrast to most normal cells where the mitochondria are the
major ATP producers (>90%) in fueling growth, human cancers detected via Positron Emission Tomography (PET) rely on both types
of power plants. In such cancers, glycolysis may contribute nearly half the ATP even in the presence of oxygen (“Warburg effect”).
Based solely on cell energetics, this presents a challenge to identify curative agents that destroy only cancer cells as they
must destroy both of their power plants causing “necrotic cell death” and leave normal cells alone. One such agent, 3-bromopyruvate
(3-BrPA), a lactic acid analog, has been shown to inhibit both glycolytic and mitochondrial ATP production in rapidly growing
cancers (Ko et al., Cancer Letts., 173, 83–91, 2001), leave normal cells alone, and eradicate advanced cancers (19 of 19)
in a rodent model (Ko et al., Biochem. Biophys. Res. Commun., 324, 269–275, 2004). A second approach is to induce only cancer
cells to undergo “apoptotic cell death.” Here, mitochondria release cell death inducing factors (e.g., cytochrome c). In a
third approach, cancer cells are induced to die by both apoptotic and necrotic events. In summary, much effort is being focused
on identifying agents that induce “necrotic,” “apoptotic” or apoptotic plus necrotic cell death only in cancer cells. Regardless
how death is inflicted, every cancer cell must die, be it fast or slow. 相似文献