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PubMed1984

Behavioral community psychology: an introduction to the special issue.

An overview of this special issue, and of behavioral community psychology, is provided, beginning with a summary of terminology and history. Five dimensions on which behavioral community interventions may be classified are then described: (a) subject matter/target behavior, (b) behavioral procedures used, (c) experimental design, (d) intervention level, and (e) time focus. The studies composing this special issue serve as illustrations of these dimensions. This is followed by a discussion of issues important in designing and implementing behavioral community projects. Finally, challenges facing the field are noted.

Behaviorism↗
PubMed1991

Development of Sertoli cell junctional specializations and the distribution of the tight-junction-associated protein ZO-1 in the mouse testis.

Basally located tight junctions between Sertoli cells in the postpubertal testis are the largest and most complex junctional complexes known. They form at puberty and are thought to be the major structural component of the "blood-testis" barrier. We have now examined the development of these structures in the immature mouse testis in conjunction with immunolocalization of the tight-junction-associated protein ZO-1 (zonula occludens 1). In testes from 5-day-old mice, tight junctional complexes are absent and ZO-1 is distributed generally over the apicolateral, but not basal, Sertoli cell membrane. As cytoskeletal and reticular elements characteristic of the mature junction are recruited to the developing junctions, between 7 and 14 days, ZO-1 becomes progressively restricted to tight junctional regions. Immunogold labeling of ZO-1 on Sertoli cell plasma membrane preparations revealed specific localization to the cytoplasmic surface of tight junctional regions. In the mature animal, ZO-1 is similarly associated with tight junctional complexes in the basal aspects of the epithelium. In addition, it is also localized to Sertoli cell ectoplasmic specializations adjacent to early elongating, but not late, spermatids just prior to sperm release. Although these structures are not tight junctions, they do have a similar cytoskeletal arrangement, suggesting that ZO-1 interacts with the submembrane cytoskeleton. These results show that, in the immature mouse testis, ZO-1 is present on the Sertoli cell plasma membrane in the absence of recognizable tight junctions. In the presence of tight junctions, however, ZO-1 is found only at the sites of junctional specializations associated with tight junctions and with elongating spermatids.

Animals↗
PubMed2007

Phenotypic, maximum genetic, and special environmental variability in prehistoric human populations.

The phenotypic variance (V(P)) may be divided into the genetic variance (V(G)), the general environmental variance (V(Eg)), and the special environmental variance (V(Es)). The latter is estimated through repeatability calculation (b). This value is considered the upper limit of heritability and represents maximum genetic variance proportion (V(Gm) = V(G) + V(Eg)) in relation to V(P) (b = (V(G) + V(Eg))/V(P)). This process allows an improved determination of biological relationships among groups from estimators maximizing the genetic information of quantitative characters. Two hundred and thirty-seven individuals inhabiting the northern coast of Chile for 4,000 years were taken as a sample. Measurement was made of six metric characters at both sides of the cranium. Special environmental values (es) were obtained by regression. The difference between these values and the phenotypic values (p) consists in the genetic values plus the general environmental values (g + eg). A mean b value of 0.83 indicated that V(Es) represents 17% of V(P). The results showed: 1) high stability of the maximum genetic variance in time and space, 2) high correlation between the biological relationships model, the phenotypic model, and the maximum genetic model, and 3) random distribution of the nongenetic variation, as expected from the quantitative genetics theory. These results support the use of phenotypic data for the interpretation of the evolution history of prehistoric populations.

Anthropometry↗
PubMed2005

Neurobiological specializations in echolocating bats.

Although the bat's nervous system follows the general mammalian plan in both its structure and function, it has undergone a number of modifications associated with flight and echolocation. The most obvious neuroanatomical specializations are seen in the cochleas of certain species of bats and in the lower brainstem auditory pathways of all microchiroptera. This article is a review of peripheral and central auditory neuroanatomical specializations in echolocating bats. Findings show that although the structural features of the central nervous system of echolocating microchiropteran bats are basically the same as those of more generalized mammals, certain pathways, mainly those having to do with accurate processing of temporal information and auditory control of motor activity, are hypertrophied and/or organized somewhat differently from those same pathways in nonecholocating species. Through the resulting changes in strengths and timing of synaptic inputs to neurons in these pathways, bats have optimized the mechanisms for analysis of complex sound patterns to derive accurate information about objects in their environment and direct behavior toward those objects.

Animals↗
PubMed1993

Multiple bacterial topoisomerases: specialization or redundancy?

In the past few years, two new DNA topoisomerases have been discovered in bacteria, bringing the total number of DNA topoisomerases in E. coli to four. Two classes of topoisomerases, type 1 and type 2, are distinguishable by their amino acid homology and their apparent reaction mechanism. Of the four E. coli topoisomerases, there are two type 1 and two type 2 enzymes. In eukaryotes, the existence of multiple type 1 and type 2 enzymes has also become apparent. The existence of these multiple enzymes provokes a question whose answer has both evolutionary and physiological implications: are these topoisomerases functionally redundant, or have they acquired sufficient specialization that they now perform unique biological reactions? In bacteria, there is evidence for both specialization and redundancy in the functions of topoisomerases.

Bacterial Proteins↗
PubMed2001

A matter of life or death: special considerations and heightened practice standards in capital sentencing evaluations.

Mental health evaluations at capital sentencing represent a complex and specialized arena of practice. The moral culpability focus of capital sentencing is distinct from guilt-phase considerations of criminal responsibility, and has a specialized literature. Capital violence risk assessment is uniquely oriented to a prison context, relying on past adjustment to incarceration, as well as group statistical data specific to capital offenders and other inmate groups. Personality testing is a more complex consideration in capital sentencing evaluations. The implications of interviewing the defendant, as well as the parameters and documentation of an interview, make full disclosure and informed consent of particular importance. Defense- and prosecution-retained experts are subject to specific ethical vulnerabilities. These are examined in this paper through the lens of current professional standards.

Capital Punishment↗
PubMed2004

Death penalty support for special offender populations of legally convicted murderers: juveniles, the mentally retarded, and the mentally incompetent.

The U.S. Supreme Court recently re-examined the constitutionality of the death penalty in the context of two of three special offender populations of murderers (juveniles, mentally retarded, and mentally incompetent). The Court reaffirmed the imposition of the death penalty for juveniles 16 and 17, while reversing itself on the mentally retarded. In reaching its decision, the Court relied on society's "evolving standards of decency." Using Likert-type items, this study is the first to have prospective jurors assess support for the death penalty for these specific offender groups. The public's support for the execution of each of the groups is then compared with existing case law. Descriptive statistics and regression analyses indicate that, as expected, the levels of support for the applicability of capital punishment to the various special offender populations are much lower than that for the general adult offender. Moreover, these findings are congruent with the holdings of the Court with one notable exception: a slight majority of respondents supported executing the mentally incompetent. Reasons for the public's apparent departure from the Supreme Court holding prohibiting the execution of mentally incompetent convicted murderers are discussed. The Court's continued role in protecting marginalized populations from "cruel and unusual punishment" is explored in the context of strong public sentiment demanding justice and finality despite changes in offenders' mental capacity.

Adolescent↗
PubMed2004

Role of the special pair in the charge-separating event in photosynthesis.

We synthesized special-pair/electron-acceptor systems consisting of a complementary slipped cofacial dimer of imidazolyl-substituted zinc porphyrin, bearing pyromellitdiimide as the electron acceptor. In the case of the dimer, the first and second oxidation potentials were split into a total of four peaks in the differential pulse voltammetry measurement. Furthermore, the shift values of the first oxidation potentials obtained by changing the solvent polarity for the dimer were almost half of those observed for the monomer. These results indicate that the radical cation is delocalized over the whole pi system of the dimer. Time-resolved transient absorption measurements revealed that, relative to the corresponding monomer, the dimer accelerated the charge separation rate, but decelerated the charge recombination rate. The smaller reorganization energy of the slipped cofacial dimer relative to that of the monomeric system demonstrates the significance of the special-pair arrangement for efficient charge separation in photosynthesis.

Electron Transport↗
PubMed2006

The prevalence and special educational requirements of dyscompetent physicians.

Underperformance among physicians is not well studied or defined; yet, the identification and remediation of physicians who are not performing up to acceptable standards is central to quality care and patient safety. Methods for estimating the prevalence of dyscompetence include evaluating available data on medical errors, malpractice claims, disciplinary actions, quality control studies, medical record review studies, and in-stream assessments of physician performance. These data provide a range of estimates from 0.6% to 50%, depending on the method. A reasonable estimate of dyscompetence appears to be 6% to 12%. Age-related cognitive decline, impairment due to substance use disorders, and other psychiatric illness can contribute to underperformance, diminishing physicians' insight into their level of performance as well as their ability to benefit from an educational experience.Currently, dyscompetent physicians in the United States are identified through either the legal system or peer review. The primary method of resolving issues of underperformance in physicians is through continuing medical education (CME). Although a number of specialized assessment and education programs exist in the United States, these programs are largely underutilized. Similar programs exist in Canada and have provided evidence of the efficacy of a more specialized and individualized educational approach for underperforming physicians. Current specialty programs focused on this population employ individual assessments of knowledge and performance, individually designed educational programs, long-term plans for maintenance of educational activity, and repeated assessment of performance level. Noting that few CME programs offer these requirements, a number of changes to current medical quality assurance programs that might foster such educational requirements for underperforming physicians are provided.

Clinical Competence↗
PubMed2002

A human homologue of Drosophila kelch associates with myosin-VIIa in specialized adhesion junctions.

Mutations in myosin-VIIa are responsible for the deaf-blindness, Usher disease. Myosin-VIIa is also highly expressed in testis, where it is associated with specialized adhesion plaques termed ectoplasmic specializations (ES) that form between Sertoli cells and germ cells. To identify new roles for myosin-VIIa, we undertook a yeast two-hybrid screen to identify proteins associated with myosin-VIIa in the ES. We identified Keap1, a human homologue of the Drosophila ring canal protein, kelch. The kelch-repeats in the C-terminus of human Keap1 associate with the SH3 domain of myosin-VIIa. Immunolocalization studies revealed that Keap1 is present with myosin-VIIa in the actin bundles of the ES. Myosin-VIIa and Keap1 copurify with ES and colocate with each other and with F-actin at the electron microscopy level. Interestingly, in many epithelial cell types including cells derived from retina and inner ear, Keap1 is a component of focal adhesions and zipper junctions. Keap1 can target to the ES in the absence of myosin-VIIa, suggesting that Keap1 associates with other molecules in the adhesion plaque. Keap1 and myosin-VIIa overlapped in expression in the inner hair cells of the cochlea, suggesting that Keap1 may be a part of a family of actin-binding proteins that could be important for myosin-VIIa function in testis and inner ear.

Actin Cytoskeleton↗
PubMed2006

Asian Tobacco Education and Cancer Awareness Research Special Population Network. A model for reducing Asian American cancer health disparities.

Asian Americans are the fastest growing and the second largest foreign-born ethnic group in the United States. Cancer is a leading cause of death among Asian Americans. The Asian Tobacco Education and Cancer Awareness Research (ATECAR) Special Population Network, Center for Asian Health, aimed to reduce or eliminate cancer health disparities in these diverse, underserved populations in Pennsylvania, New Jersey, Delaware, and New York. The ATECAR logic model was adapted from a variety of conceptual frameworks to develop and implement the network's multifaceted cancer health disparities research, training, awareness, and outreach programs. The model was the basis for the developmental phases of the network that included (1) needs assessment, infrastructure, and partnership building; (2) intervention research, training, and mentorship; and (3) evaluation, dissemination, and diffusion. Community involvement occurred at every operational level to ensure program and network sustainability. Between 2000 and 2005, the ATECAR network consisted of 88 partners, representing a cross-section of Asian communities, academia, cancer centers, and health service agencies, ensuring a viable infrastructure for the network's multidimensional cancer health disparities programs. ATECAR's research covered tobacco control, cancer prevention and intervention, and clinical trials. More than 22 research projects were conducted and their results disseminated in peer-reviewed journals. ATECAR also trained 76 junior researchers and special population investigators and 1014 community professionals in disparity issues. ATECAR's multimedia cancer awareness education program reached over 116,000 Asians. The ATECAR network's achievements have had a profound impact on Asian Americans and established a trend toward reducing cancer health disparities, especially among underserved Asian Americans. Cancer 2006. (c) 2006 American Cancer Society.

Asian↗
PubMed2005

State-dependent hemispheric specialization in the songbird brain.

Lateralization of brain functions is a widespread phenomenon in vertebrates. With the well-known lateralization in the processing of human speech and the parallels that exist between birdsong and language, songbirds are interesting for addressing such questions. In the present study, we investigated the central processing of communicative and artificial sounds in starlings, in an integrative part of the song system: the HVC. Neuronal responses to acoustic stimuli were systematically recorded in both hemispheres while the birds were awake, and then anesthetized, allowing quantitative comparisons of the responses obtained in each situation. The total proportion of responsive sites in the HVC of the left and right hemispheres of all birds revealed a significant predominance of the HVC of the right hemisphere when the birds were awake, whereas a high interindividual variability appeared when the birds were anesthetized. When neuronal responses as a whole were further examined, the responses to each type of stimulus appeared to be nonrandomly distributed over the different situations, and some specialization may appear. The results suggest a complex and state-dependent hemispheric specialization toward behaviorally relevant classes of stimuli. In awake birds, the HVC of the left hemisphere may be more involved in the processing of songs that are used in individual recognition at distance, whereas the HVC of the right hemisphere may deal with long and complex sequences of a song that is involved in short-distance communication, especially between males and females. With birds under anesthesia, this pattern is strongly modified.

Animal Communication↗
PubMed2007

Neural specialization for hovering in hummingbirds: hypertrophy of the pretectal nucleus Lentiformis mesencephali.

Hummingbirds possess an array of morphological and physiological specializations that allow them hover such that they maintain a stable position in space for extended periods. Among birds, this sustained hovering is unique to hummingbirds, but possible neural specializations underlying this behavior have not been investigated. The optokinetic response (OKR) is one of several behaviors that facilitates stabilization. In birds, the OKR is generated by the nucleus of the basal optic root (nBOR) and pretectal nucleus lentiformis mesencephali (LM). Because stabilization during hovering is dependent on the OKR, we predicted that nBOR and LM would be significantly enlarged in hummingbirds. We examined the relative size of nBOR, LM, and other visual nuclei of 37 species of birds from 13 orders, including nine hummingbird species. Also included were three species that hover for short periods of time (transient hoverers; a kingfisher, a kestrel, and a nectarivorous songbird). Our results demonstrate that, relative to brain volume, LM is significantly hypertrophied in hummingbirds compared with other birds. In the transient hoverers, there is a moderate enlargement of the LM, but not to the extent found in the hummingbirds. The same degree of hypertrophy is not, however, present in nBOR or the other visual nuclei measured: nucleus geniculatus lateralis, pars ventralis, and optic tectum. This selective hypertrophy of LM and not other visual nuclei suggests that the direction-selective optokinetic neurons in LM are critical for sustained hovering flight because of their prominent role in the OKR and gaze stabilization.

Animals↗
PubMed1981

Development of axosomatic synapses of the Xenopus spinal cord with special reference to subsurface cisterns and C-type synapses.

The relationships of highly flattened subsurface cisterns (SCCs) were investigated electron microscopically in the spinal cord at various developmental stages of tadpoles and adult toads, Xenopus laevis. In medial ventral motor cells (MVCs) of the adult, more than 90% of 156 SSCs examined were situated postsynaptically. Similarly, more than 90% of 540 SSCs in lateral motor column cells (LMCs) were postsynaptic. By contrast, in early developmental stages, the SSCs were initially formed by regional flattening of cisterns of rough-surfaced endoplasmic reticulum just beneath the cell surfaces opposite to glial processes. Then, the glial processes were displaced by nerve endings with an elongated bouton, and thus the C-type synapses were formed. The ratio of postsynaptic SSCs to the total SSCs reached the adult level at around Stage 60. This finding suggests that the SSCs in the MVCs and LMCs draw a certain type of nerve ending to form C-type synapses. Such a mechanism is totally lacking in the dorsal and lateral small nerve cells, since the SSCs in these cells were always situated under the surface opposite to glial processes throughout the developmental stages and in the adult. In mature C-type synapses, an aggregate of synaptic vesicles and a structural specialization of presynaptic membrane occurred only at the region where the postsynaptic membrane was associated with the SSC. The postsynaptic membrane itself of the C-type synapse showed no marked structural specialization at any stage of development or in the adult. The postsynaptic SSC In the mature C-type synapse seems to be involved in some way in the reception of synaptic transmission.

Animals↗
PubMed1986

Freeze-fracture study of the large myelinated club ending synapse on the goldfish Mauthner cell: special reference to the quantitative analysis of gap junctions.

The large myelinated club endings (LMCEs) of primary eighth nerve afferents form mixed synapses on the lateral dendrite of the giant Mauthner cell. The double replica freeze-fracture technique was employed to examine the intramembrane fine structure of these LMCE synapses. Morphological correlates of both chemical and electrical transmission were found at the LMCE synapses. Electrical synaptic junctions, or gap junctions, were located over much (10-20%) of the synaptic contact. These were seen in both pre-and postsynaptic membrane as tightly packed P face particle aggregates and corresponding aggregates of E face pits. Specializations characteristic of chemical synaptic junctions were most prominent at the periphery of the synaptic contact. These specializations consisted of postsynaptic E face particle aggregates which were subjacent to presynaptic active zones. The active zones were distinguishable as regions with an increased density of large particles and vesicle attachment sites represented by P face depressions and E face protuberances. Quantitative analysis of gap junction particle (connexon) number at five LMCEs revealed 24,000-106,000 connexons per LMCE. Comparison with data from electrophysiological studies of single LMCEs indicates that only a small fraction of the connexon channels are open at any given time during electrotonic transmission at an LMCE synapse.

Animals↗
PubMed1994

The motor neurons innervating the direct flight muscles of Drosophila melanogaster are morphologically specialized.

The anatomy of the motor neurons innervating six direct flight muscles in Drosophila melanogaster has been investigated by using a horseradish peroxidase backfilling technique. The somata of these motor neurons are arranged in two distinct clusters ipsilateral to the muscle they innervate. One cluster of cell bodies is located in the ventrolateral region between the prothoracic neuromere and the mesothoracic leg-related neuropil and the other is situated dorsally and posteriorly to the mesothoracic leg-related neuropil. Axons from somata in the ventrolateral cluster run in the anterior dorsal mesothoracic nerve, while axons from somata in the other cluster run in the mesothoracic accessory nerve. This distribution of somata and axons is discussed in the light of the morphological similarity and proximity of these functionally related muscles. On the basis of the branching patterns of their neurites, direct flight muscle motor neurons can be classified as stubbly, fibrous or tufted. The terminal arborizations of the motor neurons over the direct flight muscles are also morphologically specialized. Both the central and the peripheral morphological specializations of the direct flight muscle motor neurons correlate with the activity patterns exhibited by their associated muscles during flight and courtship song.

Animals↗
PubMed1977

[Effects of two special diets on the body weight of rats].

The authors studied the effects of 2 special diets on the weight behaviour of male Wistar rats (aged 4--5 weeks) from Schönerlinde near Berlin up to the age of 35 weeks. The weight behaviour of rats fed a standard diet (commercially available pellets) lies between those of the experimental rats and near that of the rats on low-fat (3%) diet. The one special diet that contains 3% of fat is low-fat (8.4% of the gross energy of the feed) and high-protein (69.3% of the gross energy); the other diet that contains 50% of fat is high-fat (76% of the gross energy). The two diets (containing 331 and 612 kcal/100 g, respectively) are not isocaloric but the animals on the low-fat diet ate twice as much as the animals on the high-fat diet. The rats on the high-protein low-fat diet were prone to copious sweating. It was generally noticed that the animals on the high-fat diet became to a greater extent hypokinetic with increasing age. The weight difference between the two dietary groups increased with increasing age, reaching its maximum value (77%) at the age of 24 weeks and then decreasing to 60% (at the age of 35 weeks). Up to the age of 12 weeks, the rats are in the more "dynamic" phase of weight increase; and from the 16th week, in the more "static" phase of weight increase.

Aging↗
PubMed1988

Cytotopographical specialization of enzymatically isolated rabbit retinal Müller (glial) cells: K+ conductivity of the cell membrane.

Müller (radial glial) cells were isolated from rabbit retinae by means of papaine and mechanical dissociation. Regional membrane properties of these cells were studied by intracellular microelectrode recordings of potential responses to local application of high K+ solutions. When different parts of the cell membrane were exposed to high K+, the amplitude of the depolarizing responses varied greatly, indicating a strong regional specialization of the membrane properties. Using morphometrical data of isolated rabbit Müller cells, and a simple circuit model, we calculated the endfoot membrane to constitute more than 80% of the total K+ conductance of the cell; the specific resistivity of the endfoot membrane was about 400 omega cm2, i.e., more than 40 times less than that of the membrane of the vitread process, which is immediately adjacent. This kind of regional membrane specialization seems to be optimized in respect to the Müller cells' ability to carry spatial buffering K+ currents.

Animals↗