Skin grafting in frog tadpoles: Local specificity of skin and behavior of epidermis

1932 ◽  
Vol 62 (1) ◽  
pp. 125-170 ◽  
Author(s):  
Herbert W. Rand ◽  
Madelene E. Pierce
2021 ◽  
Author(s):  
Zsanett Mikó ◽  
Veronika Bókony ◽  
Nikolett Ujhegyi ◽  
Edina Nemesházi ◽  
Réka Erös ◽  
...  

The widespread application of pesticides makes it important to understand the impacts of these chemicals on wildlife populations. Chlorpyrifos is an organophosphate insecticide which can affect the development and behavior of aquatic organisms and may thereby alter predator-prey interactions. To investigate how environmentally relevant, sublethal concentrations of chlorpyrifos affect anti-predator behavior and larval development of the agile frog (Rana dalmatina), we exposed tadpoles to one of three concentrations (0, 0.5 and 5 μg chlorpyrifos / L) either for a brief period of three days (acute exposure) or throughout larval development (chronic exposure). We observed tadpole activity and space use in the presence or absence of chemical cues of predatory fish. We also assessed mortality, time to metamorphosis, mass at metamorphosis, brain morphology and sex ratio. We found that tadpoles chronically exposed to 5 μg/L chlorpyrifos swam distances that were longer by more than 20 % and exhibited body masses at metamorphosis that were lower by ca. 7 % than in control individuals, but the other fitness-related traits remained unaffected. The lower concentration of chlorpyrifos applied chronically, and either one of the acute chlorpyrifos treatments did not influence any measured trait. Our results demonstrate that exposure to chlorpyrifos can induce changes in locomotor activity and may result in lowered body mass of agile frog tadpoles, but only if the insecticide is present chronically at concentrations which are rarely reached in natural waterbodies. Thus, agile frog tadpoles appear to be relatively tolerant to chlorpyrifos, but may nonetheless suffer from its presence in situations of repeated high-dose application.


2018 ◽  
Vol 41 ◽  
Author(s):  
Peter DeScioli

AbstractThe target article by Boyer & Petersen (B&P) contributes a vital message: that people have folk economic theories that shape their thoughts and behavior in the marketplace. This message is all the more important because, in the history of economic thought, Homo economicus was increasingly stripped of mental capacities. Intuitive theories can help restore the mind of Homo economicus.


2019 ◽  
Vol 42 ◽  
Author(s):  
Jeffrey R. Alberts ◽  
Christopher Harshaw ◽  
Gregory E. Demas ◽  
Cara L. Wellman ◽  
Ardythe L. Morrow

Abstract We identify the significance and typical requirements of developmental analyses of the microbiome-gut-brain (MGB) in parents, offspring, and parent-offspring relations, which have particular importance for neurobehavioral outcomes in mammalian species, including humans. We call for a focus on behavioral measures of social-emotional function. Methodological approaches to interpreting relations between the microbiota and behavior are discussed.


Author(s):  
N. David Theodore ◽  
Mamoru Tomozane ◽  
Ming Liaw

There is extensive interest in SiGe for use in heterojunction bipolar transistors. SiGe/Si superlattices are also of interest because of their potential for use in infrared detectors and field-effect transistors. The processing required for these materials is quite compatible with existing silicon technology. However, before SiGe can be used extensively for devices, there is a need to understand and then control the origin and behavior of defects in the materials. The present study was aimed at investigating the structural quality of, and the behavior of defects in, graded SiGe layers grown by chemical vapor deposition (CVD).The structures investigated in this study consisted of Si1-xGex[x=0.16]/Si1-xGex[x= 0.14, 0.13, 0.12, 0.10, 0.09, 0.07, 0.05, 0.04, 0.005, 0]/epi-Si/substrate heterolayers grown by CVD. The Si1-xGex layers were isochronally grown [t = 0.4 minutes per layer], with gas-flow rates being adjusted to control composition. Cross-section TEM specimens were prepared in the 110 geometry. These were then analyzed using two-beam bright-field, dark-field and weak-beam images. A JEOL JEM 200CX transmission electron microscope was used, operating at 200 kV.


Author(s):  
Peter Pegler ◽  
N. David Theodore ◽  
Ming Pan

High-pressure oxidation of silicon (HIPOX) is one of various techniques used for electrical-isolation of semiconductor-devices on silicon substrates. Other techniques have included local-oxidation of silicon (LOCOS), poly-buffered LOCOS, deep-trench isolation and separation of silicon by implanted oxygen (SIMOX). Reliable use of HIPOX for device-isolation requires an understanding of the behavior of the materials and structures being used and their interactions under different processing conditions. The effect of HIPOX-related stresses in the structures is of interest because structuraldefects, if formed, could electrically degrade devices.This investigation was performed to study the origin and behavior of defects in recessed HIPOX (RHIPOX) structures. The structures were exposed to a boron implant. Samples consisted of (i) RHlPOX'ed strip exposed to a boron implant, (ii) recessed strip prior to HIPOX, but exposed to a boron implant, (iii) test-pad prior to HIPOX, (iv) HIPOX'ed region away from R-HIPOX edge. Cross-section TEM specimens were prepared in the <110> substrate-geometry.


2012 ◽  
Vol 13 (4) ◽  
pp. 111-119 ◽  
Author(s):  
Alexandra Hollo

Language development is the foundation for competence in social, emotional, behavioral, and academic performance. Although language impairment (LI) is known to co-occur with behavioral and mental health problems, LI is likely to be overlooked in school-age children with emotional and behavioral disorders (EBD; Hollo, Wehby, & Oliver, in press). Because language deficits may contribute to the problem behavior and poor social development characteristic of children with EBD, the consequences of an undiagnosed language disorder can be devastating. Implications include the need to train school professionals to recognize communication deficits. Further, it is critically important that specialists collaborate to provide linguistic and behavioral support for students with EBD and LI.


1999 ◽  
Vol 4 (6) ◽  
pp. 5-6

Abstract Personality disorders are enduring patterns of inner experience and behavior that deviate markedly from those expected by the individual's culture; these inflexible and pervasive patterns reflect issues with cognition, affectivity, interpersonal functioning and impulse control, and lead to clinically significant distress or impairment in social, occupational, or other important areas of functioning. The AMA Guides to the Evaluation of Permanent Impairment, Fourth Edition, defines two specific personality disorders, in addition to an eleventh condition, Personality Disorder Not Otherwise Specified. Cluster A personality disorders include paranoid, schizoid, and schizotypal personalities; of these, Paranoid Personality Disorder probably is most common in the legal arena. Cluster B personality disorders include antisocial, borderline, histrionic, and narcissistic personality. Such people may suffer from frantic efforts to avoid perceived abandonment, patterns of unstable and intense interpersonal relationships, an identity disturbance, and impulsivity. Legal issues that involve individuals with cluster B personality disorders often involve determination of causation of the person's problems, assessment of claims of harassment, and assessment of the person's fitness for employment. Cluster C personality disorders include avoidant, dependent, and obsessive-compulsive personality. Two case histories illustrate some of the complexities of assessing impairment in workers with personality disorders, including drug abuse, hospitalizations, and inpatient and outpatient psychotherapy.


2006 ◽  
Vol 40 (12) ◽  
pp. 30
Author(s):  
HEIDI SPLETE
Keyword(s):  

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