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  1. Article ; Online: Mosquitoes Exposed to Sunlight in Florida Are Capable of Making Vitamin D

    Holick, Michael F / Stoddard, Philip K

    Anticancer research

    2022  Volume 42, Issue 10, Page(s) 5091–5094

    Abstract: Background/aim: This study aimed to determine whether mosquitoes exposed to natural sunlight are able to produce vitamin D: Results: The mosquitoes that were exposed to sunlight produced vitamin ... ...

    Abstract Background/aim: This study aimed to determine whether mosquitoes exposed to natural sunlight are able to produce vitamin D
    Results: The mosquitoes that were exposed to sunlight produced vitamin D
    MeSH term(s) Adult ; Animals ; Cholecalciferol ; Culicidae ; Female ; Florida ; Humans ; Male ; Methanol ; Sunlight ; Vitamin D
    Chemical Substances Vitamin D (1406-16-2) ; Cholecalciferol (1C6V77QF41) ; Methanol (Y4S76JWI15)
    Language English
    Publishing date 2022-10-03
    Publishing country Greece
    Document type Journal Article
    ZDB-ID 604549-2
    ISSN 1791-7530 ; 0250-7005
    ISSN (online) 1791-7530
    ISSN 0250-7005
    DOI 10.21873/anticanres.16018
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Managing Aedes aegypti populations in the first Zika transmission zones in the continental United States.

    Stoddard, Philip K

    Acta tropica

    2018  Volume 187, Page(s) 108–118

    Abstract: The African Zika virus swept across the Pacific, reaching the New World in 2014. In July, 2016, Miami-Dade County, Florida became the locus of the first mosquito-borne Zika transmission zones in the continental United States. Control efforts were guided ... ...

    Abstract The African Zika virus swept across the Pacific, reaching the New World in 2014. In July, 2016, Miami-Dade County, Florida became the locus of the first mosquito-borne Zika transmission zones in the continental United States. Control efforts were guided by the Centers for Disease Control and Prevention, including aerial and truck sprays of adulticides and larvicides. To improve our understanding of how best to fight Zika transmission in an urban environment in the developed world, trap counts of adult Aedes (Stegomyia) aegypti (L.) mosquitoes from the treatment zones were analyzed to determine efficacy of the different insecticide treatments. Analysis revealed that application of four different ester pyrethroid and one non-ester pyrethroid had no statistically significant effect on mosquito counts. Aerial application of naled, a potent organophosphate adulticide, produced significant but short-lived drops in Ae. aegypti counts in the first two applications in the first active transmission zone (Wynwood), then lost some efficacy with subsequent application. In the other active transmission zone (Miami Beach), naled produced no measurable effect in the first three applications, and only a small, transient, and marginally significant reduction in the fourth application. Repeated application of the larvicidal bacterium Bti was accompanied by steady declines of Ae. aegypti populations in both sites. Zika transmission ceased in the first transmission zone, but expanded in the second transmission zone during this period. Specific recommendations are proposed for future treatments of urban mosquitoes.
    MeSH term(s) Aedes/virology ; Animals ; Disease Vectors ; Florida ; Humans ; Insecticides ; Mosquito Control/methods ; Zika Virus/isolation & purification ; Zika Virus Infection/prevention & control ; Zika Virus Infection/transmission
    Chemical Substances Insecticides
    Language English
    Publishing date 2018-07-31
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 210415-5
    ISSN 1873-6254 ; 0001-706X
    ISSN (online) 1873-6254
    ISSN 0001-706X
    DOI 10.1016/j.actatropica.2018.07.031
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Managing Aedes aegypti populations in the first Zika transmission zones in the continental United States

    Stoddard, Philip K

    Acta tropica. 2018,

    2018  

    Abstract: The African Zika virus swept across the Pacific, reaching the New World in 2014. In July, 2016, Miami-Dade County, Florida became the locus of the first mosquito-borne Zika transmission zones in the continental United States. Control efforts were guided ... ...

    Abstract The African Zika virus swept across the Pacific, reaching the New World in 2014. In July, 2016, Miami-Dade County, Florida became the locus of the first mosquito-borne Zika transmission zones in the continental United States. Control efforts were guided by the Centers for Disease Control and Prevention, including aerial and truck sprays of adulticides and larvicides. To improve our understanding of how best to fight Zika transmission in an urban environment in the developed world, trap counts of adult Aedes (Stegomyia) aegypti (L.) mosquitoes from the treatment zones were analyzed to determine efficacy of the different insecticide treatments. Analysis revealed that application of four different ester pyrethroid and one non-ester pyrethroid had no statistically significant effect on mosquito counts. Aerial application of naled, a potent organophosphate adulticide, produced significant but short-lived drops in Ae. aegypti counts in the first two applications in the first active transmission zone (Wynwood), then lost some efficacy with subsequent application. In the other active transmission zone (Miami Beach), naled produced no measurable effect in the first three applications, and only a small, transient, and marginally significant reduction in the fourth application. Repeated application of the larvicidal bacterium Bti was accompanied by steady declines of Ae. aegypti populations in both sites. Zika transmission ceased in the first transmission zone, but expanded in the second transmission zone during this period. Specific recommendations are proposed for future treatments of urban mosquitoes.
    Keywords adulticides ; adults ; Aedes aegypti ; aerial application ; bacteria ; Centers for Disease Control and Prevention ; disease transmission ; larvicides ; mosquito-borne diseases ; naled ; pesticide application ; pyrethrins ; urban areas ; Zika virus ; Florida
    Language English
    Size p. .
    Publishing place Elsevier B.V.
    Document type Article
    Note Pre-press version
    ZDB-ID 210415-5
    ISSN 1873-6254 ; 0001-706X
    ISSN (online) 1873-6254
    ISSN 0001-706X
    DOI 10.1016/j.actatropica.2018.07.031
    Database NAL-Catalogue (AGRICOLA)

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  4. Article ; Online: Nonlethal Effects of Pesticides on Web-Building Spiders Might Account for Rapid Mosquito Population Rebound after Spray Application

    Stefan N. Rhoades / Philip K. Stoddard

    Applied Sciences, Vol 11, Iss 4, p

    2021  Volume 1360

    Abstract: Spiders are important population regulators of insect pests that spread human disease and damage crops. Nonlethal pesticide exposure is known to affect behavior of arthropods. For spiders such effects include the inability to repair their webs or capture ...

    Abstract Spiders are important population regulators of insect pests that spread human disease and damage crops. Nonlethal pesticide exposure is known to affect behavior of arthropods. For spiders such effects include the inability to repair their webs or capture prey. In this study, nonlethal exposure of Mabel’s orchard spider ( Leucauge argyrobapta ) to the synthetic pyrethroid permethrin, via web application, interfered with web reconstruction and mosquito capture ability for 1–3 days. The timing of this loss-of-predator ecosystem function corresponds to the rapid population rebound of the yellow fever mosquito ( Aedes aegypti ) following insecticide application to control arbovirus epidemics. We suggest this temporal association is functional and propose that follow-up study be conducted to evaluate its significance.
    Keywords Aedes aegypti ; Leucauge argyrobapta ; nontarget effects ; permethrin ; pyrethroid ; Tetragnathidae ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
    Language English
    Publishing date 2021-02-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: The Biology of Polymorphic Melanic Side-Spotting Patterns in Poeciliid Fishes

    Tanja C. Zerulla / Philip K. Stoddard

    Frontiers in Ecology and Evolution, Vol

    2021  Volume 8

    Abstract: Melanin-based color patterns are an emerging model for studying molecular and evolutionary mechanisms driving phenotypic correlations. Extensive literature exists on color patterns and their correlated traits in the family Poeciliidae, indicating that ... ...

    Abstract Melanin-based color patterns are an emerging model for studying molecular and evolutionary mechanisms driving phenotypic correlations. Extensive literature exists on color patterns and their correlated traits in the family Poeciliidae, indicating that these fishes are tractable models. We review the biology of polymorphic melanic side-spotting patterns characterized by macromelanophores forming irregular spotted patterns across fishes’ flanks. These patterns are present in the genera Gambusia, Limia, Phalloceros, Poecilia, and Xiphophorus. Their presence is controlled by dominant genes on autosomes or sex chromosomes. Variation in expression is under polygenic control; however, these genes’ identities are still largely unknown. In some Gambusia holbrooki and Poecilia latipinna, expression is dependent on low temperature exposure, but underlying molecular mechanisms are unknown. Spotted fish develop melanoma in rare cases and are a well-developed model for melanoma research. Little is known about other physiological correlates except that spotted G. holbrooki males exhibit higher basal cortisol levels than unspotted males and that metabolic rate does not differ between morphs in some Xiphophorus species. Behavioral differences between morphs are widespread, but specific to population, species, and social context. Spotted G. holbrooki males appear to be more social and more dominant. Juvenile spotted G. holbrooki have lower behavioral flexibility, and spotted X. variatus exhibit greater stress resistance. Findings conflict on whether morphs differ in sexual behavior and in sexual selection by females. Melanic side-spotting patterns are uncommon (<30%) in populations, although extreme high-frequency populations exist. This low frequency is surprising for dominant genes, indicating that a variety of selective pressures influence both these patterns and their correlated traits. Little is known about reproductive life history traits. Spotted G. holbrooki are larger and have higher survival when uncommon, but ...
    Keywords color polymorphism ; coloration ; melanism ; phenotypic integration ; pigmentation ; pleiotropy ; Evolution ; QH359-425 ; Ecology ; QH540-549.5
    Subject code 590
    Language English
    Publishing date 2021-01-01T00:00:00Z
    Publisher Frontiers Media S.A.
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Predation and Crypsis in the Evolution of Electric Signaling in Weakly Electric Fishes

    Philip K. Stoddard / Alex Tran / Rüdiger Krahe

    Frontiers in Ecology and Evolution, Vol

    2019  Volume 7

    Abstract: Eavesdropping by electroreceptive predators poses a conflict for weakly electric fish, which depend on their Electric Organ Discharge (EOD) signals both for navigation and communication in the dark. The EODs that allow weakly electric fish to ... ...

    Abstract Eavesdropping by electroreceptive predators poses a conflict for weakly electric fish, which depend on their Electric Organ Discharge (EOD) signals both for navigation and communication in the dark. The EODs that allow weakly electric fish to electrolocate and communicate in the dark may attract electroreceptive predators such as catfishes and Electric Eels. These predators share with their prey the synapomorphy of passive electric sense supported by ampullary electroreceptors that are highly sensitive to low-frequency electric fields. Any low-frequency spectral components of the EOD make weakly electric fish conspicuous and vulnerable to attack from electroreceptive predators. Accordingly, most weakly electric fish shift spectral energy upwards or cloak low-frequency energy with compensatory masking signals. Subadults and females in particular emit virtually no low-frequency energy in their EODs, whereas courting males include a significant low-frequency component, which likely attracts females, but makes the signals conspicuous to predators. Males of species that coexist with the most predators tend to produce the least low-frequency signal energy, expressing sexual dimorphism in their signals in less risky ways. In these respects, electric signals follow the classic responses to opposing forces of natural and sexual selection, as exemplified in the visual signals of guppies and the acoustic signals of Túngara frogs. Unique to electric fish is that the electric signal modifications that help elude detection by electroreceptive predators are additions to the basal signal rather than losses of attractive components. These enhancements that enable crypsis are energetically costly, but have also provided the evolutionary substrates for subsequent sexual selection and species identity characters.
    Keywords catfish ; electroreception ; Gymnotiformes ; Mormyridae ; predation ; sensory drive ; Evolution ; QH359-425 ; Ecology ; QH540-549.5
    Subject code 590
    Language English
    Publishing date 2019-07-01T00:00:00Z
    Publisher Frontiers Media S.A.
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Cellular mechanisms of developmental and sex differences in the rapid hormonal modulation of a social communication signal.

    Markham, Michael R / Stoddard, Philip K

    Hormones and behavior

    2013  Volume 63, Issue 4, Page(s) 586–597

    Abstract: Some gymnotiform electric fish species rapidly modify their electric signal waveforms by altering the action potential (AP) waveforms of their electrocytes, the excitable cells that produce the electric organ discharge (EOD). The fish Brachyhypopomus ... ...

    Abstract Some gymnotiform electric fish species rapidly modify their electric signal waveforms by altering the action potential (AP) waveforms of their electrocytes, the excitable cells that produce the electric organ discharge (EOD). The fish Brachyhypopomus gauderio alters EOD amplitude and pulse duration as a social signal in accordance with the prevailing social conditions, under the dual regulation of melanocortins and androgens. We show here that B. gauderio uses two distinct cellular mechanisms to change signal amplitude, and its use of these two mechanisms varies with age and sex of the signaler. EOD amplitude and waveform are regulated by the coordinated timing and shaping of two APs generated from two opposing excitable membranes in each electrocyte. The two membranes fire in sequence within 100 μs of each other with the second AP being broader than the first. We have shown previously that mature males increase EOD amplitude and duration when melanocortin peptide hormones act directly on electrocytes to selectively broaden the second AP and increase the delay between the two APs by approximately 25 μs. Here we show that females selectively broaden only the second AP as males do, but increase amplitude of both APs with no change in delay between them, a previously unreported second mechanism of EOD amplitude change in B. gauderio. Juvenile fish broaden both APs and increase the delay between the APs. Cellular mechanisms of EOD plasticity are therefore shaped during development, presumably by sex steroids, becoming sexually dimorphic at maturity.
    MeSH term(s) Action Potentials/physiology ; Aging/psychology ; Analysis of Variance ; Animal Communication ; Animals ; Circadian Rhythm ; Electric Fish/physiology ; Electric Organ/physiology ; Electrolytes ; Electrophysiological Phenomena ; Female ; Hormones/physiology ; Larva ; Male ; Sex Characteristics ; Sex Differentiation/drug effects ; Social Behavior
    Chemical Substances Electrolytes ; Hormones
    Language English
    Publishing date 2013-02-20
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 214409-8
    ISSN 1095-6867 ; 0018-506X
    ISSN (online) 1095-6867
    ISSN 0018-506X
    DOI 10.1016/j.yhbeh.2013.02.004
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Food restriction promotes signaling effort in response to social challenge in a short-lived electric fish.

    Gavassa, Sat / Stoddard, Philip K

    Hormones and behavior

    2012  Volume 62, Issue 4, Page(s) 381–388

    Abstract: Vertebrates exposed to stressful conditions release glucocorticoids to sustain energy expenditure. In most species elevated glucocorticoids inhibit reproduction. However individuals with limited remaining reproductive opportunities cannot afford to forgo ...

    Abstract Vertebrates exposed to stressful conditions release glucocorticoids to sustain energy expenditure. In most species elevated glucocorticoids inhibit reproduction. However individuals with limited remaining reproductive opportunities cannot afford to forgo reproduction and should resist glucocorticoid-mediated inhibition of reproductive behavior. The electric fish Brachyhypopomus gauderio has a single breeding season in its lifetime, thus we expect males to resist glucocorticoid-mediated inhibition of their sexual advertisement signals. We studied stress resistance in male B. gauderio (i) by examining the effect of exogenous cortisol administration on the signal waveform and (ii) by investigating the effect of food limitation on androgen and cortisol levels, the amplitude of the electric signal waveform, the responsiveness of the electric signal waveform to social challenge, and the amount of feeding activity. Exogenous cortisol administration did reduce signal amplitude and pulse duration, but endogenous cortisol levels did not rise with food limitation or social challenge. Despite food limitation, males responded to social challenges by further increasing androgen levels and enhancing the amplitude and duration of their electric signal waveforms. Food-restricted males increased androgen levels and signal pulse duration more than males fed ad libitum. Socially challenged fish increased food consumption, probably to compensate for their elevated energy expenditure. Previous studies showed that socially challenged males of this species simultaneously elevate testosterone and cortisol in proportion to signal amplitude. Thus, B. gauderio appears to protect its cortisol-sensitive electric advertisement signal by increasing food intake, limiting cortisol release, and offsetting signal reduction from cortisol with signal-enhancing androgens.
    MeSH term(s) Adaptation, Psychological/physiology ; Animal Communication ; Animals ; Caloric Restriction/psychology ; Caloric Restriction/veterinary ; Electric Fish/blood ; Electric Fish/physiology ; Electric Organ/physiopathology ; Electrophysiological Phenomena/physiology ; Female ; Hydrocortisone/blood ; Hydrocortisone/pharmacology ; Longevity/physiology ; Male ; Malnutrition/psychology ; Malnutrition/veterinary ; Physical Exertion/physiology ; Social Isolation/psychology ; Stress, Psychological/blood ; Stress, Psychological/physiopathology
    Chemical Substances Hydrocortisone (WI4X0X7BPJ)
    Language English
    Publishing date 2012-09
    Publishing country United States
    Document type Evaluation Studies ; Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 214409-8
    ISSN 1095-6867 ; 0018-506X
    ISSN (online) 1095-6867
    ISSN 0018-506X
    DOI 10.1016/j.yhbeh.2012.07.003
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article: Signal Cloaking by Electric Fish.

    Stoddard, Philip K / Markham, Michael R

    Bioscience

    2010  Volume 58, Issue 5, Page(s) 415–425

    Abstract: Electric fish produce weak electric fields to image their world in darkness and to communicate with potential mates and rivals. Eavesdropping by electroreceptive predators exerts selective pressure on electric fish to shift their signals into less- ... ...

    Abstract Electric fish produce weak electric fields to image their world in darkness and to communicate with potential mates and rivals. Eavesdropping by electroreceptive predators exerts selective pressure on electric fish to shift their signals into less-detectable high-frequency spectral ranges. Hypopomid electric fish evolved a signal-cloaking strategy that reduces their detectability by predators in the lab (and thus presumably their risk of predation in the field). These fish produce broad-frequency electric fields close to the body, but the heterogeneous local fields merge over space to cancel the low-frequency spectrum at a distance. Mature males dynamically regulate this cloaking mechanism to enhance or suppress low-frequency energy. The mechanism underlying electric-field cloaking involves electrogenic cells that produce two independent action potentials. In a unique twist, these cells orient sodium and potassium currents in the same direction, potentially boosting their capabilities for current generation. Exploration of such evolutionary inventions could aid the design of biogenerators to power implantable medical devices, an ambition that would benefit from the complete genome sequence of a gymnotiform fish.
    Language English
    Publishing date 2010-03-05
    Publishing country England
    Document type Journal Article
    ZDB-ID 280313-6
    ISSN 0006-3568
    ISSN 0006-3568
    DOI 10.1641/B580508
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Energetic cost of communication.

    Stoddard, Philip K / Salazar, Vielka L

    The Journal of experimental biology

    2010  Volume 214, Issue Pt 2, Page(s) 200–205

    Abstract: Communication signals may be energetically expensive or inexpensive to produce, depending on the function of the signal and the competitive nature of the communication system. Males of sexually selected species may produce high-energy advertisement ... ...

    Abstract Communication signals may be energetically expensive or inexpensive to produce, depending on the function of the signal and the competitive nature of the communication system. Males of sexually selected species may produce high-energy advertisement signals, both to enhance detectability and to signal their size and body condition. Accordingly, the proportion of the energy budget allocated to signal production ranges from almost nothing for many signals to somewhere in excess of 50% for acoustic signals in short-lived sexually selected species. Recent data from gymnotiform electric fish reveal mechanisms that regulate energy allocated to sexual advertisement signals through dynamical remodeling of the excitable membranes in the electric organ. Further, males of the short-lived sexually selected species, Brachyhypopomus gauderio, trade off among different metabolic compartments, allocating energy to signal production while reducing energy used in other metabolic functions. Female B. gauderio, by contrast, do not trade off energy between signaling and other functions. To fuel energetically expensive signal production, we expect a continuum of strategies to be adopted by animals of different life history strategies. Future studies should explore the relation between life history and energy allocation trade-offs.
    MeSH term(s) Animal Communication ; Animals ; Electric Fish/metabolism ; Electric Fish/physiology ; Energy Metabolism ; Female ; Gymnotiformes/metabolism ; Gymnotiformes/physiology ; Male ; Sex Characteristics
    Language English
    Publishing date 2010-12-22
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 218085-6
    ISSN 1477-9145 ; 0022-0949
    ISSN (online) 1477-9145
    ISSN 0022-0949
    DOI 10.1242/jeb.047910
    Database MEDical Literature Analysis and Retrieval System OnLINE

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