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Sample records for 3-month advanced photoperiod

  1. Biological Manipulation of Migration Rate: The Use of Advanced Photoperiod to Accelerate Smoltification in Yearling Chinook Salmon, Annual Report 1989.

    SciTech Connect

    Giorgi, Albert E.; Muir, William D.; Zaugg, Waldo S.

    1991-01-01

    Research was conducted to assess the feasibility of biologically manipulating physiological development and migratory behavior of yearling spring chinook salmon, Oncorhynchus tshawytscha. At Dworshak National Fish Hatchery, treatment groups were exposed to a variety of advanced photoperiod cycles preceding release to accelerate smolt development. Physiological development and migratory performance were described for all groups. The treatments included a 14-week exposure to a 3-month advanced photoperiod cycle, an 18-week exposure to a 3-month advanced photoperiod cycle, and an 18-week exposure to a 4-month advanced photoperiod cycle. Two additional groups, an 18-week exposure to a 3-month advanced photoperiod and a control equivalent, were reared at an elevated water temperature (11{degrees}C) for 2 weeks prior to release. Results indicated that the treated fish which were the most physiologically advanced at release were detected in the highest proportion at collector dams and also migrated fastest downstream. 26 refs., 10 figs., 5 tabs.

  2. Biological Manipulation of Migration Rate: The Use of Advanced Photoperiod to Accelerate Smoltification in Yearling Chinook Salmon, Annual Report of Research 1990.

    SciTech Connect

    Muir, William D.

    1992-06-01

    Research was conducted during 1990 to assess the feasibility of biologically manipulating physiological development and migratory behavior of yearling spring chinook salmon, Oncorhynchus tshawytscha. At Dworshak National Fish Hatchery, one treatment group was exposed to a 3-month advanced photoperiod schedule for 13 weeks preceding release to accelerate smolt development. Another group was exposed to the same advanced photoperiod schedule, but additionally was reared at an elevated water temperature (11.9{degrees}C) for 10 days prior to release. At Leavenworth National Fish Hatchery, a treatment group was exposed to a 3-month advanced photoperiod schedule for 17 weeks. Gill Na{sup +}-K{sup +}ATPase development and migratory performance were described for all groups. The treated fish which were the most physiologically advanced at release were detected in the highest proportions at collector dams and also migrated fastest downstream--similar to results obtained in 1988 and 1989.

  3. Presence of photoperiod-melatonin-induced, sexually-activated rams in spring advances puberty in autumn-born ewe lambs.

    PubMed

    Abecia, J A; Chemineau, P; Gómez, A; Keller, M; Forcada, F; Delgadillo, J A

    2016-07-01

    The objective of this study was to determine the effect of sexually activated (by specific photoperiodic treatments) vasectomized rams on the onset of puberty in autumn-born ewe lambs in spring. Photoperiodic-treated rams were assigned to one of three groups, which were sequentially exposed to two months of long days (16h light/d) and given three melatonin implants at the end of the long days (sexually-activated-rams; SAR): SAR1 (n=5; 1 December-31 January), SAR2 (n=5; 1 Jan-28 February), and SAR3 (n=5; 1 February-31 March). Control rams (CR; n=4) were exposed to the natural photoperiod. On 1 March, 50 ewe lambs born in September were assigned to the SAR rams (SAR-treated; n=25) or the CR rams (CR-treated; n=25). SAR-treated ewe lambs were housed with SAR1 rams from 1 March. SAR2 rams replaced SAR1 rams (14 April), which were replaced by SAR3 rams (22 May) until 30 June. CR-treated ewe lambs were housed with the unstimulated rams. Ovulation was identified by weekly plasma progesterone concentrations and estrous behavior, as indicated by colored rumps. A greater proportion of SAR than CR ewe lambs ovulated in April (52% vs. 0%) and May (68% vs. 0%) (P<0.0001), and were in estrus in May (64% vs. 0%) and June (92% vs. 24%) (P<0.0001). The presence of SAR rams reduced (P<0.0001) mean (±SD) age (d) at first ovulation and estrus (235±28 [7 May] and 257±24 [29 May], respectively), compared to that of CR-treated ewe lambs (277±5 [18 June] and 302±16 [14 July], respectively). In conclusion, the presence of photoperiod-melatonin-induced, sexually activated rams in spring, advanced puberty in autumn-born ewe lambs. Using this technique might provide an effective and sustainable means of increasing the productive life of ewes, while avoiding the use of hormonal treatments. PMID:27133179

  4. Simulation of forest tree species' bud burst dates for different climate scenarios: chilling requirements and photo-period may limit bud burst advancement

    NASA Astrophysics Data System (ADS)

    Lange, Maximilian; Schaber, Jörg; Marx, Andreas; Jäckel, Greta; Badeck, Franz-Werner; Seppelt, Ralf; Doktor, Daniel

    2016-04-01

    This study investigates whether the assumed increase of winter and spring temperatures is depicted by phenological models in correspondingly earlier bud burst (BB) dates. Some studies assume that rising temperatures lead to an earlier BB, but even later BB has been detected. The phenological model PIM (promoter-inhibitor-model) fitted to the extensive phenological database of the German Weather Service was driven by several climate scenarios. This model accounts for the complicated mechanistic interactions between chilling requirements, temperature and photo-period. It predicts BB with a r 2 between 0.41 and 0.62 and a RMSE of around 1 week, depending on species. Parameter sensitivities depict species dependent interactions between growth and chilling requirements as well as photo-period. A mean trend to earlier BB was revealed for the period 2002- 2100, varying between -0.05 and -0.11 days per year, depending on species. These trends are lower than for the period 1951- 2009. Within climate scenario period, trends are decreasing for beech and chestnut, stagnating for birch and increasing for oak. Results suggest that not fulfilled chilling requirements accompanied by an increasing dependency on photo-period potentially limit future BB advancement. The combination of a powerful phenological model, a large scale phenological database and several climate scenarios, offers new insights into the mechanistic comprehension of spring phenology.

  5. Is it safe? Talking to teens with HIV/AIDS about death and dying: a 3-month evaluation of Family Centered Advance Care (FACE) planning – anxiety, depression, quality of life

    PubMed Central

    Lyon, Maureen E; Garvie, Patricia A; Briggs, Linda; He, Jianping; Malow, Robert; D’Angelo, Lawrence J; McCarter, Robert

    2010-01-01

    Purpose To determine the safety of engaging HIV-positive (HIV+) adolescents in a Family Centered Advance Care (FACE) planning intervention. Patients and methods We conducted a 2-armed, randomized controlled clinical trial in 2 hospital-based outpatient clinics from 2006–2008 with HIV+ adolescents and their surrogates (n = 76). Three 60–90 minutes sessions were conducted weekly. FACE intervention groups received: Lyon FCACP Survey©, the Respecting Choices® interview, and completion of The Five Wishes©. The Healthy Living Control (HLC) received: Developmental History, Healthy Tips, Future Planning (vocational, school or vocational rehabilitation). Three-month post-intervention outcomes were: completion of advance directive (Five Wishes©); psychological adjustment (Beck Depression, Anxiety Inventories); quality of life (PedsQL™); and HIV symptoms (General Health Self-Assessment). Results Adolescents had a mean age, 16 years; 40% male; 92% African-American; 68% with perinatally acquired HIV, 29% had AIDS diagnosis. FACE participants completed advance directives more than controls, using time matched comparison (P < 0.001). Neither anxiety, nor depression, increased at clinically or statistically significant levels post-intervention. FACE adolescents maintained quality of life. FACE families perceived their adolescents as worsening in their school (P = 0.018) and emotional (P = 0.029) quality of life at 3 months, compared with controls. Conclusions Participating in advance care planning did not unduly distress HIV+ adolescents. PMID:22096382

  6. Photoperiod effects on performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Photoperiod is known to affect growth rate, BW, feed consumption, incidence of metabolic disease, and immune response of broilers. Previous studies have reported significantly lower BW in broilers receiving 18h photoperiod throughout grow-out compared to broilers receiving >20h. This study evaluat...

  7. Influence of previous photoperiodic exposure on the reproductive response to a specific photoperiod signal in ewes.

    PubMed

    Sweeney, T; Donovan, A; Karsch, F J; Roche, J F; O'Callaghan, D

    1997-04-01

    Two experiments were carried out to determine whether the reproductive response of ewes to a specific photoperiodic signal depends on the time of year that the signal is given, and, if so, whether this dependence can be attributed to the photoperiodic history of the ewes. The aim of experiment 1 was to expand upon previous findings that the reproductive response to a specific photoperiodic challenge in ewes previously maintained on natural photoperiod varies with time of year. Ewes were transferred at one of three times of year from natural photoperiod to photochambers and were immediately exposed to 35 long days (18L:6D) followed by continuous exposure to short days (8.5L: 15.5D); this treatment is referred to as LD-->SD. The three times of year when long days started corresponded to the beginning of the breeding season, the mid-breeding season, and early anestrus (September 21, December 21, March 21, respectively). In ewes exposed to LD-->SD beginning in September, the breeding season and subsequent anestrous season was not altered. In ewes exposed to LD-->SD beginning in December, the transition to anestrus was advanced (p < 0.05) relative to that in controls maintained in simulated natural photoperiod. Subsequently, half of these ewes resumed reproductive activity within 180 days; this occurred 131 +/- 8 days after transfer to short days. In contrast, all ewes exposed to LD-->SD beginning in March resumed reproductive activity; this began 100 +/- 3 days after transfer to short days (p < 0.05 versus December group). The purpose of experiment 2 was to assess the extent to which the difference in response to a photoperiodic challenge can be attributed to photoperiodic history. Ewes were maintained on short days from the winter solstice interrupted with 35 long days from March 21, June 21, September 21, or December 21. The majority of ewes exhibited an onset of reproductive activity after exposure to LD-->SD at the different times of year, and there was no group

  8. Change in photoperiodic cycle affects life span in a prosimian primate (Microcebus murinus).

    PubMed

    Perret, M

    1997-04-01

    The lesser mouse lemur, a small prosimian primate, exhibits seasonal rhythms strictly controlled by photoperiodic variations. Exposure to day lengths shorter than 12 h results in complete sexual rest, fattening, lethargy, and reduced behavioral activities; whereas exposure to day lengths greater than 12 h induces sexual activity, an increase in behavioral activities, and high hormonal levels. The objective of this study was to test whether long-term acceleration of seasonal rhythms may affect survival and longevity of this primate. In captivity, acceleration of seasonal rhythms was obtained by exposing the animals to an accelerated photoperiodic regimen consisting of 5 months of long photoperiod followed by 3 months of short photoperiod. The age-specific survival rate in animals exposed from birth to accelerated photoperiodic conditions (n = 89) was compared to the age-specific survival rate of animals maintained under a natural photoperiod (n = 68). Independent of sexes, the mean life span (45.5 +/- 2.1 months) and maximal survival (79.3 +/- 3.3 months) were significantly (p < .01) shortened in mouse lemurs exposed to the accelerated photoperiodic cycle compared to those in animals living under annual photoperiod (63.2 +/- 2.5 and 98 +/- 3.9 months for mean life span and maximal survival, respectively). This reduction of about 30% of life span was not accompanied by a desynchronization of biological rhythms under photoperiodic control and was not related to an increase in reproduction or in duration of time spent in active conditions. However, when the number of seasonal cycles experienced by 1 individual is considered rather than chronological age, the mean life span was 5 seasonal cycles and maximum survival reached 9-10 cycles, independent of sex or of photoperiodic regimen. These results suggest that in mouse lemurs, as in other seasonal mammals, longevity may depend on the expression of a fixed number of seasonal cycles rather than on a fixed biological age

  9. 9 CFR 206.3 - Monthly report.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STOCKYARDS PROGRAMS), DEPARTMENT OF AGRICULTURE SWINE CONTRACT LIBRARY § 206.3 Monthly report. (a) Do I need... swine processing plant that it operates or at which it has swine slaughtered that has the slaughtering... report, each packer must provide the following information: (1) Number of swine to be delivered...

  10. 9 CFR 206.3 - Monthly report.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STOCKYARDS PROGRAMS), DEPARTMENT OF AGRICULTURE SWINE CONTRACT LIBRARY § 206.3 Monthly report. (a) Do I need... swine processing plant that it operates or at which it has swine slaughtered that has the slaughtering... following information: (1) Number of swine to be delivered under existing contracts. Existing contracts...

  11. 9 CFR 206.3 - Monthly report.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STOCKYARDS PROGRAMS), DEPARTMENT OF AGRICULTURE SWINE CONTRACT LIBRARY § 206.3 Monthly report. (a) Do I need... swine processing plant that it operates or at which it has swine slaughtered that has the slaughtering... report, each packer must provide the following information: (1) Number of swine to be delivered...

  12. 9 CFR 206.3 - Monthly report.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STOCKYARDS PROGRAMS), DEPARTMENT OF AGRICULTURE SWINE CONTRACT LIBRARY § 206.3 Monthly report. (a) Do I need... swine processing plant that it operates or at which it has swine slaughtered that has the slaughtering... report, each packer must provide the following information: (1) Number of swine to be delivered...

  13. 9 CFR 206.3 - Monthly report.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STOCKYARDS PROGRAMS), DEPARTMENT OF AGRICULTURE SWINE CONTRACT LIBRARY § 206.3 Monthly report. (a) Do I need... swine processing plant that it operates or at which it has swine slaughtered that has the slaughtering... report, each packer must provide the following information: (1) Number of swine to be delivered...

  14. Photoperiod effects on broiler behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the effects of 3 photoperiod regimes on behavior of commercial broilers. The photoperiods were 23h for all treatments from 1-6d. Treatments 1 and 2, 20L:4D and 18L:6D respectively, were applied from 7-36d and increased to 23L:1D at 37d. Treatment 3 was a step-down/step-up pro...

  15. Photoperiodic Suppression of Drug Reinstatement

    PubMed Central

    Sorg, Barbara A.; Stark, Gemaine; Sergeeva, Anna; Jansen, Heiko T.

    2011-01-01

    The rewarding influence of drugs of abuse varies with time of day and appears to involve interactions between the circadian and the mesocorticolimbic dopamine systems. The circadian system is also intimately involved in measuring daylength. Thus, the present study examined the impact of changing daylength (photoperiod) on cocaine-seeking behaviors. Male Sprague Dawley rats were trained and tested on a 12L:12D light:dark schedule for cocaine-induced reinstatement of conditioned place preference (CPP) at three times of day (Zeitgeber time (ZT): 4, 12, and 20) to determine a preference score. Rats were then shifted to either shorter (6L:18D) or longer (18L:6D) photoperiods and then to constant conditions, re-tested for cocaine-induced reinstatement under each different condition, and then returned to their original photoperiod (12L:12D) and tested once more. Rats exhibited a circadian profile of preference score in constant darkness with a peak at 12h after lights-off. At both ZT4 and ZT20, but not at ZT12, shorter photoperiods profoundly suppressed cocaine reinstatement, which did not recover even after switching back to 12L:12D. In contrast, longer photoperiods did not alter reinstatement. Separate studies showed that the suppression of cocaine reinstatement was not due to repeated testing. In an additional experiment, we examined the photoperiodic regulation of tyrosine hydroxylase (TH) and dopamine transporter (DAT) proteins in drug-naive rats. These results revealed photoperiodic modulation of proteins in the prefrontal cortex and dorsal striatum, but not in the nucleus accumbens or ventral tegmental area. Together, these findings add further support to the circadian genesis of cocaine-seeking behaviors and demonstrate that drug-induced reinstatement is modulated by photoperiod. Furthermore, the results suggest that photoperiod partly contributes to the seasonal expression of certain drug-related behaviors in humans living at different latitudes and thus our

  16. Feeding Your 1- to 3-Month-Old

    MedlinePlus

    ... About Zika & Pregnancy Feeding Your 1- to 3-Month-Old KidsHealth > For Parents > Feeding Your 1- to 3-Month-Old Print A A A Text Size What's ... About Spitting Up During your baby's first 3 months, breast milk or formula will provide all the ...

  17. Effects of interrupted photoperiods on the induction of ovulation in anestrous mares.

    PubMed

    Malinowski, K; Johnson, A L; Scanes, C G

    1985-10-01

    The ability of interrupted photoperiods to induce early estrus and ovulation was examined. Horse mares were exposed to long (16 h light) or short (10 h light), noninterrupted photoperiods, ambient light, or various interrupted photoperiod treatments from December 1 to April 15 (135 d). Follicular development was assessed by rectal palpation and estrous behavior was determined by teasing with a stallion. Serum concentrations of progesterone were used as an indicator of corpus luteum function. Differences among the light treatment groups were compared for the following behavioral and ovarian characteristics: days to first detectable 3-cm follicle, days to first estrous behavior, days to first ovulation, the number of mares ovulating within the treatment period, and the number of ovulations within the treatment period per mare. Compared with the ambient and 10L:14D (L = h of light and D = h of darkness) photoperiod treatments, ovulation was advanced to the greatest extent by a photoperiod of 16L:8D and the interrupted photoperiod 10L:8D:2L:4D. These two stimulatory photoperiod treatments were characterized by the presence of light 8 to 10 h after dusk. Therefore, the present data are consistent with an external coincidence model for the induction of seasonal breeding in horses, with the photoinducible phase occurring within the period 8 to 10 h after dusk. PMID:4066545

  18. Similarities in the circadian clock and photoperiodism in plants

    PubMed Central

    Song, Young Hun; Ito, Shogo; Imaizumi, Takato

    2010-01-01

    Summary of recent advances Plants utilize circadian clocks to synchronize their physiological and developmental events with daily and yearly changes in the environment. Recent advances in Arabidopsis research have provided a better understanding of the molecular mechanisms of the circadian clock and photoperiodism. One of the most important questions is whether the mechanisms studied in Arabidopsis are conserved in other plants. Homologs of many Arabidopsis clock genes have been identified in various plants and some gene functions have been characterized. It seems that the circadian clocks in plants are similar. Recent success in molecular genetics has also revealed the mechanisms of photoperiodic flowering in cereals. The day-length sensing mechanisms appear to have diverged more between long-day plants and short-day plants than the circadian clock. PMID:20620097

  19. Medical Care and Your 1- to 3-Month-Old

    MedlinePlus

    ... Pregnancy Medical Care and Your 1- to 3-Month-Old KidsHealth > For Parents > Medical Care and Your 1- to 3-Month-Old Print A A A Text Size What's ... When to Call the Doctor During these early months, you may have many questions about your baby's ...

  20. Learning, Play, and Your 1- to 3-Month-Old

    MedlinePlus

    ... Pregnancy Learning, Play, and Your 1- to 3-Month-Old KidsHealth > For Parents > Learning, Play, and Your 1- to 3-Month-Old Print A A A Text Size What's ... start responding even more to you during these months — and will even give you a smile! Babies ...

  1. Transfer from long to short photoperiods affects production efficiency of day-neutral rice

    NASA Technical Reports Server (NTRS)

    Goldman, K. R.; Mitchell, C. A.

    1999-01-01

    The day-neutral, semidwarf rice (Oryza sativa L.) cultivar Ai-Nan-Tsao was grown in a greenhouse under summer conditions using high-pressure sodium lamps to extend the natural photoperiod. After allowing 2 weeks for germination, stand establishment, and thinning to a consistent planting density of 212 plants/m2, stands were maintained under continuous lighting for 35 or 49 days before shifting to 8- or 12-h photoperiods until harvest 76 days after planting. Non-shifted control treatments consisting of 8-, 12-, or 24-h photoperiods also were maintained throughout production. Tiller number increased as duration of exposure to continuous light increased before shifting to shorter photoperiods. However, shoot harvest index and yield efficiency rate were lower for all plants receiving continuous light than for those under the 8- or 12-h photoperiods. Stands receiving 12-h photoperiods throughout production had the highest grain yield per plant and equaled the 8-h-photoperiod control plants for the lowest tiller number per plant. As long as stands were exposed to continuous light, tiller formation continued. Shifting to shorter photoperiods late in the cropping cycle resulted in newly formed tillers that were either sterile or unable to mature grain before harvest. Late-forming tillers also suppressed yield of grain in early-forming tillers, presumably by competing for photosynthate or for remobilized assimilate during senescence. Stands receiving 12-h photoperiods throughout production not only produced the highest grain yield at harvest but had the highest shoot harvest index, which is important for resource-recovery strategies in advanced life-support systems proposed for space.

  2. Measuring seasonal time within the circadian system: regulation of the suprachiasmatic nuclei by photoperiod.

    PubMed

    Johnston, J D

    2005-07-01

    Day-length (photoperiod) is the primary environmental signal used to synchronise endogenous rhythms of physiology and behaviour. In mammals, the suprachiasmatic nuclei (SCN) of the hypothalamus house the master circadian clock. The SCN incorporate photoperiodic information and therefore measure both daily and seasonal time. Over the past decade, there have been significant advances in the understanding of the molecular basis of circadian clocks. It is now becoming apparent that the core molecular clock mechanism is itself regulated by photoperiod, although there is currently debate as to how this occurs. One recent model proposes that distinct groups of core 'clock genes' are associated with either morning or evening phases of the daily light/dark cycle. However, the validity of associating particular genes to morning and evening has been questioned. This article reviews the evidence for photoperiodic regulation of circadian clock function and then discusses alternative models that may explain the available data. PMID:15946164

  3. Senses and Your 1- to 3-Month-Old

    MedlinePlus

    ... enjoy listening to music (play a variety of styles) and may be fascinated by the routine sounds ... Parents MORE ON THIS TOPIC Your Child's Vision Communication and Your 1- to 3-Month-Old Feeding ...

  4. Flowering time regulation: photoperiod- and temperature-sensing in leaves

    PubMed Central

    Song, Young Hun; Ito, Shogo; Imaizumi, Takato

    2013-01-01

    Plants monitor changes in photoperiod and temperature to synchronize their flowering with seasonal changes to maximize fitness. In the Arabidopsis photoperiodic flowering pathway, the circadian clock-regulated components, such as FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 and CONSTANS, both of which have light-controlled functions, are crucial to induce the day-length specific expression of the FLOWERING LOCUS T (FT) gene in leaves. Recent advances indicate that FT transcriptional regulation is central for integrating the information derived from other important internal and external factors, such as developmental age, amount of gibberellic acid, and the ambient temperature. In this review, we describe how these factors interactively regulate the expression of FT, the main component of florigen, in leaves. PMID:23790253

  5. Photoperiodic Flowering: Time Measurement Mechanisms in Leaves

    PubMed Central

    Song, Young Hun; Shim, Jae Sung; Kinmonth-Schultz, Hannah A.; Imaizumi, Takato

    2015-01-01

    Many plants use information about changing day length (photoperiod) to align their flowering time with seasonal changes to increase reproductive success. A mechanism for photoperiodic time measurement is present in leaves, and the day-length-specific induction of the FLOWERING LOCUS T (FT) gene, which encodes florigen, is a major final output of the pathway. Here, we summarize the current understanding of the molecular mechanisms by which photoperiodic information is perceived in order to trigger FT expression in Arabidopsis as well as in the primary cereals wheat, barley, and rice. In these plants, the differences in photoperiod are measured by interactions between circadian-clock-regulated components, such as CONSTANS (CO), and light signaling. The interactions happen under certain day length conditions, as previously predicted by the external coincidence model. In these plants, the coincidence mechanisms are governed by multilayered regulation with numerous conserved as well as unique regulatory components, highlighting the breadth of photoperiodic regulation across plant species. PMID:25534513

  6. Chilling outweighs photoperiod in preventing precocious spring development.

    PubMed

    Laube, Julia; Sparks, Tim H; Estrella, Nicole; Höfler, Josef; Ankerst, Donna P; Menzel, Annette

    2014-01-01

    It is well known that increased spring temperatures cause earlier onset dates of leaf unfolding and flowering. However, a temperature increase in winter may be associated with delayed development when species' chilling requirements are not fulfilled. Furthermore, photosensitivity is supposed to interfere with temperature triggers. To date, neither the relative importance nor possible interactions of these three factors have been elucidated. In this study, we present a multispecies climate chamber experiment to test the effects of chilling and photoperiod on the spring phenology of 36 woody species. Several hypotheses regarding their variation with species traits (successional strategy, floristic status, climate of their native range) were tested. Long photoperiods advanced budburst for one-third of the studied species, but magnitudes of these effects were generally minor. In contrast to prior hypotheses, photosensitive responses were not restricted to climax or oceanic species. Increased chilling length advanced budburst for almost all species; its effect greatly exceeding that of photoperiod. Moreover, we suggest that photosensitivity and chilling effects have to be rigorously disentangled, as the response to photoperiod was restricted to individuals that had not been fully chilled. The results indicate that temperature requirements and successional strategy are linked, with climax species having higher chilling and forcing requirements than pioneer species. Temperature requirements of invasive species closely matched those of native species, suggesting that high phenological concordance is a prerequisite for successful establishment. Lack of chilling not only led to a considerable delay in budburst but also caused substantial changes in the chronological order of species' budburst. The results reveal that increased winter temperatures might impact forest ecosystems more than formerly assumed. Species with lower chilling requirements, such as pioneer or invasive

  7. Variation among individuals in photoperiod responses: Effects of breeding schedule, photoperiod, and age-related photoperiodic experience in birds.

    PubMed

    Watts, Heather E; MacDougall-Shackleton, Scott A; Hahn, Thomas P

    2015-07-01

    Many organisms use environmental cues to regulate reproductive function in order to time reproduction to coincide with favorable environmental conditions. Whereas we understand much about how environmental cues are used to time reproduction, we know relatively little about variation among individuals in responsiveness to environmental cues. However, this variation among individuals may represent a crucial component of a population's capacity to respond to changing environmental conditions. In this study, we quantify variation among individuals in photoperiod responsiveness of the avian reproductive system and investigate three potential underlying sources of this variation in environmental cue responsiveness. Specifically, we tested whether age-related photoperiodic experience, strength of the photoperiodic cue (day length), and degree of flexibility in breeding schedule influenced the degree of variation observed in experimental studies of seven species of cardueline finches. Overall, we found a high degree of variation among individuals in photoperiod response, and this was influenced by experimental photoperiod and breeding schedule. As experimental photoperiod became longer, the degree of variation declined. Opportunistic breeders showed greater variation in response compared with more seasonal breeders. We found no effect of age-related photoperiodic experience in one species for which we could examine this factor. The results of this study highlight the extent to which individuals can vary in their response to environmental cues and point to both species ecology and characteristics of the cue as important influences on the degree of this variation. PMID:25865942

  8. The effect of abrupt lengthening of the photoperiod on the onset of ovulation in gonadotrophin-treated immature rats.

    PubMed

    McCormack, C E

    1975-03-01

    Immature female rats exposed daily to a-14 h photoperiod were induced to ovulate precociously by administering pregnant mares' serum gonadotrophin (PMS) at 30 days of age (day 30). In these rats ovulation occurs on day 33 between 0130 and 0330 (midpoint of photoperiod equals 1200). The acute effect on the timing of ovulation of abruptly lengthening the photoperiod by 6 h was investigated in this preparation. When compared with controls kept on a 14-h photoperiod, adding 6 h of light to the beginning of the daily photoperiod (i.e., AM light) advanced ovulation by 2 h; adding 6 h of light to the end of the photoperiod (i.e., PM light) delayed ovulation by 5.5 h; adding 3 h of light to the beginning and to the end of the photoperiod delayed ovulation by 2 h. These results suggest that the time of release of an ovulatory quota of pituitary gonadotrophin may be advanced by exposure to AM light and delayed by exposure to PM light, but the PM light appears to have a stronger effect on the time of gonadotrophin secretion. PMID:1116482

  9. Photoperiod and ambient temperature as environmental cues for seasonal thermogenic adaptation in the Djungarian hamster, Phodopus sungorus

    NASA Astrophysics Data System (ADS)

    Heldmaier, G.; Steinlechner, S.; Rafael, J.; Latteier, B.

    1982-12-01

    For their seasonal control of thermogenesis Djungarian hamsters rely on environmental cueing by both photoperiod and ambient temperature. Their total potential for adaptive improvements of nonshivering thermogenesis is constant in summer and winter. The shortening of photoperiod in fall is used to anticipate about half of the total improvement in thermogenesis, in advance of any experience of cold, as can be concluded from the photoperiodic control of thermogenesis, cold resistance, and the protein content, cyctochrome oxidase activity and content of mitochondria in brown adipose tissue. The remainder of the seasonal thermogenic adaptation is due to stimulatory responses to chronic exposure to cold.

  10. In short photoperiods, human sleep is biphasic.

    PubMed

    Wehr

    1992-06-01

    Results of a photoperiod experiment show that human sleep can be unconsolidated and polyphasic, like the sleep of other animals. When normal individuals were transferred from a conventional 16-h photoperiod to an experimental 10-h photo-period, their sleep episodes expanded and usually divided into two symmetrical bouts, several hours in duration, with a 1-3 h waking interval between them. The durations of nocturnal melatonin secretion and of the nocturnal phase of rising sleepiness (measured in a constant routine protocol) also expanded, indicating that the timing of internal processes that control sleep and melatonin, such as circadian rhythms, had been modified by the change in photoperiod. Previous work suggests that the experimental results could be simulated with dual-oscillators, entrained separately to dawn and dusk, or with a two-process model, having a lowered threshold for sleep-onset during the scotoperiod. PMID:10607034

  11. Photoperiodic time measurement and seasonal immunological plasticity

    PubMed Central

    Stevenson, Tyler J.; Prendergast, Brian J.

    2014-01-01

    Seasonal variations in immunity are common in nature, and changes in day length are sufficient to trigger enhancement and suppression of immune function in many vertebrates. Drawing primarily on data from Siberian hamsters, this review describes formal and physiological aspects of the neuroendocrine regulation of seasonal changes in mammalian immunity. Photoperiod regulates immunity in a trait-specific manner, and seasonal changes in gonadal hormone secretion and thyroid hormone signaling all participate in seasonal immunomodulation. Photoperiod-driven changes in the hamster reproductive and immune systems are associated with changes in iodothyronine deiodinase-mediated thyroid hormone signaling, but photoperiod exerts opposite effects on the epigenetic regulation of reproductive neuroendocrine and lymphoid tissues. Photoperiodic changes in immunocompetence may explain a proportion of the annual variance in disease incidence and severity in nature, and provide a useful framework to help understand brain-immune interactions. PMID:25456046

  12. 20 CFR 210.3 - Month of service.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Month of service. 210.3 Section 210.3... RAILROAD SERVICE § 210.3 Month of service. (a) Reported. A reported month of service is any calendar month... calendar year. Any fraction or remainder in the quotient is credited as an additional month of service....

  13. Emotional and Social Development: Birth to 3 Months

    MedlinePlus

    ... Share Emotional and Social Development: Birth to 3 Months Page Content Article Body By the second month, your baby will spend much of each day ... he can smile, too. Even during his first month, he’ll experiment with primitive grins and grimaces. ...

  14. Ovulatory activity of female goats adapted to the subtropics is responsive to photoperiod.

    PubMed

    Duarte, Gerardo; Nava-Hernández, Martha Patricia; Malpaux, Benoît; Delgadillo, José Alberto

    2010-07-01

    The objective of this study was to determine whether reproductive seasonality of local well-fed female goats from subtropical Mexico (26 degrees N) can be controlled by photoperiod. The control group (n=12) remained in an open pen under natural photoperiod variations. The two experimental groups (n=8 each) were placed in light-proof rooms and exposed for 2 yr to alternations of 3 months of long days and 3 months of short days. One group was first exposed to long days, Group 1, and the other one to short days, Group 2. Blood samples were obtained twice a week to determine ovulation status by progesterone plasma concentrations. Goats from the control group displayed a seasonality of ovulations. The mean (+/-SEM) dates of the onset and end of the ovulations were September 10+/-5 d and February 16+/-4 d, respectively. In contrast, in both experimental groups, ovulations were modified (P<0.05) by the photoperiodic treatments such that ovulations started and ended during short and long days, respectively. In Groups 1 and 2, ovulations started 67+/-2 and 66+/-2 d (P>0.05), respectively, after the transfer from long to short days. In contrast, the timing of the cessation of ovulations after the transfer from short to long days differed (P<0.05) between groups (19+/-3 and 31+/-3 d for Groups 1 and 2, respectively). Local female goats from subtropical Mexico are, therefore, sensitive to photoperiodic changes that they are exposed to at this latitude and this environmental cue may control the timing of the breeding season in natural conditions. PMID:20434852

  15. Complete transurethral bladder eversion 3 months after hemipelvectomy.

    PubMed

    Lowe, Gregory; Mandalapu, Subbarao; Gilleran, Jason

    2010-02-01

    A 46-year-old white female underwent a left hemipelvectomy for chondrosarcoma. She presented with total incontinence and a bulging vaginal mass. Exam confirmed complete transurethral bladder eversion that was addressed with transvaginal multilayer bladder neck closure and suprapubic tube placement. Eventually she underwent abdominal hysterectomy, mesh sacral colpopexy, and catheterizable stoma creation. Patient is continent of urine 3 months postoperatively. We present the first reported case of bladder eversion after hemipelvectomy and propose possible pathophysiologic mechanisms. PMID:19629370

  16. Photoperiod and reproduction in female deer mice

    SciTech Connect

    Whitsett, J.M.; Miller, L.L.

    1982-03-01

    Female deer mice were exposed to a short day photoperiod beginning during 1 of 3 stages of life. In the first experiment, exposure to SD during adulthood resulted in a minimal disruption of reproductive condition; many females bore 2 litters after the onset of this treatment. In the second experiment, females reared on SD from weaning matured normally, as measured by vaginal introitus; however, vaginal closure occurred in approximately one-half of these females by 9 weeks of age. In the third experiment, females were born of mothers housed on either an SD or a long day photoperiod, and were continued on the maternal photoperiod until 6 weeks of postnatal age. The SD photoperiod markedly inhibited reproductive maturation as measured by vaginal patency, ovarian weight, and uterine weight. A comparison of reproductive organ weights and vaginal condition provided evidence for the validity of the latter measure as an index of reproductive state. As assayed by the present testing procedure, the sensitivity of the reproductive system to photoperiod decreases as a function of age in female deer mice.

  17. Effects of extended photoperiod on sandhill crane reproduction

    USGS Publications Warehouse

    Gee, G.F.; Pendleton, G.W.

    1992-01-01

    Photoperiod studies were conducted with greater sandhill cranes (Grus canadensis tabida) from 1969 to 1972 and from 1982 to 1987 at the Patuxent Wildlife Research Center, Maryland. When housed indoors and exposed to long photoperiods, males produced semen during winter. When exposed to artificially extended photoperiods during spring in outdoor pens, females apparently laid earlier in the year and laid more eggs than they would have without the added light. Cranes did not exhibit any signs of photorefractory response to extended photoperiods.

  18. PHOTON FLUX DENSITY INFLUENCES GRASS RESPONSES TO EXTENDED PHOTOPERIOD

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant sensitivity to extended photoperiod has been well documented, with little attention to the possibility that quantum flux density used to extend photoperiod has an influence on the expression of photoperiod response. This study was undertaken with 4 grass species under field conditions to exami...

  19. Cardiometabolic Health in Submariners Returning from a 3-Month Patrol

    PubMed Central

    Gasier, Heath G.; Young, Colin R.; Gaffney-Stomberg, Erin; McAdams, Douglas C.; Lutz, Laura J.; McClung, James P.

    2016-01-01

    Confined space, limited exercise equipment, rotating shift work and reduced sleep may affect cardiometabolic health in submariners. To test this hypothesis, 53 male U.S. Submariners (20–39 years) were studied before and after a 3-month routine submarine patrol. Measures included anthropometrics, dietary and physical activity, biomarkers of cardiometabolic health, energy and appetite regulation, and inflammation. Before deployment, 62% of submariners had a body fat % (BF%) ≥ 25% (obesity), and of this group, 30% met the criteria for metabolic syndrome. In obese volunteers, insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), leptin, the leptin/adiponectin ratio, and pro-inflammatory chemokines growth-related oncogene and macrophage-derived chemokine were significantly higher compared to non-obese submariners. Following the patrol, a significant mean reduction in body mass (5%) and fat-mass (11%) occurred in the obese group as a result of reduced energy intake (~2000 kJ) during the patrol; and, independent of group, modest improvements in serum lipids and a mean reduction in interferon γ-induced protein 10 and monocyte chemotactic protein 1 were observed. Since 43% of the submariners remained obese, and 18% continued to meet the criteria for metabolic syndrome following the patrol, the magnitude of weight loss was insufficient to completely abolish metabolic dysfunction. Submergence up to 3-months, however, does not appear to be the cause of obesity, which is similar to that of the general population. PMID:26867201

  20. Cardiometabolic Health in Submariners Returning from a 3-Month Patrol.

    PubMed

    Gasier, Heath G; Young, Colin R; Gaffney-Stomberg, Erin; McAdams, Douglas C; Lutz, Laura J; McClung, James P

    2016-02-01

    Confined space, limited exercise equipment, rotating shift work and reduced sleep may affect cardiometabolic health in submariners. To test this hypothesis, 53 male U.S. Submariners (20-39 years) were studied before and after a 3-month routine submarine patrol. Measures included anthropometrics, dietary and physical activity, biomarkers of cardiometabolic health, energy and appetite regulation, and inflammation. Before deployment, 62% of submariners had a body fat % (BF%) ≥ 25% (obesity), and of this group, 30% met the criteria for metabolic syndrome. In obese volunteers, insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), leptin, the leptin/adiponectin ratio, and pro-inflammatory chemokines growth-related oncogene and macrophage-derived chemokine were significantly higher compared to non-obese submariners. Following the patrol, a significant mean reduction in body mass (5%) and fat-mass (11%) occurred in the obese group as a result of reduced energy intake (~2000 kJ) during the patrol; and, independent of group, modest improvements in serum lipids and a mean reduction in interferon γ-induced protein 10 and monocyte chemotactic protein 1 were observed. Since 43% of the submariners remained obese, and 18% continued to meet the criteria for metabolic syndrome following the patrol, the magnitude of weight loss was insufficient to completely abolish metabolic dysfunction. Submergence up to 3-months, however, does not appear to be the cause of obesity, which is similar to that of the general population. PMID:26867201

  1. Photoperiodic flowering regulation in Arabidopsis thaliana

    PubMed Central

    Golembeski, Greg S.; Kinmonth-Schultz, Hannah A.; Song, Young Hun; Imaizumi, Takato

    2015-01-01

    Photoperiod, or the duration of light in a given day, is a critical cue that flowering plants utilize to effectively assess seasonal information and coordinate their reproductive development in synchrony with the external environment. The use of the model plant, Arabidopsis thaliana, has greatly improved our understanding of the molecular mechanisms that determine how plants process and utilize photoperiodic information to coordinate a flowering response. This mechanism is typified by the transcriptional activation of FLOWERING LOCUS T (FT) gene by the transcription factor CONSTANS (CO) under inductive long-day conditions in Arabidopsis. FT protein then moves from the leaves to the shoot apex, where floral meristem development can be initiated. As a point of integration from a variety of environmental factors in the context of a larger system of regulatory pathways that affect flowering, the importance of photoreceptors and the circadian clock in CO regulation throughout the day has been a key feature of the photoperiodic flowering pathway. In addition to these established mechanisms, the recent discovery of a photosynthate derivative trehalose-6-phosphate as an activator of FT in leaves has interesting implications for the involvement of photosynthesis in the photoperiodic flowering response that were suggested from previous physiological experiments in flowering induction. PMID:25684830

  2. Effect of extended photoperiod during winter on growth and onset of puberty in Murrah buffalo heifers

    PubMed Central

    Roy, Ashwani Kumar; Singh, Mahendra; Kumar, Parveen; Kumar, B. S. Bharath

    2016-01-01

    Aim: To investigate the effect of extended photoperiod on growth rate, hormonal levels, and puberty in Murrah heifers. Materials and Methods: About 14 Murrah buffalo heifers were divided into normal day photoperiod (NDP; n=7) and extended NDP (ENDP; n=7) groups. The ENDP group was exposed to 4 h of extended photoperiod with artificial light (160 lux) after sunset for 3 months during winter. Results: Group, age and group-by-age interaction effects on plasma glucose concentrations were non-significant (p>0.05). A significant effect of age on non-esterified fatty acids (p<0.05), cholesterol (p<0.01), and triglycerides (p<0.05) concentrations was observed. Group and group-by-age interaction effects on plasma T3, T4, leptin, 17 β estradiol, prolactin and melatonin concentrations were non-significant (p>0.05) while significant (p<0.05) age effect on T4, leptin and melatonin concentrations was observed. With respect to the circadian pattern of melatonin and prolactin, the group, time and group-by-time interaction effects were non-significant (p>0.05). Average daily gain and dry matter intake of heifers were non-significant between the NDP and ENDP groups but were comparatively higher in ENDP group. By the end of the experiment, 6 out of 7 heifers attained puberty in ENDP group in comparison to 4 out of 7 in NDP group. Conclusion: Extending the photoperiod by artificial light for 4 h during winter season resulted in better growth rate and early onset of puberty in Murrah buffalo heifers. PMID:27051212

  3. Maternal depressive symptoms and parenting practices 3-months postpartum.

    PubMed

    Balbierz, Amy; Bodnar-Deren, Susan; Wang, Jason J; Howell, Elizabeth A

    2015-06-01

    Using data from two postpartum depression randomized trials, we examined the association between postpartum depressive symptoms and parenting practices among a diverse group of mothers. We examined the association between safety practices (back sleep position, car seat use, smoke alarm), feeding practices (breastfeeding, infant intake of cereal, juice, water), and health care practices (routine well child and Emergency Room (ER) visits) with 3-month postpartum depressive symptoms assessed using the Edinburgh Depression Scale (EPDS ≥10). Fifty-one percent of mothers were black or Latina, 33 % had Medicaid, and 30 % were foreign born. Depressed mothers were less likely to have their infant use back sleep position (60 vs. 79 %, p < .001), always use a car seat (67 vs. 84 %, p < .001), more likely to feed their infants water, juice, or cereal (36 vs. 25 %, p = .04 respectively), and to bring their babies for ER visits (26 vs. 16 %, p = .03) as compared with non-depressed mothers. In multivariable model, depressed mothers remained less likely to have their infant use the back sleep position, to use a car seat, and to have a working smoke alarm in the home. Findings suggest the need to intervene early among mothers with depressive symptoms and reinforce positive parenting practices. PMID:25374288

  4. Maternal Depressive Symptoms and Parenting Practices 3-Months Postpartum

    PubMed Central

    Balbierz, Amy; Bodnar-Deren, Susan; Wang, Jason J; Howell, Elizabeth A

    2014-01-01

    Objectives Using data from two postpartum depression randomized trials, we examined the association between postpartum depressive symptoms and parenting practices among a diverse group of mothers. Methods We examined the association between safety practices (back sleep position, car seat use, smoke alarm), feeding practices (breastfeeding, infant intake of cereal, juice, water), and health care practices (routine well child and Emergency Room (ER) visits) with 3-month postpartum depressive symptoms assessed using the Edinburgh Depression Scale (EPDS≥10). Results Fifty-one percent of mothers were black or Latina, 33% had Medicaid, and 30% were foreign born. Depressed mothers were less likely to have their infant use back sleep position (60% vs. 79%, p<.001), always use a car seat (67% vs. 84%, p<.001), more likely to feed their infants water, juice, or cereal (36% vs. 25%, p=.04 respectively), and to bring their babies for ER visits (26% vs. 16%, p=.03) as compared with non-depressed mothers. In multivariable model, depressed mothers remained less likely to have their infant use the back sleep position, to use a car seat, and to have a working smoke alarm in the home. Conclusions Findings suggest the need to intervene early among mothers with depressive symptoms and reinforce positive parenting practices. PMID:25374288

  5. Mate Preference of Female Blue Tits Varies with Experimental Photoperiod

    PubMed Central

    Reparaz, Laura B.; van Oers, Kees; Naguib, Marc; Doutrelant, Claire; Visser, Marcel E.; Caro, Samuel P.

    2014-01-01

    Organisms use environmental cues to time their life-cycles and among these cues, photoperiod is the main trigger of reproductive behaviours such as territory defence or song activity. Whether photoperiod is also important for another behaviour closely associated with reproduction, mate choice, is unknown. In many bird species, mate choice occurs at two different times during the annual cycle that strongly differ in daylength: in late winter when photoperiod is short and social mates are chosen, and again around egg-laying when photoperiod is longer and extra-pair mates are chosen. This duality makes the role that photoperiod plays on mate choice behaviours intriguing. We investigated the effect of photoperiod on mate choice using three experimental photoperiodic treatments (9 L:15 D, 14 L:10 D, 18 L:6 D), using blue tits (Cyanistes caeruleus) as a biological model. We show that female choice was stronger under long photoperiods. In addition, female blue tits spent significantly more time near males with long tarsi and long wings. This latter preference was only expressed under long photoperiods, suggesting that some indices of male quality only become significant to females when they are strongly photostimulated, and therefore that females could select their social and extra-pair mates based on different phenotypic traits. These results shed light on the roles that photoperiod may play in stimulating pair-bonding and in refining female selectivity for male traits. PMID:24671133

  6. Bilingual Children with Primary Language Impairment: 3 Months after Treatment

    ERIC Educational Resources Information Center

    Pham, Giang; Ebert, Kerry Danahy; Kohnert, Kathryn

    2015-01-01

    Background: Evidence on the treatment effectiveness for bilingual children with primary language impairment (PLI) is needed to advance both theory and clinical practice. Of key interest is whether treatment effects are maintained following the completion of short-term intense treatments. Aims: To investigate change in select language and cognitive…

  7. Photoperiod effects on plasma cortisol levels in Gasterosteus aculeatus.

    PubMed

    Audet, C; FitzGerald, G J; Guderley, H

    1986-01-01

    No diel variations of plasma cortisol levels were found in Gasterosteus aculeatus acclimated to two different photoperiod conditions: 14L:10D and 9L:15D. However, under long photoperiods, G. aculeatus exhibited higher plasma cortisol levels than under short photoperiods, suggesting that elevated plasma cortisol levels are associated with the spring migration and/or reproductive activities. This decrease of plasma cortisol levels is particularly marked in male G. aculeatus. Under the 9L:15D photoperiod, males had lower plasma cortisol levels than females, in contrast to 14L:10D, where no significant sex differences were found. PMID:3940931

  8. POSITIONAL RELATIONSHIP BETWEEN PHOTOPERIOD RESPONSE QTL AND PHOTORECEPTOR AND VERNALIAZATION GENES IN BARLEY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Barley winterhardiness consists of the regulatory input traits of photoperiod (day length) sensitivity and vernalization response and the physical trait of low temperature tolerance. Photoperiod and vernalization are adaptive and economically significant traits and photoperiod regulates expression o...

  9. POSITIONAL RELATIONSHIP BETWEEN PHOTOPERIOD RESPONSE QTL AND PHOTORECEPTOR AND VERNALIZATION GENES IN BARLEY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Barley winterhardiness consists of the regulatory input traits of photoperiod (day length) sensitivity and vernalization response and the physical trait of low temperature tolerance. Photoperiod and vernalization are adaptive and economically significant traits and photoperiod regulates expression o...

  10. [Dynamic changes of rice (Oryza sativa L.) tiller angle under effects of photoperiod and effective accumulated temperature].

    PubMed

    Ouyang, You-Nan; Li, Chun-Sheng; Zhang, Shan-Qing; Wang, Hui-Min; Zhu, Lian-Feng; Yu, Sheng-Miao; Jin, Qian-Yu; Zhang, Guo-Ping

    2009-05-01

    Using rice variety DI508 as test material, a field experiment of different seeding dates and a test with plant growth chamber were conducted to study the dynamic changes of rice tiller angle under effects of different photoperiod and effective accumulated temperature. Under field condition, the tiller angle of DI508 plants changed gradually into erect after 10-15 days of photoperiod becoming shorter (since the Summer Solstice on 21st June), irrespective of seeding dates (4th April, 5th May, and 4th June). Under controlled photoperiod, the tiller angle changed in the same way as in the field. Shorter lighting treatment (10 hours) advanced the tiller angle change, while longer lighting treatment (14 hours) delayed the change. Effective accumulated temperature had no effects on the tiller angle change of DI508. PMID:19803166

  11. Photoperiodic growth control in perennial trees

    PubMed Central

    Azeez, Abdul; Sane, Aniruddha P

    2015-01-01

    Plants have to cope with changing seasons and adverse environmental conditions. Being sessile, plants have developed elaborate mechanisms for their survival that allow them to sense and adapt to the environment and reproduce successfully. A major adaptive trait for the survival of trees of temperate and boreal forests is the induction of growth cessation in anticipation of winters. In the last few years enormous progress has been made to elucidate the molecular mechanisms underlying SDs induced growth cessation in model perennial tree hybrid aspen (Populus tremula × P. tremuloides). In this review we discuss the molecular mechanism underlying photoperiodic control of growth cessation and adaptive responses. PMID:26340077

  12. Effects of "short" photoperiods on seedling growth of Pinus brutia.

    PubMed

    Iakovoglou, V; Radoglou, K; Kostopoulou, P; Dini-Papanastasi, O

    2012-03-01

    This study investigated how nurseries could benefit by inducing "short" photoperiods as low as 4 hr to produce "better" seedlings characterized by more vigorous roots; a substantial feature to overcome transplanting stress. The carryover effect of the photoperiod was also investigated on seedlings that grew for 30 days more underthe consistent 14 hr photoperiod. Seedlings of Pinus brutia were subjected to 4, 6, 8 and 14 hr photoperiod for 3 week. Fifteen seedlings were used to evaluate the leaf area, the root and shoot dry weight and their ratio. Six and sixteen seedlings were used to evaluate the shoot electrolyte leakage and the root growth potential, respectively. Based on the results, the 6 and 8 hr photoperiod indicated greater root allocation (4.8 and 4.9 mg, respectively) and chlorophyll content (3.7 and 4.4, respectively). They also indicated greater leaf area values (3.3 and 3.5 cm2, respectively) along with the 14 hr (3.4 cm2). The photoperiod effect continued even after seedlings were subjected at consistent photoperiod. Overall, "short" photoperiods could provide "better" P. brutia seedlings to accommodate immediate massive reforestation and afforestation needs. PMID:23033672

  13. Temperature and photoperiod responses of soybean embryos cultured in vitro

    NASA Technical Reports Server (NTRS)

    Raper, C. D. Jr; Patterson, R. P.; Raper CD, J. r. (Principal Investigator)

    1986-01-01

    Temperature and photoperiod each have direct effects on growth rate of excised embryos of soybean (Glycine max (L.) Merrill). To determine if the effects of photoperiod are altered by temperature, embryos of 'Ransom II' were cultured in vitro at 18, 24, and 30 degrees C under photoperiod durations of 12 and 18 h at an irradiance of 9 W m-2 (700 to 850 nm) and a photosynthetic photon flux density of 58 micromoles m-2 s-1 (400 to 700 nm). Accumulation rates of fresh and dry weight were greater under 18-h than 12-h photoperiods over the entire range of temperature. Water content of the culture embryos was not affected by photoperiod but was greater at 18 and 30 than 24 degrees C. The accumulation rate of dry weight increased from 18 to 26 but declined at 30 degrees C.

  14. Effects of long daily photoperiod and bovine somatotropin (Trobest) on milk yield in cows.

    PubMed

    Miller, A R; Stanisiewski, E P; Erdman, R A; Douglass, L W; Dahl, G E

    1999-08-01

    Bovine somatotropin (bST) and exposure to long daily photoperiod increase milk yield of dairy cattle. We tested the hypothesis that long daily photoperiod and bST treatment would increase milk yield in an additive manner in lactating cows. At winter solstice, 40 lactating cows were started on a 140-d experiment; cows were greater than 70 d in milk (DIM) and were balanced for uniformity of DIM and milk yield within parity. Cows were randomly assigned to one of four treatments (10/treatment): 1) natural photoperiod, 2) natural photoperiod + bST (14 mg/d Trobest i.m.), 3) long daily photoperiod (18 h of light and 6 h of darkness/d), or 4) long daily photoperiod + bST. Long daily photoperiod increased fat-corrected milk (FCM) yield 1.9 kg/d versus natural photoperiod. Treatment with bST increased FCM 5.7 kg/d versus natural photoperiod, and long daily photoperiod + bST increased FCM 5.8 kg/d versus long daily photoperiod. Long daily photoperiod + bST was additive, increasing FCM 7.7 kg/d versus natural photoperiod. Serum somatotropin increased with bST, but not photoperiod, and bST increased serum insulin-like growth factor-I. Long daily photoperiod tended to increase prolactin; bST had no effect. Long daily photoperiod + bST increased dry matter intake (DMI) relative to natural photoperiod and natural photoperiod + bST; long daily photoperiod increased DMI relative to natural photoperiod + bST. Photoperiod had no effect on net energy balance; however, bST decreased net energy balance. Generally, body weight and milk composition did not differ among treatments. In conclusion, combination of bST with long-daily photoperiod tended to amplify the increases in milk yield observed with either treatment individually. PMID:10480097

  15. Impact of photoperiod manipulation on day/night changes in melatonin, sex steroids and vitellogenin plasma levels and spawning rhythms in Senegal sole, Solea senegalensis.

    PubMed

    Oliveira, Catarina; Mañanós, Evaristo; Ramos, Jesus; Sánchez-Vázquez, Francisco Javier

    2011-07-01

    Photoperiod and temperature are known as the main synchronizers of seasonal reproduction in fish. This paper studied the role of photoperiod on the synchronization of F1 Senegal sole reproduction rhythms. Fish were maintained under constant short-photoperiod (9L:15D) from the winter solstice onwards (experimental group) or under naturally-changing photoperiod (control group), and water temperature naturally oscillated in both groups. Blood samples were collected during the reproduction season at pre-spawning (March), spawning (April) and post-spawning (May) to determine the endocrine status. Spawning events and egg quality parameters were also monitored. The results revealed a significant increase in nocturnal melatonin concentration from March to May in the control group, while in the experimental group such seasonal change did not occur. As to plasma levels of vitellogenin, testosterone, estradiol and 11keto-testosterone, differences between groups were found mostly in March, while in April and May levels were often similar. Spawning was observed in both groups, although the experimental group started slightly earlier and also finished earlier than the control group, perhaps as a result of the increase in sex steroids and VTG observed at pre-spawning. Briefly, reproduction rhythms persisted in the absence of the natural lengthening of photoperiod, although photoperiod manipulation altered the seasonal modulation of melatonin, increased sex steroids and vitellogenin at pre-spawning, and slightly advanced the timing of spawning. PMID:21466857

  16. Evidence that the photoperiod controls the annual changes in testosterone secretion, testicular and body weight in subtropical male goats.

    PubMed

    Delgadillo, José Alberto; Cortez, María Elena; Duarte, Gerardo; Chemineau, Philippe; Malpaux, Benoît

    2004-01-01

    The aim of this study was to determine whether the reproductive seasonality of local male goats from subtropical Mexico (26 degrees N) is controlled by photoperiod. The control group (n = 7) remained in an open shed under natural daylight. The two experimental groups (n = 6 each) were placed in light-proof buildings and exposed for 2 years (yr) to alternations of 3 months (mo) of long days and 3 mo of short days. One group was first exposed to long days and the other one to short days. Body and testicular weights were determined every 2 wk. Blood samples were obtained weekly to determine testosterone plasma concentrations. In the control group, the body weight exhibited variations (P < 0.0001) and it increased during the non-breeding season. In both treated groups, long days stimulated weight gain and short days inhibited it (P < 0.0001). In the control group, testicular weight displayed variations (P < 0.0001), and high values were registered in June. In the treated groups, a testicular weight reduction occurred 6-9 mo after the onset of the study. Afterwards, the changes in testicular size varied according to daylength (P < 0.01). The pattern of plasma testosterone concentration in the control group varied over the study (P < 0.0001) and the levels were higher from May-June to November. In both treated groups, the changes in testosterone secretion occurred according to photoperiod changes (P < 0.0001). Short days enhanced testosterone secretion one photoperiodic cycle after the onset of the study and long days inhibited it. Local male goats from subtropical Mexico are sensitive to photoperiodic changes and this environmental cue may control the timing of the breeding season in natural conditions. PMID:15460158

  17. Management of photoperiod to control caprine reproduction in the subtropics.

    PubMed

    Delgadillo, José Alberto; Fitz-Rodríguez, Gonzalo; Duarte, Gerardo; Véliz, Francisco Gerardo; Carrillo, Evaristo; Flores, José Alfredo; Vielma, Jesús; Hernandez, Horacio; Malpaux, Benoît

    2004-01-01

    Reproductive seasonality is observed in some breeds originating from or adapted to subtropical latitudes. In 'photoperiodic flexible breeds', such as Australian cashmere goats, the annual breeding season can be manipulated through nutrition, whereas in 'photoperiodic rigid breeds', such as Creole goats from subtropical Mexico, sexual activity can be controlled by altering the photoperiod. In males from the latter breed, artificial long days, whether or not accompanied by the administration of melatonin, stimulate sexual activity during the non-breeding season. These treated males are able to induce the sexual activity of anoestrous females through the male effect under intensive or extensive conditions. Photoperiodic treatments and the male effect can be easily integrated into different breeding management systems in subtropical latitudes. PMID:15315746

  18. Photoperiodic Treatments in Morning Glory: A Laboratory Investigation.

    ERIC Educational Resources Information Center

    Madrazo, Gerry M., Jr.; Hounshell, Paul B.

    1978-01-01

    The Japanese morning glory, a short-day plant, is an excellent specimen for studying photoperiodism. This article gives ideas for investigations including the effects of hormones, light quality, and temperature. Preparation of the seed is also discussed. (BB)

  19. The role of COP1 in repression of photoperiodic flowering.

    PubMed

    Xu, Dongqing; Zhu, Danmeng; Deng, Xing Wang

    2016-01-01

    Plants use the circadian clock as a timekeeping mechanism to regulate photoperiodic flowering in response to the seasonal changes. CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1), initially identified as a central repressor of seedling photomorphogenesis, was recently shown to be involved in the regulation of light input to the circadian clock, modulating the circadian rhythm and flowering. COP1 encodes a RING-finger E3 ubiquitin ligase and works in concert with SUPPRESSOR of phyA-105 (SPA) proteins to repress photoperiodic flowering by regulating proteasome-mediated degradation of CONSTANS (CO), a central regulator of photoperiodic flowering. In addition, COP1 and EARLY FLOWERING 3 (ELF3) indirectly modulate CO expression via the degradation of GIGANTEA (GI). Here, we summarize the current understanding of the molecular mechanisms underlying COP1's role in controlling of photoperiodic flowering. PMID:26949521

  20. HSP90B1, a thyroid hormone-responsive heat shock protein gene involved in photoperiodic signaling.

    PubMed

    Graham, Gemma; Sharp, Peter J; Li, Qiushi; Wilson, Peter W; Talbot, Richard T; Downing, Alison; Boswell, Timothy

    2009-05-29

    In order to further advance the understanding of genes involved in avian photoperiodic signaling, a chicken hypothalamic cDNA microarray was made to identify changes in gene expression in the whole hypothalamus of juvenile male domestic chickens after 4 days' photostimulation. The most robust change was a depression in heat shock protein 90B1 (HSP90B1) expression. This observation was confirmed using quantitative PCR, and it was subsequently demonstrated that the depression in HSP90B1 expression first occurs in the anterior hypothalamus after 1 day's photostimulation, and was also depressed in the anterior and basal hypothalamus after 4 days' photostimulation. Four days after an intravenous injection of thyroxine (T4), an avian photomimetic, in short day birds, HSP90B1 expression was depressed in the anterior, but not in the basal hypothalamus. Depressed HSP901 expression after photostimulation or T4 treatment was associated with increased GnRH-I mRNA and plasma LH. HSP90B1 is abundant throughout the brain where it occurs in glial cells, and is involved in regulating white matter plasticity. It is suggested that photoperiodically depressed hypothalamic HSP90B1 may affect glial function in photoperiodic signaling pathways in the neuroendocrine system. This is the first report of a thyroid hormone-responsive gene involved in photoperiodic signaling. PMID:19429192

  1. Orchestration of gene expression across the seasons: Hypothalamic gene expression in natural photoperiod throughout the year in the Siberian hamster.

    PubMed

    Petri, Ines; Diedrich, Victoria; Wilson, Dana; Fernández-Calleja, José; Herwig, Annika; Steinlechner, Stephan; Barrett, Perry

    2016-01-01

    In nature Siberian hamsters utilize the decrement in day length following the summer solstice to implement physiological adaptations in anticipation of the forthcoming winter, but also exploit an intrinsic interval timer to initiate physiological recrudescence following the winter solstice. However, information is lacking on the temporal dynamics in natural photoperiod of photoperiodically regulated genes and their relationship to physiological adaptations. To address this, male Siberian hamsters born and maintained outdoors were sampled every month over the course of one year. As key elements of the response to photoperiod, thyroid hormone signalling components were assessed in the hypothalamus. From maximum around the summer solstice (late-June), Dio2 expression rapidly declined in advance of physiological adaptations. This was followed by a rapid increase in Mct8 expression (T3/T4 transport), peaking early-September before gradually declining to minimum expression by the following June. Dio3 showed a transient peak of expression beginning late-August. A recrudescence of testes and body mass occurred from mid-February, but Dio2 expression remained low until late-April of the following year, converging with the time of year when responsiveness to short-day length is re-established. Other photoperiodically regulated genes show temporal regulation, but of note is a transient peak in Gpr50 around late-July. PMID:27406810

  2. Orchestration of gene expression across the seasons: Hypothalamic gene expression in natural photoperiod throughout the year in the Siberian hamster

    PubMed Central

    Petri, Ines; Diedrich, Victoria; Wilson, Dana; Fernández-Calleja, José; Herwig, Annika; Steinlechner, Stephan; Barrett, Perry

    2016-01-01

    In nature Siberian hamsters utilize the decrement in day length following the summer solstice to implement physiological adaptations in anticipation of the forthcoming winter, but also exploit an intrinsic interval timer to initiate physiological recrudescence following the winter solstice. However, information is lacking on the temporal dynamics in natural photoperiod of photoperiodically regulated genes and their relationship to physiological adaptations. To address this, male Siberian hamsters born and maintained outdoors were sampled every month over the course of one year. As key elements of the response to photoperiod, thyroid hormone signalling components were assessed in the hypothalamus. From maximum around the summer solstice (late-June), Dio2 expression rapidly declined in advance of physiological adaptations. This was followed by a rapid increase in Mct8 expression (T3/T4 transport), peaking early-September before gradually declining to minimum expression by the following June. Dio3 showed a transient peak of expression beginning late-August. A recrudescence of testes and body mass occurred from mid-February, but Dio2 expression remained low until late-April of the following year, converging with the time of year when responsiveness to short-day length is re-established. Other photoperiodically regulated genes show temporal regulation, but of note is a transient peak in Gpr50 around late-July. PMID:27406810

  3. DNA methylation pattern of Photoperiod-B1 is associated with photoperiod insensitivity in wheat (Triticum aestivum).

    PubMed

    Sun, Han; Guo, Zhiai; Gao, Lifeng; Zhao, Guangyao; Zhang, Wenping; Zhou, Ronghua; Wu, Yongzhen; Wang, Haiyang; An, Hailong; Jia, Jizeng

    2014-11-01

    As one of the three key components of the 'Green Revolution', photoperiod insensitivity is vital for improved adaptation of wheat (Triticum aestivum) cultivars to a wider geographical range. Photoperiod-B1a (Ppd-B1a) is one of the major genes that confers photoperiod insensitivity in 'Green Revolution' varieties, and has made a significant contribution to wheat yield improvement. In this study, we investigated the mechanisms underlying the photoperiod insensitivity of Ppd-B1a alleles from an epigenetic perspective using a combination of bisulfite genomic sequencing, orthologous comparative analysis, association analysis, linkage analysis and gene expression analysis. Based on the study of a large collection of wheat germplasm, we report two methylation haplotypes of Ppd-B1 and demonstrate that the higher methylation haplotype (haplotype a) was associated with increased copy numbers and higher expression levels of the Ppd-B1 gene, earlier heading and photoperiod insensitivity. Furthermore, assessment of the distribution frequency of the different methylation haplotypes suggested that the methylation patterns have undergone selection during the wheat breeding process. Our study suggests that DNA methylation in the regulatory region of the Ppd-B1 alleles, which is closely related to copy number variation, plays a significant role in wheat breeding, to confer photoperiod insensitivity and better adaptation to a wider geographical range. PMID:25078249

  4. Photoperiodic response may facilitate adaptation to climatic change in long-distance migratory birds.

    PubMed Central

    Coppack, Timothy; Pulido, Francisco; Czisch, Michael; Auer, Dorothee P; Berthold, Peter

    2003-01-01

    Recent climatic change is causing spring events in northern temperate regions to occur earlier in the year. As a result, migratory birds returning from tropical wintering sites may arrive too late to take full advantage of the food resources on their breeding grounds. Under these conditions, selection will favour earlier spring arrival that could be achieved by overwintering closer to the breeding grounds. However, it is unknown how daylength conditions at higher latitudes will affect the timing of life cycle stages. Here, we show in three species of Palaearctic-African migratory songbirds that a shortening of migration distance induces an advancement of springtime activities. Birds exposed to daylengths simulating migration to and wintering in southern Europe considerably advanced their spring migratory activity and testicular development. This response to the novel photoperiodic environment will enable birds wintering further north to advance spring arrival and to start breeding earlier. Thus, phenotypic flexibility in response to the photoperiod may reinforce selection for shorter migration distance if spring temperatures continue to rise. PMID:12952632

  5. Photoperiodic response may facilitate adaptation to climatic change in long-distance migratory birds.

    PubMed

    Coppack, Timothy; Pulido, Francisco; Czisch, Michael; Auer, Dorothee P; Berthold, Peter

    2003-08-01

    Recent climatic change is causing spring events in northern temperate regions to occur earlier in the year. As a result, migratory birds returning from tropical wintering sites may arrive too late to take full advantage of the food resources on their breeding grounds. Under these conditions, selection will favour earlier spring arrival that could be achieved by overwintering closer to the breeding grounds. However, it is unknown how daylength conditions at higher latitudes will affect the timing of life cycle stages. Here, we show in three species of Palaearctic-African migratory songbirds that a shortening of migration distance induces an advancement of springtime activities. Birds exposed to daylengths simulating migration to and wintering in southern Europe considerably advanced their spring migratory activity and testicular development. This response to the novel photoperiodic environment will enable birds wintering further north to advance spring arrival and to start breeding earlier. Thus, phenotypic flexibility in response to the photoperiod may reinforce selection for shorter migration distance if spring temperatures continue to rise. PMID:12952632

  6. Influence of photoperiod on the pregnant and postpartum mare.

    PubMed

    Hodge, S L; Kreider, J L; Potter, G D; Harms, P G; Fleeger, J L

    1982-10-01

    Over a 2-year period, mares (n = 32) of predominantly Quarter Horse breeding and their foals were used to study the effects of photoperiod on reproduction during the periparturient period. Specific objectives of the study were (i) to evaluate the effects of an extended photoperiod regimen (16 hours' light) on gestation length, foal development, and postpartum reproductive performance, and (ii) to measure changes in plasma progesterone concentrations during the last trimester of gestation and plasma luteinizing hormone (LH) concentrations after foaling until ovulation. Mares in the extended daylength treatment group had shorter (10 days) mean gestation length (P less than 0.01) than did control mares (exposed to normal daylight hours). Although foals of mares exposed to long photoperiod were carried for a shorter term, their birth weights tended to be heavier, but not significantly, than those of foals from control mares. Foal size, as determined by body measurements, was not affected by the photoperiod. Neither interval from parturition to 1st ovulation nor onset of estrus to ovulation were significantly affected by the extended photoperiod. Plasma progestogen concentrations increased from basal levels at prepartum weeks 4 and 5 to peak values a week before foaling in both mare groups. The LH profiles from parturition to ovulation were similar for both mare groups. However, mean plasma LH values during the 7 days before the 1st ovulation were higher (P less than 0.05) in mares exposed to extended daylength than in control mares. PMID:7149374

  7. Using the "Kalanchoe daigremontiana" Plant To Show the Effects of Photoperiodism on Plantlet Formation.

    ERIC Educational Resources Information Center

    Hershey, David R.

    2002-01-01

    Describes an activity demonstrating the importance of photoperiod on plant development. Uses the plant devil's backbone for the experiment and studies the details of photoperiodic requirement for plantlet formation. (Contains 12 references.) (YDS)

  8. To Operate or Not: Prediction of 3-Month Postoperative Mortality in Geriatric Cancer Patients

    PubMed Central

    Chou, Wen-Chi; Liu, Keng-Hao; Lu, Chang-Hsien; Hung, Yu-Shin; Chen, Miao-Fen; Cheng, Yu-Fan; Wang, Cheng-Hsu; Lin, Yung-Chang; Yeh, Ta-Sen

    2016-01-01

    Context: Appropriate selection of aging patient who fit for cancer surgery is an art-of-state. Objectives: This study aimed to identify predictive factors pertinent to 3-month postoperative mortality in geriatric cancer patients. Methods: A total of 8,425 patients over 70 years old with solid cancer received radical surgery between 2007 and 2012 at four affiliated hospitals of the Chang Gung Memorial Hospital were included. The clinical variables of patients who died within 3 months post-surgery were analyzed retrospectively. Recursive partitioning analysis (RPA) was performed by randomly selecting 50% of the patients (testing set) to identify specific groups of patients with the lowest and highest probability of 3-month postoperative mortality. The remaining 50% were used as validation set of the model. Results: Patients' gender, Eastern Cooperative Oncology Group performance (ECOG scale), Charlson comorbidity index (CCI), American Society of Anesthesiologist physical status, age, tumor staging, and mode of admission were independent variables that predicted 3-month postoperative mortality. The RPA model identified patients with an ECOG scale of 0-2, localized tumor stage, and a CCI of 0-2 as having the lowest probability of 3-month postoperative mortality (1.1% and 1.3% in the testing set and validation set, respectively). Conversely, an ECOG scale of 3-4 and a CCI >2 were associated with the highest probability of 3-month postoperative mortality (55.2% and 47.8% in the testing set and validation set, respectively). Conclusion: We identified ECOG scale and CCI score were the two most influencing factors that determined 3-month postoperative mortality in geriatric cancer patients. PMID:26722355

  9. Determination of Photoperiod-Sensitive Phase in Chickpea (Cicer arietinum L.).

    PubMed

    Daba, Ketema; Warkentin, Thomas D; Bueckert, Rosalind; Todd, Christopher D; Tar'an, Bunyamin

    2016-01-01

    Photoperiod is one of the major environmental factors determining time to flower initiation and first flower appearance in plants. In chickpea, photoperiod sensitivity, expressed as delayed to flower under short days (SD) as compared to long days (LD), may change with the growth stage of the crop. Photoperiod-sensitive and -insensitive phases were identified by experiments in which individual plants were reciprocally transferred in a time series from LD to SD and vice versa in growth chambers. Eight chickpea accessions with differing degrees of photoperiod sensitivity were grown in two separate chambers, one of which was adjusted to LD (16 h light/8 h dark) and the other adjusted to SD (10 h light/14 h dark), with temperatures of 22/16°C (12 h light/12 h dark) in both chambers. The accessions included day-neutral (ICCV 96029 and FLIP 98-142C), intermediate (ICC 15294, ICC 8621, ILC 1687, and ICC 8855), and photoperiod-sensitive (CDC Corinne and CDC Frontier) responses. Control plants were grown continuously under the respective photoperiods. Reciprocal transfers of plants between the SD and LD photoperiod treatments were made at seven time points after sowing, customized for each accession based on previous data. Photoperiod sensitivity was detected in intermediate and photoperiod-sensitive accessions. For the day-neutral accession, ICCV 96029, there was no significant difference in the number of days to flowering of the plants grown under SD and LD as well as subsequent transfers. In photoperiod-sensitive accessions, three different phenological phases were identified: a photoperiod-insensitive pre-inductive phase, a photoperiod-sensitive inductive phase, and a photoperiod-insensitive post-inductive phase. The photoperiod-sensitive phase extends after flower initiation to full flower development. Results from this research will help to develop cultivars with shorter pre-inductive photoperiod-insensitive and photoperiod-sensitive phases to fit to regions with

  10. Determination of Photoperiod-Sensitive Phase in Chickpea (Cicer arietinum L.)

    PubMed Central

    Daba, Ketema; Warkentin, Thomas D.; Bueckert, Rosalind; Todd, Christopher D.; Tar’an, Bunyamin

    2016-01-01

    Photoperiod is one of the major environmental factors determining time to flower initiation and first flower appearance in plants. In chickpea, photoperiod sensitivity, expressed as delayed to flower under short days (SD) as compared to long days (LD), may change with the growth stage of the crop. Photoperiod-sensitive and -insensitive phases were identified by experiments in which individual plants were reciprocally transferred in a time series from LD to SD and vice versa in growth chambers. Eight chickpea accessions with differing degrees of photoperiod sensitivity were grown in two separate chambers, one of which was adjusted to LD (16 h light/8 h dark) and the other adjusted to SD (10 h light/14 h dark), with temperatures of 22/16°C (12 h light/12 h dark) in both chambers. The accessions included day-neutral (ICCV 96029 and FLIP 98-142C), intermediate (ICC 15294, ICC 8621, ILC 1687, and ICC 8855), and photoperiod-sensitive (CDC Corinne and CDC Frontier) responses. Control plants were grown continuously under the respective photoperiods. Reciprocal transfers of plants between the SD and LD photoperiod treatments were made at seven time points after sowing, customized for each accession based on previous data. Photoperiod sensitivity was detected in intermediate and photoperiod-sensitive accessions. For the day-neutral accession, ICCV 96029, there was no significant difference in the number of days to flowering of the plants grown under SD and LD as well as subsequent transfers. In photoperiod-sensitive accessions, three different phenological phases were identified: a photoperiod-insensitive pre-inductive phase, a photoperiod-sensitive inductive phase, and a photoperiod-insensitive post-inductive phase. The photoperiod-sensitive phase extends after flower initiation to full flower development. Results from this research will help to develop cultivars with shorter pre-inductive photoperiod-insensitive and photoperiod-sensitive phases to fit to regions with

  11. Effect of photoperiod on reproductive activity and hair in mares.

    PubMed

    Kooistra, L H; Ginther, O J

    1975-10-01

    The effects of photoperiod on reproductive activity and hair changes in pony mares were studied in 2 experiments. In experiment I, the effect of a fixed daily photoperiod on the onset of the breeding season was studied in 36 mares from Nov 13, 1973, to June 13, 1974. The 4 treatment groups were as follows: daily photoperiod equivalent to the normal day length (control group); constant light 24 hours a day with no dark (L24:D0 group); 16-hour daily photoperiod with 8 hours of dark (L16:D8 group); and 9-hour daily photoperiod with 15 hours of dark (L9:D15 group). The intervals from beginning of experiment to 1st ovulation of breeding season, to shedding of hair in tufts, and to appearance of a smooth coat were shorter (P less than 0.05) for L16:D8 group (107.1 +/- 11.1, 56.0 +/- 0, and 145.8 +/- 4.0 days, respectively) than for control, L24:D0, and L9:D15 groups and were shorter (P less than 0.05) for L24:D0 group (less than 156.1 +/- 12.2, 99.5 +/- 9.5, and 173.9 +/- 9.9 days, respectively) than for control group (192.1 +/- 3.3, 134.9 +/- 8.9, and 205.0 +/- 0 days, respectively) or L9:D15 group (less than 200.3 +/- 5,8, 150.6 +/- 12.9, and 201.7 +/- 3.3 days, respectively). These intervals were not significantly different between the control group and the L9:D15 group, but fewer (P less than 0.05) mares in the L9:D15 group had at least 1 ovulation by termination of the project. In experiment II, the effect of photoperiod on onset of anestrus was studied in 3 groups of 7 mares each. Mares in group A, as part of a previous experiment, were induced to enter the breeding season earlier than normal by a gradual increase in daily photoperiod beginning on Oct 13, 1972. From Feb 16, 1973, to June 22, 1973, group A mares were maintained at a fixed daily photoperiod of 15 hours 23 minutes. Mares in group B, as part of a previous experiment, were kept under environmental conditions simulating normal conditions in southern Wisconsin. On June 22, 1973 (beginning of the present

  12. The consequences of photoperiodism for organisms in new climates.

    PubMed

    Grevstad, Fritzi S; Coop, Leonard B

    2015-09-01

    A change in climate is known to affect seasonal timing (phenology) of the life stages of poikilothermic organisms whose development depends on temperature. Less understood is the potential for even greater disruption to the life cycle when a phenology shift exposes photoperiod-sensitive life stages to new day lengths. We present a conceptual framework and model to investigate the ways that photoperiod-cued diapause can interact with a change in climate or latitude to influence voltinism in poikilothermic organisms. Our degree-day phenology model combines detailed spatial climate data, latitude- and date-specific photoperiods, and development and photoperiod response parameters. As an example, we model the biological control beetle Galerucella calmariensis and map the number of generations expected following its introduction into diverse climates throughout the continental United States. Incorporation of photoperiodism results in a complex geography of voltinism that differs markedly from predictions of traditional phenology models. Facultative multivoltine species will be prone to univoltism when transported to either warmer or southern climates due to exposure of the sensitive stage to shorter day lengths. When moved to more northern locations, they may attempt too many generations for the season duration thereby exposing vulnerable life stages to harsh weather in the fall. We further show that even small changes in temperature can result in large and unexpected shifts in voltinism. Analogous effects may be expected for organisms from wide variety of taxa that use photoperiod as a seasonal cue during some stage of their life cycle. Our approach is useful for understanding the performance and impacts of introduced pests and beneficial organisms as well as for predicting responses of resident species to climate change and climate variability. PMID:26552260

  13. Effect of photoperiod on the rate of 3H-thymidine incorporation of epididymal principal cells in adult Syrian hamsters

    SciTech Connect

    Johnson, L.; Bartke, A. )

    1991-04-01

    Photoperiod-induced cycles of gonadal regression and recrudescence in the Syrian hamster were used to determine if epididymal growth in adults involves mitotic activity of principal cells. In Experiment 1, the following groups of adult hamsters were examined: induced recrudescing (5L:19D (5 hr light and 19 hr dark) for 13 wk followed by 14L:10D for at least 3 wk), spontaneous recrudescing (5L:19D for 25 wk), and active gonadal state (14:10D). In Experiment 2, adult hamsters were divided into the following groups: induced recrudescing, active, and regressed (5L:19D for 16 wk). Hamsters received subcutaneous injections of 0.5 microCi 3H-thymidine/g body weight three times/wk for 3 wk. The epididymis was fixed in a glutaraldehyde followed by osmium, embedded in Epon 812, and sectioned at 1 micron. Slides were dipped in Kodak NTB-3 emulsion, exposed for 2 or 3 months, developed, and evaluated for isotopic labeling of principal and basal cell nuclei by scoring 500 to 1,000 nuclei. In Experiment 1, the percentages of labeled principal cell nuclei for the induced recrudescing, spontaneous recrudescing, and active groups were 26 {plus minus} 2%, 23 {plus minus} 5%, and 9 {plus minus} 1%, respectively. Considering the intermittent availability of 3H-thymidine during 21 days, this represents daily recruitment of 6.3%, 5.6%, and 2.2%, respectively. In Experiment 2, the percentages of labeled principal cell nuclei for induced recrudescing, active, and regressed groups were 12 {plus minus} 4%, 3 {plus minus} 1%, and 4 {plus minus} 1%, respectively. There was no effect of photoperiod on labeling pattern of basal cells (1.5 {plus minus} 0.6%, 1.2 {plus minus} 0.1%, 0.4 {plus minus} 0.1% for the three photoperiod groups, respectively).

  14. Quantifying the Effects of Photoperiod, Temperature and Daily Irradiance on Flowering Time of Soybean Isolines

    PubMed Central

    Cober, Elroy R.; Curtis, Daniel F.; Stewart, Douglas W.; Morrison, Malcolm J.

    2014-01-01

    Soybean isolines with different combinations of photoperiod sensitivity alleles were planted in a greenhouse at different times during the year resulting in natural variation in daily incident irradiance and duration. The time from planting to first flower were observed. Mathematical models, using additive and multiplicative modes, were developed to quantify the effect of photoperiod, temperature, photoperiod-temperature interactions, rate of photoperiod change, and daily solar irradiance on flowering time. Observed flowering times correlated with predicted times (R2 = 0.92, Standard Error of the Estimate (SSE) = 2.84 d, multiplicative mode; R2 = 0.91, SSE = 2.88 d, additive mode). The addition of a rate of photoperiod change function and an irradiance function to the temperature and photoperiod functions improved the accuracy of flowering time prediction. The addition of a modified photoperiod function, which allowed for photoperiod sensitivity at shorter photoperiods, improved prediction of flowering time. Both increasing and decreasing rate of photoperiod change, as well as low levels of daily irradiance delayed flowering in soybean. The complete model, which included terms for the rate of photoperiod change, photoperiod, temperature and irradiance, predicted time to first flower in soybean across a range of environmental conditions with an SEE of 3.6 days when tested with independent data. PMID:27135515

  15. A Low Baseline Glomerular Filtration Rate Predicts Poor Clinical Outcome at 3 Months after Acute Ischemic Stroke

    PubMed Central

    Kim, Hyung Jik; Kim, Jwa-Kyung; Oh, Mi Sun; Kim, Sung Gyun; Yu, Kyung-Ho

    2015-01-01

    Background and Purpose Chronic kidney disease (CKD) is an established risk factor for numerous cardiovascular diseases including stroke. The relationship between the baseline estimated glomerular filtration rate (eGFR) and clinical 3-month outcomes in patients with acute ischemic stroke were evaluated in this study. Methods This was a prospective cohort study involving a hospital-based stroke registry; 1373 patients with acute ischemic stroke were enrolled. Patients were divided into the following four groups according their eGFR (calculated using the CKD Epidemiology Collaboration equations): ≥60, 45-59, 30-44, and <30 mL/min/1.73 m2. The primary endpoint of poor functional outcome was defined as 3-month death or dependency (modified Rankin Scale score ≥3); secondary endpoints were neurological deterioration (increase in National Institutes of Health Stroke Severity score of ≥4 at discharge compared to baseline) during hospitalization and in-hospital mortality. Results The overall eGFR was 84.5±20.8 mL/min/1.73 m2 (mean±SD). The distribution of baseline renal impairment was as follows: 1,218, 82, 40, and 33 patients had eGFRs of ≥60, 45-59, 30-44, and <30 mL/min/1.73 m2, respectively. At 3 months after the stroke, 476 (34.7%) patients exhibited poor functional outcome. Furthermore, a poor functional outcome occurred more frequently with increasingly advanced stages of CKD (rates of 31.9%, 53.7%, 55.0%, and 63.6% for CKD stages 1/2, 3a, 3b, and 4/5, respectively; p<0.001). Multivariate analysis revealed that a baseline eGFR of <30 mL/min/1.73m2 increased the risk of a poor functional outcome by 2.37-fold (p=0.047). In addition, baseline renal dysfunction was closely associated with neurological deterioration during hospitalization and with in-hospital mortality. Conclusions A low baseline eGFR was strongly predictive of both poor functional outcome at 3 months after ischemic stroke and neurological deterioration/mortality during hospitalization. PMID

  16. Photoperiodic Regulation of Florigen Function in Arabidopsis thaliana

    PubMed Central

    Golembeski, Greg S.; Imaizumi, Takato

    2015-01-01

    One mechanism through which flowering in response to seasonal change is brought about is by sensing the fluctuation in day-length; the photoperiod. Flowering induction occurs through the production of the florigenic protein FLOWERING LOCUS T (FT) and its movement from the phloem companion cells in the leaf vasculature into the shoot apex, where meristematic reprogramming occurs. FT activation in response to photoperiod condition is accomplished largely through the activity of the transcription factor CONSTANS (CO). Regulation of CO expression and protein stability, as well as the timing of other components via the circadian clock, is a critical mechanism by which plants are able to respond to photoperiod to initiate the floral transition. Modulation of FT expression in response to external and internal stimuli via components of the flowering network is crucial to mediate a fluid flowering response to a variety of environmental parameters. In addition, the regulated movement of FT protein from the phloem to the shoot apex, and interactions that determine floral meristem cell fate, constitute novel mechanisms through which photoperiodic information is translated into flowering time. PMID:26157354

  17. Functional Allelic Variation at Key Photoperiod Response QTL in Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropical maize represents a valuable genetic resource containing unique alleles not present in elite temperate maize. The strong delay in flowering in response to long daylength photoperiods exhibited by most tropical maize hinders its incorporation into temperate maize breeding programs. We tested ...

  18. Vole infant development is influenced perinatally by maternal photoperiodic history.

    PubMed

    Lee, T M; Zucker, I

    1988-11-01

    Vole pups were maintained from the time of conception in the same short-day (SD) photoperiod (10 h light/day, LD 10:14); groups differed only with respect to SD photoperiodic histories of dams before gestation, which simulated those experienced by dams breeding in autumn (SD-2, 2 wk of short days), midwinter (SD-21), or late winter (SD-26). Compared with SD-2 pups, offspring born to SD-26 dams matured more rapidly with respect to body size and reproductive status. Several other somatic and behavioral measures indicated that winter preparedness was greatest in pups whose dams had experienced 2 wk and least in those that had experienced 26 wk of SD treatment before conception. A cross-fostering design, in which pups gestated in long (LD 14:10) or short photoperiods were reared postnatally in the same or opposite day length, indicated that several photoresponsive traits are influenced predominantly by prenatal photoperiod, others by postnatal day length, and others by both photoregimens. Information is communicated to fetuses about the length of time dams have been exposed to short day lengths before mating as well as about the day length prevailing during gestation. The changes induced by the mother in her pups pre- and postnatally likely facilitate adaptation of newly weaned voles to seasonally varying environmental conditions. PMID:3056043

  19. An insight into the sensitivity of maize to photoperiod changes under controlled conditions.

    PubMed

    Chen, Qiang; Zhong, Hao; Fan, Xian-Wei; Li, You-Zhi

    2015-08-01

    Response of maize to photoperiods affects adaption of this crop to environments. We characterize the phenotypes of four temperate-adapted maize foundation parents, Huangzao 4, Chang 7-2, Ye 478 and Zheng 58, and two tropically adapted maize foundation parents, M9 and Shuang M9 throughout the growth stage under three constant photoperiod regimes in a daily cycle of 24 h at 28 °C, and analysed expression of 48 photoperiod response-associated genes. Consequently, long photoperiod (LP) repressed development of the tassels of photoperiod-sensitive maize lines at V9 stage, and caused subsequent failure in flowering; failure of photoperiod-sensitive maize lines in flowering under LP was associated with lower expression of flowering-related genes; photoperiod changes could make a marked impact on spatial layout of maize inflorescence. The larger oscillation amplitude of expression of photoperiod-responsive genes occurred in LP-sensitive maize lines. In conclusion, failure in development of tassels at V9 stage under LP is an early indicator for judging photoperiod sensitivity. The adaptation of temperate-adapted maize lines to LP is due to the better coordination of expression among photoperiod-sensing genes instead of the loss of the genes. High photoperiod sensitivity of maize is due to high expression of circadian rhythm-responding genes improperly early in the light. PMID:24910171

  20. A Smile Enhances 3-Month-Olds' Recognition of an Individual Face

    ERIC Educational Resources Information Center

    Turati, Chiara; Montirosso, Rosario; Brenna, Viola; Ferrara, Veronica; Borgatti, Renato

    2011-01-01

    Recent studies demonstrated that in adults and children recognition of face identity and facial expression mutually interact (Bate, Haslam, & Hodgson, 2009; Spangler, Schwarzer, Korell, & Maier-Karius, 2010). Here, using a familiarization paradigm, we explored the relation between these processes in early infancy, investigating whether 3-month-old…

  1. Mental Rotation of Dynamic, Three-Dimensional Stimuli by 3-Month-Old Infants

    ERIC Educational Resources Information Center

    Moore, David S.; Johnson, Scott P.

    2011-01-01

    Mental rotation involves transforming a mental image of an object so as to accurately predict how the object would look if it were rotated in space. This study examined mental rotation in male and female 3-month-olds, using the stimuli and paradigm developed by Moore and Johnson (2008). Infants were habituated to a video of a three-dimensional…

  2. Auditory-Visual Context and Memory Retrieval in 3-Month-Old Infants

    ERIC Educational Resources Information Center

    Daman-Wasserman, Michelle; Brennan, Barbara; Radcliffe, Fiona; Prigot, Joyce; Fagen, Jeffrey

    2006-01-01

    In 3 experiments, 3-month-old infants were trained to move an overhead mobile by kicking 1 of their feet in the presence of a distinctive visual (crib bumpers) and auditory (music) context. In Experiment 1A, 5-day but not 1-day retention was disrupted if either or both elements of the context present during the retention test were novel. In…

  3. Parenting Anxiety and Stress: Does Gender Play a Part at 3 Months of Age?

    ERIC Educational Resources Information Center

    Scher, Anat; Sharabany, Ruth

    2005-01-01

    In this study, the authors compared 90 pairs of mothers and fathers with respect to aspects of negative emotionality experienced in the early parenting role. Mothers and fathers of 90 healthy 3-month-old infants completed questionnaires pertaining to parenting stress and separation anxiety. Mothers reported significantly higher levels of negative…

  4. The Face Perception System becomes Species-Specific at 3 Months: An Eye-Tracking Study

    ERIC Educational Resources Information Center

    Di Giorgio, Elisa; Meary, David; Pascalis, Olivier; Simion, Francesca

    2013-01-01

    The current study aimed at investigating own- vs. other-species preferences in 3-month-old infants. The infants' eye movements were recorded during a visual preference paradigm to assess whether they show a preference for own-species faces when contrasted with other-species faces. Human and monkey faces, equated for all low-level perceptual…

  5. The adverse effect of spasticity on 3-month poststroke outcome using a population-based model.

    PubMed

    Belagaje, S R; Lindsell, C; Moomaw, C J; Alwell, K; Flaherty, M L; Woo, D; Dunning, K; Khatri, P; Adeoye, O; Kleindorfer, D; Broderick, J; Kissela, B

    2014-01-01

    Several devices and medications have been used to address poststroke spasticity. Yet, spasticity's impact on outcomes remains controversial. Using data from a cohort of 460 ischemic stroke patients, we previously published a validated multivariable regression model for predicting 3-month modified Rankin Score (mRS) as an indicator of functional outcome. Here, we tested whether including spasticity improved model fit and estimated the effect spasticity had on the outcome. Spasticity was defined by a positive response to the question "Did you have spasticity following your stroke?" on direct interview at 3 months from stroke onset. Patients who had expired by 90 days (n = 30) or did not have spasticity data available (n = 102) were excluded. Spasticity affected the 3-month functional status (β = 0.420, 95 CI = 0.194 to 0.645) after accounting for age, diabetes, leukoaraiosis, and retrospective NIHSS. Using spasticity as a covariable, the model's R (2) changed from 0.599 to 0.622. In our model, the presence of spasticity in the cohort was associated with a worsened 3-month mRS by an average of 0.4 after adjusting for known covariables. This significant adverse effect on functional outcomes adds predictive value beyond previously established factors. PMID:25147752

  6. The Adverse Effect of Spasticity on 3-Month Poststroke Outcome Using a Population-Based Model

    PubMed Central

    Belagaje, S. R.; Lindsell, C.; Moomaw, C. J.; Alwell, K.; Flaherty, M. L.; Woo, D.; Dunning, K.; Khatri, P.; Adeoye, O.; Kleindorfer, D.; Broderick, J.; Kissela, B.

    2014-01-01

    Several devices and medications have been used to address poststroke spasticity. Yet, spasticity's impact on outcomes remains controversial. Using data from a cohort of 460 ischemic stroke patients, we previously published a validated multivariable regression model for predicting 3-month modified Rankin Score (mRS) as an indicator of functional outcome. Here, we tested whether including spasticity improved model fit and estimated the effect spasticity had on the outcome. Spasticity was defined by a positive response to the question “Did you have spasticity following your stroke?” on direct interview at 3 months from stroke onset. Patients who had expired by 90 days (n = 30) or did not have spasticity data available (n = 102) were excluded. Spasticity affected the 3-month functional status (β = 0.420, 95 CI = 0.194 to 0.645) after accounting for age, diabetes, leukoaraiosis, and retrospective NIHSS. Using spasticity as a covariable, the model's R2 changed from 0.599 to 0.622. In our model, the presence of spasticity in the cohort was associated with a worsened 3-month mRS by an average of 0.4 after adjusting for known covariables. This significant adverse effect on functional outcomes adds predictive value beyond previously established factors. PMID:25147752

  7. Timing of photoperiodic competency causes phenological mismatch in balsam poplar (Populus balsamifera L.).

    PubMed

    Soolanayakanahally, Raju Y; Guy, Robert D; Silim, Salim N; Song, Minghua

    2013-01-01

    Plant phenology is expected to be sensitive to climate warming. In boreal trees, spring flush is primarily temperature driven, whereas height growth cessation and autumn leaf senescence are predominantly controlled by photoperiod. Cuttings of 525 genotypes from the full range of balsam poplar were planted into two common gardens (Vancouver and Indian Head, Canada) at similar latitudes, but with differing winter temperatures and growing seasons. There was clinal variation in spring and, particularly, summer and fall phenology. Bud flush and, despite milder climate, bud set and leaf drop were earlier at Vancouver than at Indian Head by 44, 28 and 7 d, respectively. Although newly flushed growth is insensitive to photoperiod, many genotypes at both sites became competent before the summer solstice. At Vancouver, high-latitude genotypes set dormant terminal buds in mid-spring. Most other genotypes grew until midsummer or set bud temporarily and then experienced a second flush. In both gardens and in a growth chamber experiment, earlier bud set was associated with reduced height growth and higher root/shoot ratios. Shoots attained competency ~5 weeks after flushing, which would normally prevent dormancy induction before the solstice, but may be insufficient if spring advances by more than a few weeks. PMID:22702736

  8. Utilization of potatoes for life support systems. II - The effects of temperature under 24-h and 12-h photoperiods

    NASA Technical Reports Server (NTRS)

    Wheeler, Raymond M.; Steffen, Kenneth L.; Tibbitts, Theodore W.; Palta, Jiwan P.

    1986-01-01

    The effects of temperature and the photoperiod length on the growth and tuberization of Norland potatoes were investigated for two photoperiods, 12-h and 24-hr at 400 micromol/sq m per sec PPF, and at temperatures of 12, 16, 20, 24, and 28 C. It was found that stem length increased with increasing temperature under both photoperiods. The highest tuber yield was obtained at 16 C under the 24-hr photoperiod and at 20 C under the 12-hr photoperiod (i.e., increasing the photoperiod from 12 to 24 hrs effectively decreases the optimal temperature for tuber formation). Little or no tuber formation occurred at 28 C under either photoperiod.

  9. Photoperiodic control of reproduction in the domestic hen.

    PubMed

    Sharp, P J

    1993-05-01

    Egg laying in domestic hens exposed to natural lighting begins shortly after the winter solstice, peaks in early spring, begins to decrease before the fall equinox, and is at its lowest during the late fall and early winter. The seasonal cycle of egg production phase-leads that of the changes in day length. This seeming anomaly can be explained if it is accepted that 1) short days are photoperiodically neutral and do not actively inhibit gonadotropin-releasing hormone (GnRH)-I neurons; and 2) long days are photoperiodically active, transducing both stimulatory and inhibitory inputs to GnRH-I neurons. The development of a long day-induced inhibitory input results in a form of photorefractoriness. Around the winter solstice, photorefractoriness is dissipated by prolonged exposure to short days, allowing GnRH-I neurons to express a photoperiodic-independent, genotype-dependent, level of activity. This is sufficient to stimulate egg laying before the minimum photoperiod for photoinduced gonadotropin release is reached in early spring. When day length begins to decrease after the summer solstice, the photoinduced stimulatory input to GnRH-I neurons is reduced, unmasking the photoinduced inhibitory input. As a consequence, the activity of GnRH-I neurons decreases rapidly and the intensity of egg laying decreases. The minimum and maximum day lengths required to stimulate reproductive function in short-day hens, calculated from the photoperiodic response curves (PRC) for luteinizing hormone release are about 10 and 13 h, respectively, depending on genotype.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8502612

  10. Effect of increased photoperiod on hormone concentrations in thoroughbred stallions.

    PubMed

    Burns, P J; Jawad, M J; Edmundson, A; Cahill, C; Boucher, J K; Wilson, E A; Douglas, R H

    1982-01-01

    Stallions on two Central Kentucky farms (9/farm) were studied during the 1980 breeding season. On one farm stallions were exposed to an increased photoperiod (16 h light/day) from 1 December 1979; on the second farm the stallions were maintained in an ambient photoperiod. On the basis of matings per conception (total mating/mares in foal) stallions on each farm were assigned to a high fertility (1 . 9-2 . 4 matings per conception, N = 4) or low fertility (2 . 6-5 . 6 matings per conception, N = 5) group. Exposure of stallions to increased photoperiod significantly increased serum concentrations of dehydroepiandrosterone (DHA), androstenedione, testosterone and oestrone by the start of the breeding season (16 February) while concentrations of oestradiol-17 beta and total oestrogens were similar in the two groups. LH was the only hormone significantly affected by the fertility of stallions, with LH concentrations consistently higher in the 'increased light-high fertility' stallions compared to the low basal concentration observed in the other 3 groups during the early breeding season (16 Feb.-31 March). FSH concentrations were not significantly affected by photoperiod or fertility, but appeared to be consistently higher in the 'increased light-high fertility' stallions than in the 'increased light-low fertility' stallions. The 'increased light-high fertility' stallions were mated to more mares than were stallions in the other 3 groups and differences in LH and FSH concentrations may therefore have been confounded with frequency of mating. Seasonal conception rates were unaffected by increased photoperiod. PMID:6820058

  11. Photoperiodic Influences on Ultradian Rhythms of Male Siberian Hamsters

    PubMed Central

    Prendergast, Brian J.; Zucker, Irving

    2012-01-01

    Seasonal changes in mammalian physiology and behavior are proximately controlled by the annual variation in day length. Long summer and short winter day lengths markedly alter the amplitude of endogenous circadian rhythms and may affect ultradian oscillations, but the threshold photoperiods for inducing these changes are not known. We assessed the effects of short and intermediate day lengths and changes in reproductive physiology on circadian and ultradian rhythms of locomotor activity in Siberian hamsters. Males were maintained in a long photoperiod from birth (15 h light/day; 15 L) and transferred in adulthood to 1 of 7 experimental photoperiods ranging from 14 L to 9 L. Decreases in circadian rhythm (CR) robustness, mesor and amplitude were evident in photoperiods ≤14 L, as were delays in the timing of CR acrophase and expansion of nocturnal activity duration. Nocturnal ultradian rhythms (URs) were comparably prevalent in all day lengths, but 15 L markedly inhibited the expression of light-phase URs. The period (τ’), amplitude and complexity of URs increased in day lengths ≤13 L. Among hamsters that failed to undergo gonadal regression in short day lengths (nonresponders), τ’ of the dark-phase UR was longer than in photoresponsive hamsters; in 13 L the incidence and amplitude of light-phase URs were greater in hamsters that did not undergo testicular regression. Day lengths as long as 14 L were sufficient to trigger changes in the waveform of CRs without affecting UR waveform. The transition from a long- to a short-day ultradian phenotype occurred for most UR components at day lengths of 12 L–13 L, thereby establishing different thresholds for CR and UR responses to day length. At the UR-threshold photoperiod of 13 L, differences in gonadal status were largely without effect on most UR parameters. PMID:22848579

  12. Pivotal Response Treatment Parent Training for Autism: Findings from a 3-Month Follow-Up Evaluation.

    PubMed

    Gengoux, Grace W; Berquist, Kari L; Salzman, Emma; Schapp, Salena; Phillips, Jennifer M; Frazier, Thomas W; Minjarez, Mendy B; Hardan, Antonio Y

    2015-09-01

    This study's objective was to assess maintenance of treatment effects 3 months after completion of a 12-week Pivotal Response Treatment (PRT) parent education group. Families who completed the active treatment (N = 23) were followed for an additional 12 weeks to measure changes in language and cognitive skills. Results indicated a significant improvement in frequency of functional utterances, with maintenance at 3-month follow-up [F(2, 21): 5.9, p = .009]. Children also made significant gains on the Vineland Communication Domain Standard Score [F(2, 12):11.74, p = .001] and the Mullen Scales of Early Learning Composite score [F(1, 20) = 5.43, p = .03]. These results suggest that a brief PRT parent group intervention can lead to improvements in language and cognitive functioning that are maintained 12 weeks post treatment. PMID:25911977

  13. Light responses in Photoperiodism in Arabidopsis thaliana

    SciTech Connect

    Anthony R. Cashmore

    2006-08-01

    domains. It is this cysteine residue that forms a covalent adduct with the bound flavin in the photocycle of PHOT1 and FKF1. In the mutant ADO1 this cysteine is replaced by an alanine. We argue that if ADO1 functions as a photoreceptor in a similar fashion to PHOT1, then this mutant ADO1 should not be able to rescue the altered circadian phenotype of ado1 mutant plants. We find under white light, that indeed this is the case. Experiments underway are aimed at determining if the altered circadian phenotype under blue and red light are similarly unable to be rescued by the mutant gene, and we are performing similar experiments under red light with respect to the defect in hypocotyl elongation. The results from these experiments will likely support the hypothesis that ADO1 functions as a blue light photoreceptor, and they will address the question concerning whether or not the altered properties of the ado1 mutant under red light are also a reflection of this photoreceptor function. References. Briggs, W. R., Beck, C. F., Cashmore, A. R., Christie, J. M., Hughes, J., Jarillo, J. A., Kagawa, T., Kanegae, H., Liscum, E., Nagatani, A., et al. (2001). The phototropin family of photoreceptors. Plant Cell 13, 993-997. Christie, J. M., Reymond, P., Powell, G. K., Bernasconi, P., Raibekas, A. A., Liscum, E., and Briggs, W. R. (1998). Arabidopsis NPH1: A flavoprotein with the properties of a photoreceptor for phototropism. Science 282, 1698-1701. Froehlich, A. C., Liu, Y., Loros, J. J., and Dunlap, J. C. (2002). White Collar-1, a circadian blue light photoreceptor, binding to the frequency promoter. Science 297, 815-819. Imaizumi, T., Tran, H. G., Swartz, T. E., Briggs, W. R., and Kay, S. A. (2003). FKF1 is essential for photoperiodic-specific light signalling in Arabidopsis. Nature 426, 302-306. Jarillo, J. A., Capel, J., Tang, R.-H., Yang, H.-Q., Alonso, J. M., Ecker, J. R., and Cashmore, A. R. (2001a). An Arabidopsis circadian clock component interacts with both CRY1 and phy

  14. Possible Involvement of Photoperiodic Regulation in Reproductive Endocrine System of Female Olive Flounder Paralichthys olivaceus

    PubMed Central

    Kim, Hyun Chul; Lee, Chi Hoon; Hur, Sung Pyu; Kim, Byeong Hoon; Park, Jun Young; Lee, Young Don

    2015-01-01

    This study investigated possible involvement of photoperiodic regulation in reproductive endocrine system of female olive flounder. To investigate the influence on brain-pituitary axis in endocrine system by regulating photoperiod, compared expression level of Kisspeptin and sbGnRH mRNA in brain and FSH-β, LH-β and GH mRNA in pituitary before and after spawning. Photoperiod was treated natural photoperiod and long photoperiod (15L:9D) conditions from Aug. 2013 to Jun. 2014. Continuous long photoperiod treatment from Aug. (post-spawning phase) was inhibited gonadal development of female olive flounder. In natural photoperiod group, the Kiss2 expression level a significant declined in Mar. (spawning period). And also, FSH-β, LH-β and GH mRNA expression levels were increasing at this period. However, in long photoperiod group, hypothalamic Kiss2, FSH-β, LH-β and GH mRNA expression levels did not show any significant fluctuation. These results suggest that expression of hypothalamic Kiss2, GtH and GH in the pituitary would change in response to photoperiod and their possible involvement of photoperiodic regulation in reproductive endocrine system of the BPG axis. PMID:25949205

  15. Solitary Myofibroma of the Bladder Trigone in a 3-Month-Old Patient: First Case Report

    PubMed Central

    Pensabene, Marco; Siracusa, Fortunato; Rodolico, Vito; Li Voti, Giuseppe; Zambaiti, Elisa; Cimador, Marcello

    2016-01-01

    Visceral solitary myofibromas are uncommon in childhood. We report a case of a solitary asymptomatic visceral myofibroma of the bladder trigone occurring in a 3-month-old boy. Once malignancies were ruled out by cystoscopy, radical excision was performed in order to avoid any potential impairment of bladder dynamic. Postoperative course was uneventful and patient was discharged on day 3 after surgery. After 36 months of follow-up, the patient is toilet-trained and remains well; bladder function is normal.

  16. Blunt traumatic infrarenal aortic intimal flap progressing to pseudoaneurysm over 3 months

    PubMed Central

    Carr, John Alfred

    2016-01-01

    Blunt traumatic infrarenal aortic injuries are unusual, and the formation of a delayed pseudoaneurysm of the aorta is even more rare. In this report, a young woman developed a small intimal flap of the infrarenal aorta after a motor vehicle accident which progressed into a 3 cm pseudoaneurysm after 3 months. Operative repair was successful and the patient recovered. This case illustrates the importance of repeat imaging of small blunt aortic injuries since progression can occur. PMID:27252519

  17. The Relationship between Gentle Tactile Stimulation on the Fetus and Its Temperament 3 Months after Birth

    PubMed Central

    Wang, Zhe-Wei; Hua, Jing; Xu, Yu-Hong

    2015-01-01

    Objective. The aim of this study was to evaluate the effect of gentle tactile stimulation on the fetus in its temperament 3 months after birth. Method. A total of 302 mother-3-month-infant dyads enrolled the retrospective cohort study. 76 mothers had regular gentle tactile stimulation on the fetus in their pregnancy; 62 mothers had irregular tactile stimulation on the fetus, and the rest of 164 mothers who had no tactile stimulation served as nonexposure group. Temperament was assessed using the EITS (a nine-dimensional scale of temperament). Results. Significant difference in temperament type was found among infants in 3 groups at 3 months of age. In the regular practice group, the babies with easy type temperament accounted for 73.7%, which was higher than that in irregular practice group (53.2%, P = 0.012) and that in the control group (42.1%, P < 0.001). Compared to infants in no practice group, the infants who had received regular gentle tactile stimulation before birth were lower in negative mood (P = 0.047) while higher in adaptability (P < 0.001), approach (P = 0.001), and persistence (P = 0.001), respectively. Conclusion. Regular gentle tactile stimulation on fetus may promote the formation of easy type infant temperament. PMID:26180374

  18. Observed coparenting and triadic dynamics in African American fragile families at 3 months' postpartum.

    PubMed

    McHale, James P; Coates, Erica E

    2014-01-01

    This report examines coparenting and triadic interactions in 19 unmarried, first-time African American families as fathers, mothers, and 3-month-old infants navigated the Lausanne Trilogue Play (LTP; E. Fivaz-Depeursinge & A. Corboz-Warnery, ). Parents in 10 of the 19 families reported coresidence at the time of the 3-month assessment, and the other 9 sets of coparents lived apart. All participating families had taken part in a prenatal intervention emphasizing the importance of father engagement in children's lives, and in all families, parents reported episodic to regular father contact with the children at 3 months. Analyses of LTP sessions revealed that 9 of the 19 families exhibited high levels of coparenting solidarity-cooperation and family warmth accompanied by low levels of coparenting competition and disengagement. Among the remaining 10 families, competitiveness (verbal sparring, interference) and/or disengagement (repeated, episodic absenting by one or both parents from the ongoing interaction) signaled strain and challenges to solidarity. Differences between the higher and lower solidarity groups were found in father-reported relationship rapport. However, coresidentiality versus noncoresidentiality of the parents did not distinguish high- from low-solidarity groups. A case analysis of one family's triadic session is presented to elucidate the rich potential for clinical intervention in triadic work with fragile family systems. Implications of the study and its findings for theory, research, and clinical work with unmarried fathers and families, along with limits of the study design and generalizability of findings, are discussed. PMID:25798494

  19. Influence of Photoperiod on Hormones, Behavior, and Immune Function

    PubMed Central

    Walton, James C.; Weil, Zachary M.; Nelson, Randy J.

    2011-01-01

    Photoperiodism is the ability of plants and animals to measure environmental day length to ascertain time of year. Central to the evolution of photoperiodism in animals is the adaptive distribution of energetically challenging activities across the year to optimize reproductive fitness while balancing the energetic tradeoffs necessary for seasonally- appropriate survival strategies. The ability to accurately predict future events requires endogenous mechanisms to permit physiological anticipation of annual conditions. Day length provides a virtually noise free environmental signal to monitor and accurately predict time of the year. In mammals, melatonin provides the hormonal signal transducing day length. Duration of pineal melatonin is inversely related to day length and its secretion drives enduring changes in many physiological systems, including the HPA, HPG, and brain-gut axes, the autonomic nervous system, and the immune system. Thus, melatonin is the fulcrum mediating redistribution of energetic investment among physiological processes to maximize fitness and survival. PMID:21156187

  20. Photoperiodic control of circadian activity rhythms in diurnal rodents

    NASA Astrophysics Data System (ADS)

    Kramm, K. R.; Kramm, Deborah A.

    1980-03-01

    The responses of red squirrels (Tamiasciurus hudsonicus) and eastern chipmunks (Tamias striatus) to complete and skeleton light-dark (LD) cycles were compared. The skeletons, comprised of two 1-h pulses of light per day, effectively simulated the complete photoperiods in the squirrels, but not the chipmunks. Skeleton photoperiods greater than 12-h caused the chipmunks to shift activity from the longer to the shorter of the two intervals between the pulses. To interpret the mechanism of phase control, squirrels and chipmunks were kept in continuous darkness and exposed to 1-h light pulses every 10 days. The time-course of entrainment was also quantified. Both techniques produced light-response curves. The data suggest that the parametric and non-parametric contributions to entrainment are different in these two rodent species.

  1. Intra-Arterial Chemotherapy as Primary Therapy for Retinoblastoma in Infants Less than 3 Months of Age: A Series of 10 Case-Studies

    PubMed Central

    Xia, Jiejun; Liu, Zhenyin; Jiang, Hua; Shen, Gang; Li, Haibo; Jiang, Yizhou; Zhang, Jing

    2016-01-01

    Purpose Retinoblastoma is the most common primary malignant intra-ocular tumor in children. Although intra-arterial chemotherapy (IAC) by selectively infusing chemotherapy through the ophthalmic artery has become an essential technique in the treatment of advanced intra-ocular retinoblastoma in children, the outcome of IAC as primary therapy for infants less than 3 months of age remains unknown. In this retrospective study, we reviewed the outcome of IAC as primary therapy for retinoblastoma in infants less than 3 months of age. Methods We retrospectively reviewed ten retinoblastoma patients attending our center from January 2009 to September 2015 and beginning primary IAC before the age of 3 months. The patient characteristics, overall outcomes and therapy-related complications were assessed. Results The mean patient age at the first IAC treatment was 10.4 weeks (range 4.9–12.9 weeks). These eyes were classified according to the International Classification of Retinoblastoma (ICRB) as group A (n = 0), B (n = 2), C (n = 0), D (n = 9), or E (n = 2). A total of 28 catheterizations were performed, and the procedure was stopped in one patient because of internal carotid artery spasm. Each eye received a mean of 2.6 cycles of IAC (range 2–4 cycles). After IAC with a mean follow-up of 28.3 months (range 9–65 months), tumor regression was observed in 12 of 13 eyes. One eye was enucleated due to tumor progression. All patients are alive and no patient has developed metastatic disease or other malignancies. Conclusions Our experience suggests IAC as primary therapy is a feasible and promising treatment for retinoblastoma in infants less than 3 months of age. PMID:27504917

  2. Photoperiod Regulates vgf-Derived Peptide Processing in Siberian Hamsters

    PubMed Central

    Noli, Barbara; Brancia, Carla; Pilleri, Roberta; D’Amato, Filomena; Messana, Irene; Manconi, Barbara; Ebling, Francis J. P.; Ferri, Gian-Luca; Cocco, Cristina

    2015-01-01

    VGF mRNA is induced in specific hypothalamic areas of the Siberian hamster upon exposure to short photoperiods, which is associated with a seasonal decrease in appetite and weight loss. Processing of VGF generates multiple bioactive peptides, so the objective of this study was to determine the profile of the VGF-derived peptides in the brain, pituitary and plasma from Siberian hamsters, and to establish whether differential processing might occur in the short day lean state versus long day fat. Antisera against short sequences at the C- or N- termini of proVGF, as well as against NERP-1, TPGH and TLQP peptides, were used for analyses of tissues, and both immunohistochemistry and enzyme linked immunosorbent assay (ELISA) coupled with high-performance liquid (HPLC) or gel chromatography were carried out. VGF peptide immunoreactivity was found within cortex cholinergic perikarya, in multiple hypothalamic nuclei, including those containing vasopressin, and in pituitary gonadotrophs. ELISA revealed that exposure to short day photoperiod led to a down-regulation of VGF immunoreactivity in the cortex, and a less pronounced decrease in the hypothalamus and pituitary, while the plasma VGF levels were not affected by the photoperiod. HPLC and gel chromatography both confirmed the presence of multiple VGF-derived peptides in these tissues, while gel chromatography showed the presence of the VGF precursor in all tissues tested except for the cortex. These observations are consistent with the view that VGF-derived peptides have pleiotropic actions related to changing photoperiod, possibly by regulating cholinergic systems in the cortex, vasopressin hypothalamic pathways, and the reproductive axis. PMID:26555143

  3. Maternal Photoperiodic History Affects Offspring Development in Syrian Hamsters

    PubMed Central

    Beery, Annaliese K.; Paul, Matthew J.; Routman, David M.; Zucker, Irving

    2009-01-01

    During the first 7 weeks of postnatal life, short day lengths inhibit the onset of puberty in many photoperiodic rodents, but not in Syrian hamsters. In this species, timing of puberty and fecundity are independent of the early postnatal photoperiod. Gestational day length affects postnatal reproductive development in several rodents; its role in Syrian hamsters has not been assessed. We tested the hypothesis that cumulative effects of pre- and postnatal short day lengths would restrain gonadal development in male Syrian hamsters. Males with prenatal short day exposure were generated by dams transferred to short day lengths 6 weeks, 3 weeks, and 0 weeks prior to mating. Additional groups were gestated in long day lengths and transferred to short days at birth, at 4 weeks of age, or not transferred (control hamsters). In pups of dams exposed to short day treatment throughout gestation, decreased testis growth was apparent by 3 weeks and persisted through 9 weeks of age, at which time maximum testis size was attained. A subset of males (14%), whose dams had been in short days for 3 to 6 weeks prior to mating displayed pronounced delays in testicular development, similar to those of other photoperiodic rodents. This treatment also increased the percentage of male offspring that underwent little or no gonadal regression postnatally (39%). By 19 weeks of age, males housed in short days completed spontaneous gonadal development. After prolonged long day treatment to break refractoriness, hamsters that initially were classified as nonregressors underwent testicular regression in response to a 2nd sequence of short day lengths. The combined action of prenatal and early postnatal short day lengths diminishes testicular growth of prepubertal Syrian hamsters no later than the 3rd week of postnatal life, albeit to a lesser extent than in other photoperiodic rodents. PMID:18838610

  4. Photoperiod shift effects on yield characteristics of rice.

    PubMed

    Volk, G M; Mitchell, C A

    1995-01-01

    Edible yield must be maximized for each crop species selected for inclusion in the Controlled Ecological Life-Support System (CELSS) proposed by NASA to support long-term manned space missions. In a greenhouse study aimed at increasing biomass partitioning to rice (Oryza sativa L.) grain, plants of the high yielding semi-dwarf rice cultivar Ai-Nan-Tsao were started in pots under 8-h photoperiods at a density of 212 plants m-2. After different periods of time under 8-h photoperiods, pots were switched to continuous light for the remainder of the cropping cycle. Continuous light did not delay time to first panicle emergence (60 d) or time to harvest (83 d). There was a positive correlation between the length of continuous light treatments and nongrain biomass. Grain yield (1.6 +/- 0.2 g plant-1) did not increase in continuous light. Yield-efficiency rate (grain weight per length of cropping cycle, canopy volume, and weight of nongrain shoot biomass) was used to compare treatments. Small Ai-Nan-Tsao rice canopies grown under 8-h photoperiods were more efficient producers of grain than canopies grown under continuous light for a portion of the rice cropping cycle. PMID:11540306

  5. Photoperiod shift effects on yield characteristics of rice

    NASA Technical Reports Server (NTRS)

    Volk, G. M.; Mitchell, C. A.

    1995-01-01

    Edible yield must be maximized for each crop species selected for inclusion in the Controlled Ecological Life-Support System (CELSS) proposed by NASA to support long-term manned space missions. In a greenhouse study aimed at increasing biomass partitioning to rice (Oryza sativa L.) grain, plants of the high yielding semi-dwarf rice cultivar Ai-Nan-Tsao were started in pots under 8-h photoperiods at a density of 212 plants m-2. After different periods of time under 8-h photoperiods, pots were switched to continuous light for the remainder of the cropping cycle. Continuous light did not delay time to first panicle emergence (60 d) or time to harvest (83 d). There was a positive correlation between the length of continuous light treatments and nongrain biomass. Grain yield (1.6 +/- 0.2 g plant-1) did not increase in continuous light. Yield-efficiency rate (grain weight per length of cropping cycle, canopy volume, and weight of nongrain shoot biomass) was used to compare treatments. Small Ai-Nan-Tsao rice canopies grown under 8-h photoperiods were more efficient producers of grain than canopies grown under continuous light for a portion of the rice cropping cycle.

  6. Time measurement in the photoperiodic induction of sexual rest in the terrestrial isopod Armadillidium vulgare (Latreille).

    PubMed

    Nasri-Ammar, K; Souty-Grosset, C; Mocquard, J P

    2001-08-01

    The photoperiodic control of sexual rest in Armadillidium vulgare was investigated using various experimental protocols. When reared in conditions of a Nanda-Hamner (i.e. resonance) protocol from their first parturial moult to their post experimental moult, females showed a weak resonance effect in sexual rest incidence. The transfer from a long day cycle to a symmetrical skeleton photoperiod--consisting of two equal light pulses per 24 h of continuous darkness--revealed the involvement of a circadian oscillatory system in the photoperiodic clock of this species. The data, obtained in the whole experiments, suggested that both oscillator and hourglass features are involved in the photoperiodic response controlling the sexual rest in Armadillidium vulgare. Moreover, when non-24-h light-dark cycles (with a long photophase) were applied, a mechanism responsible of arrest of reproduction also implied a photoperiodic counter which accumulated and added up the photoperiodic information within a sensitive period during post parturial intermoult. PMID:11510415

  7. Changes in physical activity and fitness after 3 months of home Wii Fit™ use.

    PubMed

    Owens, Scott G; Garner, John C; Loftin, J Mark; van Blerk, Natalie; Ermin, Kevser

    2011-11-01

    The purpose of this study was to examine changes in physical activity and fitness variables in members of 8 volunteer families after 3 months of home use of the Wii Fit™ interactive video game. Pre and postintervention measurements were obtained from 21 subjects relative to physical activity (5 days of accelerometry), aerobic fitness (graded treadmill test), muscular fitness (push-ups), flexibility (sit-and-reach test), balance (composite equilibrium score), and body composition (body mass index and % body fat). Use characteristics of the Wii Fit™ device were also determined. A series of 2 (age group) × 2 (time) repeated measures analyses of variance were conducted to assess changes over time and between adults and children. Three months of home Wii Fit™ use revealed no significant age group × time interactions or main effects of group or time for daily physical activity, muscular fitness, flexibility, balance, or body composition. An age group × time interaction (p = 0.04) was observed in peak VO2 (ml·kg(-1)·min(-1)) with children displaying a significant (p = 0.03) increase after 3 months of Wii Fit™ use, whereas adults showed no significant (p = 0.50) change. Daily Wii Fit™ use per household declined by 82% (p < 0.01) from 21.5 ± 9.0 min·d(-1) during the first 6 weeks to 3.9 ± 4.0 min·d(-1) during the second 6 weeks. Most measures of health-related fitness in this exploratory study remained unchanged after 3 months of home use of the popular Wii Fit™ whole-body movement interactive video game. Modest daily Wii Fit™ use may have provided insufficient stimulus for fitness changes. PMID:21993031

  8. Photoperiodic Regulation of the Seasonal Pattern of Photosynthetic Capacity and the Implications for Carbon Cycling

    SciTech Connect

    Bauerle, William L.; Oren, Ram; Way, Danielle A.; Qian, Song S.; Stoy, Paul C.; Thornton, Peter E; Bowden, Joseph D.; Hoffman, Forrest M; Reynolds, Robert F.

    2012-01-01

    Although temperature is an important driver of seasonal changes in photosynthetic physiology, photoperiod also regulates leaf activity. Climate change will extend growing seasons if temperature cues predominate, but photoperiod-controlled species will show limited responsiveness to warming. We show that photoperiod explains more seasonal variation in photosynthetic activity across 23 tree species than temperature. Although leaves remain green, photosynthetic capacity peaks just after summer solstice and declines with decreasing photoperiod, before air temperatures peak. In support of these findings, saplings grown at constant temperature but exposed to an extended photoperiod maintained high photosynthetic capacity, but photosynthetic activity declined in saplings experiencing a naturally shortening photoperiod; leaves remained equally green in both treatments. Incorporating a photoperiodic correction of photosynthetic physiology into a global-scale terrestrial carbon-cycle model significantly improves predictions of seasonal atmospheric CO{sub 2} cycling, demonstrating the benefit of such a function in coupled climate system models. Accounting for photoperiod-induced seasonality in photosynthetic parameters reduces modeled global gross primary production 2.5% ({approx}4 PgC y{sup -1}), resulting in a >3% ({approx}2 PgC y{sup -1}) decrease of net primary production. Such a correction is also needed in models estimating current carbon uptake based on remotely sensed greenness. Photoperiod-associated declines in photosynthetic capacity could limit autumn carbon gain in forests, even if warming delays leaf senescence.

  9. Variations in the photoperiodic cloacal response of Japanese quail: association with testes weight and feather color

    SciTech Connect

    Oishi, T.; Konishi, T.

    1983-04-01

    The size of the cloacal gland was found to be a reliable indicator of testicular activity of Japanese quail. Six experiments were performed to examine the effects of alternating long and short photoperiod on the size of the cloacal gland of male Japanese quail. Three types of photoperiodic cloacal responses were distinguished. Type I birds became refractory to short photoperiods after they had experienced 5 weeks or more of short days. They maintained large cloacal glands under subsequent condition of alternating long and short photoperiod. Type II birds were intermediate types I and III birds did not become refractory to short photoperiods after experiencing 5 weeks or more of short days. The cloacal glands responded to conditions of alternating long and short photoperiods with increases or decreases in size. Feather color on the throat was found to correspond to the type of cloacal response. Type I birds had brick-red throat feathers. Type II birds had white feathers intermingled with brick-red feathers. Type III had white throat feathers. The percentages of types I, II, and III observed in the experimental population was 67, 18, and 15%, respectively. Type III birds were used to study the effects of blinding on the cloacal response to short photoperiod. Five out of eight blinded type III birds did not lose the responsiveness to short photoperiod. These results are consistent with the view that extraocular photoreceptors participate in the photoperiodic gonadal response of Japanese quail.

  10. Photoperiodic regulation of the seasonal pattern of photosynthetic capacity and the implications for carbon cycling.

    PubMed

    Bauerle, William L; Oren, Ram; Way, Danielle A; Qian, Song S; Stoy, Paul C; Thornton, Peter E; Bowden, Joseph D; Hoffman, Forrest M; Reynolds, Robert F

    2012-05-29

    Although temperature is an important driver of seasonal changes in photosynthetic physiology, photoperiod also regulates leaf activity. Climate change will extend growing seasons if temperature cues predominate, but photoperiod-controlled species will show limited responsiveness to warming. We show that photoperiod explains more seasonal variation in photosynthetic activity across 23 tree species than temperature. Although leaves remain green, photosynthetic capacity peaks just after summer solstice and declines with decreasing photoperiod, before air temperatures peak. In support of these findings, saplings grown at constant temperature but exposed to an extended photoperiod maintained high photosynthetic capacity, but photosynthetic activity declined in saplings experiencing a naturally shortening photoperiod; leaves remained equally green in both treatments. Incorporating a photoperiodic correction of photosynthetic physiology into a global-scale terrestrial carbon-cycle model significantly improves predictions of seasonal atmospheric CO(2) cycling, demonstrating the benefit of such a function in coupled climate system models. Accounting for photoperiod-induced seasonality in photosynthetic parameters reduces modeled global gross primary production 2.5% (∼4 PgC y(-1)), resulting in a >3% (∼2 PgC y(-1)) decrease of net primary production. Such a correction is also needed in models estimating current carbon uptake based on remotely sensed greenness. Photoperiod-associated declines in photosynthetic capacity could limit autumn carbon gain in forests, even if warming delays leaf senescence. PMID:22586103

  11. Seasonal patterns of photosynthetic capacity: photoperiodic control and its carbon cycling implications

    NASA Astrophysics Data System (ADS)

    Bauerle, W.; Oren, R.; Way, D.; Qian, S.; Stoy, P. C.; Thornton, P. E.; Bowden, J.; Hoffman, F. M.; Reynolds, R.

    2012-12-01

    While temperature is an important driver of seasonal changes in photosynthetic physiology, photoperiod also regulates leaf activity. Climate change will extend growing seasons if temperature cues predominate, but photoperiod-controlled species will show limited responsiveness to warming. We show that photoperiod explains more seasonal variation in photosynthetic activity across 23 tree species than temperature. Although leaves remain green, photosynthetic capacity peaks just after summer solstice and declines with decreasing photoperiod, before air temperatures peak. In support of these findings, saplings grown at constant temperature, but exposed to an extended photoperiod maintained high photosynthetic capacity, while photosynthetic activity declined in saplings experiencing a naturally shortening photoperiod; leaves remained equally green in both treatments. Incorporating a photoperiodic correction of photosynthetic physiology into a global-scale terrestrial carbon cycle model significantly improves predictions of seasonal atmospheric CO2 cycling, demonstrating the benefit of such a function in coupled climate system models. Accounting for photoperiod-induced seasonality in photosynthetic parameters reduces modeled global gross primary production ~4 PgC y-1, resulting in a ~2 PgC y-1 decrease of net primary production. Such a correction is also needed in models estimating current carbon uptake based on remotely-sensed greenness. Photoperiod-associated declines in photosynthetic capacity could limit autumn carbon gain in forests, even if warming delays leaf senescence. Assessments of late season carbon sequestration under a changing climate should focus on potential adverse impacts of warming via increased ecosystem respiration.

  12. Effect of photoperiod on flowering of cypress vine (Ipomea quamoclit L.)

    NASA Astrophysics Data System (ADS)

    Koike, Yasuhiko

    2013-05-01

    Plants of Ipomoea quamoclit L. were exposed to an 8-hour photoperiod under natural daylight, which was supplemented with 60 W incandescent lamps to give an 8- to 24-hour day. Under photoperiods of 12 hours or less, flower buds were initiated, while the period from bud formation to flowering was shortened in plants grown under a 12-hour photoperiod. Photoperiods of 12 hours or less had no effect on plant height and number of nodes. The present results suggest that Ipomoea quamoclit L. is a short-day plant.

  13. The effects of chronic photoperiod shifting on the physiology of female Long-Evans rats.

    PubMed

    Deibel, Scott H; Hong, Nancy S; Himmler, Stephanie M; McDonald, Robert J

    2014-04-01

    As the prevalence of shift work is increasing, it is important to elucidate the impact that shift work has on health. Because of the alternating work schedules present in rotating shift work and working at night, shift workers are in a chronic state of circadian disruption. Animal models of circadian disruption are useful because they offer more experimental control than the largely correlational human shift work studies. The effects of chronic circadian disruption on food preference, glucose tolerance, corticosterone secretion, and performance in a stress-inducing task were investigated in female Long-Evans rats. A 64-day photoperiod shifting paradigm was used to induce circadian disruption. Surprisingly, neither the photoperiod shifted animals, nor the control animals demonstrated a preference for either an unhealthy or healthy diet. Nor was there a difference between the groups in weight gained during photoperiod shifting. However, the photoperiod shifted rats gained significantly more weight than control animals, without eating more food during discriminative fear conditioning to context (DFCTC). Surprisingly, chronic photoperiod shifting appeared to facilitate retention in the DFCTC task. The photoperiod shifted animals also had increased serum glucose values during fasting and after a glucose challenge test. The photoperiod shifted animals only had elevated corticosterone during the final two phases of photoperiod shifting. This study demonstrates that chronic photoperiod shifting elicits weight gain when exposed to a stressful event and impairs glucose tolerance in the same individual. PMID:24631903

  14. Variation in the ability of a long day followed by a short day photoperiod signal to initiate reproductive activity in ewes at different times of the year.

    PubMed

    Sweeney, T; Donovan, A; Roche, J F; O'Callaghan, D

    1997-01-01

    Three experiments examined the importance of the time and duration of exposure to a long day followed by a short day photoperiod signal in initiating reproductive activity in ewes. In Expt 1, ewes were maintained on short days (8.5 h light:15.5 h dark) from 21 December interrupted with either 105 long days (18 h light:6 h dark; LD) from 9 February or 35 LD from 9 February, 16 March or 20 April. Exposure to long days followed by short days advanced the onset of reproductive activity in comparison to control ewes maintained on simulated natural photoperiod. Exposure to long days for 105 days delayed the onset of reproductive activity (August 2 +/- 3 days; P < 0.05) compared with 35 days beginning on the same date (July 13 +/- 5 days). The interval from the end of the long day signal to the onset of reproductive activity was shorter (P < 0.001) however, after 105 LD than after 35 LD. In Expt 2, control ewes were moved from natural photoperiod to simulated natural photoperiod on 1 November and subsequently exposed to short days from 21 December. Four other groups were also exposed to this basic photoperiodic signal sequence but it was interrupted with either 70 LD from 16 November, or 35 LD from 16 November, 21 December or 20 April. More ewes (P < 0.05) initiated reproductive activity after exposure to 70 LD from 16 November and 35 LD from 21 December or 20 April compared with control ewes maintained on short days or ewes given 35 LD from 16 November. The interval from the end of long days to the onset of reproductive activity was less (P < 0.01) in ewes given 70 LD than in ewes given 35 LD. In Expt 3, ewes on natural photoperiod were given either 90 LD from 21 September, 35 LD from 21 September, 26 October, 30 November, 4 January or 8 February followed by short days. The majority of ewes that received long followed by short days after the winter solstice resumed reproductive activity. However, all photoperiod signals given between the autumn equinox and the winter

  15. Congenital diaphragmatic hernia, Meckel's diverticulum and malrotation in a 3-month-old infant.

    PubMed

    Basani, Laxman; Aepala, Roja; Reddy, B Madhu Mohan

    2016-01-01

    Congenital diaphragmatic hernia (CDH) is a common developmental anomaly that usually presents in the neonatal period. It is known to be associated with cardiac, renal, genital and chromosomal anomalies. Late presentation of CDH (beyond 1-month of age) is seen in 13% of the cases. Malrotation is reported in 42% of CDH cases. We report a case of a 3-month-old infant with concurrent CDH, Meckel's diverticulum and malrotation. This is the first case report of such an association in an infant. PMID:27251525

  16. Posterior Urethral Polyp: First Holmium-YAG Laser Ablation on a 3-Month-Old Infant

    PubMed Central

    Keskin, Ercument; Yapanoglu, Turgut; Adanur, Senol; Ziypak, Tevfik; Altay, Mehmet Sefa; Aksoy, Yılmaz

    2016-01-01

    Abstract Background: Urethral polyps are rare benign pathologies seen in the male posterior urethra, more frequently originating from verumontanum. In this article, we aimed to discuss diagnosis and treatment of a urethral polyp causing hematuria and urinary infection in a 3-month-old male infant. This is the first case in the literature in which a urethral polyp is treated with Holmium yttrium-aluminum-garnet (YAG) laser. Case Presentation: The patient was a 3-month-old male infant, and complains were hematuria and crying during micturition. Ultrasonography and voiding cystourethrogram were used for diagnosis. Urethral polyp was observed on urethrocystoscopy. Ablation was performed with a newborn cystoscope. Conclusion: Urethral polyp can cause hematuria and urinary obstruction and should be considered in the differential diagnosis of pathologies such as posterior urethral valve and cecoureterocele that could cause infravesical obstruction. Holmium-YAG laser is a good choice of treatment with easy application possibilities using a newborn cystoscope, especially for newborns and infants who have thin urethra. PMID:27579428

  17. Promoting effects of an extended photoperiod treatment on the condition of hair coats and gonadal function in Thoroughbred weanlings

    PubMed Central

    HARADA, Takehiro; NAMBO, Yasuo; ISHIMARU, Mutsuki; SATO, Fumio; NAGAOKA, Kentaro; WATANABE, Gen; TAYA, Kazuyoshi

    2016-01-01

    ABSTRACT The effects of an extended photoperiod (EP) treatment (14.5 hr light, 9.5 hr dark) on Thoroughbred colts and fillies from December 25 at 7–9 months old to the following May at 12–14 months old on coat condition and gonadal functions were investigated. Coat condition was evaluated in April. The colts and fillies in the EP treatment group changed from winter to summer coats (molting of winter coats), whereas those in the control group did not. To determine the day of first ovulation, the plasma concentrations of progesterone were measured once a month in fillies. The day of first ovulation was advanced in the EP treatment fillies compared with the control fillies. The present study clearly demonstrated that the EP treatment advanced the molting of winter coats and advanced ovulation in fillies, even in weanlings. PMID:26858581

  18. Promoting effects of an extended photoperiod treatment on the condition of hair coats and gonadal function in Thoroughbred weanlings.

    PubMed

    Harada, Takehiro; Nambo, Yasuo; Ishimaru, Mutsuki; Sato, Fumio; Nagaoka, Kentaro; Watanabe, Gen; Taya, Kazuyoshi

    2015-01-01

    The effects of an extended photoperiod (EP) treatment (14.5 hr light, 9.5 hr dark) on Thoroughbred colts and fillies from December 25 at 7-9 months old to the following May at 12-14 months old on coat condition and gonadal functions were investigated. Coat condition was evaluated in April. The colts and fillies in the EP treatment group changed from winter to summer coats (molting of winter coats), whereas those in the control group did not. To determine the day of first ovulation, the plasma concentrations of progesterone were measured once a month in fillies. The day of first ovulation was advanced in the EP treatment fillies compared with the control fillies. The present study clearly demonstrated that the EP treatment advanced the molting of winter coats and advanced ovulation in fillies, even in weanlings. PMID:26858581

  19. Evolution of photoperiodic time measurement is independent of the circadian clock in the pitcher-plant mosquito, Wyeomyia smithii

    PubMed Central

    Emerson, Kevin J.; Dake, Sabrina J.; Bradshaw, William E.; Holzapfel, Christina M.

    2014-01-01

    For over 70 years, researchers have debated whether the ability to use day length as a cue for the timing of seasonal events (photoperiodism) is related to the endogenous circadian clock that regulates the timing of daily events. Models of photoperiodism include two components: (1) a photoperiodic timer that measures the length of the day, and (2) a photoperiodic counter that elicits the downstream photoperiodic response after a threshold number of days has been counted. Herein, we show that there is no geographical pattern of genetic association between the expression of the circadian clock and the photoperiodic timer or counter. We conclude that the photoperiodic timer and counter have evolved independently of the circadian clock in the pitcher-plant mosquito Wyeomyia smithii and hence, the evolutionary modification of photoperiodism throughout the range of W. smithii has not been causally mediated by a corresponding evolution of the circadian clock. PMID:19190920

  20. Evolution of photoperiodic time measurement is independent of the circadian clock in the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Emerson, Kevin J; Dake, Sabrina J; Bradshaw, William E; Holzapfel, Christina M

    2009-04-01

    For over 70 years, researchers have debated whether the ability to use day length as a cue for the timing of seasonal events (photoperiodism) is related to the endogenous circadian clock that regulates the timing of daily events. Models of photoperiodism include two components: (1) a photoperiodic timer that measures the length of the day, and (2) a photoperiodic counter that elicits the downstream photoperiodic response after a threshold number of days has been counted. Herein, we show that there is no geographical pattern of genetic association between the expression of the circadian clock and the photoperiodic timer or counter. We conclude that the photoperiodic timer and counter have evolved independently of the circadian clock in the pitcher-plant mosquito Wyeomyia smithii and hence, the evolutionary modification of photoperiodism throughout the range of W. smithii has not been causally mediated by a corresponding evolution of the circadian clock. PMID:19190920

  1. Influence of light and photoperiodicity on pig prolificacy.

    PubMed

    Claus, R; Weiler, U

    1985-01-01

    In the wild pig mating activity is seasonal. The main breeding period is in late autumn but a second period may occur around April. It is known from other species that seasonal variations in breeding activity are mainly regulated by photoperiod. In the domestic pig seasonal influences on prolificacy still exist: for example, AI boars not only show decreased steroid synthesis, sperm counts and libido in summer compared with the optima which occur in winter but also a biphasic pattern with a transient increase in spring. In cyclic sows ovarian function may be affected with anoestrus mainly in summer and occasionally in February/March. Additionally ovulation rate may be lower in summer and the duration of oestrus prolonged compared with that in late autumn and winter. In consequence the interval from weaning to oestrus is prolonged in summer and mating during this season leads to lower conception rates and slightly smaller litters. Light programmes which extend the daily light period to a constant 15-16 h seem to be ineffective in improving reproductive characteristics of the sow but stimulate the sucking frequency of piglets and increase survival of piglets with a low birthweight. Simulation, in summer, of the decreasing photoperiod (naturally occurring in autumn) stimulates the reproductive characteristics of AI boars, optimizing testicular steroid production, libido and semen composition. Similarly, a programme of decreasing light (20 min decrease/week) from May to August removed the seasonal increase (June-August) of the weaning-to-oestrus interval which was 5.7 days (compared with 23.6 days for the controls). An interaction between photoperiod and puberty attainment seems to exist for male and female pigs. Further experiments with appropriate light programmes, however, are necessary to clarify this interaction. PMID:3910824

  2. Eyewitness memory of a supermarket robbery: a case study of accuracy and confidence after 3 months.

    PubMed

    Odinot, Geralda; Wolters, Gezinus; van Koppen, Peter J

    2009-12-01

    In this case study, 14 witnesses of an armed robbery were interviewed after 3 months. Security camera recordings were used to assess memory accuracy. Of all information that could be remembered about 84% was correct. Although accurately recalled information had a higher confidence level on average than inaccurately recalled information, the mean accuracy-confidence correlation was rather modest (0.38). These findings indicate that confidence is not a reliable predictor of accuracy. A higher level of self-reported, post-event thinking about the incident was associated with higher confidence levels, while a higher level of self-reported emotional impact was associated with greater accuracy. A potential source of (mis)information, a reconstruction of the robbery broadcasted on TV, did not alter the original memories of the witnesses. PMID:18719983

  3. Ultrasonography of the healing process during a 3-month follow-up after a splenic injury.

    PubMed

    Rafailidis, Vasileios; Apostolou, Dimitrios; Kaitartzis, Christodoulos; Rafailidis, Dimitrios

    2015-07-01

    We present a 14-year-old boy with a grade III splenic injury due to a bicycle accident, who was treated conservatively. The boy's medical history included splenomegaly due to thalassemia. The splenic lesion was initially investigated with computed tomography (CT) and then, was followed by ultrasonography for 3 months. CT revealed a large intraparenchymal hematoma which appeared hyperechoic on ultrasonography. During follow-up, the hematoma developed a more complex echogenicity and became gradually hypoechoic. The hematoma increased in size during the first week but then, started decreasing until it eventually resolved completely. The patient had an uneventful full recovery. In this report, we discuss the ultrasonographic changes of the hematoma throughout the healing process. PMID:25623053

  4. Gastroesophageal Variceal Bleeding as a Complication of Cystic Fibrosis in a 3-Month-Old Patient.

    PubMed

    Motamed, Farzaneh; Fallahi, Gholamhossein; Ahmadi, Faezeh; Bazvand, Fatemeh; Ahmadi, Maedeh; Eftekhari, Kambiz; Rezaei, Nima

    2016-03-01

    Cystic fibrosis (CF) is a hereditary disease of mucous and sweat glands, which affects the respiratory and gastrointestinal systems. Herein, we describe a 3-month-old girl with a history of recurrent episodes of urinary tract infections that required hospitalization. She was referred to our center at the age of three months, with massive gastroesophageal variceal bleeding. In physical examination, she had clubbing, hepatosplenomegaly, and mild ascites. Laboratory studies revealed high serum levels of liver enzymes and low level of Albumin. As of suspicious to CF, sweat tests were performed twice which confirmed the diagnosis of CF. Gastrointestinal bleeding due to gastroesophageal varices is a rare complication of CF, which could result as a consequence of hepatobiliary involvement of disease. Early diagnosis of CF could prevent severe complications and even death in this group of patients. PMID:27107529

  5. Subclavian Artery Pseudoaneurysm Formation 3 Months after a Game of Rugby Union

    PubMed Central

    Evans, T.; Roy, S.; Rocker, M.

    2015-01-01

    Pseudoaneurysms of the subclavian artery remain a rare complication after fracture of the clavicle. We report a case of delayed diagnosis of a subclavian artery pseudoaneurysm after a closed fracture of the clavicle in a 15-year-old patient, 3 months after the original injury while playing rugby union. Despite several attendances to the Emergency Department with vague symptoms, the final diagnosis was confirmed by duplex ultrasound and Computed Tomography of the thorax. Surgical repair was indicated due to acute limb ischaemia from distal embolisation from a large pseudoaneurysm, with the patient making a full recovery. This case highlights the need for clinical vigilance when assessing patients, particularly on repeated occasions when their recovery appears to be impaired. A thorough history and clinical examination can raise suspicion of even rare occurrences and aid prompt management. PMID:26351589

  6. A dissociation between recognition and reactivation: The renewal effect at 3 months of age.

    PubMed

    Cuevas, Kimberly; Learmonth, Amy E; Rovee-Collier, Carolyn

    2016-03-01

    Extinction allows organisms to adapt to an ever-changing environment. Despite its theoretical and applied significance, extinction has never been systematically studied with human infants. Using the operant mobile task, we examined whether 3-month-olds would exhibit evidence of original learning following extinction. In a recognition paradigm, infants exhibited renewal when tested in the acquisition context (ABA renewal) or a neutral context (ABC and AAB renewal) 1 day following extinction (Experiment 1a) and spontaneous recovery 3 days following extinction (Experiment 1b). In Experiments 2a-2b, we used a reminder paradigm to examine whether the extinguished response could be reinstated after the operant response had been forgotten. We failed, however, to find reinstatement of extinguished responding after spontaneous forgetting, regardless of the reminder and test contexts. We attributed this retention failure to competing responses at test. Although extinguished responding is recovered during infancy, this effect is elusive after the response has been forgotten. PMID:26394803

  7. Photoperiodic regulation of testis function in rats: mediation by a circadian mechanism

    SciTech Connect

    Nelson, R.J.; Bamat, M.K.; Zucker, I.

    1982-05-01

    Laboratory rats traditionally are classified as nonphotoperiodic because variations in daylength have little or no effect on their gonadal function. After olfactory bulbectomy, however, rats show clear evidence of photoperiodic regulation of the gonads. The present study demonstrates, by means of resonance experiments, that the testicular response to daylength in rats is mediated by a circadian photoperiodic time measurement system similar to that of photoperiodic rodents. Olfactory-bulbectomized rats were maintained in fixed photoperiods in which a 6 h light period was coupled with dark periods of 18, 30, 42, or 54 h; a fifth group was maintained in a 45L:10D photoperiod. Rats from the 6L:30D, 6L:54D and 14L:10D photoperiods had testes and seminal vesicle weights, plasma testosterone titers and spermatogenesis indices indicative of functional reproductive status. Rats exposed to the 6L:18D and 6L:42D photoperiods had reduced testicular and seminal vesicle weights, lower testosterone levels and reduced spermatogenesis. Researchers hypothesize that photo- and nonphotoperiodic rodent species use similar mechanisms for distinguishing long from short photoperiods, but differ in the extent to which discrimination of short daylengths is transduced into altered gonadal activity.

  8. Photoperiodic modulation of voluntary ethanol intake in C57BL/6 mice.

    PubMed

    Rosenwasser, A M; Fixaris, M C; McCulley, W D

    2015-08-01

    Seasonal and geographic variations in light exposure influence human mood and behavior, including alcohol consumption. Similarly, manipulation of the environmental lighting regimen modulates voluntary ethanol intake in experimental animals. Nevertheless, previous studies in rats and hamsters have been somewhat inconsistent, and little is known concerning such effects in mice. In the present study, we maintained male C57Bl/6 mice in running-wheel cages under either short- or long-photoperiod light-dark cycles (LD 6:18 vs. LD 18:6); subsequently, the same animals were maintained under short or long "skeleton photoperiods", consisting of two daily 15-min light pulses signaling dusk and dawn (SP 6:18 vs. SP 18:6). Running wheels were locked mechanically for half the animals under each photoperiod. Analysis of running wheel patterns showed that mice displayed stable circadian adaptation to both standard LD cycles and skeleton photoperiods. Mice consumed more ethanol and less water, and thus showed higher ethanol preference, under LD 6:18 and SP 6:18 relative to the corresponding long-photoperiod regimens. While running-wheel access increased water intake, ethanol intake was unaffected by this manipulation. These effects are consistent with previous studies showing that short photoperiods or constant darkness increases ethanol intake in rodents. Further, the similarity of the effects of complete and skeleton photoperiods suggests that these effects are mediated by photoperiod-induced alterations in the circadian entrainment pattern, rather than by light exposure per se. PMID:25992479

  9. Effects of photoperiod on reproduction, nymphal development timing and diapause in Amblyomma maculatum (Acari: Ixodidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Female engorgement weight, oviposition, and molting times of larvae and nymphs of Amblyomma maculatum Koch were studied at various photoperiods under constant humidity and temperature in the laboratory. Ticks were held at 0:24, 10:14, 12:12, or 14:10 (L:D) photoperiods during the egg through unfed ...

  10. Anthracnose disease response for photoperiod-insensitive Ethiopian germplasm from the U.S. sorghum collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ethiopia is an important center of genetic diversity for sorghum germplasm; however, photoperiod-sensitivity limits the utilization of this genetic resource. The United States National Plant Germplasm System maintains 180 Ethiopian sorghum accessions that are less sensitive to photoperiod and these...

  11. Role of photoperiod and melatonin in seasonal acclimatization of the djungarian hamster, Phodopus sungorus

    NASA Astrophysics Data System (ADS)

    Steinlechner, S.; Heldmaier, G.

    1982-12-01

    The Djungarian hamster, Phodopus sungorus, shows a clear annual cycle in some thermogenic parameters such as nonshivering thermogenesis (NST) and cold resistance. These seasonal changes were found to be basically controlled by natural changes in photoperiod. Further support for this view was obtained by exposing the hamsters to artificial long and short photoperiods. Implantation of melatonin during fall and winter results in an increased thermogenic capacity in both short and long day hamsters comparable to that shown by values of control hamsters exposed to short photoperiods during winter. This thermotropic action of melatonin and of short photoperiod could be found only in fall and winter whereas during spring and summer, melatonin, like photoperiod, had no influence on thermogenic capacities. These results show that the actions of melatonin and photoperiod vary with the season and that they depend upon the photoperiodic history of the hamsters. Our results further indicate that the pineal gland with its hormone melatonin is involved in mediation of photoperiodic control of seasonal acclimatization.

  12. Research update: Yield and nutritive value of photoperiod-sensitive sorghum and sorghum-sudangrass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate the yield of photoperiod-sensitive forage sorghum and sorghum-sudangrass against non-photoperiod-sensitive sorghum, sorghum-sudangrass, or corn silage. Forages were planted on two dates at two locations (Marshfield and Hancock, WI). Results suggested some ...

  13. Genetic Control of Photoperiod Sensitivity in Maize Revealed by Joint Multiple Population Analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reduced photoperiod sensitivity was critical to the evolution of broad geographical adaptability in maize, but modern tropical maize retains photoperiod sensitivity, hindering its use in temperate maize breeding programs. Many flowering time genes have been identified in diverse plant species, but t...

  14. Analysis of Photoperiod Requirements of Soft Winter Wheat from the Eastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Photoperiod response plays a major role in determining the climatic adaptation of wheat, and variation is commonly associated with Ppd loci on group two chromosomes. Seventy-three soft winter wheat (SWW) cultivars from the eastern U.S. were tested for photoperiod response in growth chambers. Floweri...

  15. Thyroid Hormone Signalling Genes Are Regulated by Photoperiod in the Hypothalamus of F344 Rats

    PubMed Central

    Russell, Laura; Darras, Veerle M.; Morgan, Peter J.

    2011-01-01

    Seasonal animals adapt their physiology and behaviour in anticipation of climate change to optimise survival of their offspring. Intra-hypothalamic thyroid hormone signalling plays an important role in seasonal responses in mammals and birds. In the F344 rat, photoperiod stimulates profound changes in food intake, body weight and reproductive status. Previous investigations of the F344 rat have suggested a role for thyroid hormone metabolism, but have only considered Dio2 expression, which was elevated in long day photoperiods. Microarray analysis was used to identify time-dependent changes in photoperiod responsive genes, which may underlie the photoperiod-dependent phenotypes of the juvenile F344 rat. The most significant changes are those related to thyroid hormone metabolism and transport. Using photoperiod manipulations and melatonin injections into long day photoperiod (LD) rats to mimic short day (SD), we show photoinduction and photosuppression gene expression profiles and melatonin responsiveness of genes by in situ hybridization; TSHβ, CGA, Dio2 and Oatp1c1 genes were all elevated in LD whilst in SD, Dio3 and MCT-8 mRNA were increased. NPY was elevated in SD whilst GALP increased in LD. The photoinduction and photosuppression profiles for GALP were compared to that of GHRH with GALP expression following GHRH temporally. We also reveal gene sets involved in photoperiodic responses, including retinoic acid and Wnt/ß-catenin signalling. This study extends our knowledge of hypothalamic regulation by photoperiod, by revealing large temporal changes in expression of thyroid hormone signalling genes following photoperiod switch. Surprisingly, large changes in hypothalamic thyroid hormone levels or TRH expression were not detected. Expression of NPY and GALP, two genes known to regulate GHRH, were also changed by photoperiod. Whether these genes could provide links between thyroid hormone signalling and the regulation of the growth axis remains to be

  16. Effect of photoperiod on the annual cycle of testis growth in a tropical mammal, the little red flying fox, Pteropus scapulatus.

    PubMed

    O'Brien, G M; Curlewis, J D; Martin, L

    1993-05-01

    Little red flying foxes (Pteropus scapulatus) are seasonal breeders: they mate in late spring/early summer, and young are born the following autumn. In captivity, males housed outdoors in a normal breeding colony in natural daylight showed a single cycle of testis growth and regression each year. During reproductive quiescence, testicular volume was approximately 2 cm3; recrudescence began soon after the winter solstice; testicular volume was maximum at approximately 6.5 cm3 at the spring equinox; and regression was complete by the end of summer. To test whether photoperiod entrains or synchronizes the cycle, groups of males were housed indoors, without females, at constant temperature, and artificial lighting was timed to either mimic naturally changing daylength or provide alternating 3-month periods of short (11 h light:13 h dark) or long (16 h light:8 h dark) days (two groups, three months out of phase with each other). During 18 months, the applied photoperiod protocol had no effect on the frequency of testicular cycles (which remained at one per year), the time course of recrudescence and regression (as described above for normal outdoor control males), or the completeness of growth and regression stages. These results suggest that male P. scapulatus are not reproductively photoresponsive. PMID:8345455

  17. Photoperiod, temperature, and regional patterns of conceptions in the USA

    NASA Astrophysics Data System (ADS)

    Randall, Walter

    1993-03-01

    Twenty-two years of monthly values of birth data for the USA, 1967 through 1988, were analyzed by visual inspection. The data were transformed to remove the influence of length of month and of linear trend, and the values were lagged 9 months to approximate the time of conception. Then, 11-year monthly averages were obtained and plotted as standard scores. Thus two 11-year sets of data were independently analyzed, providing the opportunity of replication. Four distinct temporal patterns were found, differing in month of occurrence of the initial trough and peak and the relative sizes of the two troughs; these characteristics of the temporal pattern change systematically with latitude in the eastern and midwestern states. Data from two other continents, the United Kingdom and Australia, also were analyzed using the same method and found to exhibit a temporal pattern during the year similar to the northern states of the USA. Two biologically relevant variables, temperature and photoperiod, were considered as possible controllers and regulators of the annual rhythmicity. Comparisons of the trends in conceptions with these environmental variables, and inspections of the temperatures and photoperiods at which peaks and troughs in conceptions were found, indicated that these environmental variables could not account for the annual rhythmicity in conceptions.

  18. Structural Growth Trajectories and Rates of Change in the First 3 Months of Infant Brain Development

    PubMed Central

    Holland, Dominic; Chang, Linda; Ernst, Thomas M.; Curran, Megan; Buchthal, Steven D.; Alicata, Daniel; Skranes, Jon; Johansen, Heather; Hernandez, Antonette; Yamakawa, Robyn; Kuperman, Joshua M.; Dale, Anders M.

    2016-01-01

    IMPORTANCE The very early postnatal period witnesses extraordinary rates of growth, but structural brain development in this period has largely not been explored longitudinally. Such assessment may be key in detecting and treating the earliest signs of neurodevelopmental disorders. OBJECTIVE To assess structural growth trajectories and rates of change in the whole brain and regions of interest in infants during the first 3 months after birth. DESIGN, SETTING, AND PARTICIPANTS Serial structural T1-weighted and/or T2-weighted magnetic resonance images were obtained for 211 time points from 87 healthy term-born or term-equivalent preterm-born infants, aged 2 to 90 days, between October 5, 2007, and June 12, 2013. MAIN OUTCOMES AND MEASURES We segmented whole-brain and multiple subcortical regions of interest using a novel application of Bayesian-based methods. We modeled growth and rate of growth trajectories nonparametrically and assessed left-right asymmetries and sexual dimorphisms. RESULTS Whole-brain volume at birth was approximately one-third of healthy elderly brain volume, and did not differ significantly between male and female infants (347 388 mm3 and 335 509 mm3, respectively, P = .12). The growth rate was approximately 1%/d, slowing to 0.4%/d by the end of the first 3 months, when the brain reached just more than half of elderly adult brain volume. Overall growth in the first 90 days was 64%. There was a significant age-by-sex effect leading to widening separation in brain sizes with age between male and female infants (with male infants growing faster than females by 200.4 mm3/d, SE = 67.2, P = .003). Longer gestation was associated with larger brain size (2215 mm3/d, SE = 284, P = 4×10−13). The expected brain size of an infant born one week earlier than average was 5% smaller than average; at 90 days it will not have caught up, being 2% smaller than average. The cerebellum grew at the highest rate, more than doubling in 90 days, and the hippocampus

  19. Contingency Learning and Reactivity in Preterm and Full-Term Infants at 3 Months.

    PubMed

    Haley, David W; Grunau, Ruth E; Oberlander, Tim F; Weinberg, Joanne

    2008-11-01

    Learning difficulties in preterm infants are thought to reflect impairment in arousal regulation. We examined relationships among gestational age, learning speed, and behavioral and physiological reactivity in 55 preterm and 49 full-term infants during baseline, contingency, and nonreinforcement phases of a conjugate mobile paradigm at 3 months corrected age. For all infants, negative affect, looking duration, and heart rate levels increased during contingency and nonreinforcement phases, whereas respiratory sinus arrhythmia (RSA, an index of parasympathetic activity) decreased and cortisol did not change. Learners showed greater RSA suppression and less negative affect than nonlearners. This pattern was particularly evident in the preterm group. Overall, preterm infants showed less learning, spent less time looking at the mobile, and had lower cortisol levels than full-term infants. Preterm infants also showed greater heart rate responses to contingency and dampened heart rate responses to nonreinforcement compared to full-term infants. Findings underscore differences in basal and reactivity measures in preterm compared to full-term infants and suggest that the capacity to regulate parasympathetic activity during a challenge enhances learning in preterm infants. PMID:20717491

  20. Last 3 months of life in home-ventilated patients: the family perception.

    PubMed

    Vitacca, M; Grassi, M; Barbano, L; Galavotti, G; Sturani, C; Vianello, A; Zanotti, E; Ballerin, L; Potena, A; Scala, R; Peratoner, A; Ceriana, P; Di Buono, L; Clini, E; Ambrosino, N; Hill, N; Nava, S

    2010-05-01

    We studied the family's perception of care in patients under home mechanical ventilation during the last 3 months of life. In 11 respiratory units, we submitted a 35-item questionnaire to relatives of 168 deceased patients exploring six domains: symptoms, awareness of disease, family burden, dying, medical and technical problems. Response rate was 98.8%. The majority of patients complained respiratory symptoms and were aware of the severity and prognosis of the disease. Family burden was high especially in relation to money need. During hospitalisation, 74.4% of patients were admitted to the intensive care unit (ICU). 78 patients died at home, 70 patients in a medical ward and 20 in ICU. 27% of patients received resuscitation manoeuvres. Hospitalisations and family economical burden were unrelated to diagnosis and mechanical ventilation. Families of the patients did not report major technical problems on the use of ventilators. In comparison with mechanical invasively ventilated patients, noninvasively ventilated patients were more aware of prognosis, used more respiratory drugs, changed ventilation time more frequently and died less frequently when under mechanical ventilation. We have presented good points and bad points regarding end-of-life care in home mechanically ventilated patients. Noninvasive ventilation use and diagnosis have impact on this burden. PMID:19717483

  1. Plasticity of visual attention in Isha yoga meditation practitioners before and after a 3-month retreat.

    PubMed

    Braboszcz, Claire; Cahn, B Rael; Balakrishnan, Bhavani; Maturi, Raj K; Grandchamp, Romain; Delorme, Arnaud

    2013-01-01

    Meditation has lately received considerable interest from cognitive neuroscience. Studies suggest that daily meditation leads to long lasting attentional and neuronal plasticity. We present changes related to the attentional systems before and after a 3 month intensive meditation retreat. We used three behavioral psychophysical tests - a Stroop task, an attentional blink task, and a global-local letter task-to assess the effect of Isha yoga meditation on attentional resource allocation. 82 Isha yoga practitioners were tested at the beginning and at the end of the retreat. Our results showed an increase in correct responses specific to incongruent stimuli in the Stroop task. Congruently, a positive correlation between previous meditation experience and accuracy to incongruent Stroop stimuli was also observed at baseline. We also observed a reduction of the attentional blink. Unexpectedly, a negative correlation between previous meditation experience and attentional blink performance at baseline was observed. Regarding spatial attention orientation as assessed using the global-local letter task, participants showed a bias toward local processing. Only slight differences in performance were found pre- vs. post- meditation retreat. Biasing toward the local stimuli in the global-local task and negative correlation of previous meditation experience with attentional blink performance is consistent with Isha practices being focused-attention practices. Given the relatively small effect sizes and the absence of a control group, our results do not allow clear support nor rejection of the hypothesis of meditation-driven neuronal plasticity in the attentional system for Isha yoga practice. PMID:24376429

  2. Study on toxicity of danshensu in beagle dogs after 3-month continuous intravenous infusion.

    PubMed

    Li, Guisheng; Gao, Yonglin; Li, Shenjun; Li, Chunmei; Zhu, Xiaoyin; Li, Min; Liu, Zhifeng

    2009-09-01

    Danshensu (3-(3,4-dihydroxyphenyl) lactic acid), a natural phenolic acid, is isolated from root of Salvia miltiorrhiza, and is widely used as a traditional Chinese medicine for treatment of various cardiovascular diseases. In the present study, toxicity of danshensu was evaluated in male and female dogs after 3-month continuous intravenous infusion. Beagle dogs were treated with danshensu at doses of 17, 50, and 150 mg/kg/day, and observed for 90 days followed by recovery periods. Measurements included clinical observations, body weight, food consumption, temperature, electro-cardiography (EGC), hematology, blood chemistry, urinalysis, gross necropsy, organ weight, and histopathology. No significant adverse effects on these parameters were observed. The only treatment-related finding was a hard knot at injection site observed in the 150 mg/kg group after 2-3 weeks continuous administration, and returned to normal after 3-4 days withdrawal. From these results, it might be concluded that danshensu did not produce any significant cumulative toxicity at the doses administered, as reflected by the various parameters investigated. PMID:19778246

  3. A 3-month age difference profoundly alters the primary rat stromal vascular fraction phenotype.

    PubMed

    Quaade, Marlene Louise; Jensen, Charlotte Harken; Andersen, Ditte Caroline; Sheikh, Søren Paludan

    2016-06-01

    The stromal vascular fraction (SVF) is a heterogeneous population obtained from collagenase digestion of adipose tissue. When cultured the population becomes more homogeneous and the cells are then termed adipose stromal/stem cells (ASCs). Both the freshly isolated primary SVF population and the cultured ASC population possess regenerative abilities suggested to be mediated by paracrine mechanisms mainly. The use of ASCs and SVF cells, both in animal studies and human clinical studies, has dramatically increased during recent years. However, more knowledge regarding optimal donor characteristics such as age is demanded. Here we report that even a short age difference has an impact on the phenotype of primary SVF cells. We observed that a 3-month difference in relatively young adult rats affects the expression pattern of several mesenchymal stem cell markers in their primary SVF. The younger animals had significantly more CD90+/CD44+/CD29+/PDGFRα+primary cells, than the aged rats, suggesting an age dependent shift in the relative cell type distribution within the population. Taken together with recent studies of much more pronounced age differences, our data strongly suggest that donor age is a very critical parameter that should be taken into account in future stem cell studies, especially when using primary cells. PMID:27265810

  4. Photoperiodism and Crassulacean acid metabolism : II. Relations between leaf aging and photoperiod in Crassulacean acid metabolism induction.

    PubMed

    Brulfert, J; Guerrier, D; Queiroz, O

    1982-05-01

    Measurements of net CO2 exchange, malate accumulation, properties and capacity of phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) in leaves of different ages of two short-day dependent Crassulacean acid metabolism (CAM) plants (Kalanchoe blossfeldiana v. Poelln. Tom thumb and K. velutina Welw.) show that, in both species: a) young leaves from plants grown under long days display a CO2 exchange pattern typical of C3 plants; b) leaf aging promotes CAM under long-day conditions; c) short-day treatment induces CAM in young leaves to a higher degree than aging under long days; d) at least in K. blossfeldiana, the PEPC form developed with leaf aging under long days and the enzyme form synthetized de novo in young leaves grown under short days were shown to have similar properties. Short days also promote CAM in older leaves though at a lesser extent than in young leaves: The result is that this photoperiodic treatment increases the general level of CAM performance by the whole plant. The physiological meaning of the control of PEPC capacity by photoperiodism could be to afford a precisely timed seasonal increase in CAM potentiality, enabling the plant to immediately optimize its response to the onset of drought periods. PMID:24276160

  5. Short photoperiod increases energy intake, metabolic thermogenesis and organ mass in silky starlings Sturnus sericeus

    PubMed Central

    WANG, Jia-Qi; WANG, Jia-Jia; WU, Xu-Jian; ZHENG, Wei-Hong; LIU, Jin-Song

    2016-01-01

    Environmental cues play important roles in the regulation of an animal’s physiology and behavior. One such cue, photoperiod, plays an important role in the seasonal acclimatization of birds. It has been demonstrated that an animal’s body mass, basal metabolic rate (BMR), and energy intake, are all affected by photoperiod. The present study was designed to examine photoperiod induced changes in the body mass, metabolism and metabolic organs of the silky starling, Sturnus sericeus. Captive silky starlings increased their body mass and BMR during four weeks of acclimation to a short photoperiod. Birds acclimated to a short photoperiod also increased the mass of certain organs (liver, gizzard and small intestine), and both gross energy intake (GEI) and digestible energy intake (DEI), relative to those acclimated to a long photoperiod. Furthermore, BMR was positively correlated with body mass, liver mass, GEI and DEI. These results suggest that silky starlings increase metabolic thermogenesis when exposed to a short photoperiod by increasing their body and metabolic organ mass, and their GEI and DEI. These findings support the hypothesis that bird species from temperate climates typically display high phenotypic flexibility in thermogenic capacity. PMID:27029864

  6. A neotropical forest bird can measure the slight changes in tropical photoperiod

    PubMed Central

    Hau, M.; Wikelski, M.; Wingfield, J. C.

    1998-01-01

    Many tropical birds breed seasonally, but it is largely unknown which environmental cues they use to time reproduction. Changes in tropical photoperiod have been regarded as too small to be used as a proximate environmental cue. This hypothesis, however, has never been rigorously tested. Here, we report on experimental evidence that photoperiodic changes characteristic of tropical latitudes stimulate reproductive activity in a neotropical bird from the forest understory. In the central Republic of Panam (9 degrees N), photoperiod varies annually between 12 hours (December) and 13 hours (June). Free-living spotted antbirds (Hylophylax n. naevioides) had regressed gonads in December, but increased gonads ahead of the rainy (the breeding) season in May. Captive spotted antbirds exposed to a 'long' photoperiod of 13 hours increased gonadal size eight-fold and song activity six-fold over that of control birds remaining on a simulated 'short' photoperiod of 12 hours of daylight. Moreover, even a photoperiod of 12 hours 17 minutes was sufficient to stimulate gonadal growth in photostimulated birds over that of controls. The dramatic changes in gonadal development were not accompanied by similar changes in hormone titres such as luteinizing hormone and testosterone as expected from temperate zone birds. We propose a more general role of the tropical photoperiod in the regulation of seasonal events in tropical organisms, or in temperate zone species migrating to the tropics.

  7. Short photoperiod increases energy intake, metabolic thermogenesis and organ mass in silky starlings Sturnus sericeus.

    PubMed

    Wang, Jia-Qi; Wang, Jia-Jia; Wu, Xu-Jian; Zheng, Wei-Hong; Liu, Jin-Song

    2016-03-18

    Environmental cues play important roles in the regulation of an animal's physiology and behavior. One such cue, photoperiod, plays an important role in the seasonal acclimatization of birds. It has been demonstrated that an animal's body mass, basal metabolic rate (BMR), and energy intake, are all affected by photoperiod. The present study was designed to examine photoperiod induced changes in the body mass, metabolism and metabolic organs of the silky starling, Sturnus sericeus. Captive silky starlings increased their body mass and BMR during four weeks of acclimation to a short photoperiod. Birds acclimated to a short photoperiod also increased the mass of certain organs (liver, gizzard and small intestine), and both gross energy intake (GEI) and digestible energy intake (DEI), relative to those acclimated to a long photoperiod. Furthermore, BMR was positively correlated with body mass, liver mass, GEI and DEI. These results suggest that silky starlings increase metabolic thermogenesis when exposed to a short photoperiod by increasing their body and metabolic organ mass, and their GEI and DEI. These findings support the hypothesis that bird species from temperate climates typically display high phenotypic flexibility in thermogenic capacity. PMID:27029864

  8. The influence of photoperiod on gonadotrophin-releasing hormone stimulated luteinising hormone release in the anoestrous mare.

    PubMed

    Nequin, L G; King, S S; Matt, K S; Jurak, R C

    1990-09-01

    The transition from anoestrus to oestrus in mares is controlled by photoperiod. The present study examined whether additional daylength would accelerate the mares' response to gonadotrophin-releasing-hormone (GnRH). Nine anoestrous mares were placed under ambient or artificial long lighting on 7th January. The four month experimental period was divided into a three-day sequence which was repeated at 21 day intervals. Ovaries were palpated rectally on Day 1; saline was injected (1 ml intravenously [iv]) on Day 2; GnRH was administered (0.59 microgram/kg bodyweight iv) on Day 3. Blood was taken at -60, 0, 15, 30, 60 and 120 mins relative to saline or GnRH treatment. Serum luteinising hormone (LH) was determined by a homologous equine radioimmunoassay (RIA). Several criteria were employed to define a positive response to GnRH and the results were analysed by Fisher's exact probability test. Treatment with artificial light allowed a response to GnRH within six weeks whereas the mares in ambient lighting took 12 weeks to respond to GnRH. The advancement in the time of response to GnRH under the long photoperiod could be related to changes in pituitary LH content, accelerated follicular activity or alterations in other brain-pituitary hormone levels. PMID:2226401

  9. Identifying yield-optimizing environments for two cowpea breeding lines by manipulating photoperiod and harvest scenario

    NASA Technical Reports Server (NTRS)

    Ohler, T. A.; Mitchell, C. A.

    1996-01-01

    Photoperiod and harvest scenario of cowpea (Vigna unguiculata L. Walp) canopies were manipulated to optimize productivity for use in future controlled ecological life-support systems. Productivity was measured by edible yield rate (EYR:g m-2 day-1), shoot harvest index (SHI: g edible biomass [g total shoot dry weight]), and yield-efficiency rate (YER:g edible biomass m-2 day-1 per[g nonedible shoot dry weight]). Breeding lines 'IT84S-2246' (S-2246) and "IT82D-889' (D-889) were grown in a greenhouse under 8-, 12-, or 24-h photoperiods. S-2246 was short-day and D-889 was day-neutral for flowering. Under each photoperiod, cowpeas were harvested either for leaves only, seeds only, or leaves plus seeds (mixed harvest). Photoperiod did not affect EYR of either breeding line for any harvest scenario tested. Averaged over both breeding lines, seed harvest gave the highest EYR at 6.7 g m-2 day-1. The highest SHI (65%) and YER (94 mg m-2 day-1 g-1) were achieved for leaf-only harvest of D-889 under an 8-h photoperiod. For leaf-only harvest of S-2246, both SHI and YER increased with increasing photoperiod, but declined for seed-only and mixed harvests. However, photoperiod had no effect on SHI or YER for D-889 for any harvest scenario. A second experiment utilized the short-day cowpea breeding line 'IT89KD-288' (D-288) and the day-neutral breeding line 'IT87D-941-1' (D-941) to compare yield parameters using photoperiod extension under differing lamp types. This experiment confirmed the photoperiod responses of D-889 and S-2246 to a mixed-harvest scenario and indicated that daylength extension with higher irradiance from high pressure sodium lamps further suppressed EYR, SHI, and YER of the short-day breeding line D-288.

  10. Differential changes in self-reported aspects of interoceptive awareness through 3 months of contemplative training

    PubMed Central

    Bornemann, Boris; Herbert, Beate M.; Mehling, Wolf E.; Singer, Tania

    2015-01-01

    Interoceptive body awareness (IA) is crucial for psychological well-being and plays an important role in many contemplative traditions. However, until recently, standardized self-report measures of IA were scarce, not comprehensive, and the effects of interoceptive training on such measures were largely unknown. The Multidimensional Assessment of Interoceptive Awareness (MAIA) questionnaire measures IA with eight different scales. In the current study, we investigated whether and how these different aspects of IA are influenced by a 3-months contemplative intervention in the context of the ReSource project, in which 148 subjects engaged in daily practices of “Body Scan” and “Breath Meditation.” We developed a German version of the MAIA and tested it in a large and diverse sample (n = 1,076). Internal consistencies were similar to the English version (0.56–0.89), retest reliability was high (rs: 0.66–0.79), and the MAIA showed good convergent and discriminant validity. Importantly, interoceptive training improved five out of eight aspects of IA, compared to a retest control group. Participants with low IA scores at baseline showed the biggest changes. Whereas practice duration only weakly predicted individual differences in change, self-reported liking of the practices and degree of integration into daily life predicted changes on most scales. Interestingly, the magnitude of observed changes varied across scales. The strongest changes were observed for the regulatory aspects of IA, that is, how the body is used for self-regulation in daily life. No significant changes were observed for the Noticing aspect (becoming aware of bodily changes), which is the aspect that is predominantly assessed in other IA measures. This differential pattern underscores the importance to assess IA multi-dimensionally, particularly when interested in enhancement of IA through contemplative practice or other mind–body interventions. PMID:25610410

  11. Jointly structuring triadic spaces of meaning and action: book sharing from 3 months on

    PubMed Central

    Rossmanith, Nicole; Costall, Alan; Reichelt, Andreas F.; López, Beatriz; Reddy, Vasudevi

    2014-01-01

    This study explores the emergence of triadic interactions through the example of book sharing. As part of a naturalistic study, 10 infants were visited in their homes from 3–12 months. We report that (1) book sharing as a form of infant-caregiver-object interaction occurred from as early as 3 months. Using qualitative video analysis at a micro-level adapting methodologies from conversation and interaction analysis, we demonstrate that caregivers and infants practiced book sharing in a highly co-ordinated way, with caregivers carving out interaction units and shaping actions into action arcs and infants actively participating and co-ordinating their attention between mother and object from the beginning. We also (2) sketch a developmental trajectory of book sharing over the first year and show that the quality and dynamics of book sharing interactions underwent considerable change as the ecological situation was transformed in parallel with the infants' development of attention and motor skills. Social book sharing interactions reached an early peak at 6 months with the infants becoming more active in the coordination of attention between caregiver and book. From 7 to 9 months, the infants shifted their interest largely to solitary object exploration, in parallel with newly emerging postural and object manipulation skills, disrupting the social coordination and the cultural frame of book sharing. In the period from 9 to 12 months, social book interactions resurfaced, as infants began to effectively integrate manual object actions within the socially shared activity. In conclusion, to fully understand the development and qualities of triadic cultural activities such as book sharing, we need to look especially at the hitherto overlooked early period from 4 to 6 months, and investigate how shared spaces of meaning and action are structured together in and through interaction, creating the substrate for continuing cooperation and cultural learning. PMID:25540629

  12. Effect of photoperiod on developmental fitness in Ophraella communa (Coleoptera: Chrysomelidae).

    PubMed

    Zhou, Zhong-Shi; Luo, Min; Guo, Jian-Ying; Chen, Hong-Song; Wan, Fang-Hao

    2014-10-01

    Ophraella communa LeSage (Coleoptera: Chrysomelidae) is an important biological control agent of the common ragweed, Ambrosia artemisiifolia L., in China. Development and fecundity of O. communa, and hatch rate of progeny eggs were studied at five photoperiods (8:16, 10:14, 12:12, 14:10, and 16:8 [L:D] h). The highest survival rate of eggs was 92% at the photoperiod of 16:8 (L:D) h, and those of both larvae and pupae were observed at the photoperiod of 14:10 (L:D) h (85 and 96%). The shortest developmental durations of larvae and pupae were observed at photoperiods of 14:10 and 16:8 (L:D) h. Fecundity was 1,159-1,976 eggs per female from photoperiods of 8:16 to 16:8 (L:D) h. The hatch rates of progeny eggs were 67-92% from photoperiods of 8:16 to 16:8 (L:D) h, and photoperiods did not affect developmental duration of progeny eggs. The intrinsic rate for increase (r), the net reproductive rate (r0), and the finite rate of increase (λ) reached the maximum values at 16:8 (L:D) h (0.2219 d(-1), 721 hatched eggs and 1.2484 d(-1), respectively) and 14:10 (L:D) h (0.2133 d(-1), 605.6 hatched eggs and 1.2378 d(-1), respectively). Their minimum values were observed at the photoperiod of 8:16 (L:D) h, which were 0.1731 d(-1), 212.2 hatched eggs and 0.1890 d(-1), respectively. The shortest T value was 29.7 d at a photoperiod of 16:8 (L:D) h and the longest was 31.4 d at a photoperiod of 12:12 (L:D) h. Our study shows that O. communa could survive and reproduce successfully at different photoperiods, thus may expand its distribution to regions with different photoperiods. PMID:25203359

  13. Climate change-driven species' range shifts filtered by photoperiodism

    NASA Astrophysics Data System (ADS)

    Saikkonen, Kari; Taulavuori, Kari; Hyvönen, Terho; Gundel, Pedro E.; Hamilton, Cyd E.; Vänninen, Irene; Nissinen, Anne; Helander, Marjo

    2012-04-01

    Forecasts of species range shifts as a result of climate change are essential, because invasions by exotic species shape biodiversity and therefore ecosystem functions and services. Ecologists have focused on propagule pressure (for example, the number of individuals and invasion events), the characteristics of an invading species, and its new abiotic and biotic environment to predict the likelihood of range expansion and invasion. Here, we emphasize the role of photoperiodic response on the range expansion of species. Unlike temperature, the latitudinal gradient of seasonal changes in day length is a stable, abiotic environmental factor that does not change with local or global climate. Predicting range expansions across latitudes and the subsequent consequences for native communities requires a more comprehensive understanding of how species use day length to coordinate seasonal growth, reproduction, physiology and synchronization of life cycles with interacting individuals and species.

  14. Critical appraisal of 3-monthly paliperidone depot injections in the treatment of schizophrenia

    PubMed Central

    Carpiniello, Bernardo; Pinna, Federica

    2016-01-01

    Aims Three-monthly injections of paliperidone palmitate (PP-3M) represent a new and recently introduced long-acting antipsychotic therapeutic option. This review focuses on available data relating to the efficacy and safety of PP-3M and its position in the current therapeutic scenario. Method An analysis of PubMed, Scopus, and ISI Web of Knowledge databases was conducted, and all available papers on PP-3M, including poster presentations, were selected and considered for the purpose of the present review. Findings: to date, three full papers have been published, the first, a Phase 1 randomized, open label study investigating the pharmacokinetics, safety, and tolerability of the drug; the second, a Phase 3 double blind study vs placebo focusing on efficacy and tolerability; and the last relating to the practical use of PP-3M. The five posters identified describe data reported in the above-cited papers. Overall, the pharmacokinetic findings obtained in these studies highlight the feasibility of administering PP-3M on a 3-monthly basis, subsequent to the administration of four 1-monthly injections of PP at doses 3.5 times higher than the stabilized dose of 1-monthly injections of PP (ie, 175, 300, 450, and 525 mgs). The published studies highlight a significantly longer time to relapse compared to placebo, and significantly better results compared to placebo for all secondary end-points (Positive and Negative Syndrome Scale, Clinical Global Impression-Severity Scale, Personal and Social Performance Scale scores), in addition to reasonably good safety and tolerability profiles. Conclusion PP-3M emerges as a potential candidate for use as a first-line long-acting agent in the maintenance treatment of patients with schizophrenia. Further studies should however be conducted to confirm this expectation. In view of its efficacy, tolerability, and safety, together with the longer timespan between injections, PP-3M currently represents one of the best available options, and

  15. Photoperiod alters metabolic gene expression in bovine liver potentially through suppressors of cytokine signaling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research has demonstrated effects of day length (photoperiod) on multiple physiological processes in cattle including reproduction, lactation, immune function, growth and carcass composition. Many of these effects are mediated by changes in prolactin (PRL) and PRL signaling. Recent research...

  16. Photoperiodic inhibition of testicular development is mediated by the pineal gland in white-footed mice

    SciTech Connect

    Johnston, P.G.; Boshes, M.; Zucker, I.

    1982-05-01

    White-footed mice were maintained in short or long photoperiods from birth to 60 days of age (10 h vs. 14 h of light per day). Testes weights and spermatogenesis were substantially reduced in short daylengths. Pinealectomy at 5-7 days of age eliminated the suppressive effect of photoperiod on the reproductive system. However, testicular development was not retarded in intact males kept from 25 to 60 days of age in short daylengths. Exposure to short daylengths prior to 25 days of age contributes to photoperiodic inhibition of testicular development. Removal of the pineal gland did not consistently affect gonadal maturation in long photoperiods. The pineal gland transduces the effects of short daylengths on reproductive development. Some effects of long daylengths on the neuroendocrine axis of white-footed mice may also be mediated by the pineal gland.

  17. Photoperiodic inhibition of testicular development is mediated by the pineal gland in white-footed mice.

    PubMed

    Johnston, P G; Boshes, M; Zucker, I

    1982-05-01

    White-footed mice were maintained in short or long photoperiods from birth to 60 days of age (10 h vs. 14 h of light per day). Testes weights and spermatogenesis were substantially reduced in short daylengths. Pinealectomy at 5-7 days of age eliminated the suppressive effect of photoperiod on the reproductive system. However, testicular development was not retarded in intact males kept from 25 to 60 days of age in short daylengths. Exposure to short daylengths prior to 25 days of age contributes to photoperiodic inhibition of testicular development. Removal of the pineal gland did not consistently affect gonadal maturation in long photoperiods. The pineal gland transduces the effects of short daylengths on reproductive development. Some effects of long daylengths on the neuroendocrine axis of white-footed mice may also be mediated by the pineal gland. PMID:7200810

  18. Pineal 5-methoxytryptophol rhythms in the box turtle: effect of photoperiod and environmental temperature.

    PubMed

    Skene, D J; Vivien-Roels, B; Pevet, P

    1989-03-13

    The effect of different photoperiods and temperatures on pineal 5-methoxytryptophol (ML) content was investigated in male box turtles, Terrapene carolina triunguis. A rhythm in pineal ML was evident in the long photoperiod (18 h light (L)-6 h dark (D] with high daytime levels of 178 +/- 48 pg/gland (means +/- S.E.M.) which dropped to 38 +/- 6 pg/gland during lights off. In the short photoperiod (8L:16D) no clearcut ML rhythm was observed. Diurnal (10.00-12.00 h) ML concentrations rose linearly (P less than 0.05) with increasing ambient temperatures (5, 15, 20 and 27 degrees C). Day/night differences in ML levels, however, were not significant. Pineal ML in the box turtle thus seems to be modified by the photoperiod and, to a lesser extent, by temperature. PMID:2710400

  19. PHYTOCHROME C is an essential light receptor for photoperiodic flowering in the temperate grass, Brachypodium distachyon.

    PubMed

    Woods, Daniel P; Ream, Thomas S; Minevich, Gregory; Hobert, Oliver; Amasino, Richard M

    2014-09-01

    We show that in the temperate grass, Brachypodium distachyon, PHYTOCHROME C (PHYC), is necessary for photoperiodic flowering. In loss-of-function phyC mutants, flowering is extremely delayed in inductive photoperiods. PHYC was identified as the causative locus by utilizing a mapping by sequencing pipeline (Cloudmap) optimized for identification of induced mutations in Brachypodium. In phyC mutants the expression of Brachypodium homologs of key flowering time genes in the photoperiod pathway such as GIGANTEA (GI), PHOTOPERIOD 1 (PPD1/PRR37), CONSTANS (CO), and florigen/FT are greatly attenuated. PHYC also controls the day-length dependence of leaf size as the effect of day length on leaf size is abolished in phyC mutants. The control of genes upstream of florigen production by PHYC was likely to have been a key feature of the evolution of a long-day flowering response in temperate pooid grasses. PMID:25023399

  20. Seasonal control of odour preferences of meadow voles (Microtus pennsylvanicus) by photoperiod and ovarian hormones.

    PubMed

    Ferkin, M H; Zucker, I

    1991-07-01

    During the spring-summer breeding season, female meadow voles prefer odours of males over those of females, but in the autumn-winter season of reproductive quiescence this preference is reversed. Females housed in long (14 h light/day) and short (10 h light/day) photoperiods, respectively, had odour preferences comparable to those of spring and autumn voles, respectively. The preference of long-photoperiod voles for male over female odours was reversed by ovariectomy and restored by treatment with oestradiol. By contrast, neither ovariectomy nor oestradiol affected odour preferences of short-photoperiod voles. Long days appear to influence olfactory preferences by altering ovarian hormone secretion. The failure of oestradiol to affect odour preferences in short photoperiods suggests that the neural substrates mediating this behavioural response are refractory to oestrogens during the nonbreeding season. PMID:1886099

  1. Exogenous Melatonin Administration Affects Self-grooming and Conspecific Odor Preferences in Long-Photoperiod Meadow Voles (Microtus pennsylvanicus)

    PubMed Central

    Ferkin, Michael H.; Leonard, Stuart T.; Gilless, Jerry P.

    2007-01-01

    For meadow voles, Microtus pennsylvanicus, seasonal differences exist in self-grooming and in odor preferences for conspecifics, two behaviors which facilitate sexual interactions in this species. Both behaviors are mediated by photoperiodically-induced changes in circulating gonadal steroid hormone titers which, in turn, can be transduced by the duration of the melatonin signal that a seasonally breeding animal receives. The goal of this study was to determine whether exogenous melatonin administration affects circulating gonadal steroid hormone titers in meadow voles, and whether it influences their odor preferences and self-grooming behavior to same-and opposite-sex conspecifics. Long-photoperiod voles that did not receive exogenous melatonin had higher testosterone (males) and estradiol (females) titers than did short-photoperiod voles and long-photoperiod voles treated with melatonin for 12 weeks; the latter had similar estradiol and testosterone titers. Long-photoperiod voles that did not receive melatonin preferred the scent marks of long-photoperiod opposite-sex conspecifics and spent more time self-grooming in response to their odors than those of either long-photoperiod same-sex, short photoperiod same-sex, or short-photoperiod opposite-sex conspecifics. Long-photoperiod voles that received melatonin, however, no longer preferred the marks of long-photoperiod opposite-sex conspecifics and no longer spent more time self-grooming in response to their odors, not unlike the odor preferences and self-grooming behavior of short-photoperiod voles. As a whole, the data suggest that the duration of the melatonin signal is likely involved in mediating the photoperiodically-induced changes in gonadal steroid hormones that mediate a meadow vole’s odor preferences for opposite-sex conspecifics and its self-grooming response to those marks. PMID:17449071

  2. Photoperiodism and crassulacean acid metabolism : I. Immunological and kinetic evidences for different patterns of phosphoenolpyruvate carboxylase isoforms in photoperiodically inducible and non-inducible Crassulacean acid metabolism plants.

    PubMed

    Brulfert, J; Müller, D; Kluge, M; Queiroz, O

    1982-05-01

    Plants of Kalanchoe blossfeldiana v. Poelln. Tom Thumb and Sedum morganianum E. Walth. were grown under controlled photoperiodic conditions under either short or long days. Gaz exchange measurements confirmed that in K. blossfeldiana Crassulacean acid metabolism (CAM) was photoperiodically inducible and that S. morganianum performed CAM independently of photoperiod. With K. blossfeldiana, a comparison of catalytic and regulatory properties of phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) from short-day and long-day grown plants showed differences, but not with S. morganianum. Ouchterlony double diffusion tests and immunotitration experiments (using a S. morganianum PEPC antibody) established that CAM is induced in K. blossfeldiana-but not in S. morganianum-through the synthesis of a new PEPC isoform; this form shows an immunological behavior different from that prevailing under non-inductive conditions and can be considered as specific for CAM performance. PMID:24276159

  3. Effects of photoperiod on wheat growth, development and yield in CELSS

    NASA Astrophysics Data System (ADS)

    Yunze, Shen; Shuangsheng, Guo

    2014-12-01

    A Controlled Ecological Life Support System (CELSS) is a sealed system used in spaceflight in order to provide astronauts with food and O2 by plants. It is of great significance to increase the energy-using efficiency because energy is extremely deficient in the space. Therefore, the objective of this research was to increase the energy-using efficiency of wheat by regulating the photoperiod. Sixteen treatments were set in total: four photoperiods before flowering (PBF) combined with four photoperiods after flowering (PAF) of 12 h, 16 h, 20 h and 24 h. The light source was red-blue LED (90% red+10% blue). As a result, the growth period of wheat was largely extended by shorter PBF, particularly the number of days from tillering to jointing and from jointing to heading. The period from flowering to maturity was extended by shorter PAF. Shorter PBF and longer PAF could increase not only the yield but also the energy-using efficiency of wheat. As for the nutritional quality, longer photoperiod (both PBF and PAF) increased starch concentration as well as decreased protein concentration of seeds. The effects of PBF and PAF were interactional. The lighting strategy with PBF of 12 h and PAF of 24 h was proved to be the optimum photoperiod for wheat cultivation in CELSS. The mechanisms of photoperiod effect contain two aspects. Firstly, photoperiod is a signal for many processes in plant growth, particularly the process of ear differentiation. Shorter PBF promoted the ear differentiation of wheat, increasing the spikelet number, floret number and seed number and thus enhancing the yield. Secondly, longer photoperiod leads to more light energy input and longer time of photosynthesis, so that longer PAF provided more photosynthate and increased seed yield.

  4. Responses of alloplasmic (cytoplasm=Triticum timopheevii) and euplasmic wheats (Triticum aestivum) to photoperiod and vernalization.

    PubMed

    Ward, R W; Heyne, E G; Paulsen, G M

    1983-07-01

    Studies were conducted to determine the influence of the male sterility-inducing cytoplasm of Triticum timopheevii (Zhuk.) Zhuk. on response of several common winter wheat (T. aestivum L.) nuclear genotypes to photoperiod and vernalization. Comparative studies of cytoplasmic substitution lines provide information on the role of the cytoplasmic genetic mechanism in growth and development. In the case of cytoplasmic male sterility-based hybrid production systems, ubiquity of sterility-inducing cytoplasm in derived hybrids warrants thorough characterization of its influence on plant phenotype. Factorial combinations of cytoplasm (T. timopheevii and T. aestivum), nuclear genotype, and photoperiod or vernalization treatments were evaluated under hydroponic conditions in controlled environment chambers. Interaction of cytoplasm, photoperiod, and nuclear genotype was significant in one or more experiments for days to anthesis and potential spikelet number, and interaction of cytoplasm, vernalization, and nuclear genotype was significant for days to spike emergence. Long day length was associated with increased percentage seed set in one study, but interactions of photoperiod and cytoplasm were not detected for percentage seed set. Interactions involving cytoplasm and photoperiod or vernalization were interpreted as evidence of the existence of genetic factors in cytoplsam of T. timopheevii which alter photoperiod or vernalization responses of alloplasmic plants relative to responses exhibited by euplasmic plants. Since photoperiod and vernalization responses are critical to adaptation, T. timopheevii cytoplasm can alter adaptability of T. aestivum. The specific effect would be nuclear genotype dependent, and does not appear to be of a magnitude greater than that induced by nuclear genetic variability at loci conditioning photoperiod or vernalization responses or other adaptation-determining characteristics. Normal multilocation/year testing of alloplasmic hybrids should

  5. Genetics of Heading Time in Wheat (TRITICUM AESTIVUM L.). I. the Inheritance of Photoperiodic Response.

    PubMed

    Klaimi, Y Y; Qualset, C O

    1973-05-01

    The inheritance of photoperiodic response was studied in crosses involving four spring wheats (Sonora 64, Pitic 62, Justin and Thatcher) and three winter wheats (Blackhull, Early Blackhull and Extra Early Blackhull). The parental cultivars were classified into a photoperiod-sensitive group (Justin, Thatcher, Blackhull and Early Blackhull) and a relatively photoperiod-insensitive group (Sonora 64, Pitic 62 and Extra Early Blackhull) based on their heading response when vernalized and grown under different daylength regimes.-F(1) data indicated that daylength insensitivity is not always dominant over day-length sensitivity and that the dominance relationship with respect to photoperiodic response depends on the alleles present in the parents. The heading patterns after vernalization and growth under short days of F(1), F(2), F(3) and backcross generations of a 4-parent diallel cross involving Justin, Sonora 64, Extra Early Blackhull and Blackhull could be satisfactorily explained on the basis of two major loci with three alleles at each locus. The genotype for each parent was suggested in terms of these loci. Genes with minor effects also influenced the photoperiodic response in a quantitative manner.-Diallel cross analysis of the number of days to heading (log scale) indicated significant additive and dominance genetic variances, a high average degree of dominance for earliness (photoperiod insensitivity) and a preponderance of recessive alleles in the parents acting in the direction of lateness (photoperiod sensitivity). Estimation of the genetic components of variation contained in the generation means of individual crosses (untransformed data) showed that, besides additivity and dominance, epistasis was also an important factor in the genetic control of photoperiodic response in wheat. PMID:17248607

  6. DNA methylation changes induced by long and short photoperiods in Nasonia.

    PubMed

    Pegoraro, Mirko; Bafna, Akanksha; Davies, Nathaniel J; Shuker, David M; Tauber, Eran

    2016-02-01

    Many organisms monitor the annual change in day length and use this information for the timing of their seasonal response. However, the molecular mechanisms underlying photoperiodic timing are largely unknown. The wasp Nasonia vitripennis is an emerging model organism that exhibits a strong photoperiodic response: Short autumnal days experienced by females lead to the induction of developmental arrest (diapause) in their progeny, allowing winter survival of the larvae. How female Nasonia control the developmental trajectory of their offspring is unclear. Here, we took advantage of the recent discovery that DNA methylation is pervasive in Nasonia and tested its role in photoperiodism. We used reduced representation bisulfite sequencing (RRBS) to profile DNA methylation in adult female wasps subjected to different photoperiods and identified substantial differential methylation at the single base level. We also show that knocking down DNA methyltransferase 1a (Dnmt1a), Dnmt3, or blocking DNA methylation pharmacologically, largely disrupts the photoperiodic diapause response of the wasps. To our knowledge, this is the first example for a role of DNA methylation in insect photoperiodic timing. PMID:26672019

  7. DNA methylation changes induced by long and short photoperiods in Nasonia

    PubMed Central

    Pegoraro, Mirko; Bafna, Akanksha; Davies, Nathaniel J.; Shuker, David M.; Tauber, Eran

    2016-01-01

    Many organisms monitor the annual change in day length and use this information for the timing of their seasonal response. However, the molecular mechanisms underlying photoperiodic timing are largely unknown. The wasp Nasonia vitripennis is an emerging model organism that exhibits a strong photoperiodic response: Short autumnal days experienced by females lead to the induction of developmental arrest (diapause) in their progeny, allowing winter survival of the larvae. How female Nasonia control the developmental trajectory of their offspring is unclear. Here, we took advantage of the recent discovery that DNA methylation is pervasive in Nasonia and tested its role in photoperiodism. We used reduced representation bisulfite sequencing (RRBS) to profile DNA methylation in adult female wasps subjected to different photoperiods and identified substantial differential methylation at the single base level. We also show that knocking down DNA methyltransferase 1a (Dnmt1a), Dnmt3, or blocking DNA methylation pharmacologically, largely disrupts the photoperiodic diapause response of the wasps. To our knowledge, this is the first example for a role of DNA methylation in insect photoperiodic timing. PMID:26672019

  8. Coordination of Plastid and Light Signaling Pathways upon Development of Arabidopsis Leaves under Various Photoperiods

    PubMed Central

    Lepistö, Anna; Rintamäki, Eevi

    2012-01-01

    Plants synchronize their cellular and physiological functions according to the photoperiod (the length of the light period) in the cycle of 24 h. Photoperiod adjusts several traits in the plant life cycle, including flowering and senescence in annuals and seasonal growth cessation in perennials. Photoperiodic development is controlled by the coordinated action of photoreceptors and the circadian clock. During the past 10 years, remarkable progress has been made in understanding the molecular mechanism of the circadian clock, especially with regard to the transition of Arabidopsis from the vegetative growth to the reproductive phase. Besides flowering photoperiod also modifies plant photosynthetic structures and traits. Light signals controlling biogenesis of chloroplasts and development of leaf photosynthetic structures are perceived both by photoreceptors and in chloroplasts. In this review, we provide evidence suggesting that the photoperiodic development of Arabidopsis leaves mimics the acclimation of plant to various light intensities. Furthermore, the chloroplast-to-nucleus retrograde signals that adjust acclimation to light intensity are proposed to contribute also to the signaling pathways that control photoperiodic acclimation of leaves. PMID:22199239

  9. Genome wide transcriptional profiling of acclimation to photoperiod in high-latitude accessions of Arabidopsis thaliana.

    PubMed

    Lewandowska-Sabat, Anna Monika; Winge, Per; Fjellheim, Siri; Dørum, Guro; Bones, Atle Magnar; Rognli, Odd Arne

    2012-04-01

    Three Arabidopsis thaliana accessions originating from the northernmost boundary of the species distribution in Norway (59-68°N) were used to study global wide transcriptional responses to 16 and 24 h photoperiods during flower initiation. Significant analysis of microarrays (SAM), analyses of statistically overrepresented gene ontologies (GOstat) and gene set enrichment analyses (GSEA) were used to identify candidate genes and genetic pathways underlying phenotypic adaptations of accessions to different photoperiods. Statistical analyses identified 732 and 258 differentially expressed genes between accessions in 16 and 24 h photoperiod, respectively. Among significantly expressed genes, ethylene mediated signaling pathway was significantly overrepresented in 16 h photoperiod, while genes involved in response to auxin stimulus were found to be significantly overrepresented in 24 h photoperiod. Several gene sets were found to be differentially expressed among accessions, e.g. cold acclimation, dehydration response, phytochrome signaling, vernalization response and circadian clock regulated flowering time genes. These results revealed several candidate genes and pathways likely involved in transcriptional control of photoperiodic response. In particular, ethylene and auxin signaling pathway may represent candidate genes contributing to local adaptation of high-latitude accessions of A. thaliana. PMID:22325875

  10. Deep-brain photoreceptors (DBPs) involved in the photoperiodic gonadal response in an avian species, Gallus gallus.

    PubMed

    Kang, Seong W; Kuenzel, Wayne J

    2015-01-15

    Three primitive photoreceptors [melanopsin (Opn4), neuropsin/opsin5 (Opn5) and vertebrate ancient opsin (VAOpn)] were reported as possible avian deep-brain photoreceptors (DBPs) involved in the perception of photoperiodic information affecting the onset and development of reproduction. The objective of this study was to determine the effect of long-day photostimulation and/or sulfamethazine treatment (SMZ, a compound known to advance light-induced testes development) on gene expression of DBPs and key hypothalamic and pituitary genes involved in avian reproductive function. Two-week old chicks were randomly selected into four experimental groups: short-day control (SC, LD8:16), short-day+SMZ (SS, LD8:16, 0.2% diet SMZ), long-day control (LC, LD16:8), and long-day+SMZ (LS, LD16:8, 0.2% diet SMZ). Birds were sampled on days 3, 7, and 28 after initiation of a long-day photoperiod and/or SMZ dietary treatments. Three brain regions [septal-preoptic, anterior hypothalamic (SepPre/Ant-Hypo) region, mid-hypothalamic (Mid-Hypo) region, posterior-hypothalamic (Post-Hypo) region], and anterior pituitary gland were dissected. Using quantitative real-time RT-PCR, we determined changes of expression levels of genes in distinct brain regions; Opn4 and Opn5 in SepPre/Ant-Hypo and Post-Hypo regions and, VAOpn in the Mid-Hypo region. Long-day treatment resulted in a significantly elevated testes weight on days 7 and 28 compared to controls, and SMZ augmented testes weight in both short- and long-day treatment after day 7 (P<0.05). Long-day photoperiodic treatment on the third day unexpectedly induced a large 8.4-fold increase of VAOpn expression in the Mid-Hypo region, a 15.4-fold increase of Opn4 and a 97.8-fold increase of Opn5 gene expression in the Post-Hypo region compared to SC birds (P<0.01). In contrast, on days 7 and 28, gene expression of the three DBPs was barely detectable. LC group showed a significant increase in GnRH-1 and TRH mRNA in the Mid-Hypo compared to SC on

  11. Inhibitory effect of increased photoperiod on wool follicle growth.

    PubMed

    Pearson, A J; Parry, A L; Ashby, M G; Choy, V J; Wildermoth, J E; Craven, A J

    1996-01-01

    The relationships between circulating prolactin (PRL), wool follicle growth and daylength were investigated in 24 New Zealand Wiltshire ewes housed indoors from September 1989 to May 1991. Twelve control (C) ewes were maintained under natural photoperiod. Two other groups were held in short days (SD; 8 h light: 16 h darkness) commencing from the winter solstice (22 June 1990) for either three (group SD3, n = 7) or six (group SD6, n = 5) months before reversion to natural daylength. Skin was sampled at one- to four-week intervals for histological determination of percentages of growing primary and secondary follicles. Hourly blood samples over 24 h were collected via jugular cannulae from C sheep in March and July and then monthly from all animals until December 1990 for estimation of mean monthly PRL concentrations for each treatment group. Between autumn (March 1990) and winter (July) primary follicle activity (PFA) and secondary follicle activity (SFA) declined in C ewes (PFA: 97 to 43%, SFA: 100 to 57%). Follicle regrowth during July and August in eight C ewes preceded the initial rise in plasma PRL from the winter minimum (1.6 ng/ml). Across the three groups, four instances of decreased follicle activity were observed, closely following or concurrent with increases in plasma PRL concentrations. The resumption of spring growth in four C sheep was temporarily checked by falls in follicle activities during September and October as PRL concentrations began to increase (3.4 to 8.9 ng/ml). Follicle activity also declined in November and December in eight C sheep, coincident with the rapid rise in PRL to a seasonal maximum in late November (165.4 ng/ml). The increase in SD3 follicle activity over spring was not delayed by short days but during October, after release from treatment, PRL concentrations rose (1.8 to 12.0 ng/ml) and follicle activity declined (PFA: 65 to 38%, SFA: 68 to 43%). In SD6 ewes, PRL concentrations were suppressed (2.1 ng/ml) and relatively

  12. Externally Contingent and Unstable Self-Worth as Predictors of Depression in College Women: A 3-Month Study

    ERIC Educational Resources Information Center

    Lopez, Frederick G.; Thorne, Brittany; Schoenecker, Sydney; Siffert, Kevin; Chaliman, Rebecca; Castleberry, Erica

    2014-01-01

    Undergraduate women completed measures of externally contingent self-worth, self-esteem instability, and depression at the beginning (Time 1) and again 3 months later near the end (Time 2) of an academic semester. Findings indicated that when Time 1 depression scores were controlled for, each Time 1 facet of self-esteem made significant…

  13. Positive, but Not Negative, Facial Expressions Facilitate 3-Month-Olds' Recognition of an Individual Face

    ERIC Educational Resources Information Center

    Brenna, Viola; Proietti, Valentina; Montirosso, Rosario; Turati, Chiara

    2013-01-01

    The current study examined whether and how the presence of a positive or a negative emotional expression may affect the face recognition process at 3 months of age. Using a familiarization procedure, Experiment 1 demonstrated that positive (i.e., happiness), but not negative (i.e., fear and anger) facial expressions facilitate infants'…

  14. Recognition of Faces and Greebles in 3-Month-Old Infants: Influence of Temperament and Cognitive Abilities

    ERIC Educational Resources Information Center

    Spangler, Sibylle M.; Freitag, Claudia; Schwarzer, Gudrun; Vierhaus, Marc; Teubert, Manuel; Lamm, Bettina; Kolling, Thorsten; Graf, Frauke; Goertz, Claudia; Fassbender, Ina; Lohaus, Arnold; Knopf, Monika; Keller, Heidi

    2011-01-01

    The aim of the present study was to investigate whether temperament and cognitive abilities are related to recognition performance of Caucasian and African faces and of a nonfacial stimulus class, Greebles. Seventy Caucasian infants were tested at 3 months with a habituation/dishabituation paradigm and their temperament and cognitive abilities…

  15. Infants' Vocal Engagement Oriented towards Mother versus Stranger at 3 Months and Avoidant Attachment Behavior at 12 Months

    ERIC Educational Resources Information Center

    Volker, Susanne

    2007-01-01

    The aim of the present study was to demonstrate that mother avoidance in infants at the age of 12 months can be predicted by the infants' differential vocal engagement to mother versus a female stranger at the age of 3 months. Differential engagement in favor of the mother was supposed to relate to low future avoidance. The vocal behavior of 26…

  16. Complete sternal cleft - A rare congenital malformation and its repair in a 3-month-old boy: A case report.

    PubMed

    Kothari, Paras; Gupta, Abhaya; Patil, Prashant S; Kekre, Geeta; Kamble, Ravi; Dikshit, Kiran Vishesh

    2016-01-01

    Complete midline sternal cleft is a rare congenital anomaly resulting from failed midline ventral fusion of the sternal bars. Very few cases of complete sternal cleft have been described in literature. We present a case of complete sternal cleft in a 3-month-old child. The patient underwent primary closure of the defect using stainless steel wires. PMID:27046980

  17. Holistic Face Processing in Newborns, 3-Month-Old Infants, and Adults: Evidence from the Composite Face Effect

    ERIC Educational Resources Information Center

    Turati, Chiara; Di Giorgio, Elisa; Bardi, Lara; Simion, Francesca

    2010-01-01

    Holistic face processing was investigated in newborns, 3-month-old infants, and adults through a modified version of the composite face paradigm and the recording of eye movements. After familiarization to the top portion of a face, participants (N = 70) were shown 2 aligned or misaligned faces, 1 of which comprised the familiar top part. In the…

  18. CORTICAL EVENT-RELATED POTENTIALS TO SPEECH SOUNDS IN 3- MONTH OLD BREAST AND FORMULA-FED INFANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies showing that infants can differentially process and discriminate speech stimuli have not considered the influence of diet as an experimental variable. To investigate this relationship, cortical auditory evoked potentials (ERPs) to syllables were recorded (128 electrodes) from 3 month old inf...

  19. Rapidly alternating photoperiods disrupt central and peripheral rhythmicity and decrease plasma glucose, but do not affect glucose tolerance or insulin secretion in sheep.

    PubMed

    Varcoe, Tamara J; Gatford, Kathryn L; Voultsios, Athena; Salkeld, Mark D; Boden, Michael J; Rattanatray, Leewen; Kennaway, David J

    2014-09-01

    Disrupting circadian rhythms in rodents perturbs glucose metabolism and increases adiposity. To determine whether these effects occur in a large diurnal animal, we assessed the impact of circadian rhythm disruption upon metabolic function in sheep. Adult ewes (n = 7) underwent 3 weeks of a control 12 h light-12 h dark photoperiod, followed by 4 weeks of rapidly alternating photoperiods (RAPs) whereby the time of light exposure was reversed twice each week. Measures of central (melatonin secretion and core body temperature) and peripheral rhythmicity (clock and metabolic gene expression in skeletal muscle) were obtained over 24 h in both conditions. Metabolic homeostasis was assessed by glucose tolerance tests and 24 h glucose and insulin profiles. Melatonin and core body temperature rhythms resynchronized within 2 days of the last photoperiod shift. High-amplitude Bmal1, Clock, Nr1d1, Cry2 and Per3 mRNA rhythms were apparent in skeletal muscle, which were phase advanced by up to 3.5 h at 2 days after the last phase shift, whereas Per1 expression was downregulated at this time. Pparα, Pgc1α and Nampt mRNA were constitutively expressed in both conditions. Nocturnal glucose concentrations were reduced following chronic phase shifts (zeitgeber time 0, -5.5%; zeitgeber time 12, -2.9%; and zeitgeber time 16, -5.7%), whereas plasma insulin, glucose tolerance and glucose-stimulated insulin secretion were not altered. These results demonstrate that clock gene expression within ovine skeletal muscle oscillates over 24 h and responds to changing photoperiods. However, metabolic genes which link circadian and metabolic clocks in rodents were arrhythmic in sheep. Differences may be due to the ruminant versus monogastric digestive organization in each species. Together, these results demonstrate that despite disruptions to central and peripheral rhythmicity following exposure to rapidly alternating photoperiods, there was minimal impact on glucose homeostasis in

  20. Scintigraphy at 3 months after single lung transplantation and observations of primary graft dysfunction and lung function.

    PubMed

    Belmaati, Esther Okeke; Iversen, Martin; Kofoed, Klaus F; Nielsen, Michael B; Mortensen, Jann

    2012-06-01

    Scintigraphy has been used as a tool to detect dysfunction of the lung before and after transplantation. The aims of this study were to evaluate the development of the ventilation-perfusion relationships in single lung transplant recipients in the first year, at 3 months after transplantation, and to investigate whether scintigraphic findings at 3 months were predictive for the outcome at 12 months in relation to primary graft dysfunction (PGD) and lung function. A retrospective study was carried out on all patients who prospectively and consecutively were referred for a routine lung scintigraphy procedure 3 months after single lung transplantation (SLTX). A total of 41 patients were included in the study: 20 women and 21 men with the age span of patients at transplantation being 38-66 years (mean ± SD: 54.2 ± 6.0). Patient records also included lung function tests and chest X-ray images. We found no significant correlation between lung function distribution at 3 months and PGD at 72 h. There was also no significant correlation between PGD scores at 72 h and lung function at 6 and 12 months. The same applied to scintigraphic scores for heterogeneity at 3 months compared with lung function at 6 and 12 months. Fifty-five percent of all patients had decreased ventilation function measured in the period from 6 to 12 months. Forty-nine percent of the patients had normal perfusion evaluations, and 51% had abnormal perfusion evaluations at 3 months. For ventilation evaluations, 72% were normal and 28% were abnormal. There was a significant difference in the normal versus abnormal perfusion and ventilation scintigraphic images evaluated from the same patients. Ventilation was distributed more homogenously in the transplanted lung than perfusion in the same lung. The relative distribution of perfusion and ventilation to the transplanted lung of patients with and without a primary diagnosis of fibrosis did not differ significantly from each other. We conclude that PGD

  1. Extrinsic light:dark cycles, rather than endogenous circadian cycles, affect the photoperiodic counter in the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Emerson, Kevin J; Letaw, Alathea D; Bradshaw, William E; Holzapfel, Christina M

    2008-07-01

    A wide diversity of organisms use photoperiod (daylength) as an environmental cue to anticipate the changing seasons and to time various life-history events such as dormancy and migration. Photoperiodic time measurement consists of two main components, (1) the photoperiodic timer that discriminates between long and short days, and (2) the photoperiodic counter that accumulates and stores information from the timer and then induces the phenotypic output. Herein, we use extended night treatments to show that light is necessary to accumulate photoperiodic information across the geographic range of the mosquito, Wyeomyia smithii and that the photoperiodic counter counts extrinsic (external) light:dark cycles and not endogenous (internal) circadian cycles. PMID:18427810

  2. Extrinsic light:dark cycles, rather than endogenous circadian cycles, affect the photoperiodic counter in the pitcher-plant mosquito, Wyeomyia smithii

    PubMed Central

    Emerson, Kevin J.; Letaw, Alathea D.; Bradshaw, William E.; Holzapfel, Christina M.

    2014-01-01

    A wide diversity of organisms use photoperiod (daylength) as an environmental cue to anticipate the changing seasons and to time various life-history events such as dormancy and migration. Photoperiodic time measurement consists of two main components, (1) the photoperiodic timer that discriminates between long and short days, and (2) the photoperiodic counter that accumulates and stores information from the timer and then induces the phenotypic output. Herein, we use extended night treatments to show that light is necessary to accumulate photoperiodic information across the geographic range of the mosquito, Wyeomyia smithii and that the photoperiodic counter counts extrinsic (external) light:dark cycles and not endogenous (internal) circadian cycles. PMID:18427810

  3. Photoperiodic and circadian bifurcation theories of depression and mania.

    PubMed

    Kripke, Daniel F; Elliott, Jeffrey A; Welsh, David K; Youngstedt, Shawn D

    2015-01-01

    Seasonal effects on mood have been observed throughout much of human history.  Seasonal changes in animals and plants are largely mediated through the changing photoperiod (i.e., the photophase or duration of daylight).  We review that in mammals, daylight specifically regulates SCN (suprachiasmatic nucleus) circadian organization and its control of melatonin secretion.  The timing of melatonin secretion interacts with gene transcription in the pituitary pars tuberalis to modulate production of TSH (thyrotropin), hypothalamic T3 (triiodothyronine), and tuberalin peptides which modulate pituitary production of regulatory gonadotropins and other hormones.  Pituitary hormones largely mediate seasonal physiologic and behavioral variations.  As a result of long winter nights or inadequate illumination, we propose that delayed morning offset of nocturnal melatonin secretion, suppressing pars tuberalis function, could be the main cause for winter depression and even cause depressions at other times of year.  Irregularities of circadian sleep timing and thyroid homeostasis contribute to depression.  Bright light and sleep restriction are antidepressant and conversely, sometimes trigger mania.  We propose that internal desynchronization or bifurcation of SCN circadian rhythms may underlie rapid-cycling manic-depressive disorders and perhaps most mania.  Much further research will be needed to add substance to these theories. PMID:26180634

  4. Photoperiodic and circadian bifurcation theories of depression and mania

    PubMed Central

    Kripke, Daniel F.; Elliott, Jeffrey A.; Welsh, David K.; Youngstedt, Shawn D.

    2015-01-01

    Seasonal effects on mood have been observed throughout much of human history.  Seasonal changes in animals and plants are largely mediated through the changing photoperiod (i.e., the photophase or duration of daylight).  We review that in mammals, daylight specifically regulates SCN (suprachiasmatic nucleus) circadian organization and its control of melatonin secretion.  The timing of melatonin secretion interacts with gene transcription in the pituitary pars tuberalis to modulate production of TSH (thyrotropin), hypothalamic T3 (triiodothyronine), and tuberalin peptides which modulate pituitary production of regulatory gonadotropins and other hormones.  Pituitary hormones largely mediate seasonal physiologic and behavioral variations.  As a result of long winter nights or inadequate illumination, we propose that delayed morning offset of nocturnal melatonin secretion, suppressing pars tuberalis function, could be the main cause for winter depression and even cause depressions at other times of year.  Irregularities of circadian sleep timing and thyroid homeostasis contribute to depression.  Bright light and sleep restriction are antidepressant and conversely, sometimes trigger mania.  We propose that internal desynchronization or bifurcation of SCN circadian rhythms may underlie rapid-cycling manic-depressive disorders and perhaps most mania.  Much further research will be needed to add substance to these theories. PMID:26180634

  5. Effect of photoperiod on gibberellin biosynthetic enzymes in spinach

    SciTech Connect

    Gilmour, S.J.; Bleecker, A.B.; Zeevaart, J.A.D.

    1986-04-01

    The photoperiodic control of stem elongation in spinach, a long day (LD) rosette plant, is mediated by gibberellins (GAs). The early 13-hydroxylated GA biosynthetic pathway from GA/sub 12/ to GA/sub 20/ operates in spinach: GA/sub 12/ ..-->.. GA/sub 53/ ..-->.. GA/sub 44/ ..-->.. GA/sub 19/ ..-->.. GA/sub 20/. Two enzymes of this pathway, those converting GA/sub 53/ to GA/sub 44/ (GA/sub 53/ oxidase) and GA/sub 19/ to GA/sub 20/ (GA/sub 19/ oxidase), are regulated by light. The enzyme converting GA/sub 44/ to GA/sub 19/ (GA/sub 44/ oxidase) is not light-regulated. In the light GA/sub 53/ and GA/sub 18/ oxidase activities are increased, therefore causing the GA biosynthetic pathway to be turned on. This leads to the production of an active GA in LD, which causes an increase in stem elongation. Two the enzymes, GA/sub 44/ and GA/sub 53/ oxidases, can be separated from one another by anion exchange HPLC. Estimates of the molecular weights of these two enzymes based on gel filtration HPLC will be reported.

  6. Effects of photoperiod on boll weevil (Coleoptera: Curculionidae) development, survival, and reproduction.

    PubMed

    Greenberg, S M; Sappington, T W; Adamczyk, J J; Liu, T-X; Setamou, M

    2008-12-01

    Effects of photoperiod on development, survival, feeding, and oviposition of boll weevils, Anthonomus grandis grandis Boheman, were assessed under five different photophases (24, 14, 12, 10, and 0 h) at a constant 27 degrees C temperature and 65% RH in the laboratory. Analyses of our results detected positive relationships between photoperiod and puncturing (mean numbers of oviposition and feeding punctures per day), and oviposition (oviposition punctures/oviposition+feeding punctures) activities, and the proportion of squares attacked by boll weevil females. When boll weevil females developed in light:darkness cycles, they produced a significantly higher percentage of eggs developing to adulthood than those developed in 24-h light or dark conditions. In long photoperiod (24:0 and 14:10 h), the number of female progeny was significantly higher and their development time was significantly shorter than those developed in short photoperiod (0:24 and 10:14 h). Lifetime oviposition was significantly highest at 12- and 14-h photophase, lowest at 0- and 10-h photophase, and intermediate at 24 h of light. Life table calculations indicated that boll weevil populations developed in a photoperiod of 14:10 and 12:12 (L:D) h will increase an average of two-fold each generation (Ro) compared with boll weevils developed in 24:0- and 10:14-h photoperiods and 15-fold compared with those at 0:24 h. Knowledge of the photoperiod-dependent population growth potential is critical for understanding population dynamics to better develop sampling protocols and timing insecticide applications. PMID:19161681

  7. Effect of reverse photoperiod on in vitro regeneration and piperine production in Piper nigrum L.

    PubMed

    Ahmad, Nisar; Abbasi, Bilal Haider; Fazal, Hina; Khan, Mubarak Ali; Afridi, Muhammad Siddique

    2014-01-01

    In this study, a novel approach for in vitro regeneration of Piper nigrum L. has been applied in order to increase healthy biomass, phytochemicals and piperine production via reverse photoperiod (16hD/8hL). Leaf portions of the seed-derived plants were placed on an MS-medium fortified with different PGRs. Under 16hD/8hL, thidiazuron (TDZ; 4.0 mg L⁻¹) and BA (1.5 mg L⁻¹) was found to be the most effective (<90%) in callus induction. Two concentrations (1.5, 2.0 mg L⁻¹) of the IBA produced>80% shoots from callus cultures. Healthy shoots were transferred to rooting medium and higher percentage of rooting (<90%) was observed on IBA (1.5 mg L⁻¹). These in vitro tissues were subjected to amino acid analysis, spectrophotometry, and HPLC. ARG, SER, THR, and TYR were the most abundant components out of 17 amino acids. Higher amino acid production was observed under normal photoperiod (16hL/8hD) than under reverse photoperiod (16hD/8hL). The highest total phenolic content (TPC; 9.91 mg/g-DW) and flavonoid content (7.38 mg/g-DW) were observed in callus cultures incubated under 16hL/8hD than other tissues incubated under 16hD/8hL photoperiod. Higher DPPH and PoMo activities were observed in tissues incubated under 16hL/8hD photoperiod, while ABTS and Fe²⁺ chelating activities were found higher in tissues incubated under reverse photoperiod. Significant quantities of piperine content were observed in all tissues except callus cultures. These results suggest that reverse photoperiod is a promising approach for callus induction, phytochemicals and piperine production for commercial applications. PMID:24439548

  8. Growth Pattern Responses to Photoperiod across Latitudes in a Northern Damselfly

    PubMed Central

    Śniegula, Szymon; Nilsson-Örtman, Viktor; Johansson, Frank

    2012-01-01

    Background Latitudinal clines in temperature and seasonality impose strong seasonal constraints on ectotherms. Studies of population differentiation in phenotypic plasticity of life history traits along latitudinal gradients are important for understanding how organisms have adapted to seasonal environments and predict how they respond to climate changes. Such studies have been scarce for species with a northern distribution. Methodology/Principle Finding Larvae of the northern damselfly Coenagrion johanssoni originating from semivoltine central, partivoltine northern, and partivoltine northernmost Swedish populations were reared in the laboratory. To investigate whether larvae use photoperiodic cues to induce compensatory growth along this latitudinal gradient, larvae were reared under two different photoperiods corresponding to a northern and southern latitude. In addition, field adult size was assessed to test the strength of possible compensatory growth mechanisms under natural conditions and hatchling size was measured to test for maternal effects. We hypothesized that populations originating from lower latitudes would be more time constrained than high-latitude populations because they have a shorter life cycle. The results showed that low-latitude populations had higher growth rates in summer/fall. In general northern photoperiods induced higher growth rates, but this plastic response to photoperiod was strongest in the southernmost populations and negligible in the northernmost population. During spring, central populations grew faster under the southern rather than the northern photoperiod. On the other hand, northern and northernmost populations did not differ between each other and grew faster in the northern rather than in the southern photoperiod. Field sampled adults did not differ in size across the studied regions. Conclusion/Significance We found a significant differentiation in growth rate across latitudes and latitudinal difference in growth rate

  9. Responses of the mammary transcriptome of dairy cows to altered photoperiod during late gestation.

    PubMed

    Bentley, P A; Wall, E H; Dahl, G E; McFadden, T B

    2015-10-01

    Cows exposed to short day photoperiod (SD, 8L:16D) during the 60-day nonlactating period prior to parturition produce more milk in their subsequent lactation compared with cows exposed to long day photoperiod (LD, 16L:8D). Although this response is well established in dairy cows, the underlying mechanisms are not understood. We hypothesized that differential gene expression in cows exposed to SD or LD photoperiods during the dry period could be used to identify the functional basis for the subsequent increase in milk production during lactation. Pregnant, multiparous cows were maintained on an SD or LD photoperiod for 60 days prior to parturition. Mammary biopsies were obtained on days -24 and -9 relative to parturition and Affymetrix GeneChip Bovine Genome Arrays were used to quantify gene expression. Sixty-four genes were differentially expressed (P ≤ 0.05 and fold-change ≥ |1.5|) between SD and LD treatments. Many of these genes were associated with cell growth and proliferation, or immune function. Ingenuity Pathway Analysis predicted upstream regulators to include TNF, TGF-β1, interferon-γ, and several interleukins. In addition, expression of 125 genes was significantly different between day -24 and day -9; those genes were associated with milk component metabolism and immune function. The interaction of photoperiod and time affected 32 genes associated with insulin-like growth factor I signaling. Genes differentially expressed in response to photoperiod were associated with mammary development and immune function consistent with the enhancement of milk yield in the ensuing lactation. Our results provide insight into the mechanisms by which photoperiod affects the mammary gland and subsequently lactation. PMID:26175502

  10. Effects of Photoperiod and Temperature on Growth and Development in Clouded Salamander (Hynobius nebulosus) Larvae.

    PubMed

    Kukita, Sayuri; Gouda, Mika; Ikeda, Sakiko; Ishibashi, Sakiko; Furuya, Tatsunori; Nakamura, Keiji

    2015-06-01

    Day length is one of the most important factors that organisms use to predict seasonal changes in their environment. Several amphibians regulate their growth and development in response to photoperiod. However, many studies have not focused on the ecological effects of the photoperiodic response on growth and development because they use tropical animals, animals from a commercial source or from unknown localities, or extreme light regimens for experiments. In the present study, we examined the effects of photoperiod on growth and development in the clouded salamander (Hynobius nebulosus) by raising larvae under different photoperiods and at different temperatures in the laboratory. The average larval period under a long-day photoperiod of L16:D8 was longer than that under L12:D12 at 15°C or 20°C, although the difference between the photoperiods was only significant for 15°C. Juveniles weighed more at metamorphosis under L16:D8 than those under L12:D12, irrespective of temperature, suggesting that a longer developmental period results in a heavier body weight. The head width of juveniles did not differ for different photoperiods at either temperature. However, the growth rate of the head width under L12:D12 was faster than that under L16:D8 at 15°C. Long day length appears to produce larger H. nebulosus juveniles in a relatively stable aquatic environment with a low population density. Thus, development may be accelerated when the day length becomes shorter as winter approaches, and larvae may have increased the growth rate of their head widths to compensate for the shorter growing period under shorter day lengths. PMID:26003982

  11. Inadequacy of 3-month Oswestry Disability Index outcome for assessing individual longer-term patient experience after lumbar spine surgery.

    PubMed

    Asher, Anthony L; Chotai, Silky; Devin, Clinton J; Speroff, Theodore; Harrell, Frank E; Nian, Hui; Dittus, Robert S; Mummaneni, Praveen V; Knightly, John J; Glassman, Steven D; Bydon, Mohamad; Archer, Kristin R; Foley, Kevin T; McGirt, Matthew J

    2016-08-01

    OBJECTIVE Prospective longitudinal outcomes registries are at the center of evidence-driven health care reform. Obtaining real-world outcomes data at 12 months can be costly and challenging. In the present study, the authors analyzed whether 3-month outcome measurements sufficiently represent 12-month outcomes for patients with degenerative lumbar disease undergoing surgery. METHODS Data from 3073 patients undergoing elective spine surgery for degenerative lumbar disease were entered into a prospective multicenter registry (N(2)QOD). Baseline, 3-month, and 12-month follow-up Oswestry Disability Index (ODI) scores were recorded. The absolute differences between actual 12- and 3-month ODI scores was evaluated. Additionally, the authors analyzed the absolute difference between actual 12-month ODI scores and a model-predicted 12-month ODI score (the model used patients' baseline characteristics and actual 3-month scores). The minimal clinically important difference (MCID) for ODI of 12.8 points and the substantial clinical benefit (SCB) for ODI of 18.8 points were used based on the previously published values. The concordance rate of achieving MCID and SCB for ODI at 3-and 12-months was computed. RESULTS The 3-month ODI scores differed from 12-month scores by an absolute difference of 11.9 ± 10.8, and predictive modeling estimations of 12-month ODI scores differed from actual 12-month scores by a mean (± SD) of 10.7 ± 9.0 points (p = 0.001). Sixty-four percent of patients (n = 1982) achieved an MCID for ODI at 3 months in comparison with 67% of patients (n = 2088) by 12 months; 51% (n = 1731) and 61% (n = 1860) of patients achieved SCB for ODI at 3 months and 12 months, respectively. Almost 20% of patients had ODI scores that varied at least 20 points (the point span of an ODI functional category) between actual 3- and 12-month values. In the aggregate analysis of achieving MCID, 77% of patients were concordant and 23% were discordant in achieving or not achieving

  12. Rice tungro spherical virus resistance into photoperiod-insensitive japonica rice by marker-assisted selection.

    PubMed

    Shim, Junghyun; Torollo, Gideon; Angeles-Shim, Rosalyn B; Cabunagan, Rogelio C; Choi, Il-Ryong; Yeo, Un-Sang; Ha, Woon-Goo

    2015-09-01

    Rice tungro disease (RTD) is one of the destructive and prevalent diseases in the tropical region. RTD is caused by Rice tungro spherical virus (RTSV) and Rice tungro bacilliform virus. Cultivation of japonica rice (Oryza sativa L. ssp japonica) in tropical Asia has often been restricted because most japonica cultivars are sensitive to short photoperiod, which is characteristic of tropical conditions. Japonica1, a rice variety bred for tropical conditions, is photoperiod-insensitive, has a high yield potential, but is susceptible to RTD and has poor grain quality. To transfer RTD resistance into Japonica1, we made two backcrosses (BC) and 8 three-way crosses (3-WC) among Japonica1 and RTSV-resistant cultivars. Among 8,876 BC1F2 and 3-WCF2 plants, 342 were selected for photoperiod-insensitivity and good grain quality. Photoperiod-insensitive progenies were evaluated for RTSV resistance by a bioassay and marker-assisted selection (MAS), and 22 BC1F7 and 3-WCF7 lines were selected based on the results of an observational yield trial. The results demonstrated that conventional selection for photoperiod-insensitivity and MAS for RTSV resistance can greatly facilitate the development of japonica rice that is suitable for cultivation in tropical Asia. PMID:26366118

  13. The role of photoperiods on photobioreactors - A potential strategy to reduce costs.

    PubMed

    Maroneze, Mariana Manzoni; Siqueira, Stefania Fortes; Vendruscolo, Raquel Guidetti; Wagner, Roger; de Menezes, Cristiano Ragagnin; Zepka, Leila Queiroz; Jacob-Lopes, Eduardo

    2016-11-01

    The aim of this work was evaluate the role of photoperiods (long-term, frequencies and short) on the growth and lipid content of microalgae Scenedesmus obliquus CPCC05. The results showed that Scenedesmus obliquus can store sufficient energy to sustain cell growth for continuous periods of up to 2h in the dark, without affecting the photosynthetic rate. The values for maximum biomass (9.58mg/Lh) and lipid productivities (2.56mg/Lh) were obtained at photoperiod of 0.91:0.09s (light:dark) and 48 t/d, respectively. Moreover, the best trade-offs between biomass productivity and light energy economy occurred in photoperiods of 0.5:0.5s and 0.91:0.09s (light:dark), and those between lipid productivity and light energy economy occurred in the frequency photoperiod of 24 and 48 t/d. Thus, the use of the photoperiods are an effective strategy for reducing costs of microalgal biomass production. PMID:27521786

  14. Circadian Clock and Photoperiodic Response in Arabidopsis: From Seasonal Flowering to Redox Homeostasis

    PubMed Central

    2015-01-01

    Many of the developmental responses and behaviors in plants that occur throughout the year are controlled by photoperiod; among these, seasonal flowering is the most characterized. Molecular genetic and biochemical analyses have revealed the mechanisms by which plants sense changes in day length to regulate seasonal flowering. In Arabidopsis thaliana, induction of the expression of a florigen, FLOWERING LOCUS T (FT) protein, is a major output of the photoperiodic flowering pathway. The circadian clock coordinates the expression profiles and activities of the components in this pathway. Light-dependent control of CONSTANS (CO) transcription factor activity is a crucial part of the induction of the photoperiodic expression of FT. CO protein is stabilized only in the long day afternoon, which is when FT is induced. In this review, we summarize recent progress in the determination of the molecular architecture of the circadian clock and mechanisms underlying photoperiodic flowering. In addition, we introduce the molecular mechanisms of other biological processes, such as hypocotyl growth and reactive oxygen species production, which are also controlled by alterations in photoperiod. PMID:25346271

  15. Expression of vasopressin receptors in hamster hypothalamus is sexually dimorphic and dependent upon photoperiod.

    PubMed Central

    Dubois-Dauphin, M; Theler, J M; Zaganidis, N; Dominik, W; Tribollet, E; Pévet, P; Charpak, G; Dreifuss, J J

    1991-01-01

    The distribution of vasopressin receptors was studied in the brain of a photoperiodic animal, the Siberian hamster. Attention was focused on [3H]vasopressin binding sites located in the hypothalamic ventromedial nucleus, medial tuberal nucleus, and ventral premammillary nucleus in males or females kept in long or short photoperiod conditions. Displacement experiments with structural analogs suggested that vasopressin receptors in the hamster hypothalamus are of the vasopressor (V1) type. Quantitative data obtained with a gaseous detector of beta-particles indicated that in the ventromedial nucleus and in the ventral premammillary nucleus of animals in long photoperiod, the number of beta-particles emitted per unit area was significantly greater in males than in females. In the ventromedial hypothalamic nucleus, in both males and females, the number of beta-particles emitted was significantly lower in short than in long photoperiod conditions. In the ventral premammillary nucleus, shortening of the photoperiod had a significant effect in reducing the amount of [3H]vasopressin bound in females, but not in males. These data suggest that, in the hamster, the control of the expression of vasopressin receptors differs among various hypothalamic nuclei and may depend on the sex and/or on the level of circulating gonadal steroids. Images PMID:1837144

  16. In the first 3 months after stroke is progressive resistance training safe and does it improve activity? A systematic review.

    PubMed

    Salter, Karen; Musovic, Amie; F Taylor, Nicholas

    2016-10-01

    BACKGROUND Progressive resistance training (PRT) can improve strength and function in people with chronic stroke, but less is known about whether this intervention is safe and beneficial during the first 3 months following stroke. OBJECTIVE To systematically review the evidence about the safety and effectiveness of PRT to improve activity in people within the first 3 months after stroke. METHODS After database searching and selection of studies a risk of bias assessment was conducted. Data for the primary outcome of safety was synthesised descriptively and meta-analyses for other outcomes were conducted using a random effects model. RESULTS The quality of the 5 included studies ranged from good to excellent (mean 24.2, range 20-28). For the trials investigating adverse events, none reported any significant increase in events after PRT. There was high level evidence that PRT had little or no effect on strength (SMD (standardized mean difference) 0.17, 95% CI -0.16 to 0.50, I(2) = 0%). There were no significant benefit for upper limb function (SMD 0.11, 95% CI -0.41 to 0.63, I(2) = 0%) and mobility (SMD 0.11, 95% CI -0.21 to 0.43, I(2) = 27%) after PRT compared with controls. CONCLUSIONS There was no evidence reported that PRT is unsafe in people within the first 3 months after stroke, although there was a lack of reporting about adverse events. The lack of demonstration of effect in improving muscle strength and activity suggests there is insufficient evidence to recommend the prescription of PRT for people within the first 3 months after stroke. PMID:27077991

  17. A domestication related mutation in the thyroid stimulating hormone receptor gene (TSHR) modulates photoperiodic response and reproduction in chickens.

    PubMed

    Karlsson, Anna-Carin; Fallahshahroudi, Amir; Johnsen, Hanna; Hagenblad, Jenny; Wright, Dominic; Andersson, Leif; Jensen, Per

    2016-03-01

    The thyroid stimulating hormone receptor gene (TSHR) has been suggested to be a "domestication locus" in the chicken. A strong selective sweep over TSHR in domestic breeds together with significant effects of a mutation in the gene on several domestication related traits, indicate that the gene has been important for chicken domestication. TSHR plays a key role in the signal transduction of seasonal reproduction, which is characteristically less strict in domestic animals. We used birds from an advanced intercross line between ancestral Red Junglefowl (RJF) and domesticated White Leghorn (WL) to investigate effects of the mutation on reproductive traits as well as on TSHB, TSHR, DIO2 and DIO3 gene expression during altered day length (photoperiod). We bred chickens homozygous for either the mutation (d/d) or wild type allele (w/w), allowing assessment of the effect of genotype at this locus while also controlling for background variation in the rest of the genome. TSHR gene expression in brain was significantly lower in both d/d females and males and d/d females showed a faster onset of egg laying at sexual maturity than w/w. Furthermore, d/d males showed a reduced testicular size response to decreased day length, and lower levels of TSHB and DIO3 expression. Additionally, purebred White Leghorn females kept under natural short day length in Sweden during December had active ovaries and lower levels of TSHR and DIO3 expression compared to Red Junglefowl females kept under similar conditions. Our study indicates that the TSHR mutation affects photoperiodic response in chicken by reducing dependence of seasonal reproduction, a typical domestication feature, and may therefore have been important for chicken domestication. PMID:26873630

  18. Seasonal evaluations of urinary androgen metabolites and semen quality in domestic long-tailed chinchilla (Chinchilla lanigera) under natural photoperiod.

    PubMed

    Dominchin, M F; Bianconi, S; Ponzio, M F; Fiol de Cuneo, M F; Ruiz, R D; Busso, J M

    2014-02-01

    Chinchilla spp. is a South American hystricomorph rodent genus currently considered almost extinct in the wild. The high quality of chinchilla fur motivated the harvesting of chinchillas for the fur market. Reproductive biology advances come from studies on commercially exploited animals, especially Chinchilla lanigera. We studied seasonal variation of urinary androgen metabolites, sperm concentration and sperm functional activity in males of domestic Chinchilla lanigera under natural photoperiod. In Córdoba city (31° S-64° W; Argentina), within the same latitudes as those of the historic Andean distribution (tropical deserts; 15°-34° S), domestic males (n=7) were studied in May (autumn), August (winter), November (spring), and February (summer). Urine was seasonally collected (over 24h; once for season, 4 in total) to measure urinary androgen metabolites (RIA), before semen collection by electroejaculation. The results indicated that although testicular volume (relative to body weight) and values of sperm functional activity did not show seasonal changes, a seasonal variation in androgen excretion was detected, with the highest values occurring during "short" light/dark cycles (autumn-winter). In addition, viable spermatozoa with intact acrosome mean values during winter-spring were higher than in autumn or summer. This study provides information that might contribute to the assessment of testicular activity in male chinchilla subjected to genetic selection in the fur industry. In addition, since domestic chinchilla still share some genomic characteristics with their counterparts in the wild, results presented may alsocontribute to ex situ breeding program of endangered chinchilla. In conclusion, natural photoperiod cycle affects testicular activity in domestic chinchilla. PMID:24503344

  19. Dental plaque associated with self-ligating brackets during the initial phase of orthodontic treatment: A 3-month preliminary study

    PubMed Central

    Al-Anezi, Saud A

    2014-01-01

    Background: To compare changes in the amount and distribution of dental plaque associated with placement of elastomeric modules over a self-ligating bracket during orthodontic treatment and to relate these changes to the periodontal inflammation. Materials and Methods: A cross-arch randomization trial was carried out at Bristol Dental School, United Kingdom. Clinical measurements of periodontal inflammation and plaque accumulation and microbiological test were done on 24 patients aged 11-14 years [Mean (SD) age = 12.6 (1.01) years] wearing fixed appliances (Damon 2 brackets, Ormco, Orange, CA, USA) at the start and 3 months into fixed orthodontic treatment. Results: In the first 3 months of treatment there was no statistically significant difference in bleeding on probing between incisors with and without elastomeric modules (P = 0.125 and 0.508, respectively). The difference in plaque accumulation was not statistically significant (P = 0.78). The difference in probing depths between the incisors was not statistically significant (P = 0.84). The microbiological analysis showed no difference. Conclusions: Based on this preliminary 3 months study, elastomeric modules were not significantly associated with any increased risk during treatment when compared to self-ligating brackets. The longer term studies are needed to further confirm the findings of the present study. PMID:24987657

  20. A screening questionnaire to predict no return to work within 3 months for low back pain claimants.

    PubMed

    Du Bois, Marc; Donceel, Peter

    2008-03-01

    The objective of the present study was to develop a short prediction questionnaire for estimating the risk of no return to work (RTW) within 3 months of sick leave to facilitate triage and management of a patient population of subacute low-back pain (LBP) sufferers. We conducted a prospective study with a 3-month follow-up on 186 patients with LBP introducing a claim for sickness benefits to the largest sickness fund in Belgium. Patients completed a screening questionnaire within 2 weeks after claim submission. All patients were invited for clinical assessment, at 6-8 weeks of sick leave, by the medical adviser. Patients' work status was recorded by the sickness fund. About 20% of the patients did not resume work at 3 months' sick leave. They were more likely to experience pain below the knee, to have an own previous prediction of a 100% no RTW and to have a severe interference of pain on daily activities. The screening tool based on these three items correctly classified 73.7% of the non-resumers and 78.4% of the resumers at a cut-off score of 0.22. The findings of this study provide evidence of the utility of a short screening questionnaire for future use in intervention studies in a social security setting. PMID:18172698

  1. Pain-related stress in the Neonatal Intensive Care Unit and salivary cortisol reactivity to socio-emotional stress in 3-month-old very preterm infants.

    PubMed

    Provenzi, Livio; Giusti, Lorenzo; Fumagalli, Monica; Tasca, Hilarj; Ciceri, Francesca; Menozzi, Giorgia; Mosca, Fabio; Morandi, Francesco; Borgatti, Renato; Montirosso, Rosario

    2016-10-01

    Very preterm (VPT) infants are hospitalized in the Neonatal Intensive Care Unit (NICU) and exposed to varying levels of skin-breaking procedures (pain-related stress), even in absence of severe clinical conditions. Repeated and prolonged pain exposure may alter hypothalamic-pituitary-adrenal (HPA) axis reactivity in VPT infants. During the post-discharge period, altered HPA axis reactivity has been documented in response to non-social stressors, using salivary cortisol as a biomarker. However, little is known about the effects of NICU pain-related stress on subsequent HPA axis reactivity to socio-emotional stress in infants. We examined the relationship between pain-related stress in NICU and HPA axis reactivity (i.e., salivary cortisol reactivity) to an age-appropriate socio-emotional condition in 37 healthy VPT infants compared to 53 full-term (FT) controls. The number of skin-breaking procedures was obtained across NICU stay for VPT infants. At 3 months (corrected age for prematurity), all infants participated in the maternal Face-to-Face Still-Face (FFSF) procedure, in order to assess HPA axis reactivity to socio-emotional stress (i.e., maternal unresponsiveness). VPT infants exhibited a blunted salivary cortisol reactivity, which was associated with the amount of skin-breaking procedures during NICU: greater pain-related stress predicted lower salivary cortisol reactivity, adjusting for neonatal confounders. These findings further advance our knowledge of how early exposure to pain-related stress in NICU contributes to the programming of an altered HPA axis reactivity to socio-emotional stress in 3-month-old VPT infants, even in the absence of major perinatal complications. PMID:27428089

  2. Evolution of time-keeping mechanisms: early emergence and adaptation to photoperiod

    PubMed Central

    Hut, R. A.; Beersma, D. G. M.

    2011-01-01

    Virtually all species have developed cellular oscillations and mechanisms that synchronize these cellular oscillations to environmental cycles. Such environmental cycles in biotic (e.g. food availability and predation risk) or abiotic (e.g. temperature and light) factors may occur on a daily, annual or tidal time scale. Internal timing mechanisms may facilitate behavioural or physiological adaptation to such changes in environmental conditions. These timing mechanisms commonly involve an internal molecular oscillator (a ‘clock’) that is synchronized (‘entrained’) to the environmental cycle by receptor mechanisms responding to relevant environmental signals (‘Zeitgeber’, i.e. German for time-giver). To understand the evolution of such timing mechanisms, we have to understand the mechanisms leading to selective advantage. Although major advances have been made in our understanding of the physiological and molecular mechanisms driving internal cycles (proximate questions), studies identifying mechanisms of natural selection on clock systems (ultimate questions) are rather limited. Here, we discuss the selective advantage of a circadian system and how its adaptation to day length variation may have a functional role in optimizing seasonal timing. We discuss various cases where selective advantages of circadian timing mechanisms have been shown and cases where temporarily loss of circadian timing may cause selective advantage. We suggest an explanation for why a circadian timing system has emerged in primitive life forms like cyanobacteria and we evaluate a possible molecular mechanism that enabled these bacteria to adapt to seasonal variation in day length. We further discuss how the role of the circadian system in photoperiodic time measurement may explain differential selection pressures on circadian period when species are exposed to changing climatic conditions (e.g. global warming) or when they expand their geographical range to different latitudes or

  3. Variation in the timing of the reproductive season among breeds of sheep in relation to differences in photoperiodic synchronization of an endogenous rhythm.

    PubMed

    O'Callaghan, D; Karsch, F J; Boland, M P; Hanrahan, J P; Roche, J F

    1992-11-01

    Photoperiod may regulate seasonal reproduction either by providing the primary driving force for the reproductive transitions or by synchronizing an endogenous reproductive rhythm. This study evaluated whether breed differences in timing of the reproductive seasons of Finnish Landrace (Finn) and Galway ewes are due to differences in photoperiodic drive of the reproductive transitions or to differences in photoperiodic synchronization of the endogenous rhythm of reproductive activity. The importance of decreasing photoperiod after the summer solstice in determining the onset and duration of the breeding season was tested by housing ewes from the summer solstice in either a simulated natural photoperiod or a fixed summer-solstice photoperiod (18 h light:6 h dark; summer-solstice hold). Onset of the breeding season within each breed did not differ between these photoperiodic treatments, but Galway ewes began and ended their breeding season earlier than Finn ewes. The duration of the breeding season was shorter in Galway ewes on summer-solstice hold than on simulated natural photoperiod; duration did not differ between photoperiodic treatments in Finn ewes. The requirement for increasing photoperiod after the winter solstice for initiation of anoestrus was tested by exposing ewes from the winter solstice to either a simulated natural photoperiod or a winter-solstice hold photoperiod (8.5 h light:15.5 h dark). Onset of anoestrus within each breed did not differ between these photoperiodic treatments, but the time of this transition differed between breeds. These observations suggest that genetic differences in timing of the breeding season in Galway and Finn ewes do not reflect differences in the extent to which photoperiod drives the reproductive transitions, because neither breed requires shortening days to enter the breeding season or lengthening days to end it at appropriate times. These findings are consistent with the hypothesis that photoperiod synchronizes an

  4. Effects of photoperiod and temperature on the timing of bud burst in Norway spruce (Picea abies).

    PubMed

    Partanen, Jouni; Koski, Veikko; Hänninen, Heikki

    1998-12-01

    We examined the effects of several photoperiod and temperature regimes imposed during the winter-spring period on the timing of bud burst in rooted cuttings of Norway spruce (Picea abies (L.) Karst.) grown in a greenhouse in Finland. The treatments were initiated in November and December after the cuttings had been exposed to natural chilling and freezing events. Irrespective of the treatments applied, time to bud burst decreased with increased duration of previous exposure to natural chilling and freezing events. Fluctuating day/night temperatures and continuous lengthening of the photoperiod hastened bud burst. Shortening the photoperiod delayed bud burst, suggesting that little or no ontogenetic development toward bud burst takes place during mild periods before the winter solstice. In the case of climatic warming, this phenomenon may prevent the premature onset of growth that has been predicted by computer simulations with models that only consider temperature regulation of bud burst. PMID:12651402

  5. Application of artificial photoperiod in fish: a factor that increases susceptibility to infectious diseases?

    PubMed

    Valenzuela, Ariel; Campos, Victor; Yañez, Francisco; Alveal, Katherine; Gutiérrez, Pamela; Rivas, Meyling; Contreras, Nancy; Klempau, Alfredo; Fernandez, Italo; Oyarzun, Ciro

    2012-08-01

    This paper describes and evaluates the mortality associated with the potential stressor effect induced by application of artificial photoperiods in rainbow trout (Oncorhynchus mykiss). After application of artificial photoperiods, high mortalities of trout subjected to this management were recorded (36% in LD 14:10 and 25% in LD 24:0) as compared to controls (7%). The recorded signology related to diseased trout included darkening, lethargy and erratic swimming. Among the morphological changes, skin lesions and ulcerative-type necrosis could be observed. Blood tests, histopathology and isolation of pathogens identified as Flavobacterium psychrophilum, associated with Aeromonas, Pseudomonas and Saprolegnia sp., were performed. The application of artificial photoperiods suggests that fish may be more susceptible to opportunistic diseases; thus, it is advisable to emphasize preventive measures in fish subjected to this management. PMID:22160663

  6. Photoperiod and temperature effects on in vitro growth and flowering of P. pusilla, an epiphytic orchid.

    PubMed

    Vaz, Ana Paula A; Figueiredo-Ribeiro Rd, Rita de Cássia L; Kerbauy, Gilberto B

    2004-05-01

    Psygmorchis pusilla Dodson and Dressler, an epiphytic orchid, has been shown to be an interesting model to study in vitro flower formation. In the present study, the effects of photoperiod and temperature on vegetative and reproductive development were investigated. Although photoperiod had limited effects on leaf number, an etiolating process was verified in darkness and a higher growth was detected under long days. A positive relationship was observed between long days and floral spike formation. However, plant incubation under 20 h photoperiod or longer days negatively affected floral bud development, inhibiting anthesis and reducing flower longevity. Higher soluble sugar and starch levels were detected in plants cultivated under long days, while chlorophyll and carotenoids contents were negatively affected under these conditions. Plants showed great sensitivity to temperature variations; 27 degrees C being the most adequate for growth, leaf and floral spike formation. Temperatures of 22 and 32 degrees C were not appropriate for in vitro development of P. pusilla. PMID:15191744

  7. Carbon dioxide effects on potato growth under different photoperiods and irradiance

    NASA Technical Reports Server (NTRS)

    Wheeler, Raymond M.; Tibbitts, Theodore W.; Fitzpatrick, Ann H.

    1991-01-01

    The effects of atmospheric CO2 concentration, photosynthetic photon flux (PPF), and the length of the photoperiod on the tuber yield were investigated for three potato cultivars (Norland, Russet Burbank, and Denali), by growing these cultivars for 90 days in atmospheres containing 350 or 1000 micromol/mol CO2, at photoperiods of 12- or 24-hr, and at PPFs of 400 or 800 micromol/sq m per sec. Air temperatures and relative humidity were kept at 16 C and 70 percent, respectively. It was found that the tuber yield of Denali potatoes showed the greatest increase (21 percent) in response to increased CO2 across all irradiance treatments, while the tuber yields of Russet and Norland were increased 18 and 9 percent, respectively. Greater plant growth from CO2 enrichment was observed under lower PPF and the shorter (12 hr) photoperiod.

  8. Functional and evolutionary characterization of the CONSTANS gene family in short-day photoperiodic flowering in soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CONSTANS (CO) plays a central role in photoperiodic flowering control of plants. However, much remains unknown about the function of the CO gene family in soybean and the molecular mechanisms underlying the short-day photoperiodic flowering of soybean. We identified 26 CO homologs (GmCOLs) in the so...

  9. Heading date QTL in winter wheat (Triticum aestivum L.) coincide with major developmental genes Vernalization-1 and Photoperiod-1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In wheat (Triticum aestivum L.), time from planting to spike emergence is influenced by genes controlling vernalization requirement and photoperiod response. Characterizing the available genetic diversity of known and novel alleles of Vernalization-1 (Vrn-1) and Photoperiod-1 (Ppd-1) in winter wheat...

  10. The role of photoperiod and temperature in diapause induction of the endoparasitoid wasp, Microplitis mediator (Haliday) (Hymenoptera: Braconidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diapause in Microplitis mediator is manifested during the pupal stage and normally occurs during the winter season because of a photoperiodic response which is highly dependant on temperature. In the reported study, diapause was determine by photoperiod and mediated by temperature, which supports th...

  11. Effect of photoperiod change on chronobiology of cercarial emergence of Schistosoma japonicum derived from hilly and marshy regions of China.

    PubMed

    Wang, Su-Rong; Zhu, Yuan-Jian; Ge, Qing-Peng; Yang, Meng-Jia; Huang, Ji-Lei; Huang, Wen-Qiao; Zhuge, Hong-Xiang; Lu, Da-Bing

    2015-12-01

    The chronobiology of cercarial emergence appeared to be a genetically controlled behavior, adapted to definitive host species, for schistosome. However, a few physiological and ecological factors, for example the change of photoperiod, were reported to affect the rhythmic emergence of cercariae. Therefore, the effect of photoperiod change on cercarial emergence of two Schistosoma japonicum isolates, the hilly and the marshland, was investigated. Four shedding experiments each under a different photoperiod were conducted. Under a natural photoperiod, two distinct shedding modes, one from the hilly region and one from the marshland, were observed. Under a reversed photoperiod, the regular pattern (i.e. under a natural photoperiod) of S. japonicum cercarial emergence was reversed for the marshland isolate and disappeared for the hilly isolate. With an input of a 2 h darkness from 7am to 9am, the cercarial emergence peak were delayed for the two isolates; whereas with an input of a 2 h darkness from 5pm to 7pm, neither effect on the cercarial emergence rhythm was observed. The total cercariae emerged for both parasite isolates varied with a different photoperiod. The results indicate that the change of photoperiod could affect the chronobiology of S japonicum cercarial emergence. PMID:26484419

  12. Photoperiodic control of seasonal development and dormancy in tropical stem-succulent trees.

    PubMed

    Borchert, R; Rivera, G

    2001-03-01

    Tropical stem-succulent trees store large quantities of water in their trunks yet remain leafless during the early and mid dry season. In contrast to most other tropical trees, bud break of vegetative buds is not induced in fully hydrated stem succulents between the winter solstice and the spring equinox by leaf abscission, abnormal rain showers or irrigation. Vegetative buds of leafless trees are therefore in a state of endo-dormancy similar to that of temperate perennial plants during early winter. Highly synchronous bud break regularly occurs soon after the spring equinox, often weeks before the first rainfalls of the wet season. These observations suggested that endo-dormancy and bud break might be induced by declining and increasing photoperiods after the autumn and spring equinoxes, respectively. In phenological field observations, we confirmed highly synchronous bud break after the spring equinox in many trees of five stem-succulent species in the northern and southern hemispheres. Shoot growth of potted saplings of Plumeria rubra L. was arrested by a decline in day length below 12 h after the autumn equinox, but continued in saplings maintained in a 13-h photoperiod. Conversely, exposure to a 13-h photoperiod induced bud break of dormant apical buds in saplings and cuttings in January, whereas plants maintained in the natural day length of < 11.7 h remained dormant. Photoperiodic control of endo-dormancy of vegetative buds in stem succulents is thus supported by field observations and experimental variation of the photoperiod. At low latitudes, where annual variation of day length is less than 1 h, bud dormancy is induced and broken by variations in photoperiod of less than 30 min. PMID:11276415

  13. Photoperiod Extension Enhances Sexual Megaspore Formation and Triggers Metabolic Reprogramming in Facultative Apomictic Ranunculus auricomus

    PubMed Central

    Klatt, Simone; Hadacek, Franz; Hodač, Ladislav; Brinkmann, Gina; Eilerts, Marius; Hojsgaard, Diego; Hörandl, Elvira

    2016-01-01

    Meiosis, the key step of sexual reproduction, persists in facultative apomictic plants functional to some extent. However, it still remains unclear how and why proportions of reproductive pathways vary under different environmental stress conditions. We hypothesized that oxidative stress mediates alterations of developmental pathways. In apomictic plants we expected that megasporogenesis, the stage directly after meiosis, would be more affected than later stages of seed development. To simulate moderate stress conditions we subjected clone-mates of facultative apomictic Ranunculus auricomus to 10 h photoperiods, reflecting natural conditions, and extended ones (16.5 h). Reproduction mode was screened directly after megasporogenesis (microscope) and at seed stage (flow cytometric seed screening). Targeted metabolite profiles were performed with HPLC–DAD to explore if and which metabolic reprogramming was caused by the extended photoperiod. Prolonged photoperiods resulted in increased frequencies of sexual vs. aposporous initials directly after meiosis, but did not affect frequencies of sexual vs. asexual seed formation. Changes in secondary metabolite profiles under extended photoperiods affected all classes of compounds, and c. 20% of these changes separated the two treatments. Unexpectedly, the renowned antioxidant phenylpropanoids and flavonoids added more to clone-mate variation than to treatment differentiation. Among others, chlorophyll degradation products, non-assigned phenolic compounds and more lipophilic metabolites also contributed to the dissimilarity of the metabolic profiles of plants that had been exposed to the two different photoperiods. The hypothesis of moderate light stress effects was supported by increased proportions of sexual megaspore development at the expense of aposporous initial formation. The lack of effects at the seed stage confirms the basic assumption that only meiosis and sporogenesis would be sensitive to light stress. The

  14. Photoperiod Extension Enhances Sexual Megaspore Formation and Triggers Metabolic Reprogramming in Facultative Apomictic Ranunculus auricomus.

    PubMed

    Klatt, Simone; Hadacek, Franz; Hodač, Ladislav; Brinkmann, Gina; Eilerts, Marius; Hojsgaard, Diego; Hörandl, Elvira

    2016-01-01

    Meiosis, the key step of sexual reproduction, persists in facultative apomictic plants functional to some extent. However, it still remains unclear how and why proportions of reproductive pathways vary under different environmental stress conditions. We hypothesized that oxidative stress mediates alterations of developmental pathways. In apomictic plants we expected that megasporogenesis, the stage directly after meiosis, would be more affected than later stages of seed development. To simulate moderate stress conditions we subjected clone-mates of facultative apomictic Ranunculus auricomus to 10 h photoperiods, reflecting natural conditions, and extended ones (16.5 h). Reproduction mode was screened directly after megasporogenesis (microscope) and at seed stage (flow cytometric seed screening). Targeted metabolite profiles were performed with HPLC-DAD to explore if and which metabolic reprogramming was caused by the extended photoperiod. Prolonged photoperiods resulted in increased frequencies of sexual vs. aposporous initials directly after meiosis, but did not affect frequencies of sexual vs. asexual seed formation. Changes in secondary metabolite profiles under extended photoperiods affected all classes of compounds, and c. 20% of these changes separated the two treatments. Unexpectedly, the renowned antioxidant phenylpropanoids and flavonoids added more to clone-mate variation than to treatment differentiation. Among others, chlorophyll degradation products, non-assigned phenolic compounds and more lipophilic metabolites also contributed to the dissimilarity of the metabolic profiles of plants that had been exposed to the two different photoperiods. The hypothesis of moderate light stress effects was supported by increased proportions of sexual megaspore development at the expense of aposporous initial formation. The lack of effects at the seed stage confirms the basic assumption that only meiosis and sporogenesis would be sensitive to light stress. The

  15. Photoperiod Influences Growth and mll (Mixed-Lineage Leukaemia) Expression in Atlantic Cod

    PubMed Central

    Nagasawa, Kazue; Giannetto, Alessia; Fernandes, Jorge M. O.

    2012-01-01

    Photoperiod is associated to phenotypic plasticity of somatic growth in several teleost species. However, the molecular mechanisms underlying this phenomenon are currently unknown but it is likely that epigenetic regulation by methyltransferases is involved. The MLL (mixed-lineage leukaemia) family comprises histone methyltransferases that play a critical role in regulating gene expression during early development in mammals. So far, these genes have received scant attention in teleost fish. In the present study, the mean weight of Atlantic cod juveniles reared under continuous illumination was found to be 13% greater than those kept under natural photoperiod conditions for 120 days. We newly determined cDNA sequences of five mll (mll1, mll2, mll3a, mll4b and mll5) and two setd1 (setd1a and setd1ba) paralogues from Atlantic cod. Phylogenetic analysis revealed that the cod genes clustered within the appropriate mll clade and comparative mapping of mll paralogues showed that these genes lie within a region of conserved synteny among teleosts. All mll and setd1 genes were highly expressed in gonads and fast muscle of adult cod, albeit at different levels, and they were differentially regulated with photoperiod in muscle of juvenile fish. Following only one day of exposure to constant light, mll1, mll4b and setd1a were up to 57% lower in these fish compared to the natural photoperiod group. In addition, mRNA expression of myogenic regulatory factors (myog and myf-5) and pax7 in fast muscle was also affected by different photoperiod conditions. Notably, myog was significantly elevated in the continuous illumination group throughout the time course of the experiment. The absence of a day/night cycle is associated with a generalised decrease in mll expression concomitant with an increase in myog transcript levels in fast muscle of Atlantic cod, which may be involved in the observed epigenetic regulation of growth by photoperiod in this species. PMID:22590633

  16. Simulating the Influence of Vernalization, Photoperiod and Optimum Temperature on Wheat Developmental Rates

    PubMed Central

    McMaster, Gregory S.; White, Jeffrey W.; Hunt, L. A.; Jamieson, P. D.; Dhillon, S. S.; Ortiz-Monasterio, J. I.

    2008-01-01

    Background and Aims Accurately representing development is essential for applying crop simulations to investigate the effects of climate, genotypes or crop management. Development in wheat (Triticum aestivum, T. durum) is primarily driven by temperature, but affected by vernalization and photoperiod, and is often simulated by reducing thermal-time accumulation using vernalization or photoperiod factors or limiting accumulation when a lower optimum temperature (Toptl) is exceeded. In this study Toptl and methods for representing effects of vernalization and photoperiod on anthesis were examined using a range of planting dates and genotypes. Methods An examination was made of Toptl values of 15, 20, 25 and 50 °C, and either the most limiting or the multiplicative value of the vernalization and photoperiod development rate factors for simulating anthesis. Field data were from replicated trials at Ludhiana, Punjab, India with July through to December planting dates and seven cultivars varying in vernalization response. Key Results Simulations of anthesis were similar for Toptl values of 20, 25 and 50 °C, but a Toptl of 15 °C resulted in a consistent bias towards predicting anthesis late for early planting dates. Results for Toptl above 15 °C may have occurred because mean temperatures rarely exceeded 20 °C before anthesis for many planting dates. For cultivars having a strong vernalization response, anthesis was more accurately simulated when vernalization and photoperiod factors were multiplied rather than using the most limiting of the two factors. Conclusions Setting Toptl to a high value (30 °C) and multiplying the vernalization and photoperiod factors resulted in accurately simulating anthesis for a wide range of planting dates and genotypes. However, for environments where average temperatures exceed 20 °C for much of the pre-anthesis period, a lower Toptl (23 °C) might be appropriate. These results highlight the value of testing a model over a wide range

  17. Temperature rather than photoperiod controls growth cessation and dormancy in Sorbus species

    PubMed Central

    Heide, Ola M.

    2011-01-01

    Environmental regulation of growth and dormancy of four Sorbus genotypes was studied in controlled environments. Emphasis was placed on assessment of the presence and nature of the deficient photoperiodic dormancy regulation system that has previously been reported for some woody Rosaceae species. Two genotypes of Sorbus aucuparia L. maintained indeterminate growth for 8 weeks and 9 weeks at temperatures of 15 °C and 21 °C in both 20 h and 10 h photoperiods, while at 9 °C, in the same photoperiodic conditions, they immediately ceased growing. At the higher temperatures, initiation of new leaves (nodes) was unaffected by photoperiod, while internode elongation was significantly enhanced by long days (LD). However, even after prolonged exposure to 9 °C, most plants resumed growth when moved to high temperature and LD, indicating a shallow state of dormancy. Seedlings of Sorbus intermedia (J. F. Ehrh.) Pers. and micro-propagated plantlets of S. commixta Hedl. ‘Dodong’ were also unaffected by photoperiod during primary growth, but failed to elongate and gradually became dormant regardless of temperature and day-length conditions. However, after chilling and breaking of dormancy, the plants elongated vigorously but changed to a determinate mode of growth. Furthermore, a temperature of 9 °C was found to be fully effective for breaking dormancy in S. intermedia plants. It is concluded that deficient photoperiodic dormancy control seems widespread in the Rosaceae and that, in such plants, both dormancy induction and release is brought about by low temperature. The potential impacts of climate change on such trees are discussed. PMID:21862485

  18. Circadian rhythmicity and photoperiodism in the pitcher-plant mosquito: can the seasonal timer evolve independently of the circadian clock?

    PubMed

    Bradshaw, W E; Holzapfel, C M; Mathias, D

    2006-04-01

    The two major rhythms of the biosphere are daily and seasonal; the two major adaptations to these rhythms are the circadian clock, mediating daily activities, and the photoperiodic timer, mediating seasonal activities. The mechanistic connection between the circadian clock and the photoperiodic timer remains unresolved. Herein, we show that the rhythmic developmental response to exotic light:dark cycles, usually used to infer a causal connection between the circadian clock and the photoperiodic timer, has evolved independently of the photoperiodic timer in the pitcher-plant mosquito Wyeomyia smithii across the climatic gradient of eastern North America from Florida to Canada and from the coastal plain to the mountains. We conclude that the photoperiodic timing of seasonal events can evolve independently of the daily circadian clock. PMID:16671002

  19. Androgenic induction of brain sexual dimorphism depends on photoperiod in meadow voles.

    PubMed

    Kelly, K K

    1993-02-01

    Male meadow voles maintained in a long photoperiod (LP) from birth have heavier brains than do females, but in short photoperiods (SP) this sex dimorphism is absent. Testosterone propionate (TP) administration on the second day of postnatal life produced significant increases in brain weight of LP but not SP females at 35 days of age. Short daylengths reduce the responsiveness of the meadow vole nervous system to the masculinizing effects of perinatal testosterone and may, in part, mediate the seasonally reduced sex difference in brain weight. PMID:8446686

  20. Maxillary sinus floor augmentation using a nano-crystalline hydroxyapatite silica gel: case series and 3-month preliminary histological results.

    PubMed

    Canullo, Luigi; Dellavia, Claudia; Heinemann, Friedhelm

    2012-03-20

    The aim of this case series is to histologically examine a new hydroxyapatite in sinus lift procedure after 3 months. Ten 2-stage sinus lifts were performed in 10 healthy patients having initial bone height of 1-2mm and bone width of 5mm, asking for a fixed implant-supported rehabilitation. After graft material augmentation, a rough-surfaced mini-implant was inserted to maintain stability of the sinus widow. A bioptical core containing a mini-implant was retrieved 3 months after maxillary sinus augmentation with NanoBone(®) and processed for undecalcified histology. From the histomorphometric analysis, NanoBone(®) residuals accounted for the 38.26% ± 8.07% of the bioptical volume, marrow spaces for the 29.23% ± 5.18% and bone for the 32.51% ± 4.96% (new bone: 20.64% ± 2.96%, native bone: 11.87% ± 3.27%). Well-mineralized regenerated bone with lamellar parallel-fibred structure and Haversian systems surrounded the residual NanoBone(®) particles. The measured bone-to-implant contact amounted to 26.02% ± 5.46%. No connective tissue was observed at the implant boundary surface. In conclusion, the tested material showed good histological outcomes also 3 months after surgery. In such critical conditions, the use of a rough-surfaced mini-implant showed BIC values supposed to be effective also in case of functional loading. Although longer follow-up and a wider patient size are needed, these preliminary results encourage further research on this biomaterial for implant load also under early stage and critical conditions. PMID:21640571

  1. Bipolar radiofrequency ablation of benign thyroid nodules using a multiple overlapping shot technique in a 3-month follow-up.

    PubMed

    Kohlhase, Konstantin David; Korkusuz, Yücel; Gröner, Daniel; Erbelding, Christian; Happel, Christian; Luboldt, Wolfgang; Grünwald, Frank

    2016-08-01

    Purpose The aim of this study was to evaluate the decrease of benign thyroid nodules after bipolar radiofrequency ablation (RFA) in a 3-month follow-up using a multiple overlapping shot technique ('MOST'). Methods A total of 18 patients with 20 symptomatic benign thyroid nodules (17 cold nodules, 3 hyperfunctioning nodules) were treated in one single session by bipolar RFA. Bipolar ablation was performed using MOST. The nodule volumes were measured prior to ablation and 3 months after the procedure using ultrasound. The population consisted of either solid (>80% solid tissue within the volume of interest), complex, or cystic nodules (<20% solid tissue within the volume of interest). Results Bipolar RFA resulted in a highly significant (p < 0.0001) decrease of nodule volume (ΔV), median 5.3 mL (range 0.13-43.1 mL), corresponding to a relative reduction in mean of 56 ± 17.9%. Median initial volume was 8 mL (range 0.48-62 mL); 3 months after ablation a median volume of 2.3 mL (range 0.3-32 mL) was measured. Nodule growth ≥50% occurred in 70% (14 nodules). At the follow-up no complications such as infections, persisting pain, nerve injuries or immunogen stimulation occurred. Patients with cold nodules (15) remained euthyroid, with hyperfunctioning nodules either euthyroid (2) or latent hypofunctional (1). Conclusion The use of bipolar RFA is an effective, safe and suitable thermoablative technique to treat benign thyroid nodules. Combined with the multiple overlapping shot technique it allows sufficient ablation. PMID:27126512

  2. Postnatal depression among Sudanese women: prevalence and validation of the Edinburgh Postnatal Depression Scale at 3 months postpartum

    PubMed Central

    Khalifa, Dina Sami; Glavin, Kari; Bjertness, Espen; Lien, Lars

    2015-01-01

    Purpose Postnatal depression (PND) rates in low-resource countries have reached levels between 4.9% and 59%. Maternal mental health has not been researched in Sudan, and there are no existing statistics on prevalence or significant risk factors for PND. Consequently, no screening test has been validated to screen for PND at the primary health care level. This study investigates the 3 months prevalence of PND and validates the Edinburgh Postnatal Depression Scale (EPDS) against the Mini-International Neuropsychiatric Interview (MINI). Methodology Pregnant Sudanese women in the second and third trimesters were recruited to the study during routine antenatal care visits in two major maternity hospitals in Khartoum state. They were screened for PND at 3 months postpartum using the EPDS. Test positive women were matched with test negative women according to nearest date of birth. A clinical psychologist verified their depression status using the MINI. Results The follow-up rate was 79%. At a cutoff point of ≥12, the 3 months prevalence of PND was 9.2%. The sensitivity and specificity of the EPDS were 89% and 82%, respectively. The EPDS and MINI showed a strong positive relationship (odds ratio =36). The positive predictive value and negative predictive value, using this study’s prevalence, were 33% and 98.7%, respectively. The receiver operator characteristic analysis showed an area under the curve of 0.89. The cut-off point ≥12 was the most acceptable point as it had the lowest number needed to diagnose (1.4) and a false-positive rate of 18%. Conclusion The EPDS is a valid tool for screening for PND on a Sudanese population. It was accepted, easily administered, and understood by postnatal women. Health care personnel, especially village midwives, should be trained on screening and referral of depressed women for clinical evaluation and management. Due to limited resources available in Sudan, shorter screening tests need to be validated in the future. PMID

  3. [Endogenous affective disorder, seasons of birth and photoperiodicity].

    PubMed

    Brochard, A; Escande, M; Schmitt, L; Granier, F; Girard, M; Charlet, J P; Moron, P

    1994-01-01

    In a retrospective study, we compared the months of birth of 3,106 psychiatric inpatients to those of 1,943 surgical patients collected during the same period 1981-1991 in the same hospital, and of a sample of 10,003,572 births in France in 1977-1989. DSM III-R categories were modified so to allow a comparison with former studies, and psychiatric patients were distributed among seven categories: Bipolars (N = 294), Unipolars (N = 287), Neurotic-reactive depressions (N = 582), First Major Depressive episode (N = 214), Schizophrenia (N = 244), Schizo-Affectives (N = 52) and Other Diagnosies (N = 1,433). Months of birth were grouped in quarters and semesters, according to the usual calendar, but also to temperature and the photoperiodic cycle. The main results were: 1. A seasonnality of births in the General Population sample, with a spring maximum (p < 0.001). 2. An absence of deviation from the general population and the surgical sample among Neurotic-reactive Depressions and Other Diagnoses. 3. A deviation from the general population and from other comparison groups (surgical cases and Other Diagnoses) among Unipolars and First Major Depressive Episodes (most of those being late episodes), with a significant excess of births during the "dark" or "cold" season of the year, especially around the winter solstice. The Bipolar group followed the same tendency, though to a lesser degree and for subjects born before 1940 only. The most significant results were found among Unipolars, which differ from the general population either by quarters (p < 0.0005) or by semesters (p < 0.0005) and from surgical cases by quarters (p < 0.01) and by semesters (p < 0.001). The results were similar for First Major Depressive episodes, although this category was theoretically "anosological". As the median age was high in this category, it might group a number of late depressive episodes, near to "involutionnal melancholia". Thus, our results seem to be relevant to the traditional

  4. Short, natural, and extended photoperiod response in BC2F4 lines of bread wheat with different photoperiod-1 (Ppd-1) alleles.

    PubMed

    Bentley, A R; Horsnell, R; Werner, C P; Turner, A S; Rose, G A; Bedard, C; Howell, P; Wilhelm, E P; Mackay, I J; Howells, R M; Greenland, A; Laurie, D A; Gosman, N

    2013-04-01

    Flowering is a critical period in the life cycle of flowering plant species, resulting in an irreversible commitment of significant resources. Wheat is photoperiod sensitive, flowering only when daylength surpasses a critical length; however, photoperiod insensitivity (PI) has been selected by plant breeders for >40 years to enhance yield in certain environments. Control of flowering time has been greatly facilitated by the development of molecular markers for the Photoperiod-1 (Ppd-1) homeoloci, on the group 2 chromosomes. In the current study, an allelic series of BC2F4 lines in the winter wheat cultivars 'Robigus' and 'Alchemy' was developed to elucidate the influence on flowering of eight gene variants from the B- and D-genomes of bread wheat and the A-genome of durum wheat. Allele effects were tested in short, natural, and extended photoperiods in the field and controlled environments. Across genetic background and treatment, the D-genome PI allele, Ppd-D1a, had a more potent effect on reducing flowering time than Ppd-B1a. However, there was significant donor allele effect for both Ppd-D1a and Ppd-B1a, suggesting the presence of linked modifier genes and/or additional sources of latent sensitivity. Development of Ppd-A1a BC2F4 lines derived from synthetic hexaploid wheat provided an opportunity to compare directly the flowering time effect of the A-genome allele from durum with the B- and D-genome variants from bread wheat for the first time. Analyses indicated that the reducing effect of Ppd-A1a is comparable with that of Ppd-D1a, confirming it as a useful alternative source of PI. PMID:23420880

  5. Hysteroscopic myomectomy outcomes after 3-month treatment with either Ulipristal Acetate or GnRH analogues: a retrospective comparative study.

    PubMed

    Sancho, Javier Monleón; Delgado, Verónica Serrano de la Cruz; Valero, Maria José Nuñez; Soteras, Marta Gurrea; Amate, Vicente Payá; Carrascosa, Antonio Abad

    2016-03-01

    Ulipristal Acetate (UPA) modifies the endometrium, as well as fibroids, and therefore it might make hysteroscopic surgery more difficult. To confirm that pre-treatment with UPA is as safe and effective an option as pre-treatment with GnRH analogues, considered the gold standard. We present the first series of 26 hysteroscopic myomectomies after 3 months treatment with UPA and we compare the results with a series of 24 cases pretreated with GnRH analogues. This was a retrospective cohort study between July 2013 and May 2015. We analyszed patients with submucous myomas >2.5 in diameter. Hysteroscopic myomectomy was performed after 3 months of treatment with either UPA (5mg daily) or the GnRH agonist (3.75mg/month). Both groups were similar in age, myoma initial size and classification. There were no significant differences between UPA and GnRHa treated groups in terms of percentage of myomas resected (93% vs 98%), duration of surgery (38 vs 37min), fluid deficit (200 vs 350ml) and complications. In the surgeon's subjective opinion, UPA treatment was associated with an easier resection. Based on our experience, previous treatment with UPA does not difficult Hhysteroscopic myomectomy. Endometrial changes have no impact on surgery. Safety and feasibility are comparable to hysteroscopic myomectomies with previous treatment with GnRH analogues. This allows us to take advantage of the reduction in size of fibroids before surgery with less side effects. PMID:26871272

  6. Short-term effects after a 3-month aerobic or anaerobic exercise programme in Hong Kong Chinese.

    PubMed

    Ko, G T C

    2004-04-01

    Information on the beneficial effects of exercise in Chinese concerning weight reduction and fat loss is limited. We studied 18 young, healthy Chinese volunteers and assessed the short-term effects of exercise on their anthropometric and biochemical parameters. They had not done regular exercise before the study and were randomly assigned to aerobic or anaerobic exercise group (9 subjects in each group). Professional trainers on aerobic and anaerobic exercise were invited to teach and supervise the whole group on the exercise programme. The study lasted 3 months with exercise of at least 3 sessions per week of 30 min each. Of the 18 subjects, 7 (38.9%) were men and 11 (61.1%) women. Their mean age was 28.9 +/- 3.6 yr (men: 29.6 +/- 4.2 yr, women: 28.5 +/- 3.4 yr, p value: NS). After the 3-month exercise programme, body weight and body mass index reduction were significant only in the aerobic group but not in the anaerobic one, while body fat percentage was improved in both groups. This suggests anaerobic exercise may increase the lean to fat body mass ratio. Plasma glucose was reduced in the aerobic group but not in the anaerobic one. Plasma insulin level was, otherwise, similar before and after exercise in both groups. This is compatible with a blunted insulin hormonal response to endurance exercise and an improved tissue sensitivity to insulin. PMID:15244106

  7. Effect of marginal maternal zinc intake on zinc absorption and growth of 3-month-old infant rhesus monkeys

    SciTech Connect

    Loennerdal, B.K.; Keen, C.L.; Bell, J.G.; Golub, M.S.; Hendrickx, A.G.; Gershwin, M.E. )

    1990-09-01

    One compensatory mechanism for marginal zinc intake may be through an enhanced absorption of zinc. Such a compensatory mechanism could be of value to the neonate, as poor zinc nutriture during early life has severe consequences on growth and development. We studied the uptake of zinc by 3-month-old infant rhesus monkeys born to dams fed control diets 100 micrograms of zinc per gram of diet or zinc-restricted diets (4 micrograms of zinc per gram of diet). Zinc uptake/retention was studied by feeding 3-month-old infant monkeys that had fasted an infant formula containing zinc 65 by gavage. Whole body radioactivity was counted immediately after intubation and on days 10 and 17 after intubation. Regardless of dietary group, 65-zinc retention was high, ranging from 33% to 71% of the dose fed to the monkeys. There were no significant differences between the two dietary groups in the percentage of zinc retention at days 10 and 17. Independent of the dietary group, there was no correlation between plasma zinc and zinc absorption. A positive correlation was found between weight gain and zinc retention in the marginal zinc infants, while a negative correlation between weight gain and zinc retention was observed in the control infants. These observations suggest that the mechanisms underlying growth may be different in infants born to dams fed control vs marginal zinc diets.

  8. Twilight and photoperiod affect behavioral entrainment in the house mouse (Mus musculus).

    PubMed

    Comas, M; Hut, R A

    2009-10-01

    The effect of twilight transitions on entrainment of C57BL/6JOlaHsd mice (Mus musculus) was studied using light-dark cycles of different photoperiods (6, 12, and 18 h) and twilight transitions of different durations (0, 1, and 2 h). Phase angle differences of the onset, center of gravity, and offset of activity, activity duration (alpha), as well as free-running period (tau) in continuous darkness were analyzed. The main finding was that for all conditions the onset of activity was close to dusk or lights-off except for the short photoperiod with 2 h of twilight where activity onset was on average 5.3 (SEM 1.07) h after lights-off. This finding contrasts with the results of Boulos and Macchi for Syrian hamsters where a 5.9-h earlier activity onset was observed when similar photoperiod and twilight conditions are compared with a rectangular LD cycle. The authors suggest the opposite effects of 2 h of twilight in the 2 species may be related to their different free-running periods under DD conditions following entrainment to short photoperiod with 2-h twilight conditions. Since the authors observed larger variation in phase angle of entrainment in longer twilight conditions, twilight does not necessarily form a stronger zeitgeber. PMID:19755585

  9. Diapause response to photoperiod in an Arizona population of Lygus hesperus (Hemiptera: Miridae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The western tarnished plant bug (Lygus hesperus Knight) is an important crop pest in the western U.S. that overwinters in an adult diapause. However, knowledge of L. hesperus diapause is incomplete. Eggs from field-collected adults were reared under photoperiods of 10:14, 11:13, 12:12, and 13:10 (L:...

  10. Photoperiodic effects on diapause-associated gene expression trajectories in European Leptinotarsa decemlineata populations.

    PubMed

    Lehmann, P; Piiroinen, S; Kankare, M; Lyytinen, A; Paljakka, M; Lindström, L

    2014-10-01

    Behavioural and physiological changes during diapause, an important strategy of insects for surviving harsh seasonal conditions, have been intensively studied. The genetic and molecular mechanisms underpinning diapause development are less well known. We took a candidate gene approach to study prediapause gene expression patterns in the Colorado potato beetle (Leptinotarsa decemlineata), an invasive insect that has rapidly spread northwards to high seasonality environments. Newly eclosed beetles originating from southern (Italy) and northern (Russia) Europe were reared under short- [12 h light (L):12 h dark (D)] and long-day (18L:6D) photoperiods for 10 days. This time period includes the sensitive period for the photoperiodic induction and initiation of diapause. Gene expression trajectories of 12 diapause-related genes (regulatory, metabolic and stress-resistance) were analysed from 0-, 5- and 10-day-old beetles. Gene expression differences increased with age, deviating significantly between populations and photoperiods in 10-day-old beetles. The gene expression profiles, particularly those related to energy metabolism and stress-resistance, indicate that beetles originating from Russia also prepare for diapause under the long-day photoperiod and show qualitative differences in the diapausing phenotype. Our study shows that population-dependent differences seen in behavioural and physiological traits connected with diapause in L. decemlineata are also evident in the expression trajectories of diapause-related genes. PMID:24924142

  11. Effects of photoperiod and temperature on diapause induction in Conogethes punctiferalis (Lepidoptera: Pyralidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The yellow peach moth, Conogethes punctiferalis (Guenée), a multivoltine species that overwinters as diapausing larvae, is one of the most serious insect pests on maize in China. Effect of photoperiod and temperature on larval diapause was examined under empirical laboratory conditions. Short-day ...

  12. Short photoperiod condition increases susceptibility to stress in adolescent male rats.

    PubMed

    Xu, Ling-Zhi; Liu, Li-Jing; Yuan, Ming; Li, Su-Xia; Yue, Xiao-Dong; Lai, Ju-Lian; Lu, Lin

    2016-03-01

    The seasonality of depressive symptoms is prevalent in children and adolescents. However, the mechanisms that underlie such susceptibility to seasonal influences on mood disorders are unclear. We examined the effects of a short photoperiod condition on the susceptibility to subchronic unpredictable mild stress (SCUS) and rhythmic alterations of plasma corticosterone (CORT), melatonin, and neuropeptide Y (NPY) in adolescent male rats. Compared with the 12h/12h light/dark photoperiod control (CON) rats, the 8h/16h photoperiod SCUS rats exhibited significant anhedonia, a core symptom of human depression, together with a blunted diurnal rhythm and elevation of 24h CORT, melatonin, and NPY levels. The 8h/16h photoperiod condition also blunted the rhythmicity of CORT, caused a phase inversion of melatonin, and caused a phase delay of NPY compared with 12h/12h CON rats. Such abnormalities of plasma CORT, NPY, and melatonin might cause adolescent individuals to present higher stress reactivity and greater vulnerability to stress over their lifetimes. The present study provides evidence of the susceptibility to the seasonality of stress-related disorders in adolescence. PMID:26655789

  13. Photoperiod constraints on tree phenology, performance and migration in a warming world.

    PubMed

    Way, Danielle A; Montgomery, Rebecca A

    2015-09-01

    Increasing temperatures should facilitate the poleward movement of species distributions through a variety of processes, including increasing the growing season length. However, in temperate and boreal latitudes, temperature is not the only cue used by trees to determine seasonality, as changes in photoperiod provide a more consistent, reliable annual signal of seasonality than temperature. Here, we discuss how day length may limit the ability of tree species to respond to climate warming in situ, focusing on the implications of photoperiodic sensing for extending the growing season and affecting plant phenology and growth, as well as the potential role of photoperiod in controlling carbon uptake and water fluxes in forests. We also review whether there are patterns across plant functional types (based on successional strategy, xylem anatomy and leaf morphology) in their sensitivity to photoperiod that we can use to predict which species or groups might be more successful in migrating as the climate warms, or may be more successfully used for forestry and agriculture through assisted migration schemes. PMID:25142260

  14. The effect of photoperiod on tuberization in cultivated x wild potato species hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild Solanum species offer a valuable source of genetic diversity for potato improvement. Most of these species are found in equatorial South and Central America and they do not tuberize under long day photoperiods typical of those in the major potato production areas of North America, Europe and As...

  15. Yield and nutritive value of photoperiod-sensitive sorghum and sorghum-sudangrass in central Wisconsin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to evaluate the yield and nutrient composition of photoperiod sensitive (PS) and non-PS forage sorghum, sorghum-sudangrass, and sudangrass compared to corn planted on 2 dates and harvested using single or multiple-cut harvest strategies at 2 research stations (Marshfield and Ha...

  16. Effects of short photoperiod on energy intake, thermogenesis, and reproduction in desert hamsters (Phodopus roborovskii).

    PubMed

    Zhang, Xueying; Zhao, Zhijun; Vasilieva, Nina; Khrushchova, Anastasia; Wang, Dehua

    2015-03-01

    Desert hamsters (Phodopus roborovskii) are the least known species in the genus Phodopus with respect to ecology and physiology, and deserve scientific attention, particularly because of their small body size. Here, the responses of energy metabolism and reproductive function to short photoperiods in desert hamsters were investigated. Male and female desert hamsters were acclimated to either long day (LD) (L:D 16:8 h) or short day (SD) photoperiods (L:D 8:16 h) for three months, and then the females were transferred back to an LD photoperiod for a further five months, while at the end of the SD acclimation the males were killed and measurements were taken for serum leptin as well as molecular markers for thermogenesis. We found that like the other two species from the genus Phodopus, the desert hamsters under SD decreased body mass, increased adaptive thermogenesis as indicated by elevated mitochondrial protein content and uncoupling protein-1 content in brown adipose tissue, and suppressed reproduction compared to those under LD. However, different from the other two species, desert hamsters did not show any differences in energy intake or serum leptin concentration between LD and SD. These data suggest that different species from the same genus respond in different ways to the environmental signals, and the desert adapted species are not as sensitive to change in photoperiod as the other two species. PMID:25311843

  17. Photoperiod and growing degree days effect on dry matter partitioning in Jerusalem artichoke

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of photoperiod and growing degree days (GDD) on dry matter and dry partitioning in Jerusalem artichoke was investigated during 2008-09 and 2009-10. Three Jerusalem artichoke genotypes (CN-52867, JA-89 and HEL-65) were planted in 15 day-intervals between with thirteen different dates (Sep...

  18. Photoperiod and E-genes Directly Influence the Duration of Soybean Reproductive Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Duration of the reproductive phase (DRP) is critical for soybean [Glycine max (L.) Merr.] yield. Manipulation of this phase may benefit breeding for higher yield. The soybean E-gene series control time to flowering and maturity through a photoperiod-mediated response. It is possible that E-genes and...

  19. Photoperiod and aggression induce changes in ventral gland compounds exclusively in male Siberian hamsters.

    PubMed

    Rendon, Nikki M; Soini, Helena A; Scotti, Melissa-Ann L; Weigel, Ellen R; Novotny, Milos V; Demas, Gregory E

    2016-05-01

    Chemical communication is a critical component of social behavior as it facilitates social encounters, allows for evaluation of the social partner, defines territories and resources, and advertises information such as sex and physiological state of an animal. Odors provide a key source of information about the social environment to rodents; however, studies identifying chemical compounds have thus far focused primarily on few species, particularly the house mouse. Moreover, considerably less attention has been focused on how environmental factors, reproductive phenotype, and behavioral context alter these compounds outside of reproduction. We examined the effects of photoperiod, sex, and social context on chemical communication in the seasonally breeding Siberian hamster. We sampled ventral gland secretions in both male and female hamsters before and after an aggressive encounter and identified changes in a range of volatile compounds. Next, we investigated how photoperiod, reproductive phenotype, and aggression altered ventral gland volatile compound composition across the sexes. Males exhibited a more diverse chemical composition, more sex-specific volatiles, and showed higher levels of excretion compared to females. Individual volatiles were also differentially excreted across photoperiod and reproductive phenotype, as well as differentially altered in response to an aggressive encounter. Female volatile compound composition, in contrast, did not differ across photoperiods or in response to aggression. Collectively, these data contribute to a greater understanding of context-dependent changes in chemical communication in a seasonally breeding rodent. PMID:26944610

  20. A neuroendocrine role for chemerin in hypothalamic remodelling and photoperiodic control of energy balance

    PubMed Central

    Helfer, Gisela; Ross, Alexander W.; Thomson, Lynn M.; Mayer, Claus D.; Stoney, Patrick N.; McCaffery, Peter J.; Morgan, Peter J.

    2016-01-01

    Long-term and reversible changes in body weight are typical of seasonal animals. Thyroid hormone (TH) and retinoic acid (RA) within the tanycytes and ependymal cells of the hypothalamus have been implicated in the photoperiodic response. We investigated signalling downstream of RA and how this links to the control of body weight and food intake in photoperiodic F344 rats. Chemerin, an inflammatory chemokine, with a known role in energy metabolism, was identified as a target of RA. Gene expression of chemerin (Rarres2) and its receptors were localised within the tanycytes and ependymal cells, with higher expression under long (LD) versus short (SD) photoperiod, pointing to a physiological role. The SD to LD transition (increased food intake) was mimicked by 2 weeks of ICV infusion of chemerin into rats. Chemerin also increased expression of the cytoskeletal protein vimentin, implicating hypothalamic remodelling in this response. By contrast, acute ICV bolus injection of chemerin on a 12 h:12 h photoperiod inhibited food intake and decreased body weight with associated changes in hypothalamic neuropeptides involved in growth and feeding after 24 hr. We describe the hypothalamic ventricular zone as a key site of neuroendocrine regulation, where the inflammatory signal, chemerin, links TH and RA signaling to hypothalamic remodeling. PMID:27225311

  1. Photoperiodic Diapause and the Establishment of Aedes albopictus (Diptera: Culicidae) in North America.

    PubMed

    Armbruster, Peter A

    2016-09-01

    The invasion and range expansion of Aedes albopictus (Skuse) in North America represents an outstanding opportunity to study processes of invasion, range expansion, and climatic adaptation. Furthermore, knowledge obtained from such research is relevant to developing novel strategies to control this important vector species. Substantial evidence indicates that the photoperiodic diapause response is an important adaptation to climatic variation across the range of Ae. albopictus in North America. Photoperiodic diapause is a key determinant of abundance in both space and time, and the timing of entry into and exit out of diapause strongly affects seasonal population dynamics and thus the potential for arbovirus transmission. Emerging genomic technologies are making it possible to develop high-resolution, genome-wide genetic markers that can be used for genetic mapping of traits relevant to disease transmission and phylogeographic studies to elucidate invasion history. Recent work using next-generation sequencing technologies (e.g., RNA-seq), combined with physiological experiments, has provided extensive insight into the transcriptional basis of the diapause response in Ae. albopictus Applying this knowledge to identify novel targets for vector control represents an important future challenge. Finally, recent studies have begun to identify traits other than diapause that are affected by photoperiodism. Extending this work to identify additional traits influenced by photoperiod should produce important insights into the seasonal biology of Ae. albopictus. PMID:27354438

  2. Influence of photoperiod on growth for three desert CAM species. [Agave deserti, Ferocactus acanthodes, Opuntia ficus-indica

    SciTech Connect

    Nobel, P.S. )

    1989-03-01

    Agave deserti, Ferocactus acanthodes, and Opuntia ficus-indica were maintained in environmental growth chambers under a constant total daily photosynthetically active radiation (PAR) for 1 yr to investigate the effects of photoperiod on growth of these Crassulacean acid metabolism (CAM) species. As the photoperiod was increased from 6 h to 18 h, growth increased 33% for A. deserti, 81% for F. acanthodes, and 50% for O. ficus-indica. Such increases were explained based on PAR saturation of the C{sub 3} photosynthetic carbon reduction cycle utilized by CAM plants during the daytime. In particular, the highest instantaneous PAR occurred for the shortest photoperiod and led to less growth for the same total daily PAR. Also, the total daily net CO{sub 2} uptake which occurred primarily at night, increased 53% as the photoperiod was increased from 6 to 18 h for O. ficus-indica, even though the accompanying night length decreased. The only other observed morphological effect was the sevenfold increase in the number of new cladodes initiated as the photoperiod was increased from 6 h to 18 h for O. ficus-indica. The influence of photoperiod on the daily pattern of net CO{sub 2} uptake and lack of effect of drought on plant survival under long photoperiods for O. ficus-indica differ from previous reports on this and other CAM species.

  3. The contribution of an hourglass timer to the evolution of photoperiodic response in the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Bradshaw, W E; Quebodeaux, I M C; Holzapfel, C M

    2003-10-01

    Photoperiodism, the ability to assess the length of day or night, enables a diverse array of plants, birds, mammals, and arthropods to organize their development and reproduction in concert with the changing seasons in temperate climatic zones. For more than 60 years, the mechanism controlling photoperiodic response has been debated. Photoperiodism may be a simple interval timer, that is, an hourglasslike mechanism that literally measures the length of day or night or, alternatively, may be an overt expression of an underlying circadian oscillator. Herein, we test experimentally whether the rhythmic response in Wyeomyia smithii indicates a causal, necessary relationship between circadian rhythmicity and the evolutionary modification of photoperiodic response over the climatic gradient of North America, or may be explained by a simple interval timer. We show that a day-interval timer is sufficient to predict the photoperiodic response of W. smithii over this broad geographic range and conclude that rhythmic responses observed in classical circadian-based experiments alone cannot be used to infer a causal role for circadian rhythmicity in the evolution of photoperiodic time measurement. More importantly, we argue that the pursuit of circadian rhythmicity as the central mechanism that measures the duration of night or day has distracted researchers from consideration of the interval-timing processes that may actually be the target of natural selection linking internal photoperiodic time measurement to the external seasonal environment. PMID:14628922

  4. Genetic variation in male sexual behaviour in a population of white-footed mice in relation to photoperiod

    PubMed Central

    Sharp, Kathy; Bucci, Donna; Zelensky, Paul K.; Chesney, Alanna; Tidhar, Wendy; Broussard, David R.; Heideman, Paul D.

    2015-01-01

    In natural populations, genetic variation in seasonal male sexual behaviour could affect behavioural ecology and evolution. In a wild-source population of white-footed mice, Peromyscus leucopus, from Virginia, U.S.A., males experiencing short photoperiod show high levels of genetic variation in reproductive organ mass and neuroendocrine traits related to fertility. We tested whether males from two divergent selection lines, one that strongly suppresses fertility under short photoperiod (responder) and one that weakly suppresses fertility under short photoperiod (nonresponder), also differ in photoperiod-dependent sexual behaviour and responses to female olfactory cues. Under short, but not long, photoperiod, there were significant differences between responder and nonresponder males in sexual behaviour and likelihood of inseminating a female. Males that were severely oligospermic or azoospermic under short photoperiod failed to display sexual behaviour in response to an ovariectomized and hormonally primed receptive female. However, on the day following testing, females were positive for spermatozoa only when paired with a male having a sperm count in the normal range for males under long photoperiod. Males from the nonresponder line showed accelerated reproductive development under short photoperiod in response to urine-soiled bedding from females, but males from the responder line did not. The results indicate genetic variation in sexual behaviour that is expressed under short, but not long, photoperiod, and indicate a potential link between heritable neuroendocrine variation and male sexual behaviour. In winter in a natural population, this heritable behavioural variation could affect fitness, seasonal life history trade-offs and population growth. PMID:25983335

  5. Photoperiodic effects on seasonal physiology, reproductive status and hypothalamic gene expression in young male F344 rats.

    PubMed

    Tavolaro, F M; Thomson, L M; Ross, A W; Morgan, P J; Helfer, G

    2015-02-01

    Seasonal or photoperiodically sensitive animals respond to altered day length with changes in physiology (growth, food intake and reproductive status) and behaviour to adapt to predictable yearly changes in the climate. Typically, different species of hamsters, voles and sheep are the most studied animal models of photoperiodism. Although laboratory rats are generally considered nonphotoperiodic, one rat strain, the inbred Fischer 344 (F344) rat, has been shown to be sensitive to the length of daylight exposure by changing its physiological phenotype and reproductive status according to the season. The present study aimed to better understand the nature of the photoperiodic response in the F344 rat. We examined the effects of five different photoperiods on the physiological and neuroendocrine responses. Young male F344 rats were held under light schedules ranging from 8 h of light/day to 16 h of light/day, and then body weight, including fat and lean mass, food intake, testes weights and hypothalamic gene expression were compared. We found that rats held under photoperiods of ≥ 12 h of light/day showed increased growth and food intake relative to rats held under photoperiods of ≤ 10 h of light/day. Magnetic resonance imaging analysis confirmed that these changes were mainly the result of a change in lean body mass. The same pattern was evident for reproductive status, with higher paired testes weight in photoperiods of ≥ 12 h of light/day. Accompanying the changes in physiological status were major changes in hypothalamic thyroid hormone (Dio2 and Dio3), retinoic acid (Crabp1 and Stra6) and Wnt/β-Catenin signalling genes (sFrp2 and Mfrp). Our data demonstrate that a photoperiod schedule of 12 h of light/day is interpreted as a stimulatory photoperiod by the neuroendocrine system of young male F344 rats. PMID:25443173

  6. Evolutionary divergence of circadian and photoperiodic phenotypes in the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Mathias, Derrick; Reed, Laura K; Bradshaw, William E; Holzapfel, Christina M

    2006-04-01

    For decades, chronobiologists have investigated the relationship between the circadian clock that mediates daily activities and the photoperiodic timer that mediates seasonal activities. The main experiment used to infer a circadian basis for photoperiodic time measurement is the Nanda-Hamner protocol (NH). Herein, the authors compare additive and nonadditive (dominance and epistasis) genetic effects that lead to the divergence of populations of the pitcher-plant mosquito, Wyeomyia smithii, for critical photoperiod (CPP) and amplitude of the rhythmic response to NH for 3 temporal-geographic scales: 1) Over geological time between populations in northern and southern clades, 2) over millennial time between populations within the northern clade, and 3) over generational time between lines selected for long and short CPP from within a single population. The authors show that the pattern of additive, dominance, and epistatic effects depends on the time scale over which populations or lines have diverged. Patterns for genetic differences between populations for CPP and response to NH reveal similarities over geological and millennial time scales but differences over shorter periods of evolution. These results, and the observation that neither the period nor amplitude of the NH rhythm are significantly correlated with CPP among populations, lead the authors to conclude that the rhythmic response to NH has evolved independently of photoperiodic response in populations of W. smithii. The implication is that in this species, genetic modification of the circadian clock has not been the basis for the adaptive modification of photoperiodic time measurement over the climatic gradient of North America. PMID:16603677

  7. Interaction of Photoperiod and Vernalization Determines Flowering Time of Brachypodium distachyon1[C][W][OPEN

    PubMed Central

    Ream, Thomas S.; Woods, Daniel P.; Schwartz, Christopher J.; Sanabria, Claudia P.; Mahoy, Jill A.; Walters, Eric M.; Kaeppler, Heidi F.; Amasino, Richard M.

    2014-01-01

    Timing of flowering is key to the reproductive success of many plants. In temperate climates, flowering is often coordinated with seasonal environmental cues such as temperature and photoperiod. Vernalization is an example of temperature influencing the timing of flowering and is defined as the process by which a prolonged exposure to the cold of winter results in competence to flower during the following spring. In cereals, three genes (VERNALIZATION1 [VRN1], VRN2, and FLOWERING LOCUS T [FT]) have been identified that influence the vernalization requirement and are thought to form a regulatory loop to control the timing of flowering. Here, we characterize natural variation in the vernalization and photoperiod responses in Brachypodium distachyon, a small temperate grass related to wheat (Triticum aestivum) and barley (Hordeum vulgare). Brachypodium spp. accessions display a wide range of flowering responses to different photoperiods and lengths of vernalization. In addition, we characterize the expression patterns of the closest homologs of VRN1, VRN2 (VRN2-like [BdVRN2L]), and FT before, during, and after cold exposure as well as in different photoperiods. FT messenger RNA levels generally correlate with flowering time among accessions grown in different photoperiods, and FT is more highly expressed in vernalized plants after cold. VRN1 is induced by cold in leaves and remains high following vernalization. Plants overexpressing VRN1 or FT flower rapidly in the absence of vernalization, and plants overexpressing VRN1 exhibit lower BdVRN2L levels. Interestingly, BdVRN2L is induced during cold, which is a difference in the behavior of BdVRN2L compared with wheat VRN2 during cold. PMID:24357601

  8. Interaction of photoperiod and vernalization determines flowering time of Brachypodium distachyon.

    PubMed

    Ream, Thomas S; Woods, Daniel P; Schwartz, Christopher J; Sanabria, Claudia P; Mahoy, Jill A; Walters, Eric M; Kaeppler, Heidi F; Amasino, Richard M

    2014-02-01

    Timing of flowering is key to the reproductive success of many plants. In temperate climates, flowering is often coordinated with seasonal environmental cues such as temperature and photoperiod. Vernalization is an example of temperature influencing the timing of flowering and is defined as the process by which a prolonged exposure to the cold of winter results in competence to flower during the following spring. In cereals, three genes (VERNALIZATION1 [VRN1], VRN2, and FLOWERING LOCUS T [FT]) have been identified that influence the vernalization requirement and are thought to form a regulatory loop to control the timing of flowering. Here, we characterize natural variation in the vernalization and photoperiod responses in Brachypodium distachyon, a small temperate grass related to wheat (Triticum aestivum) and barley (Hordeum vulgare). Brachypodium spp. accessions display a wide range of flowering responses to different photoperiods and lengths of vernalization. In addition, we characterize the expression patterns of the closest homologs of VRN1, VRN2 (VRN2-like [BdVRN2L]), and FT before, during, and after cold exposure as well as in different photoperiods. FT messenger RNA levels generally correlate with flowering time among accessions grown in different photoperiods, and FT is more highly expressed in vernalized plants after cold. VRN1 is induced by cold in leaves and remains high following vernalization. Plants overexpressing VRN1 or FT flower rapidly in the absence of vernalization, and plants overexpressing VRN1 exhibit lower BdVRN2L levels. Interestingly, BdVRN2L is induced during cold, which is a difference in the behavior of BdVRN2L compared with wheat VRN2 during cold. PMID:24357601

  9. In Hospital and 3-Month Mortality and Functional Recovery Rate in Patients Treated for Hip Fracture by a Multidisciplinary Team

    PubMed Central

    Rostagno, Carlo; Buzzi, Roberto; Campanacci, Domenico; Boccacini, Alberto; Cartei, Alessandro; Virgili, Gianni; Belardinelli, Andrea; Matarrese, Daniela; Ungar, Andrea; Rafanelli, Martina; Gusinu, Roberto; Marchionni, Niccolò

    2016-01-01

    Objectives Medical comorbidities affect outcome in elderly patients with hip fracture. This study was designed to preliminarily evaluate the usefulness of a hip-fracture unit led by an internal medicine specialist. Methods In-hospital and 3-month outcomes in patients with hip fracture were prospectively evaluated in 121 consecutive patients assessed before and followed after surgery by a multidisciplinary team led by internal medicine specialist; 337 consecutive patients were recalled from ICD-9 discharge records and considered for comparison regarding in-hospital mortality. Results In the intervention period, patients treated within 48 hours were 54% vs. 26% in the historical cohort (P<0.0001). In-hospital mortality remained stable at about 2.3 per 1000 person-days. At 3 months, 10.3% of discharged patients had died, though less than 8% of patients developed postoperative complications (mainly pneumonia and respiratory failure). The presence of more than 2 major comorbidities and the loss of 3 or more BADL were independent predictors of death. 50/105 patients recovered previous functional capacity, but no independent predictor of functional recovery could be identified. Mean length of hospital stay significantly decreased in comparison to the historical cohort (13.6± 4.7 vs 17 ± 5 days, p = 0.0001). Combined end-point of mortality and length of hospitalization < 12 days was significantly lower in study period (27 vs 34%, p <0.0132). Conclusions Identification and stabilization of concomitant clinical problems by internal medicine specialists may safely decrease time to surgery in frail subjects with hip fracture. Moreover, integrated perioperative clinical management may shorten hospital stay with no apparent increase in in-hospital mortality and ultimately improve the outcome. These results are to be confirmed by a larger study presently ongoing at our institution. PMID:27389193

  10. Response of garlic (Allium sativum L.) bolting and bulbing to temperature and photoperiod treatments.

    PubMed

    Wu, Cuinan; Wang, Mengyi; Cheng, Zhihui; Meng, Huanwen

    2016-01-01

    This research was conducted to evaluate the effect of temperature and photoperiod treatments on the bolting and bulb formation of three local garlic cultivars (cvs) in two consecutive years. Naturally vernalized plants of cvs G107, G025 and G064 were transplanted into growth chambers and subjected to various combinations of temperature [T15/10, 15°C/10°C; T20/15, 20°C/15°C and T25/18, 25°C/18°C (day/night)] and photoperiod (L8, 8 h and L14,14 h) treatments. Plant growth, endogenous phytohormone and methyl jasmonate (MeJA) levels, along with the bolting and yield of garlic were evaluated. The experimental results from two consecutive years indicated that higher temperature (20°C or 25°C) and longer photoperiod (14 h) treatments significantly enhanced the garlic bolting, bulbing and cloving with a shorter growth period and a higher bulb weight. Moreover, the endogenous phytohormone and MeJA levels in the test plants were significantly increased by the higher temperature (25°C for the phytohormone level; 20°C for the MeJA level) and longer photoperiod [14 h, except for abscisic acid (ABA), which had the highest level at 8 h] conditions and were decreased by the lowest test temperature (15°C) and shorter photoperiod (8 h, except for ABA) conditions. This response coincided with that of the bulbing index, bolting rate, growth period and bulb weight. In addition, plants treated under the conditions of 20°C/15°C-14 h and 25°C/18°C-14 h produced the highest phytohormone levels (except for ABA) for cvs G025 and G064, respectively, and showed the best bolting and bulbing behavior. It is reasonable to assume that endogenous phytohormone (especially gibberellic acid) and MeJA levels are highly related to garlic bolting and bulbing, which might lead to the different responses of the three studied cultivars to the combination of temperature and photoperiod treatments. Furthermore, cvs G107 and G025 bolt well and have better bulb formation under 20

  11. Response of garlic (Allium sativum L.) bolting and bulbing to temperature and photoperiod treatments

    PubMed Central

    Wu, Cuinan; Wang, Mengyi; Cheng, Zhihui; Meng, Huanwen

    2016-01-01

    ABSTRACT This research was conducted to evaluate the effect of temperature and photoperiod treatments on the bolting and bulb formation of three local garlic cultivars (cvs) in two consecutive years. Naturally vernalized plants of cvs G107, G025 and G064 were transplanted into growth chambers and subjected to various combinations of temperature [T15/10, 15°C/10°C; T20/15, 20°C/15°C and T25/18, 25°C/18°C (day/night)] and photoperiod (L8, 8 h and L14,14 h) treatments. Plant growth, endogenous phytohormone and methyl jasmonate (MeJA) levels, along with the bolting and yield of garlic were evaluated. The experimental results from two consecutive years indicated that higher temperature (20°C or 25°C) and longer photoperiod (14 h) treatments significantly enhanced the garlic bolting, bulbing and cloving with a shorter growth period and a higher bulb weight. Moreover, the endogenous phytohormone and MeJA levels in the test plants were significantly increased by the higher temperature (25°C for the phytohormone level; 20°C for the MeJA level) and longer photoperiod [14 h, except for abscisic acid (ABA), which had the highest level at 8 h] conditions and were decreased by the lowest test temperature (15°C) and shorter photoperiod (8 h, except for ABA) conditions. This response coincided with that of the bulbing index, bolting rate, growth period and bulb weight. In addition, plants treated under the conditions of 20°C/15°C–14 h and 25°C/18°C–14 h produced the highest phytohormone levels (except for ABA) for cvs G025 and G064, respectively, and showed the best bolting and bulbing behavior. It is reasonable to assume that endogenous phytohormone (especially gibberellic acid) and MeJA levels are highly related to garlic bolting and bulbing, which might lead to the different responses of the three studied cultivars to the combination of temperature and photoperiod treatments. Furthermore, cvs G107 and G025 bolt well and have better bulb

  12. Pineal and circulating melatonin rhythms in the box turtle, Terrapene carolina triunguis: effect of photoperiod, light pulse, and environmental temperature.

    PubMed

    Vivien-Roels, B; Pévet, P; Claustrat, B

    1988-02-01

    Pineal and circulating melatonin concentrations have been measured throughout the 24-hr cycle in the box turtle, Terrapene carolina triunguis, under different conditions of photoperiod and temperature. An obvious effect of photoperiod on the duration of the night rise of pineal and circulating melatonin is observed; the period of elevated melatonin is 4.30 hr in long photoperiod (18L:6D) and 11.00 hr in short photoperiod (8L:16D). A single pulse of 1 hr illumination beginning 1.30 hr after the onset of darkness, in a 16L:8D cycle, has no effect on pineal or circulating melatonin levels. A clear effect of environmental temperature on the amplitude of the day-night rhythm of melatonin production is observed. A possible role of the pineal of poikilotherms in the transduction of several environmental factors, via the daily pattern of melatonin secretion, is hypothesized. PMID:3366352

  13. Circadian rhythmicity and photoperiodism in the pitcher-plant mosquito: adaptive response to the photic environment or correlated response to the seasonal environment?

    PubMed

    Bradshaw, W E; Quebodeaux, M C; Holzapfel, C M

    2003-05-01

    Many plants and animals use the length of day or photoperiod to cue their seasonal patterns of development, reproduction, dormancy, and migration. Among temperate arthropods, the median or critical photoperiod increases with latitude or altitude. Concomitantly, in beetles, moths, mites, flies, and mosquitoes, there is a declining expression of a rhythmic, presumably circadian-based, component of photoperiodic response. It has been proposed that the long summer days in the north select for a reduced response to light by the circadian clock, which results in this declining rhythmic expression and, consequently, longer northern critical photoperiods. However, these patterns might also be due to direct, seasonal selection on the critical photoperiod itself, which results in a correlated reduction in the rhythmic component as a result of internal physiological constraints within the organism. Using standard light duration and selection experiments, we show that evolution of photoperiodic time measurement in the mosquito, Wyeomyia smithii, results from the direct response of critical photoperiod to seasonal selection and a correlated response of the rhythmic component of photoperiodic time measurement. We conclude that expression of the circadian clock is necessary neither for the central mechanism of photoperiodic time measurement nor for the adaptive modification of critical photoperiod. PMID:12858281

  14. Dose-response to 3 months of quercetin-containing supplements on metabolite and quercetin conjugate profile in adults.

    PubMed

    Cialdella-Kam, Lynn; Nieman, David C; Sha, Wei; Meaney, Mary Pat; Knab, Amy M; Shanely, R Andrew

    2013-06-01

    Quercetin, a flavonol in fruits and vegetables, has been demonstrated to have antioxidant, anti-inflammatory and immunomodulating influences. The purpose of the present study was to determine if quercetin, vitamin C and niacin supplements (Q-500 = 500 mg/d of quercetin, 125 mg/d of vitamin C and 5 mg/d of niacin; Q-1000 = 1000 mg/d of quercetin, 250 mg/d of vitamin C and 10 mg/d of niacin) would alter small-molecule metabolite profiles and serum quercetin conjugate levels in adults. Healthy adults (fifty-eight women and forty-two men; aged 40-83 years) were assigned using a randomised double-blinded placebo-controlled trial to one of three supplement groups (Q-1000, Q-500 or placebo). Overnight fasted blood samples were collected at 0, 1 and 3 months. Quercetin conjugate concentrations were measured using ultra-performance liquid chromatography (UPLC)-MS/MS, and metabolite profiles were measured using two MS platforms (UPLC-quadrupole time-of-flight MS (TOFMS) and GC-TOFMS). Statistical procedures included partial least square discriminant analysis (PLS-DA) and linear mixed model analysis with repeated measures. After accounting for age, sex and BMI, quercetin supplementation was associated with significant shifts in 163 metabolites/quercetin conjugates (false discovery rate, P<0·05). The top five metabolite shifts were an increase in serum guaiacol, 2-oxo-4-methylthiobutanoic acid, allocystathionine and two bile acids. Inflammatory and oxidative stress metabolites were not affected. PLS-DA revealed a clear separation only between the 1000 mg/d and placebo groups (Q(2)Y = 0·763). The quercetin conjugate, isorhamnetin-3-glucuronide, had the highest concentration at 3 months followed by quercetin-3-glucuronide, quercetin-3-sulphate and quercetin diglucuronide. In human subjects, long-term quercetin supplementation exerts disparate and wide-ranging metabolic effects and changes in quercetin conjugate concentrations. Metabolic shifts were apparent at the 1000 mg

  15. Ethyl glucuronide in human hair after daily consumption of 16 or 32 g of ethanol for 3 months.

    PubMed

    Kronstrand, Robert; Brinkhagen, Linda; Nyström, Fredrik H

    2012-02-10

    The overall objectives of the study were to develop a sensitive method for ethyl glucuronide (EtG) determination in hair and then investigate if a low or moderate intake of ethanol could be differentiated from total abstinence. Forty-four subjects were included in the study, 12 males (7 drinkers and 5 abstinent) and 32 females (14 drinkers and 18 abstinent). The study lasted 3 months and the female drinkers consumed one glass (16 g of ethanol) and the males consumed two glasses (32 g of ethanol) of wine (13.5-14%) daily. Hair samples were collected as close as possible above the skin and the proximal 2 cm were analyzed for EtG. Hair was cut into pieces of about 0.5 cm length and washed before incubation overnight in water and then extracted on Clean Screen EtG Carbon columns. The LC/MS/MS system consisted of a Waters ACQUITY UPLC connected to an API 4000 triple quadrupole instrument. Two transitions for EtG and one for the internal standard EtG-D(5) were measured. The method was linear from 60 to 10,000 pg/sample. Imprecision studies were performed at three levels as well as with an authentic sample. Total imprecision was 16% at 200 pg/sample, 8% at 1000 pg/sample, 6% at 8000 pg/sample and 13% at 29 pg/mg in the authentic sample. Of those who drank two glasses of wine every day, four had measurable amounts of EtG in their hair (5-11 pg/mg), and in only one of the females drinking one glass of wine EtG was quantified (3 pg/mg). Among the 23 abstinent subjects two had traces of EtG in the hair. We conclude that persons who ingested 16 or 32 g of ethanol daily for 3 months presented with low concentrations of EtG in hair, well below the proposed threshold for overconsumption set at 30 pg/mg. In addition, none of those who ingested 16 g/day had concentrations over the proposed abstinence threshold of 7 pg/mg. PMID:21367545

  16. Association analysis of photoperiodic flowering time genes in west and central African sorghum [Sorghum bicolor (L.) Moench

    PubMed Central

    2012-01-01

    Background Photoperiod-sensitive flowering is a key adaptive trait for sorghum (Sorghum bicolor) in West and Central Africa. In this study we performed an association analysis to investigate the effect of polymorphisms within the genes putatively related to variation in flowering time on photoperiod-sensitive flowering in sorghum. For this purpose a genetically characterized panel of 219 sorghum accessions from West and Central Africa was evaluated for their photoperiod response index (PRI) based on two sowing dates under field conditions. Results Sorghum accessions used in our study were genotyped for single nucleotide polymorphisms (SNPs) in six genes putatively involved in the photoperiodic control of flowering time. Applying a mixed model approach and previously-determined population structure parameters to these candidate genes, we found significant associations between several SNPs with PRI for the genes CRYPTOCHROME 1 (CRY1-b1) and GIGANTEA (GI). Conclusions The negative values of Tajima's D, found for the genes of our study, suggested that purifying selection has acted on genes involved in photoperiodic control of flowering time in sorghum. The SNP markers of our study that showed significant associations with PRI can be used to create functional markers to serve as important tools for marker-assisted selection of photoperiod-sensitive cultivars in sorghum. PMID:22394582

  17. Effect of Light Intensity and Photoperiod on Growth and Biochemical Composition of a Local Isolate of Nostoc calcicola.

    PubMed

    Khajepour, Fateme; Hosseini, Seyed Abbas; Ghorbani Nasrabadi, Rasoul; Markou, Giorgos

    2015-08-01

    A study was conducted to investigate the effect of light intensity (21, 42, and 63 μmol photons m(-2) s(-1)) and photoperiod (8:16, 12:12, and 16:8 h light/dark) on the biomass production and its biochemical composition (total carotenoids, chlorophyll a, phycoerythrin (PE), phycocyanin (PC) and allophycocyanin (APC), total protein, and carbohydrates) of a local isolate of Nostoc calcicola. The results revealed that N. calcicola prefers dim light; however, the most of the levels of light intensity and photoperiod investigated did not have a significant impact on biomass production. Increasing light intensity biomass content of chlorophyll a, PE, PC, APC, and total protein decreased, while total carotenoids and carbohydrate increased. The same behavior was observed also when light duration (photoperiod) increased. The interaction effect of increasing light intensity and photoperiod resulted in an increase of carbohydrate and total carotenoids, and to the decrease of chlorophyll a, PE, PC, APC, and total protein content. The results indicate that varying the light regime, it is capable to manipulate the biochemical composition of the local isolate of N. calcicola, producing either valuable phycobiliproteins or proteins under low light intensity and shorter photoperiods, or producing carbohydrates and carotenoids under higher light intensities and longer photoperiods. PMID:26100389

  18. Internode and petiole elongation of soybean in response to photoperiod and end-of-day light quality

    NASA Technical Reports Server (NTRS)

    Thomas, J. F.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1985-01-01

    Elongation of main stem internodes and petioles of soybeans, Glycine max 'Ransom,' was examined in response to various photoperiod/temperature combinations and to end-of-day (EOD) light quality. Photoperiod treatments consisted of 10, 14, and 16 h in combination with day/night temperatures of 18/14, 22/18, 26/22, 30/26, and 34/30 C. The EOD treatments consisted of exposing plants to illumination from either incandescent (high far-red component, FR) or fluorescent (high red component, R) lamps during the final 0.5 h of a 10-h photoperiod. Internode elongation was not significantly promoted by the photoperiod treatments, and, in fact, under the two highest temperature regimes, internode elongation was suppressed under the longer photoperiods. Petiole elongation, however, was enhanced under the longer photoperiods at all temperatures. In the EOD light study, internode and petiole elongation was significantly greater on plants exposed to 0.5 h EOD from incandescent lamps than from fluorescent. Under the incandescent EOD treatment, plants increased dry matter production by 41% and exhibited greater partitioning of assimilates in stem and root portions than under fluorescent EOD.

  19. Quantitative trait loci associated with photoperiodic response and stage of diapause in the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Mathias, Derrick; Jacky, Lucien; Bradshaw, William E; Holzapfel, Christina M

    2007-05-01

    A wide variety of temperate animals rely on length of day (photoperiodism) to anticipate and prepare for changing seasons by regulating the timing of development, reproduction, dormancy, and migration. Although the molecular basis of circadian rhythms regulating daily activities is well defined, the molecular basis for the photoperiodic regulation of seasonal activities is largely unknown. We use geographic variation in the photoperiodic control of diapause in the pitcher-plant mosquito Wyeomyia smithii to create the first QTL map of photoperiodism in any animal. For critical photoperiod (CPP), we detect QTL that are unique, a QTL that is sex linked, QTL that overlap with QTL for stage of diapause (SOD), and a QTL that interacts epistatically with the circadian rhythm gene, timeless. Results presented here confirm earlier studies concluding that CPP is under directional selection over the climatic gradient of North America and that the evolution of CPP is genetically correlated with SOD. Despite epistasis between timeless and a QTL for CPP, timeless is not located within any detectable QTL, indicating that it plays an ancillary role in the evolution of photoperiodism in W. smithii. Finally, we highlight one region of the genome that includes loci contributing to CPP, SOD, and hormonal regulation of development. PMID:17339202

  20. Quantitative Trait Loci Associated with Photoperiodic Response and Stage of Diapause in the Pitcher-Plant Mosquito, Wyeomyia smithii

    PubMed Central

    Mathias, Derrick; Jacky, Lucien; Bradshaw, William E.; Holzapfel, Christina M.

    2007-01-01

    A wide variety of temperate animals rely on length of day (photoperiodism) to anticipate and prepare for changing seasons by regulating the timing of development, reproduction, dormancy, and migration. Although the molecular basis of circadian rhythms regulating daily activities is well defined, the molecular basis for the photoperiodic regulation of seasonal activities is largely unknown. We use geographic variation in the photoperiodic control of diapause in the pitcher-plant mosquito Wyeomyia smithii to create the first QTL map of photoperiodism in any animal. For critical photoperiod (CPP), we detect QTL that are unique, a QTL that is sex linked, QTL that overlap with QTL for stage of diapause (SOD), and a QTL that interacts epistatically with the circadian rhythm gene, timeless. Results presented here confirm earlier studies concluding that CPP is under directional selection over the climatic gradient of North America and that the evolution of CPP is genetically correlated with SOD. Despite epistasis between timeless and a QTL for CPP, timeless is not located within any detectable QTL, indicating that it plays an ancillary role in the evolution of photoperiodism in W. smithii. Finally, we highlight one region of the genome that includes loci contributing to CPP, SOD, and hormonal regulation of development. PMID:17339202

  1. Effects of Photoperiod Extension on Clock Gene and Neuropeptide RNA Expression in the SCN of the Soay Sheep

    PubMed Central

    Dardente, Hugues; Wyse, Cathy A.; Lincoln, Gerald A.; Wagner, Gabriela C.; Hazlerigg, David G.

    2016-01-01

    In mammals, changing daylength (photoperiod) is the main synchronizer of seasonal functions. The photoperiodic information is transmitted through the retino-hypothalamic tract to the suprachiasmatic nuclei (SCN), site of the master circadian clock. To investigate effects of day length change on the sheep SCN, we used in-situ hybridization to assess the daily temporal organization of expression of circadian clock genes (Per1, Per2, Bmal1 and Fbxl21) and neuropeptides (Vip, Grp and Avp) in animals acclimated to a short photoperiod (SP; 8h of light) and at 3 or 15 days following transfer to a long photoperiod (LP3, LP15, respectively; 16h of light), achieved by an acute 8-h delay of lights off. We found that waveforms of SCN gene expression conformed to those previously seen in LP acclimated animals within 3 days of transfer to LP. Mean levels of expression for Per1-2 and Fbxl21 were nearly 2-fold higher in the LP15 than in the SP group. The expression of Vip was arrhythmic and unaffected by photoperiod, while, in contrast to rodents, Grp expression was not detectable within the sheep SCN. Expression of the circadian output gene Avp cycled robustly in all photoperiod groups with no detectable change in phasing. Overall these data suggest that synchronizing effects of light on SCN circadian organisation proceed similarly in ungulates and in rodents, despite differences in neuropeptide gene expression. PMID:27458725

  2. Temperature dependence and evolutionary adjustment of critical night length in insect photoperiodism

    PubMed Central

    Pittendrigh, Colin S.; Takamura, Tsuguhiko

    1987-01-01

    The photoperiodic responses of Drosophila auraria are shown to involve its circadian system functioning as the “clock” that measures the duration of darkness at night. Attempts at further clarification of this finding were based on the widely held assumption that adaptive adjustment of critical night length is caused by change in the circadian system's entrainment behavior. Three different experimental programs yielded data that are incompatible with this starting premise. Collectively, the observations suggest a new interpretation of the lability (phenotypic and genetic) of critical night length based on change in the level of response to all night-length measurements—not on the measurements themselves. This proposition is found especially relevant to the temperature dependence of photoperiodic responses and its role in controlling the onset and termination of the breeding season at different latitudes. PMID:16593882

  3. Pineal and photoperiodic influences on fat deposition, pelage, and testicular activity in male meadow voles.

    PubMed

    Smale, L; Dark, J; Zucker, I

    1988-01-01

    Pinealectomy completely prevented gonadal regression as well as reduction in body weight and white adipose tissue content of the gonadal and retroperitoneal fat deposits in male meadow voles transferred from long to short day lengths. Pineal influences on pelage characteristics depended on which parameter was assessed. For instance, the increase in guard hair length observed in short-day control voles was blocked by pinealectomy; however, a similar increase in underhair length was unaffected by removal of the pineal gland. Photoperiod-dependent changes in fat deposition, testicular activity, and guard hair length presumably rely on altered pineal secretory activity to transduce the effects of day length on the neuroendocrine axis; however, mechanisms independent of pineal activity may be capable of mediating photoperiodic control of underhair growth. PMID:2979644

  4. Photoperiod and gonadal hormones influence odor preferences of the male meadow vole, Microtus pennsylvanicus.

    PubMed

    Ferkin, M H; Gorman, M R

    1992-05-01

    Male meadow voles housed in a long photoperiod (14 h light/day, LP) preferred female to male odors, whereas males maintained in a short photoperiod (10 h light/day, SP) did not display preferences for odors of either sex. These odor-preference patterns matched those of free-living males during spring and autumn, respectively. The preference of LP male voles for female over male odors was eliminated by gonadectomy and reinstated by treatment with testosterone. In SP males, although gonadectomy did not affect odor choices, a preference for female odors was induced by testosterone treatment. Treatment with estradiol did not alter odor preferences of LP or SP males. In conjunction with previous result, the present findings suggest that hormonal responsiveness of neural substrates that control odor preferences are sexually dimorphic and may reflect sex differences in reproductive strategies. PMID:1615048

  5. Histologic evaluation of a biopsy specimen obtained 3 months after rotator cuff augmentation with GraftJacket Matrix.

    PubMed

    Snyder, Stephen J; Arnoczky, Steven P; Bond, James L; Dopirak, Ryan

    2009-03-01

    Understanding the cellular response to a biologic graft used in rotator cuff applications is important because foreign-body reactions and inflammation complications have historically been seen with xenograft-derived grafts. The purpose of this study was to histologically evaluate a biopsy specimen taken from a rotator cuff of a 62-year-old man 3 months after augmentation with an acellular human dermal graft, GraftJacket Matrix-MaxForce Extreme (Wright Medical Technology, Arlington, TN). The graft material was intact and filled with numerous elastic fibers and blood vessels. Extensive host cellular infiltration was evident along the margins of the graft, whereas the more central regions were more sparsely populated. Calcification and infection were not evident. There was little to no inflammatory response. The orientation of the collagen fibers indicated early organization of new tissue. The incorporation of the GraftJacket Matrix-MaxForce Extreme evidenced by cellular infiltration, alignment of collagen fibers, and blood vessel ingrowth shows that this graft exhibits key biologic factors of the remodeling process when used as an augmentation device in rotator cuff repair. PMID:19245998

  6. The impact of psychiatric disorders with cardiac syndrome X on quality of life: 3 months prospective study

    PubMed Central

    Altintas, Ebru; Yigit, Fatma; Taskintuna, Nilgun

    2014-01-01

    The aim of the study is to investigate the impact of psychiatric disorders with cardiac syndrome X (CSX) on the patients’ quality of life, as well as the efficacy of psychiatric support. Fifty-six CSX and fifty-three Coronary Heart Disease patients were included in the study after coronary angiography. Patients were evaluated right after the angiography and 3 months thereafter. The socio-demographic characteristics, comorbid disorders, Beck Anxiety (BAI), Depression (BDI) Inventory, and Health Related Quality of Life (SF-36) were compared between groups. The most common mental disorders was depression which account for 41%, the next were anxiety disorders (64%, n = 36) and somatoform (24%, n = 14). Initially, BAI, BDI in the CSX group were significantly higher when compared to the control group. There was significant difference in all subgroups of SF-36 at the end of the second evaluation versus the first evaluation in the CSX patients. The present study revealed that patients with CSX have higher prevalence of psychiatric comorbidities and lower quality of life. Psychiatric approaches are benefit for CSX patients to improvement their quality of life. PMID:25419392

  7. Osteomyelitis at the injection site of adrenalin through an intraosseous needle in a 3-month-old infant.

    PubMed

    Stoll, E; Golej, J; Burda, G; Hermon, M; Boigner, H; Trittenwein, G

    2002-06-01

    Intraosseous (IO) puncture is considered for the administration of drugs and fluids when vascular access cannot be achieved rapidly. Adrenaline/epinephrine, adenosine, crystalloids, colloids and blood products can be applied and administered effectively using this route during resuscitation of children. This technique is relatively simple with complications of <1%. These may include tibial fracture, lower extremity compartment syndrome and osteomyelitis. A case is described in which a 3-month-old male infant presented for emergency resuscitation requiring IO infusion utilising both tibial bones. High doses of adrenaline (1:1000; 0.1 mg/kg) were administered in the right tibial epiphysis only after the standard initial concentration (1:10000; 0.01 mg/kg) had minimal effect. A local inflammatory reaction was noted 24 h later in the right tibial region, which developed into cutaneous necrosis, and was eventually resected. Radiologically, no osseous lesion could be demonstrated, however, a bone scintigram revealed osteomyelitis. Upon surgical revision, purulent destruction was evident requiring removal of the epiphysis and part of the metaphysis. Although osteomyelitis is a rare complication which may be caused by sepsis, or contamination during insertion, we speculate that adrenaline in high concentrations may promote the development of osteomyelitis and the drug should be applied cautiously in more diluted concentrations. PMID:12062848

  8. Higher Retail Prices of Sugar-Sweetened Beverages 3 Months After Implementation of an Excise Tax in Berkeley, California

    PubMed Central

    Rojas, Nadia; Grummon, Anna H.; Madsen, Kristine A.

    2015-01-01

    Objectives. We assessed the short-term ability to increase retail prices of the first US 1-cent-per-ounce excise tax on the distribution of sugar-sweetened beverages (SSBs), which was implemented in March 2015 by Berkeley, California. Methods. In 2014 and 2015, we examined pre- to posttax price changes of SSBs and non-SSBs in a variety of retailers in Berkeley and in the comparison cities Oakland and San Francisco, California. We examined price changes by beverage, brand, size, and retailer type. Results. For smaller beverages (≤ 33.8 oz), price increases (cents/oz) in Berkeley relative to those in comparison cities were 0.69 (95% confidence interval [CI] = 0.36, 1.03) for soda, 0.47 (95% CI = 0.08, 0.87) for fruit-flavored beverages, and 0.47 (95% CI = 0.25, 0.69) for SSBs overall. For 2-liter bottles and multipacks of soda, relative price increases were 0.46 (95% CI = 0.03, 0.89) and 0.49 (95% CI = 0.21, 0.77). We observed no relative price increases for nontaxed beverages overall. Conclusions. Approximately 3 months after the tax was implemented, SSB retail prices increased more in Berkeley than in nearby cities, marking a step in the causal pathway between the tax and reduced SSB consumption. PMID:26444622

  9. A 3-month-old infant with recurrent apparent life-threatening events in a car seat.

    PubMed

    DelRosso, Lourdes M

    2015-04-01

    A 3-month-old infant was brought to clinic for evaluation of recurrent apparent life-threatening events (ALTEs). Two ALTE episodes occurred while the infant was sleeping in a safety car seat. The first one occurred when he was 4 weeks old. His mother noticed that he was not breathing; he appeared limp with full body cyanosis. His mother picked him up from the car seat, and he started breathing spontaneously and without any sign of distress. His skin color returned to normal. He was evaluated at the ED where the physical examination was normal. He was hospitalized 1 day for observation. During this time, workup, including ECG and chest radiograph, was normal. The parents were instructed on cardiorespiratory resuscitation and recommended to change car seats. The infant was discharged with an apnea monitor. He wore the apnea monitor while in the car seat. A second similar episode occurred at 10 weeks of age for which he was seen at the ED and referred to our clinic for further evaluation. Neither episode was related to feeding. PMID:25846540

  10. Mobile phone text messaging and Telephone follow-up in type 2 diabetic patients for 3 months: a comparative study

    PubMed Central

    2012-01-01

    Background To investigate and to compare the effectiveness of a nurse short message service (SMS) by cellular phone and telephone follow-up by nurse on Glycosylated hemoglobin (HbA1c) levels in people with type 2 diabetes. Methods Semi experimental study consisted of 77 patients with type 2 diabetes that randomly assigned to two groups: telephone follow-up (n = 39) and short message service (n = 38). Telephone interventions were applied by researcher for 3 months. SMS group that received message daily for 12 weeks. Data gathering instrument include data sheet to record HbA1c and questionnaire that consisted of demographic characteristics. Data gathering was performed at two points: initial the study and after 12 weeks. Data analyzed using descriptive and inferential statistics methods with SPSS version 11.5. Results Demographic variables were compared and all of them were homogenous. Results of this study showed that both interventions had significant mean changes in HbA1c; for the telephone group (p = 0.001), with a mean change of −0.93% and for the SMS group (p = 0.001), with a mean change of −1.01%. Conclusion Finding of this research showed that intervention using SMS via cellular phone and nurse-led-telephone follow up improved HbA1c for three months in type 2 diabetic patients and it can consider as alternative methods for diabetes control. PMID:23497735

  11. Maintenance of sperm production in bucks during a third year of short photoperiodic cycles.

    PubMed

    Delgadillo, J A; Leboeuf, B; Chemineau, P

    1993-01-01

    We have previously shown that reproductive seasonality of bucks was prevented for 2 consecutive years by short photoperiodic cycles. To determine the effect of the length of treatment time on bucks subjected to the same photoperiod conditions, experiments were continued for a third consecutive year on 3 groups of 6 Alpine and Saanen bucks. The control group was kept under natural photoperiodic conditions, while the experimental groups were exposed alternately to 1 month of long days and 1 month of short days (group 2M) or to 2 months of long days and 2 months of short days (group, 4M). Prolactin profiles indicated that bucks from both experimental groups responded adequately to rapid photoperiod changes as their plasma prolactin levels were significantly higher in long days (mean +/- SEM; 2M: 61.1 +/- 15.9 ng/ml; 4M: 102.2 +/- 13.5 ng/ml) than in short days (2M: 35.3 +/- 8.2 ng/ml; 4M: 46.1 +/- 9.0 ng/ml). Testosterone secretion was also dependent on day length (P < 0.0001), since testosterone concentrations of experimental animals were higher during long days (2M: 7.0 +/- 0.7 ng/ml; 4M: 10.2 +/- 1.1 ng/ml) than during short days (2M: 4.3 +/- 0.4 ng/ml; 4M: 5.0 +/- 0.9 ng/ml). Furthermore, controls displayed a high level of sexual behavior (always higher than 10%) and the proportion of bucks unable to ejaculate was significantly lower (P < 0.01) than the experimental animals (2M: 25.6%; 4M: 28.1%).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8142042

  12. Comparative Proteomic Analysis of the Response of Maize (Zea mays L.) Leaves to Long Photoperiod Condition.

    PubMed

    Wu, Liuji; Tian, Lei; Wang, Shunxi; Zhang, Jun; Liu, Ping; Tian, Zhiqiang; Zhang, Huimin; Liu, Haiping; Chen, Yanhui

    2016-01-01

    Maize (Zea mays L.), an important industrial material and food source, shows an astonishing environmental adaptation. A remarkable feature of its post-domestication adaptation from tropical to temperate environments is adaptation to a long photoperiod (LP). Many photoperiod-related genes have been identified in previous transcriptomics analysis, but proteomics shows less evidence for this mechanism of photoperiod response. In this study, we sampled newly expanded leaves of maize at the three- and six-leaf stages from an LP-sensitive introgression line H496, the donor CML288, LP-insensitive inbred line, and recurrent parent Huangzao4 (HZ4) grown under long days (15 h light and 9 h dark). To characterize the proteomic changes in response to LP, the iTRAQ-labeling method was used to determine the proteome profiles of plants exposed to LP. A total of 943 proteins differentially expressed at the three- and six-leaf stages in HZ4 and H496 were identified. Functional analysis was performed by which the proteins were classified into stress defense, signal transduction, carbohydrate metabolism, protein metabolism, energy production, and transport functional groups using the WEGO online tool. The enriched gene ontology categories among the identified proteins were identified statistically with the Cytoscape plugin ClueGO + Cluepedia. Twenty Gene Ontology terms showed the highest significance, including those associated with protein processing in the endoplasmic reticulum, splicesome, ribosome, glyoxylate, dicarboxylate metabolism, L-malate dehydrogenase activity, and RNA transport. In addition, for subcellular location, all proteins showed significant enrichment of the mitochondrial outer membrane. The sugars producted by photosynthesis in plants are also a pivotal metabolic output in the circadian regulation. The results permit the prediction of several crucial proteins to photoperiod response and provide a foundation for further study of the influence of LP treatments on

  13. Photoperiod-modulated testis maturation in Atlantic cod (Gadus morhua, L.).

    PubMed

    Almeida, Fernanda F L; Taranger, Geir Lasse; Norberg, Birgitta; Karlsen, Orjan; Bogerd, Jan; Schulz, Rüdiger W

    2009-04-01

    Precocious male puberty is a significant problem in Atlantic cod aquaculture. While photoperiod manipulation can inhibit testis growth, a detailed analysis of effects on spermatogenesis is missing. Starting July 1, 2004, prepubertal fish were exposed to different photoperiod regimens in indoor tanks for 17 mo. Testis histology, germ cell dynamics (proliferation and apoptosis), and plasma androgen levels were analyzed. In the natural light (NL) group, testis growth started in September 2004 and was completed in February 2005, when a 2-mo spawning period started. In the constant light (LL) group, none or very few spermatogenic cysts were recruited into spermatogenesis, and apoptotic germ cell loss was high. A change of photoperiod from NL to LL at winter solstice (December 21, 2004) resulted in premature (2 mo) completion of the reproductive cycle, while changing from LL to NL at winter solstice triggered faster than normal testis development. Plasma testosterone levels increased in the NL group from spermatogonial proliferation toward meiosis, while those of 11-ketotestosterone increased toward spermiogenesis and spermiation. Plasma androgen levels did not rise under LL conditions. Comparing fish with developing testes from all groups indicated that low androgen levels were associated with a high incidence of spermatogonial apoptosis; we also found that androgen receptor mRNA expression was most prominent in Sertoli cells in contact with growing spermatogonial clones. Our data show that an inhibitory photoperiod (LL) reduced or blocked differentiation of spermatogonia, increased apoptosis (particularly among proliferating spermatogonia), and was associated with reduced androgen levels, a situation possibly reflecting insufficient gonadotropic stimulation. PMID:19038862

  14. Social, but not photoperiodic, influences on reproductive function in male Peromyscus aztecus.

    PubMed

    Demas, G E; Nelson, R J

    1998-02-01

    Nontropical rodents rely on environmental factors to restrict breeding to a specific time of the year. Among these factors, photoperiod appears to be the primary environmental cue used for predicting optimal breeding conditions. The purpose of the present study was to characterize reproductive function, as well as photoperiodic and social responsiveness in male Peromyscus aztecus, which occupy low-latitude, high-altitude habitats. In experiment 1, adult male P. aztecus were individually housed in either long (16L:8D) or short days (8L:16D) for 10 wk. Short-day mice did not differ from long-day mice on any reproductive or nonreproductive parameter. Comparisons to related Peromyscus species suggested that relative reproductive organ size and function were reduced in both long- and short-day males. Because ad libitum food and water were available, we reasoned that males in both photoperiodic conditions lacked social stimuli. To test this hypothesis, adult male P. aztecus were housed in long days either individually or with a female conspecific in experiment 2. Mice housed with females had significantly larger relative paired testes and epididymal masses, and higher testicular sperm counts and serum testosterone levels compared to those of individually housed mice. Taken together, these results suggest that social factors may play a more prominent role than photoperiod in stimulating reproductive development in laboratory-housed P. aztecus. These results are consistent with the results found for other low-latitude rodent species and suggest that P. aztecus uses a flexible rather than obligatory breeding strategy. PMID:9475393

  15. Comparative Proteomic Analysis of the Response of Maize (Zea mays L.) Leaves to Long Photoperiod Condition

    PubMed Central

    Wu, Liuji; Tian, Lei; Wang, Shunxi; Zhang, Jun; Liu, Ping; Tian, Zhiqiang; Zhang, Huimin; Liu, Haiping; Chen, Yanhui

    2016-01-01

    Maize (Zea mays L.), an important industrial material and food source, shows an astonishing environmental adaptation. A remarkable feature of its post-domestication adaptation from tropical to temperate environments is adaptation to a long photoperiod (LP). Many photoperiod-related genes have been identified in previous transcriptomics analysis, but proteomics shows less evidence for this mechanism of photoperiod response. In this study, we sampled newly expanded leaves of maize at the three- and six-leaf stages from an LP-sensitive introgression line H496, the donor CML288, LP-insensitive inbred line, and recurrent parent Huangzao4 (HZ4) grown under long days (15 h light and 9 h dark). To characterize the proteomic changes in response to LP, the iTRAQ-labeling method was used to determine the proteome profiles of plants exposed to LP. A total of 943 proteins differentially expressed at the three- and six-leaf stages in HZ4 and H496 were identified. Functional analysis was performed by which the proteins were classified into stress defense, signal transduction, carbohydrate metabolism, protein metabolism, energy production, and transport functional groups using the WEGO online tool. The enriched gene ontology categories among the identified proteins were identified statistically with the Cytoscape plugin ClueGO + Cluepedia. Twenty Gene Ontology terms showed the highest significance, including those associated with protein processing in the endoplasmic reticulum, splicesome, ribosome, glyoxylate, dicarboxylate metabolism, L-malate dehydrogenase activity, and RNA transport. In addition, for subcellular location, all proteins showed significant enrichment of the mitochondrial outer membrane. The sugars producted by photosynthesis in plants are also a pivotal metabolic output in the circadian regulation. The results permit the prediction of several crucial proteins to photoperiod response and provide a foundation for further study of the influence of LP treatments on

  16. Differences in Number of Midbrain Dopamine Neurons Associated with Summer and Winter Photoperiods in Humans

    PubMed Central

    Aumann, Tim D.; Raabus, Mai; Tomas, Doris; Prijanto, Agustinus; Churilov, Leonid; Spitzer, Nicholas C.; Horne, Malcolm K.

    2016-01-01

    Recent evidence indicates the number of dopaminergic neurons in the adult rodent hypothalamus and midbrain is regulated by environmental cues, including photoperiod, and that this occurs via up- or down-regulation of expression of genes and proteins that are important for dopamine (DA) synthesis in extant neurons (‘DA neurotransmitter switching’). If the same occurs in humans, it may have implications for neurological symptoms associated with DA imbalances. Here we tested whether there are differences in the number of tyrosine hydroxylase (TH, the rate-limiting enzyme in DA synthesis) and DA transporter (DAT) immunoreactive neurons in the midbrain of people who died in summer (long-day photoperiod, n = 5) versus winter (short-day photoperiod, n = 5). TH and DAT immunoreactivity in neurons and their processes was qualitatively higher in summer compared with winter. The density of TH immunopositive (TH+) neurons was significantly (~6-fold) higher whereas the density of TH immunonegative (TH-) neurons was significantly (~2.5-fold) lower in summer compared with winter. The density of total neurons (TH+ and TH- combined) was not different. The density of DAT+ neurons was ~2-fold higher whereas the density of DAT- neurons was ~2-fold lower in summer compared with winter, although these differences were not statistically significant. In contrast, midbrain nuclear volume, the density of supposed glia (small TH- cells), and the amount of TUNEL staining were the same in summer compared with winter. This study provides the first evidence of an association between environmental stimuli (photoperiod) and the number of midbrain DA neurons in humans, and suggests DA neurotransmitter switching underlies this association. PMID:27428306

  17. S22153, a melatonin antagonist, dissociates different aspects of photoperiodic responses in Syrian hamsters.

    PubMed

    Pitrosky, B; Delagrange, P; Rettori, M C; Pévet, P

    2003-01-22

    In the Syrian hamster, short photoperiod (SP) induces changes in several physiological functions (body mass, reproduction, hibernation), and these responses involve the pineal hormone melatonin. The present study investigated the effects of a melatonin antagonist, S22153, on photoperiodic adaptation of male Syrian hamster. When constantly released from subcutaneous implants, S22153 had no effect on body or testes masses of animals kept in long photoperiod. S22153 decreased the total hibernation duration observed in animals exposed to SP and low temperature. The decrease in hibernation duration was due to a marked reduction in the number and duration of hypothermic bouts. Moreover, S22153 significantly inhibited the increase of interscapular brown adipose tissue (BAT) mass induced by SP. However, neither the gonadal atrophy nor the body mass increase induced by SP were affected by S22153. These results show that S22153 affects only part of the physiological changes controlled by SP and cold. Whether the decreases in BAT mass and hibernation duration are linked still remains an open question. PMID:12527445

  18. An Evolutionarily Conserved DOF-CONSTANS Module Controls Plant Photoperiodic Signaling.

    PubMed

    Lucas-Reina, Eva; Romero-Campero, Francisco J; Romero, José M; Valverde, Federico

    2015-06-01

    The response to daylength is a crucial process that evolved very early in plant evolution, entitling the early green eukaryote to predict seasonal variability and attune its physiological responses to the environment. The photoperiod responses evolved into the complex signaling pathways that govern the angiosperm floral transition today. The Chlamydomonas reinhardtii DNA-Binding with One Finger (CrDOF) gene controls transcription in a photoperiod-dependent manner, and its misexpression influences algal growth and viability. In short days, CrDOF enhances CrCO expression, a homolog of plant CONSTANS (CO), by direct binding to its promoter, while it reduces the expression of cell division genes in long days independently of CrCO. In Arabidopsis (Arabidopsis thaliana), transgenic plants overexpressing CrDOF show floral delay and reduced expression of the photoperiodic genes CO and FLOWERING LOCUS T. The conservation of the DOF-CO module during plant evolution could be an important clue to understanding diversification by the inheritance of conserved gene toolkits in key developmental programs. PMID:25897001

  19. An Evolutionarily Conserved DOF-CONSTANS Module Controls Plant Photoperiodic Signaling1[OPEN

    PubMed Central

    2015-01-01

    The response to daylength is a crucial process that evolved very early in plant evolution, entitling the early green eukaryote to predict seasonal variability and attune its physiological responses to the environment. The photoperiod responses evolved into the complex signaling pathways that govern the angiosperm floral transition today. The Chlamydomonas reinhardtii DNA-Binding with One Finger (CrDOF) gene controls transcription in a photoperiod-dependent manner, and its misexpression influences algal growth and viability. In short days, CrDOF enhances CrCO expression, a homolog of plant CONSTANS (CO), by direct binding to its promoter, while it reduces the expression of cell division genes in long days independently of CrCO. In Arabidopsis (Arabidopsis thaliana), transgenic plants overexpressing CrDOF show floral delay and reduced expression of the photoperiodic genes CO and FLOWERING LOCUS T. The conservation of the DOF-CO module during plant evolution could be an important clue to understanding diversification by the inheritance of conserved gene toolkits in key developmental programs. PMID:25897001

  20. Photoperiodic Control of Carbon Distribution during the Floral Transition in Arabidopsis[C][W][OPEN

    PubMed Central

    Ortiz-Marchena, M. Isabel; Albi, Tomás; Lucas-Reina, Eva; Said, Fatima E.; Romero-Campero, Francisco J.; Cano, Beatriz; Ruiz, M. Teresa; Romero, José M.; Valverde, Federico

    2014-01-01

    Flowering is a crucial process that demands substantial resources. Carbon metabolism must be coordinated with development through a control mechanism that optimizes fitness for any physiological need and growth stage of the plant. However, how sugar allocation is controlled during the floral transition is unknown. Recently, the role of a CONSTANS (CO) ortholog (Cr-CO) in the control of the photoperiod response in the green alga Chlamydomonas reinhardtii and its influence on starch metabolism was demonstrated. In this work, we show that transitory starch accumulation and glycan composition during the floral transition in Arabidopsis thaliana are regulated by photoperiod. Employing a multidisciplinary approach, we demonstrate a role for CO in regulating the level and timing of expression of the GRANULE BOUND STARCH SYNTHASE (GBSS) gene. Furthermore, we provide a detailed characterization of a GBSS mutant involved in transitory starch synthesis and analyze its flowering time phenotype in relation to its altered capacity to synthesize amylose and to modify the plant free sugar content. Photoperiod modification of starch homeostasis by CO may be crucial for increasing the sugar mobilization demanded by the floral transition. This finding contributes to our understanding of the flowering process. PMID:24563199

  1. Sample Preparation of Arabidopsis thaliana Shoot Apices for Expression Studies of Photoperiod-Induced Genes.

    PubMed

    Andrés, Fernando; Torti, Stefano; Vincent, Coral; Coupland, George

    2016-01-01

    Plants produce new organs from a population of pluripotent cells which are located in specific tissues called meristems. One of these meristems, the shoot apical meristem (SAM), gives rise to leaves during the vegetative phase and flowers during the reproductive phase. The transition from vegetative SAM to an inflorescence meristem (IM) is a dramatic developmental switch, which has been particularly well studied in the model species Arabidopsis thaliana. This developmental switch is controlled by multiple environmental signals such as day length (or photoperiod), and it is accompanied by changes in expression of hundreds of genes. A major interest in plant biology is to identify and characterize those genes which are regulated in the stem cells of the SAM in response to the photoperiodic signals. In this sense, techniques such as RNA in situ hybridization (RNA ISH) have been very successfully employed to detect the temporal and spatial expression patterns of genes in the SAM. This method can be specifically optimized for photoperiodic-flowering studies. In this chapter, we describe improved methods to generate plant material and histological samples to be combined with RNA ISH in flowering-related studies. PMID:26867617

  2. Integration of photoperiod and cold temperature signals into flowering genetic pathways in Arabidopsis

    PubMed Central

    Lee, Jae-Hyung; Park, Chung-Mo

    2015-01-01

    Appropriate timing of flowering is critical for propagation and reproductive success in plants. Therefore, flowering time is coordinately regulated by endogenous developmental programs and external signals, such as changes in photoperiod and temperature. Flowering is delayed by a transient shift to cold temperatures that frequently occurs during early spring in the temperate zones. It is known that the delayed flowering by short-term cold stress is mediated primarily by the floral repressor FLOWERING LOCUS C (FLC). However, how the FLC-mediated cold signals are integrated into flowering genetic pathways is not fully understood. We have recently reported that the INDUCER OF CBF EXPRESSION 1 (ICE1), which is a master regulator of cold responses, FLC, and the floral integrator SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) constitute an elaborated feedforward-feedback loop that integrates photoperiod and cold temperature signals to regulate seasonal flowering in Arabidopsis. Cold temperatures promote the binding of ICE1 to FLC promoter to induce its expression, resulting in delayed flowering. However, under floral inductive conditions, SOC1 induces flowering by blocking the ICE1 activity. We propose that the ICE1-FLC-SOC1 signaling network fine-tunes the timing of photoperiodic flowering during changing seasons. PMID:26430754

  3. Integration of photoperiod and cold temperature signals into flowering genetic pathways in Arabidopsis.

    PubMed

    Lee, Jae-Hyung; Park, Chung-Mo

    2015-01-01

    Appropriate timing of flowering is critical for propagation and reproductive success in plants. Therefore, flowering time is coordinately regulated by endogenous developmental programs and external signals, such as changes in photoperiod and temperature. Flowering is delayed by a transient shift to cold temperatures that frequently occurs during early spring in the temperate zones. It is known that the delayed flowering by short-term cold stress is mediated primarily by the floral repressor FLOWERING LOCUS C (FLC). However, how the FLC-mediated cold signals are integrated into flowering genetic pathways is not fully understood. We have recently reported that the INDUCER OF CBF EXPRESSION 1 (ICE1), which is a master regulator of cold responses, FLC, and the floral integrator SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) constitute an elaborated feedforward-feedback loop that integrates photoperiod and cold temperature signals to regulate seasonal flowering in Arabidopsis. Cold temperatures promote the binding of ICE1 to FLC promoter to induce its expression, resulting in delayed flowering. However, under floral inductive conditions, SOC1 induces flowering by blocking the ICE1 activity. We propose that the ICE1-FLC-SOC1 signaling network fine-tunes the timing of photoperiodic flowering during changing seasons. PMID:26430754

  4. Cellular changes in the hamster testicular interstitium with ageing and after exposure to short photoperiod.

    PubMed

    Beltrán-Frutos, E; Seco-Rovira, V; Ferrer, C; Madrid, J F; Sáez, F J; Canteras, M; Pastor, L M

    2016-04-01

    The aim of this study was to evaluate the cellular changes that occur in the hamster testicular interstitium in two very different physiological situations involving testicular involution: ageing and exposure to a short photoperiod. The animals were divided into an 'age group' with three subgroups - young, adult and old animals - and a 'regressed group' with animals subjected to a short photoperiod. The testicular interstitium was characterised by light and electron microscopy. Interstitial cells were studied histochemically with regard to their proliferation, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP in situ nick end labelling (TUNEL+) and testosterone synthetic activity. We identified two types of Leydig cell: Type A cells showed a normal morphology, while Type B cells appeared necrotic. With ageing, pericyte proliferation decreased but there was no variation in the index of TUNEL-positive Leydig cells. In the regressed group, pericyte proliferation was greater and TUNEL-positive cells were not observed in the interstitium. The testicular interstitium suffered few ultrastructural changes during ageing and necrotic Leydig cells were observed. In contrast, an ultrastructural involution of Leydig cells with no necrosis was observed in the regressed group. In conclusion, the testicular interstitium of Mesocricetus auratus showed different cellular changes in the two groups (age and regressed), probably due to the irreversible nature of ageing and the reversible character of changes induced by short photoperiod. PMID:25437143

  5. Perception of photoperiod in individual buds of mature trees regulates leaf-out.

    PubMed

    Zohner, Constantin M; Renner, Susanne S

    2015-12-01

    Experimental data on the perception of day length and temperature in dormant temperate zone trees are surprisingly scarce. In order to investigate when and where these environmental signals are perceived, we carried out bagging experiments in which buds on branches of Fagus sylvatica, Aesculus hippocastanum and Picea abies trees were exposed to natural light increase or kept at constant 8-h days from December until June. Parallel experiments used twigs cut from the same trees, harvesting treated and control twigs seven times and then exposing them to 8- or 16-h days in a glasshouse. Under 8-h days, budburst in Fagus outdoors was delayed by 41 d and in Aesculus by 4 d; in Picea, day length had no effect. Buds on nearby branches reacted autonomously, and leaf primordia only reacted to light cues in late dormancy after accumulating warm days. Experiments applying different wavelength spectra and high-resolution spectrometry to buds indicate a phytochrome-mediated photoperiod control. By demonstrating local photoperiodic control of buds, revealing the time when these signals are perceived, and showing the interplay between photoperiod and chilling, this study contributes to improved modelling of the impact of climate warming on photosensitive species. PMID:26096967

  6. FLOWERING BHLH transcriptional activators control expression of the photoperiodic flowering regulator CONSTANS in Arabidopsis

    PubMed Central

    Ito, Shogo; Song, Young Hun; Josephson-Day, Anna R.; Miller, Ryan J.; Breton, Ghislain; Olmstead, Richard G.; Imaizumi, Takato

    2012-01-01

    Many plants monitor day-length changes throughout the year and use the information to precisely regulate the timing of seasonal flowering for maximum reproductive success. In Arabidopsis thaliana, transcriptional regulation of the CONSTANS (CO) gene and posttranslational regulation of CO protein are crucial mechanisms for proper day-length measurement in photoperiodic flowering. Currently, the CYCLING DOF FACTOR proteins are the only transcription factors known to directly regulate CO gene expression, and the mechanisms that directly activate CO transcription have remained unknown. Here we report the identification of four CO transcriptional activators, named FLOWERING BHLH 1 (FBH1), FBH2, FBH3, and FBH4. All FBH proteins are related basic helix–loop–helix-type transcription factors that preferentially bind to the E-box cis-elements in the CO promoter. Overexpression of all FBH genes drastically elevated CO levels and caused early flowering regardless of photoperiod, whereas CO levels were reduced in the fbh quadruple mutants. In addition, FBH1 is expressed in the vascular tissue and bound near the transcription start site of the CO promoter in vivo. Furthermore, FBH homologs in poplar and rice induced CO expression in Arabidopsis. These results indicate that FBH proteins positively regulate CO transcription for photoperiodic flowering and that this mechanism may be conserved in diverse plant species. Our results suggest that the diurnal CO expression pattern is generated by a concert of redundant functions of positive and negative transcriptional regulators. PMID:22334645

  7. Continuous Melatonin Attenuates the Regressing Activities of Short Photoperiod in Male Golden Hamsters

    PubMed Central

    Choi, Donchan

    2013-01-01

    Golden hamsters reproduce in a limited time of a year. Their sexual activities are active in summer but inactive in winter during which day length does not exceed night time and environmental conditions are severe to them. The reproductive activities are determined by the length of light in a day (photoperiod). Melatonin is synthesized and secreted only at night time from the pineal gland. Duration of elevated melatonin is longer in winter than summer, resulting in gonadal regression. The present study aimed at the influences of continuous melatonin treatments impinging on the gonadal function in male golden hamsters. Animals received empty or melatonin-filled capsules for 10 weeks. They were divided into long photoperiod (LP) and short photoperiod (SP). All the animals maintained in LP (either empty or melatonin-filled capsules) showed large testes, implying that melatonin had no effects on testicular functions. Animals housed in SP displayed completely regressed testes. But animals kept in SP and implanted with melatonin capsules exhibited blockage of full regression by SP. These results suggest that constant release of melatonin prohibits the regressing influence of SP. PMID:25949127

  8. Influence of ovaries and photoperiod on reproductive function in the mare.

    PubMed

    Freedman, L J; Garcia, M C; Ginther, O J

    1979-01-01

    A 16 h daily photoperiod hastened the onset of the ovulatory season (first ovulation); gonadotrophin and follicular changes prior to the onset were similar in intact light-treated and control mares. A preovulatory decline in FSH concentrations before the onset of the ovulatory season preceded the decrease in number of follicles (15--25 mm) and the rise in LH concentrations which was temporally associated with the growth of an ovulatory follicle. Seasonal changes of FSH and LH concentrations were found in ovariectomized mares and were influenced by photoperiod. During the anovulatory season, there was no ovarian influence on gonadotrophin concentrations. However, during the ovulatory season the ovaries exerted a positive influence on seasonally elevated LH concentrations during oestrus and a negative influence during dioestrus. The ovaries exerted a negative influence on seasonally elevated FSH concentrations throughout the oestrous cycle. The onset of the ovulatory season occurred at the time of the first sustained increase in LH concentrations resulting from positive seasonal (increasing photoperiod) and ovarian influences. PMID:289843

  9. Effect of temperature and photoperiod on maturation of Cephalothrix hongkongiensis (Nemertea: Palaeonemertea)

    NASA Astrophysics Data System (ADS)

    Li, Yingdong; Song, Xiaoyue; Zhang, Shanshan; Zhu, Lin; Sun, Shichun

    2014-07-01

    The limited knowledge about the relationships between environmental factors and the maturation and reproductive seasonality of nemerteans is mostly obtained from field studies, and in many cases is conjectural. Few species have been studied under well-controlled laboratory conditions. In this work, the effects of temperature and photoperiod on gonad development and spawning of Cephalothrix hongkongiensis were observed by rearing worms under different temperatures and photoperiods. Worms reared at 4°C and 6°C showed no growth or gonadal development, and all died within 109 days. At 8°C and 12°C, gonads could be seen from 90 days to the termination of the 360-day experiment, but no spawning was observed. Worms maintained at 16, 24, and 28°C showed both gonadal development and spawning, and matured faster at higher temperatures. Under a fixed temperature (16°C), photoperiod did not have any significant impact on maturation and spawning. It is likely that temperature plays a major role in regulating the maturation and reproductive cycle of C. hongkongiensis.

  10. Influence of photoperiodism on the spatio-temporal accumulation of steviol glycosides in Stevia rebaudiana (Bertoni).

    PubMed

    Ceunen, Stijn; Geuns, Jan M C

    2013-01-01

    The effect of photoperiodism on steviol glycoside (SVgly) accumulation was investigated in Stevia rebaudiana. Topped plants were cultivated to develop new branches under a 16h or 8h photoperiod. During different ontogenetic phases, leaves, stems, lateral shoots, roots and reproductive organs were collected and analysed for nine SVglys. Long-day (LD) conditions prolonged vegetative growth, significantly increasing leaf biomass and total SVgly content. In both photoperiods, declines in SVglys were observed during reproductive development, occurring mainly in mature leaves under LDs or young leaves under SDs. When lateral shoots were included in plants under LDs, total leaf and SVgly yield per branch significantly increased, indicating a harvest during flowering is possible. The ratio of rebaudioside A (Reb A) to stevioside (ST) amounts was influenced by ontogeny and daylength, with larger ratios during vegetative growth under SDs. Linear correlations were observed between dry matter and total SVglys and between the major SVglys individually. Minor SVglys showed larger fluctuations, especially under SDs. Under LDs, the Reb A to ST ratio was inversely correlated with both leaf dry matter and total SVglys. The highly dynamic nature of the observed patterns suggests a complex regulation of SVgly metabolism on molecular and biochemical level. PMID:23199688

  11. Topography and raytracing analysis of patients with excellent visual acuity 3 months after excimer laser photorefractive keratectomy for myopia.

    PubMed

    Maguire, L J; Zabel, R W; Parker, P; Lindstrom, R L

    1991-01-01

    We performed topography and raytracing analysis 3 months after surgery on five consecutive eyes of five patients, which had excimer laser photorefractive keratectomy for myopia. Three of the five eyes had uncorrected postoperative visual acuity of 20/20 or better. Two eyes had an uncorrected vision of 20/40. In three of five eyes, the area of excimer ablation was centered within 1.0 mm of the optical axis. Three other eyes showed decentration that ranged from 1.1 to 1.5 mm. The range of surface power seen within 2 mm of the central keratoscope ring was as follows: patient CK = 37.50 to 39.50 diopters; patient CA = 40.50 D to 44.80 D; patient CW = 37.90 D to 42.20 D; patient AC = 35.50 D to 39.00 D; patient DT = 34.50 D to 41.40 D. Topography patterns differed from eye to eye. A raytracing program modeled refraction of 20/80 and 20/20 "E" of 100%, 50%, 25%, 12.5% and 6.25% contrast through all measured points on the central 10 keratoscope rings of the five postoperative corneas. The five computer-derived images were ranked subjectively according to the observed degree of image degradation by three observers. Two eyes showed discernible 20/20 E's even at the 12.5% contrast level. Little to no ghost image was seen. Two eyes showed degraded but discernible 20/20 letters at higher levels of contrast only. These eyes showed moderate ghost images that were most apparent in the high-contrast 20/80 letters. One eye showed poor resolution of the 100% contrast 20/20 letter and moderately severe ghost images.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2043557

  12. A 3-Month Jump-Landing Training Program: A Feasibility Study Using the RE-AIM Framework

    PubMed Central

    Aerts, Inne; Cumps, Elke; Verhagen, Evert; Mathieu, Niels; Van Schuerbeeck, Sander; Meeusen, Romain

    2013-01-01

    Context: Evaluating the translatability and feasibility of an intervention program has become as important as determining the effectiveness of the intervention. Objective: To evaluate the applicability of a 3-month jump-landing training program in basketball players, using the RE-AIM (reach, effectiveness, adoption, implementation, and maintenance) framework. Design: Randomized controlled trial. Setting: National and regional basketball teams. Patients or Other Participants: Twenty-four teams of the second highest national division and regional basketball divisions in Flanders, Belgium, were randomly assigned (1:1) to a control group and intervention group. A total of 243 athletes (control group = 129, intervention group = 114), ages 15 to 41 years, volunteered. Intervention(s): All exercises in the intervention program followed a progressive development, emphasizing lower extremity alignment during jump-landing activities. Main Outcome Measure(s): The results of the process evaluation of the intervention program were based on the 5 dimensions of the RE-AIM framework. The injury incidence density, hazard ratios, and 95% confidence intervals were determined. Results: The participation rate of the total sample was 100% (reach). The hazard ratio was different between the intervention group and the control group (0.40 [95% confidence interval = 0.16, 0.99]; effectiveness). Of the 12 teams in the intervention group, 8 teams (66.7%) agreed to participate in the study (adoption). Eight of the participating coaches (66.7%) felt positively about the intervention program and stated that they had implemented the training sessions of the program as intended (implementation). All coaches except 1 (87.5%) intended to continue the intervention program the next season (maintenance). Conclusions: Compliance of the coaches in this coach-supervised jump-landing training program was high. In addition, the program was effective in preventing lower extremity injuries. PMID:23675788

  13. How a hat may affect 3-month-olds' recognition of a face: an eye-tracking study.

    PubMed

    Bulf, Hermann; Valenza, Eloisa; Turati, Chiara

    2013-01-01

    Recent studies have shown that infants' face recognition rests on a robust face representation that is resilient to a variety of facial transformations such as rotations in depth, motion, occlusion or deprivation of inner/outer features. Here, we investigated whether 3-month-old infants' ability to represent the invariant aspects of a face is affected by the presence of an external add-on element, i.e. a hat. Using a visual habituation task, three experiments were carried out in which face recognition was investigated by manipulating the presence/absence of a hat during face encoding (i.e. habituation phase) and face recognition (i.e. test phase). An eye-tracker system was used to record the time infants spent looking at face-relevant information compared to the hat. The results showed that infants' face recognition was not affected by the presence of the external element when the type of the hat did not vary between the habituation and test phases, and when both the novel and the familiar face wore the same hat during the test phase (Experiment 1). Infants' ability to recognize the invariant aspects of a face was preserved also when the hat was absent in the habituation phase and the same hat was shown only during the test phase (Experiment 2). Conversely, when the novel face identity competed with a novel hat, the hat triggered the infants' attention, interfering with the recognition process and preventing the infants' preference for the novel face during the test phase (Experiment 3). Findings from the current study shed light on how faces and objects are processed when they are simultaneously presented in the same visual scene, contributing to an understanding of how infants respond to the multiple and composite information available in their surrounding environment. PMID:24349378

  14. Dried blood spot analysis of donepezil in support of a GLP 3-month dose-range finding study in rats.

    PubMed

    Meier-Davis, Susan R; Meng, Min; Yuan, Weiwei; Diehl, Lisa; Arjmand, Fatima M; Lucke, Rebecca M; Huang, Betsy; Wen, Jianye; Shudo, Jutaro; Nagata, Tetsuto

    2012-01-01

    Donepezil hydrochloride is a reversible acetyl cholinesterase inhibitor approved for Alzheimer disease treatment. As an alternate therapy, a donepezil hydrochloride transdermal patch is in development. Recommended nonclinical safety studies include a 3-month Good Laboratory Practice (GLP) dose-range finding (DRF) study prior to conducting the 2-year dermal carcinogenicity study in rats. Demonstration of systemic exposure is necessary to interpret the in vivo data. Previous nonclinical reports supporting oral dosing have utilized liquid chromatography tandem mass spectrometry (LC/MS/MS) to quantify donepezil concentrations in plasma. Smaller species with limited blood volumes do not allow serial sampling to derive the full pharmacokinetic profile from a single animal. Therefore, the option of another analytical method requiring decreased sample volumes is desirable as it would decrease the required number of animals while obtaining the complete profile. The dried blood spot (DBS) technique allows drug level measurement from a few microliters; however, the method is still not widely utilized in GLP studies. Because donepezil plasma levels are known by the oral route, DBS was used to bridge the previous oral data and to support a 13-week GLP DRF study for repeated topical application in rats, comparing oral administration with 4 topical formulations. The DBS method was validated and demonstrated robustness and reproducibility for application to the DRF study. The assay results were comparable to a previously reported plasma LC/MS/MS assay-derived pharmacokinetic profile and provided justification for selection of the topical formulation and dose levels for the subsequent dermal carcinogenicity study. PMID:22705881

  15. Prescription patterns of analgesics in the last 3 months of life: a retrospective analysis of 10202 lung cancer patients

    PubMed Central

    Gao, W; Gulliford, M; Higginson, I J

    2011-01-01

    Background: To describe the prescription patterns of analgesics during the last 3 months of life in lung cancer and to determine the associated factors. Methods: Data on lung cancer patients (N=10 202) who died during 2000–2008 were extracted from the General Practice Research Database (GPRD). This database records prescriptions of patients received from UK general practices (GP), but not those from non-GP routes. Prescription prevalences were estimated. The associated factors were investigated using log-binomial regression. Results: The overall prescription prevalences were 50.4% (95% confidence interval (CI): 49.4–51.4%) for level 1 (e.g., paracetamol), 34.1% (95% CI: 33.2–35.0%) for level 2 (weak opioids), and 55.5 % (95% CI: 54.5–56.4%) for level 3 analgesics (strong opioids). Prescription prevalence of analgesics of all levels showed an increasing trend over the period 2000–2008 (annual increases range: 1.1–1.5%) but a decreasing trend with age (average decrease per group range: −5.8 to −1.8%). Patients in the older age groups were less likely to be prescribed level 3 analgesics than those in the younger age groups (PR‘90+' vs ‘<50'=0.55 (95% CI: 0.45–0.67); PR‘80−89' vs ‘<50'=0.73 (95% CI: 0.66–0.79); PR‘70−79' vs ‘<50'=0.84 (95% CI: 0.77–0.90)). Conclusion: Analgesics have been increasingly prescribed in lung cancer. However, analgesics, especially at level 3, were relatively under-prescribed to people older than 70 years, warranting further investigation. PMID:21540860

  16. Mother-preterm infant interactions at 3 months of corrected age: influence of maternal depression, anxiety and neonatal birth weight

    PubMed Central

    Neri, Erica; Agostini, Francesca; Salvatori, Paola; Biasini, Augusto; Monti, Fiorella

    2015-01-01

    Maternal depression and anxiety represent risk factors for the quality of early mother-preterm infant interactions, especially in the case of preterm birth. Despite the presence of many studies on this topic, the comorbidity of depressive and anxious symptoms has not been sufficiently investigated, as well as their relationship with the severity of prematurity and the quality of early interactions. The Aim of this study was to evaluate the quality of early mother-infant interactions and the prevalence of maternal depression and anxiety comparing dyads of extremely low birth weight (ELBW) and very low birth weight (VLBW) preterm infants with full-term ones. Seventy seven preterm infants (32 ELBW; 45 VLBW) and 120 full term (FT) infants and their mothers were recruited. At 3 months of corrected age, 5 min of mother-infant interactions were recorded and later coded through the Global Ratings Scales. Mothers completed the Edinburgh Postnatal Depression Scale and Penn State Worry Questionnaire. Infant levels of development were assessed through the Griffiths Mental Development Scales. A relation emerged among the severity of prematurity, depression, anxiety, and the quality of interactions. When compared with the FT group, the ELBW interactions were characterized by high maternal intrusiveness and low remoteness, while the VLBW dyads showed high levels of maternal sensitivity and infant communication. Depression was related to maternal remoteness and negative affective state, anxiety to low sensitivity, while infant interactive behaviors were impaired only in case of comorbidity. ELBW’s mothers showed the highest prevalence of depressive and anxious symptoms; moreover, only in FT dyads, low maternal sensitivity, negative affective state and minor infant communication were associated to the presence of anxious symptoms. The results confirmed the impact of prematurity on mother–infant interactions and on maternal affective state. Early diagnosis can help to plan

  17. Gibberellins and stem growth as related to photoperiod Silene armeria L

    SciTech Connect

    Talon, M.; Zeevaart, J.A.D. )

    1990-04-01

    Stem growth and flowering in the long-day plant Silene armeria L. are induced by exposure to a minimum of 3 to 6 long days (LD). Stem growth continues in subsequent short days (SD), albeit at a reduced rate. The growth retardant tetcyclacis inhibited stem elongation induced by LD, but had no effect on flowering. This indicates that photoperiodic control of stem growth in Silene is mediated by gibberellins (GA). The objective of this study was to analyze the effects of photoperiod on the levels and distribution of endogenous GAs in Silene and to determine the nature of the photoperiodic after-effect on stem growth in this plant. The GAs identified in extracts from Silene by full-scan combined gas chromatography-mass spectrometry are members of the early 13-hydroxylation pathway. All of these GAs were present in plants under SD as well as under LD conditions. The GA{sub 53} level was highest in plants in SD, and decreased in plants transferred to LD conditions. By contrast, GA{sub 19}, GA{sub 20}, and GA{sub 1} initially increased in plants transferred to LD, and then declined. Likewise, when Silene plants were returned from LD to SD, there was an increase in GA{sub 53}, and a decrease in GA{sub 19}, GA{sub 20}, and GA{sub 1} which ultimately reached levels similar to those found in plants kept in SD. Thus, measurements of GA levels in whole shoots of Silene as well as in individual parts of the plant suggest that the photoperiod modulates GA metabolism mainly through the rate of conversion of GA{sub 53}. As a result of LD induction, GA{sub 1} accumulates at its highest level in shoot tips which, in turn, results in stem elongation. In addition, LD also appear to increase the sensitivity of the tissue to GA, and this effect is presumably responsible for the photoperiodic after-effect on stem elongation in Silene.

  18. Photoperiod-dependent changes in the phase of core clock transcripts and global transcriptional outputs at dawn and dusk in Arabidopsis.

    PubMed

    Flis, Anna; Sulpice, Ronan; Seaton, Daniel D; Ivakov, Alexander A; Liput, Magda; Abel, Christin; Millar, Andrew J; Stitt, Mark

    2016-09-01

    Plants use the circadian clock to sense photoperiod length. Seasonal responses like flowering are triggered at a critical photoperiod when a light-sensitive clock output coincides with light or darkness. However, many metabolic processes, like starch turnover, and growth respond progressively to photoperiod duration. We first tested the photoperiod response of 10 core clock genes and two output genes. qRT-PCR analyses of transcript abundance under 6, 8, 12 and 18 h photoperiods revealed 1-4 h earlier peak times under short photoperiods and detailed changes like rising PRR7 expression before dawn. Clock models recapitulated most of these changes. We explored the consequences for global gene expression by performing transcript profiling in 4, 6, 8, 12 and 18 h photoperiods. There were major changes in transcript abundance at dawn, which were as large as those between dawn and dusk in a given photoperiod. Contributing factors included altered timing of the clock relative to dawn, light signalling and changes in carbon availability at night as a result of clock-dependent regulation of starch degradation. Their interaction facilitates coordinated transcriptional regulation of key processes like starch turnover, anthocyanin, flavonoid and glucosinolate biosynthesis and protein synthesis and underpins the response of metabolism and growth to photoperiod. PMID:27075884

  19. A comparative study on photoperiodic control of seasonal cycles in the females of migratory yellow breasted bunting and the resident tree sparrow.

    PubMed

    Dixit, Anand S; Singh, Namram S; Sougrakpam, Ramita

    2014-11-01

    We studied the detailed pattern of seasonality in reproduction and the associated functions in the females of migratory yellow breasted bunting (Emberiza aureola) and resident tree sparrow (Passer montanus) under natural and artificial photoperiods. They exhibited seasonal cycles of ovarian development, moult and bill colour under natural photoperiods which were found linked to the annual solar cycle. Photosensitive birds of both the species, when exposed to 9L/15D, 12L/12D and 14L/10D for 18 months, showed follicular growth followed by regression and development of photorefractoriness only under artificial long photoperiods (12L/12D and 14L/10D). Fattening and body weight increase were noticed only in bunting exposed to long natural and artificial photoperiods. Both species exhibited complete postnuptial moult of body and primary feathers under long natural and artificial photoperiods (except primaries moult under 12L/12D in bunting) that progressed with gonadal regression suggesting their photoperiodic control. In addition, bunting also showed an incomplete prenuptial moult of body feathers during gonadal stimulation. Thus, the moult and body weight responses of bunting differed significantly when compared with those of sparrows. Exposure of photosensitive birds to 24 h light-dark cycles with increasing photophase suggested that the threshold photoperiods of about 12 h in bunting and about 11 h in sparrow initiate follicular growth exceeding which the rate of growth increases with increasing photoperiods. However, the threshold photoperiod was found to be response specific in bunting. PMID:25246220

  20. A Microarray-Based Analysis Reveals that a Short Photoperiod Promotes Hair Growth in the Arbas Cashmere Goat

    PubMed Central

    Guo, Jun; Wu, Dubala; Hao, Bayasihuliang; Li, Yurong; Zhao, Cunfa

    2016-01-01

    Many animals exhibit different behaviors in different seasons. The photoperiod can have effects on migration, breeding, fur growth, and other processes. The cyclic growth of the fur and feathers of some species of mammals and birds, respectively, is stimulated by the photoperiod as a result of hormone-dependent regulation of the nervous system. To further examine this phenomenon, we evaluated the Arbas Cashmere goat (Capra hircus), a species that is often used in this type of research. The goats were exposed to an experimentally controlled short photoperiod to study the regulation of cyclic cashmere growth. Exposure to a short photoperiod extended the anagen phase of the Cashmere goat hair follicle to increase cashmere production. Assessments of tissue sections indicated that the short photoperiod significantly induced cashmere growth. This conclusion was supported by a comparison of the differences in gene expression between the short photoperiod and natural conditions using gene chip technology. Using the gene chip data, we identified genes that showed altered expression under the short photoperiod compared to natural conditions, and these genes were found to be involved in the biological processes of hair follicle growth, structural composition of the hair follicle, and the morphogenesis of the surrounding skin appendages. Knowledge about differences in the expression of these genes as well as their functions and periodic regulation patterns increases our understanding of Cashmere goat hair follicle growth. This study also provides preliminary data that may be useful for the development of an artificial method to improve cashmere production by controlling the light cycle, which has practical significance for livestock breeding. PMID:26814503

  1. A Microarray-Based Analysis Reveals that a Short Photoperiod Promotes Hair Growth in the Arbas Cashmere Goat.

    PubMed

    Liu, Bin; Gao, Fengqin; Guo, Jun; Wu, Dubala; Hao, Bayasihuliang; Li, Yurong; Zhao, Cunfa

    2016-01-01

    Many animals exhibit different behaviors in different seasons. The photoperiod can have effects on migration, breeding, fur growth, and other processes. The cyclic growth of the fur and feathers of some species of mammals and birds, respectively, is stimulated by the photoperiod as a result of hormone-dependent regulation of the nervous system. To further examine this phenomenon, we evaluated the Arbas Cashmere goat (Capra hircus), a species that is often used in this type of research. The goats were exposed to an experimentally controlled short photoperiod to study the regulation of cyclic cashmere growth. Exposure to a short photoperiod extended the anagen phase of the Cashmere goat hair follicle to increase cashmere production. Assessments of tissue sections indicated that the short photoperiod significantly induced cashmere growth. This conclusion was supported by a comparison of the differences in gene expression between the short photoperiod and natural conditions using gene chip technology. Using the gene chip data, we identified genes that showed altered expression under the short photoperiod compared to natural conditions, and these genes were found to be involved in the biological processes of hair follicle growth, structural composition of the hair follicle, and the morphogenesis of the surrounding skin appendages. Knowledge about differences in the expression of these genes as well as their functions and periodic regulation patterns increases our understanding of Cashmere goat hair follicle growth. This study also provides preliminary data that may be useful for the development of an artificial method to improve cashmere production by controlling the light cycle, which has practical significance for livestock breeding. PMID:26814503

  2. Existence of a photoinducible phase for ovarian development and photoperiod-related alteration of clock gene expression in a damselfish.

    PubMed

    Takeuchi, Yuki; Hada, Noriko; Imamura, Satoshi; Hur, Sung-Pyo; Bouchekioua, Selma; Takemura, Akihiro

    2015-10-01

    The sapphire devil, Chrysiptera cyanea, is a reef-associated damselfish and their ovarian development can be induced by a long photoperiod. In this study, we demonstrated the existence of a photoinducible phase for the photoperiodic ovarian development in the sapphire devil. Induction of ovarian development under night-interruption light schedules and Nanda-Hamner cycles revealed that the photoinducible phase appeared in a circadian manner between ZT12 and ZT13. To characterize the effect of photoperiod on clock gene expression in the brain of this species, we determined the expression levels of the sdPer1, sdPer2, sdCry1, and sdCry2 clock genes under constant light and dark conditions (LL and DD) and photoperiodic (short and long photoperiods). The expression of sdPer1 exhibited clear circadian oscillation under both LL and DD conditions, while sdPer2 and sdCry1 expression levels were lower under DD than under LL conditions and sdCry2 expression was lower under LL than under DD conditions. These results suggest a key role for sdPer1 in circadian clock cycling and that sdPer2, sdCry1, and sdCry2 are light-responsive clock genes in the sapphire devil. After 1 week under a long photoperiod, we observed photoperiod-related changes in sdPer1, sdPer2, and sdCry2 expression, but not in sdCry1 expression. These results suggest that the expression patterns of some clock genes exhibit seasonal variation according to seasonal changes in day length and that such seasonal alteration of clock gene expression may contribute to seasonal recognition by the sapphire devil. PMID:26093172

  3. Patient-reported outcomes 3 months after spine surgery: is it an accurate predictor of 12-month outcome in real-world registry platforms?

    PubMed

    Parker, Scott L; Asher, Anthony L; Godil, Saniya S; Devin, Clinton J; McGirt, Matthew J

    2015-12-01

    OBJECT The health care landscape is rapidly shifting to incentivize quality of care rather than quantity of care. Quality and outcomes registry platforms lie at the center of all emerging evidence-driven reform models and will be used to inform decision makers in health care delivery. Obtaining real-world registry outcomes data from patients 12 months after spine surgery remains a challenge. The authors set out to determine whether 3-month patient-reported outcomes accurately predict 12-month outcomes and, hence, whether 3-month measurement systems suffice to identify effective versus noneffective spine care. METHODS All patients undergoing lumbar spine surgery for degenerative disease at a single medical institution over a 2-year period were enrolled in a prospective longitudinal registry. Patient-reported outcome instruments (numeric rating scale [NRS], Oswestry Disability Index [ODI], 12-Item Short Form Health Survey [SF-12], EQ-5D, and the Zung Self-Rating Depression Scale) were recorded prospectively at baseline and at 3 months and 12 months after surgery. Linear regression was performed to determine the independent association of 3- and 12-month outcome. Receiver operating characteristic (ROC) curve analysis was performed to determine whether improvement in general health state (EQ-5D) and disability (ODI) at 3 months accurately predicted improvement and achievement of minimum clinical important difference (MCID) at 12 months. RESULTS A total of 593 patients undergoing elective lumbar surgery were included in the study. There was a significant correlation between 3-month and 12-month EQ-5D (r = 0.71; p < 0.0001) and ODI (r = 0.70; p < 0.0001); however, the authors observed a sizable discrepancy in achievement of a clinically significant improvement (MCID) threshold at 3 versus 12 months on an individual patient level. For postoperative disability (ODI), 11.5% of patients who achieved an MCID threshold at 3 months dropped below this threshold at 12 months; 10

  4. Impact of postpartum depressive and anxiety symptoms on mothers' emotional tie to their infants 2-3 months postpartum: a population-based study from rural Bangladesh.

    PubMed

    Edhborg, Maigun; Nasreen, Hashima-E; Kabir, Zarina Nahar

    2011-08-01

    The purpose of this study was to investigate the impact of depressive and anxiety symptoms on maternal bonding to the infant 2-3 months postpartum and the influence of the mother's bonding to the infant during pregnancy and to her own caregiver during her childhood on maternal bonding 2-3 months postpartum. This study originated from a community-based cohort study carried out in rural Bangladesh. Trained staff collected data and administrated the questionnaires during the third trimester of pregnancy, at childbirth and 2-3 months postpartum. Maternal depressive and anxiety symptoms were assessed with the Edinburgh Postnatal Depression Scale and the State Anxiety Inventory and the mother's emotional bonding to the infant with the Postpartum Bonding Questionnaire. The results showed that 11% of the women reported depressive symptoms, 35% anxiety symptoms, 3.4% both depressive and anxiety symptoms and 51% neither depressive nor anxiety symptoms. Mothers with depressive symptoms were older, were poorer, fewer were literate, reported more intimate partner violence and showed lower emotional bonding to their infants 2-3 months postpartum compared to mentally well and anxious mothers. Approximately 11% of the mothers reported mild bonding disturbances and nearly one third of them showed depressive symptoms. Depressive symptoms and giving birth to a girl were negatively associated to a mother's emotional bonding to her infant, while maternal anxiety symptoms and high bonding to the foetus during pregnancy were positively associated to the mother's emotional bonding to the infant 2-3 months postpartum. PMID:21626173

  5. Population Pharmacokinetics Analysis To Inform Efavirenz Dosing Recommendations in Pediatric HIV Patients Aged 3 Months to 3 Years

    PubMed Central

    Luo, Man; Chapel, Sunny; Sevinsky, Heather; Savant, Ishani; Cirincione, Brenda; Bertz, Richard

    2016-01-01

    Efavirenz (EFV) is a nonnucleoside reverse transcriptase inhibitor approved worldwide for the treatment of HIV in adults and children over 3 years of age or weighing over 10 kg. Only recently EFV was approved in children over 3 months and weighing at least 3.5 kg in the United States and the European Union. The objective of this analysis was to support the selection of an appropriate dose for this younger pediatric population and to explore the impact of CYP2B6 genetic polymorphisms on EFV systemic exposures. A population pharmacokinetic (PPK) model was developed using data from three studies in HIV-1-infected pediatric subjects (n = 168) and one study in healthy adults (n = 24). The EFV concentration-time profile was best described by a two-compartment model with first-order absorption and elimination. Body weight was identified as a significant predictor of efavirenz apparent clearance (CL), oral central volume of distribution (VC), and absorption rate constant (Ka). The typical values of efavirenz apparent CL, VC, oral peripheral volume of distribution (VP), and Ka for a reference pediatric patient were 4.8 liters/h (4.5 to 5.1 liters/h), 84.9 liters (76.8 to 93.0 liters), 287 liters (252.6 to 321.4 liters), and 0.414 h−1 (0.375 to 0.453 h−1), respectively. The final model was used to simulate steady-state efavirenz concentrations in pediatric patients weighing <10 kg to identify EFV doses that produce comparable exposure to adult and pediatric patients weighing ≥10 kg. Results suggest that administration of EFV doses of 100 mg once daily (QD) to children weighing ≥3.5 to <5 kg, 150 mg QD to children weighing ≥5 to <7.5 kg, and 200 mg QD to children weighing ≥7.5 to <10 kg produce exposures within the target range. Further evaluation of the impact of CYP2B6 polymorphisms on EFV PK showed that the identification of CYP2B6 genetic status is not predictive of EFV exposure and thus not informative to guide pediatric dosing regimens. PMID:27067333

  6. Population Pharmacokinetics Analysis To Inform Efavirenz Dosing Recommendations in Pediatric HIV Patients Aged 3 Months to 3 Years.

    PubMed

    Luo, Man; Chapel, Sunny; Sevinsky, Heather; Savant, Ishani; Cirincione, Brenda; Bertz, Richard; Roy, Amit

    2016-06-01

    Efavirenz (EFV) is a nonnucleoside reverse transcriptase inhibitor approved worldwide for the treatment of HIV in adults and children over 3 years of age or weighing over 10 kg. Only recently EFV was approved in children over 3 months and weighing at least 3.5 kg in the United States and the European Union. The objective of this analysis was to support the selection of an appropriate dose for this younger pediatric population and to explore the impact of CYP2B6 genetic polymorphisms on EFV systemic exposures. A population pharmacokinetic (PPK) model was developed using data from three studies in HIV-1-infected pediatric subjects (n = 168) and one study in healthy adults (n = 24). The EFV concentration-time profile was best described by a two-compartment model with first-order absorption and elimination. Body weight was identified as a significant predictor of efavirenz apparent clearance (CL), oral central volume of distribution (VC), and absorption rate constant (Ka). The typical values of efavirenz apparent CL, VC, oral peripheral volume of distribution (VP), and Ka for a reference pediatric patient were 4.8 liters/h (4.5 to 5.1 liters/h), 84.9 liters (76.8 to 93.0 liters), 287 liters (252.6 to 321.4 liters), and 0.414 h(-1) (0.375 to 0.453 h(-1)), respectively. The final model was used to simulate steady-state efavirenz concentrations in pediatric patients weighing <10 kg to identify EFV doses that produce comparable exposure to adult and pediatric patients weighing ≥10 kg. Results suggest that administration of EFV doses of 100 mg once daily (QD) to children weighing ≥3.5 to <5 kg, 150 mg QD to children weighing ≥5 to <7.5 kg, and 200 mg QD to children weighing ≥7.5 to <10 kg produce exposures within the target range. Further evaluation of the impact of CYP2B6 polymorphisms on EFV PK showed that the identification of CYP2B6 genetic status is not predictive of EFV exposure and thus not informative to guide pediatric dosing regimens. PMID:27067333

  7. Factors associated with morbidity, mortality, and growth of dairy heifer calves up to 3 months of age.

    PubMed

    Windeyer, M C; Leslie, K E; Godden, S M; Hodgins, D C; Lissemore, K D; LeBlanc, S J

    2014-02-01

    Calfhood disease is an important problem on many dairy operations that can have substantial effects on heifer survival and productivity, and has economic and welfare impacts. Neonatal calf diarrhea (NCD) and bovine respiratory disease (BRD) are the most common causes of morbidity and mortality in young dairy cattle. The objective of this observational study was to investigate factors associated with the risks of morbidity and mortality, and with growth, in commercial dairy heifers calves. A total of 2874 heifer calves from 19 commercial dairy farms in Minnesota and Ontario were enrolled at 1-7 days of age and followed for approximately 3 months. Using cut-points of serum total protein of 5.2 and 5.7 g/dl, the incidences of failure of transfer of passive immunity (FTPI) were 11 and 32%, respectively. A cut-point of 5.7 g/dl was the most predictive of BRD before 5 weeks of age (sensitivity=40%, specificity=69%). The positive predictive value was poor (PPV=18%), but the negative predictive value was good (NPV=87%). A cut-point of 5.2g/dl was most predictive of death before 5 weeks of age (sensitivity=27%, specificity=89%, PPV=5%, NPV=98%). Serum total protein during the first week of life was a poor predictor of NCD. Over 23% of calves were treated for diarrhea. Risk factors were weight at enrollment, other diseases before 2 weeks of age, and an interaction between season of birth and herd-level incidence of NCD. Almost 22% of calves were treated at least once for BRD. Factors associated with an increased risk of BRD included herd-level incidence of BRD, season of birth, navel dipping, other diseases before 2 weeks of age, failure of transfer of passive immunity, and manual control of temperature in pre-weaning housing. Administration of supplemental antibody products at birth was associated with a reduced incidence of BRD. Overall mortality was 3.5%. Risk of mortality was increased by treatment for BRD and other diseases. The mean average weight gain was 0.95 kg

  8. The effects of phytochrome-mediated light signals on the developmental acquisition of photoperiod sensitivity in rice

    PubMed Central

    Yoshitake, Yoshihiro; Yokoo, Takayuki; Saito, Hiroki; Tsukiyama, Takuji; Quan, Xu; Zikihara, Kazunori; Katsura, Hitomi; Tokutomi, Satoru; Aboshi, Takako; Mori, Naoki; Inoue, Hiromo; Nishida, Hidetaka; Kohchi, Takayuki; Teraishi, Masayoshi; Okumoto, Yutaka; Tanisaka, Takatoshi

    2015-01-01

    Plants commonly rely on photoperiodism to control flowering time. Rice development before floral initiation is divided into two successive phases: the basic vegetative growth phase (BVP, photoperiod-insensitive phase) and the photoperiod-sensitive phase (PSP). The mechanism responsible for the transition of rice plants into their photoperiod-sensitive state remains elusive. Here, we show that se13, a mutation detected in the extremely early flowering mutant X61 is a nonsense mutant gene of OsHY2, which encodes phytochromobilin (PΦB) synthase, as evidenced by spectrometric and photomorphogenic analyses. We demonstrated that some flowering time and circadian clock genes harbor different expression profiles in BVP as opposed to PSP, and that this phenomenon is chiefly caused by different phytochrome-mediated light signal requirements: in BVP, phytochrome-mediated light signals directly suppress Ehd2, while in PSP, phytochrome-mediated light signals activate Hd1 and Ghd7 expression through the circadian clock genes' expression. These findings indicate that light receptivity through the phytochromes is different between two distinct developmental phases corresponding to the BVP and PSP in the rice flowering process. Our results suggest that these differences might be involved in the acquisition of photoperiod sensitivity in rice. PMID:25573482

  9. Photoperiod alters fear responses and basolateral amygdala neuronal spine density in white-footed mice (Peromyscus leucopus).

    PubMed

    Walton, James C; Haim, Achikam; Spieldenner, James M; Nelson, Randy J

    2012-08-01

    Photoperiodism is a biological phenomenon in which environmental day length is monitored to ascertain time of year to engage in seasonally appropriate adaptations. This trait is common among organisms living outside of the tropics. White-footed mice (Peromyscus leucopus) are small photoperiodic rodents which display a suite of adaptive responses to short day lengths, including reduced hippocampal volume, impairments in hippocampal-mediated memory, and enhanced hypothalamic-pituitary-adrenal axis reactivity. Because these photoperiodic changes in brain and behavior mirror some of the etiology of post-traumatic stress disorder (PTSD), we hypothesized that photoperiod may also alter fear memory and neuronal morphology within the hippocampus-basolateral amygdala-prefrontal cortex fear circuit. Ten weeks of exposure to short days increased fear memory in an auditory-cued fear conditioning test. Short days also increased dendritic spine density of the neurons of the basolateral amygdala, without affecting morphology of pyramidal neurons within the infralimbic region of the medial prefrontal cortex. Taken together, photoperiodic phenotypic changes in brain morphology and physiology induced by a single environmental factor, exposure to short day lengths, affect responses to fearful stimuli in white-footed mice. These results have potential implications for understanding seasonal changes in fear responsiveness, as well as for expanding translational animal models for studying gene-environment interactions underlying psychiatric diseases, such as PTSD. PMID:22652395

  10. The RING-Finger Ubiquitin Ligase HAF1 Mediates Heading date 1 Degradation during Photoperiodic Flowering in Rice[OPEN

    PubMed Central

    Yang, Ying; Fu, Debao; Zhu, Chunmei; He, Yizhou; Zhang, Huijun; Liu, Tao; Li, Xianghua; Wu, Changyin

    2015-01-01

    The photoperiodic response is one of the most important factors determining heading date in rice (Oryza sativa). Although rhythmic expression patterns of flowering time genes have been reported to fine-tune the photoperiodic response, posttranslational regulation of key flowering regulators has seldom been elucidated in rice. Heading date 1 (Hd1) encodes a zinc finger transcription factor that plays a crucial role in the photoperiodic response, which determines rice regional adaptability. However, little is known about the molecular mechanisms of Hd1 accumulation during the photoperiod response. Here, we identify a C3HC4 RING domain-containing E3 ubiquitin ligase, Heading date Associated Factor 1 (HAF1), which physically interacts with Hd1. HAF1 mediates ubiquitination and targets Hd1 for degradation via the 26S proteasome-dependent pathway. The haf1 mutant exhibits a later flowering heading date under both short-day and long-day conditions. In addition, the haf1 hd1 double mutant headed as late as hd1 plants under short-day conditions but exhibited a heading date similar to haf1 under long-day conditions, thus indicating that HAF1 may determine heading date mainly through Hd1 under short-day conditions. Moreover, high levels of Hd1 accumulate in haf1. Our results suggest that HAF1 is essential to precise modulation of the timing of Hd1 accumulation during the photoperiod response in rice. PMID:26296966

  11. Asymbiotic Germination Response to Photoperiod and Nutritional Media in Six Populations of Calopogon tuberosus var. tuberosus (Orchidaceae): Evidence for Ecotypic Differentiation

    PubMed Central

    Kauth, Philip J.; Kane, Michael E.; Vendrame, Wagner A.; Reinhardt-Adams, Carrie

    2008-01-01

    Background and Aims Ecotypic differentiation has been explored in numerous plant species, but has been largely ignored in the Orchidaceae. Applying a specific germination protocol for widespread seed sources may be unreliable due to inherent physiological or genetic differences in localized populations. It is crucial to determine whether ecotypic differentiation exists for restoration and conservation programmes. Calopogon tuberosus var. tuberosus, a widespread terrestrial orchid of eastern North America, is a model species to explore ecotypic differences in germination requirements, as this species occupies diverse habitats spanning a wide geographical range. Methods Mature seeds were collected from south Florida, north central Florida, three locations in South Carolina, and the upper Michigan peninsula. Effects of three photoperiods (8/16, 12/12, 16/8 h L/D) were examined on asymbiotic in vitro seed germination and seedling development of C. tuberosus. Germination and early development was monitored for 8 weeks, while advanced development was monitored for an additional 8 weeks. In an additional experiment, asymbiotic seed germination and development was monitored for 8 weeks on six culture media (BM-1 terrestrial orchid medium, Knudson C, Malmgrem, half-strength MS, P723, and Vacin and Went). A tetrazolium test for embryo viability was performed. Key Results Short days promoted the highest germination among Florida populations, but few differences among photoperiods in other seed sources existed. Different media had little effect on the germination of Michigan and Florida populations, but germination of South Carolina seeds was higher on media with higher calcium and magnesium. Tetrazolium testing confirmed that South Carolina seeds exhibited low viability while viability was higher in Florida seeds. Seed germination and corm formation was rapid in Michigan seeds across all treatments. Michigan seedlings allocated more biomass to corms compared with other seed

  12. Video Evidence That London Infants Can Resettle Themselves Back to Sleep After Waking in the Night, as well as Sleep for Long Periods, by 3 Months of Age

    PubMed Central

    Hovish, Kimberly; Owen, Charlie

    2015-01-01

    ABSTRACT: Objective: Most infants become settled at night by 3 months of age, whereas infants not settled by 5 months are likely to have long-term sleep-waking problems. We assessed whether normal infant development in the first 3 months involves increasing sleep-period length or the ability to resettle autonomously after waking in the night. Methods: One hundred one infants were assessed at 5 weeks and 3 months of age using nighttime infrared video recordings and parental questionnaires. Results: The clearest development was in sleep length; 45% of infants slept continuously for ≥5 hours at night at 3 months compared with 10% at 5 weeks. In addition, around a quarter of infants woke and resettled themselves back to sleep in the night at each age. Autonomous resettling at 5 weeks predicted prolonged sleeping at 3 months suggesting it may be a developmental precursor. Infants reported by parents to sleep for a period of 5 hours or more included infants who resettled themselves and those with long sleeps. Three-month olds fed solely breast milk were as likely to self-resettle or have long sleep bouts as infants fed formula or mixed breast and formula milk. Conclusions: Infants are capable of resettling themselves back to sleep in the first 3 months of age; both autonomous resettling and prolonged sleeping are involved in “sleeping through the night” at an early age. Findings indicate the need for physiological studies of how arousal, waking, and resettling develop into sustained sleeping and of how environmental factors support these endogenous and behavioral processes. PMID:26035139

  13. Effect of breeding stage and photoperiod on gonadal and serotonergic axes in domestic ganders.

    PubMed

    Gumułka, Małgorzata; Rozenboim, Israel

    2015-11-01

    Reduction in reproductive potential of ganders with progress in seasonal breeding is a known problem in commercial geese production. The role of changes in hypothalamic-pituitary-gondal axis and testis functions in this process is not clear. This article presents studies on the hypothalamic (GnRH-I, vasoactive intestinal peptide), pituitary (LHβ, prolactin [PRL], PRL receptor [PRLR]), testis (PRLR) axis messenger RNA (mRNA) expression during different stages of the breeding period and photoperiodic conditions. Testis mass; histologic and functional (testosterone [T]) parameters; and plasma concentrations of T, LH, and PRL were evaluated. We collected (six times) samples from 2-year-old ganders (n = 48) maintained in short day (10L:14D) during the period from November to July. Moreover, in the peak of sexual activity (March), an additional group was on exposure (6 weeks) to long day (LD; 16L:8D). During the first half of reproduction (January, March; photosensitive period), GnRH-I (1.9 vs. 0.3 relative quantity [RQ]) and LHβ (3.0 vs. 0.7 RQ) mRNA transcript expression and concentrations of T (1.9-2.9 vs. 0.3 ng/mL), LH (13.6-7.4 vs. 0.7 ng/mL) were found to be higher (P < 0.05) than at the end of breeding (July). With progress in breeding, marked elevation (P < 0.05) in PRL (22.0-387.1 ng/mL) concentration related to similar changes in vasoactive intestinal peptide (0.9-3.0 RQ) and PRL mRNA abundance (1.3-11.5 RQ; May, July) was observed. However, testis PRLR mRNA increased (P < 0.05) only at the end of reproduction (1.2 RQ) compared to the peak of sexual activity (0.4 RQ; March). Furthermore, changes in mRNA transcript expression of the lactotrophic axis were accompanied with reduction of testis weight (left: 11.1-5.8 g), spermatogenesis (spermatogenic index: 5.4-3.0), and steroidogenesis (T: 24.8-1.3 ng/g testis), which may suggest their pivotal inhibitory modulation role in the regression of seasonal reproductive activity in ganders. The LD conditions (similar

  14. Photoperiod control of downstream movements of Atlantic salmon Salmo salar smolts

    USGS Publications Warehouse

    Zydlewski, Gayle B.; Stich, Daniel S.; McCormick, Stephen D.

    2014-01-01

    This study provides the first direct observations that photoperiod controls the initiation of downstream movement in Atlantic salmon Salmo salar smolts. Under simulated natural day length (LDN) conditions and seasonal increases in temperature, smolts increased their downstream movements five-fold for a period of 1 month in late spring. Under the same conditions, parr did not show changes in downstream movement behaviour. When given a shortened day length (10L:14D) beginning in late winter, smolts did not increase the number of downstream movements. An early increase in day length (16L:8D) in late winter resulted in earlier initiation and termination of downstream movements compared to the LDN group. Physiological status and behaviour were related but not completely coincident: gill Na+/K+-ATPase activity increased in all treatments and thyroid hormone was elevated prior to movement in 16L:8D treatment. The most parsimonious model describing downstream movement of smolts included synergistic effects of photoperiod treatment and temperature, indicating that peak movements occurred at colder temperatures in the 16L:8D treatment than in LDN, and temperature did not influence movement of smolts in the 10L:14D treatment. The complicated interactions of photoperiod and temperature are not surprising since many organisms have evolved to rely on correlations among environmental cues and windows of opportunity to time behaviours associated with life-history transitions. These complicated interactions, however, have serious implications for phenological adjustments and persistence ofS. salar populations in response to climate change.

  15. Low temperature limits photoperiod control of smolting in atlantic salmon through endocrine mechanisms

    USGS Publications Warehouse

    McCormick, S.D.; Moriyama, S.

    2000-01-01

    We have examined the interaction of photoperiod and temperature in regulating the parr-smolt transformation and its endocrine control. Atlantic salmon juveniles were reared at a constant temperature of 10??C or ambient temperature (2??C from January to April followed by seasonal increase) under simulated natural day length. At 10??C, an increase in day length [16 h of light and 8 h of darkness (LD 16:8)] in February accelerated increases in gill Na+K+-ATPase activity, whereas fish at ambient temperature did not respond to increased day length. Increases in gill Na+K+-ATPase activity under both photoperiods occurred later at ambient temperature than at 10??C. Plasma growth hormone (GH), insulin-like growth factor, and thyroxine increased within 7 days of increased day length at 10??C and remained elevated for 5-9 wk; the same photoperiod treatment at 2??C resulted in much smaller increases of shorter duration. Plasma cortisol increased transiently 3 and 5 wk after LD 16:8 at 10??C and ambient temperature, respectively. Plasma thyroxine was consistently higher at ambient temperature than at 10??C. Plasma triiodothyronine was initially higher at 10??C than at ambient temperature, and there was no response to LD 16:8 under either temperature regimen. There was a strong correlation between gill Na+K+-ATPase activity and plasma GH; correlations were weaker with other hormones. The results provide evidence that low temperature limits the physiological response to increased day length and that GH, insulin-like growth factor I, cortisol, and thyroid hormones mediate the environmental control of the parr-smolt transformation.

  16. Possible mechanisms of weight loss of Siberian hamsters (Phodopus sungorus sungorus) exposed to short photoperiod.

    PubMed

    Atgié, C; Sauvant, P; Ambid, L; Carpéné, C

    2009-12-01

    Several weeks of short day photoperiod (SD) exposure promote a dramatic decrease of white adipose tissue (WAT) mass in Siberian hamsters(Phodopus sungorus sungorus). This slimming effect is accompanied by changes in the adipocyte responsiveness to adrenergic stimulation that are still under debate. We investigated whether possible changes in the antilipolytic responses, and/or lipogenic activities could be involved in such lipid deposition/mobilisation imbalance. Male Siberian hamsters were exposed for 11 weeks to SD or long day photoperiod and basal or stimulated lipolytic and lipogenic activities were measured on white adipocytes. As expected, the body mass of SD-animals was decreased. Besides a slight reduction in the basal lipolysis and in the maximal response to dibutyryl-cAMP, the responses to adrenergic and non-adrenergic lipolytic agents (forskolin, adenosine deaminase) were similar in both groups. Fat mass loss was likely not resulting from changes in the lipolytic responses of adipocytes to biogenic amines (e.g. octopamine), which were unaltered, or to a direct lipolytic stimulation by melatonin or histamine, which were inactive. Antilipolytic responses to insulin or tyramine were slightly decreased in SD-adipocytes. Basal or insulin-stimulated lipid accumulation in WAT, measured by glucose incorporation into lipids, did not change after SD-exposure. However, a significant decrease in the lipoprotein lipase activity was observed in the WAT of SDanimals. Despite the observed changes, the weight loss of SD-exposed Siberian hamsters was likely not resulting only from impaired antilipolytic orde novo lipogenic activities in white adipocytes, but either from other dramatic changes occurring during seasonal photoperiod-sensitive body weight regulation. PMID:20358351

  17. Effect of refractoriness to long photoperiod on sperm production and quality in tomcats.

    PubMed

    Nuñez Favre, R; Bonaura, M C; Tittarelli, C M; Stornelli, M C; de la Sota, R L; Stornelli, M A

    2012-12-01

    The aim of this study was to assess whether refractoriness to long photoperiod (LP) could be reversed by subjecting tomcats to a period of short days. Our hypothesis was that photoperiod changes can avoid refractoriness and restore sperm quality and production to that before refractoriness. Tomcats (n = 6) were housed in a conditioned room with LP (12L: 12D) for 45 days of acclimation and then maintained under LP for 18 month. Then, tomcats were changed to a period of decreasing light at a rate of 8 min/day for 1 month. Tomcats stayed for 1 month with short photoperiod (SP; 8L: 16D) and then were switched back to a period of increasing light at a rate of 8 min/day for 1 month. The experiment was completed after tomcats remained in LP for 2 months. Toms were anaesthetized and semen samples were collected by electroejaculation every 2 weeks. Sperm parameters were evaluated in all ejaculates, and data were analysed by anova. Motility, velocity, volume, sperm concentration, total sperm count, viability, acrosome integrity, plasma membrane integrity and sperm morphology were higher during LP compared with a refractory LP (p < 0.01). Likewise, velocity, viability, acrosome integrity, plasma membrane integrity and sperm morphology were higher in a LP compared with a SP (p < 0.05). On the other hand, motility, volume, concentration and total sperm count were similar between LP and SP (p > 0.20).Whereas motility, velocity, viability, acrosome integrity and plasma membrane integrity were similar in a refractory LP compared with SP (p > 0.05), volume, sperm concentration, total sperm count and sperm morphology were lower in a refractory LP compared with SP (p < 0.05). In conclusion, refractoriness and reduced sperm production and quality induced by a prolonged LP of 18 month can be restored after placing tomcats to a SP. PMID:23279508

  18. Matrix metalloproteinase inhibition influences aspects of photoperiod stimulated ovarian recrudescence in Siberian hamsters

    PubMed Central

    Shahed, Asha; Simmons, Jamie; Featherstone, Sydney L; Young, Kelly A.

    2015-01-01

    Blocking matrix metalloproteinase (MMP) activity in vivo with inhibitor GM6001 impedes photostimulated ovarian recrudescence in photoregressed Siberian hamsters. Since direct and indirect effects of MMPs influence a myriad of ovarian functions, we investigated the effect of in vivo MMP inhibition during recrudescence on ovarian mRNA expression of steroidogenic acute regulatory protein (StAR), 3β-hy-droxysteroid dehydrogenase (3β-HSD), Cyp19a1 aromatase, epidermal growth factor receptor (EGFR), amphiregulin (Areg), estrogen receptors (Esr1 and Esr2), tissue inhibitors of MMPs (TIMP-1,-2,-3), proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor A (VEGFA), its receptor VEGFR-2, and angiopoietin-2 (Ang-2). Female Siberian hamsters were randomly assigned to one of four photoperiod groups: stimulatory long (LD) or inhibitory short (SD) photoperiods, or transferred from SD to LD for 2 weeks (post-transfer, PT). Half of the PT hamsters were injected (ip) daily with GM6001 (PTG). SD exposure reduced ovarian StAR, 3β-HSD, Cyp19a1, Esr1, Esr2, TIMPs 2–3, PCNA, VEGFR-2 and Ang-2 mRNA expression (p < 0.05), and 2 weeks of photostimulation restored mRNA expression of 3β-HSD and PCNA and increased Areg and VEGFA mRNA expression in the PT group. GM6001 treatment during photostimulation (PTG) increased TIMP-1, -2 and -3 and PCNA mRNA, but inhibited Areg mRNA expression compared to PT. Neither photoperiod nor GM6001 altered EGFR expression. Results of this study suggest that in vivo inhibition of MMP activity by GM6001 may impede ovarian recrudescence, particularly follicular growth, in two ways: (1) directly by partially inhibiting the release of EGFR ligands like Areg, thereby potentially affecting EGFR activation and its downstream pathway, and (2) indirectly by its effect on TIMPs which themselves can affect proliferation, angiogenesis and follicular growth. PMID:25910436

  19. Sensitivity to the photoperiod and potential migratory features of neuroblasts in the adult sheep hypothalamus.

    PubMed

    Batailler, Martine; Derouet, Laura; Butruille, Lucile; Migaud, Martine

    2016-07-01

    Adult neurogenesis, a process that consists in the generation of new neurons from adult neural stem cells, represents a remarkable illustration of the brain structural plasticity abilities. The hypothalamus, a brain region that plays a key role in the neuroendocrine regulations including reproduction, metabolism or food intake, houses neural stem cells located within a hypothalamic neurogenic niche. In adult sheep, a seasonal mammalian species, previous recent studies have revealed photoperiod-dependent changes in the hypothalamic cell proliferation rate. In addition, doublecortin (DCX), a microtubule-associated protein expressed in immature migrating neurons, is highly present in the vicinity of the hypothalamic neurogenic niche. With the aim to further explore the mechanism underlying adult sheep hypothalamic neurogenesis, we first show that new neuron production is also seasonally regulated since the density of DCX-positive cells changes according to the photoperiodic conditions at various time points of the year. We then demonstrate that cyclin-dependant kinase-5 (Cdk5) and p35, two proteins involved in DCX phosphorylation and known to be critically involved in migration processes, are co-expressed with DCX in young hypothalamic neurons and are capable of in vivo interaction. Finally, to examine the migratory potential of these adult-born neurons, we reveal the rostro-caudal extent of DCX labeling on hypothalamic sagittal planes. DCX-positive cells are found in the most rostral nuclei of the hypothalamus, including the preoptic area many of which co-expressed estrogen receptor-α. Thus, beyond the confirmation of the high level of neuron production during short photoperiod in sheep, our results bring new and compelling elements in support of the existence of a hypothalamic migratory path that is responsive to seasonal stimuli. PMID:26336953

  20. Soybean fruit development and set at the node level under combined photoperiod and radiation conditions

    PubMed Central

    Nico, Magalí; Mantese, Anita I.; Miralles, Daniel J.; Kantolic, Adriana G.

    2016-01-01

    In soybean, long days during post-flowering increase seed number. This positive photoperiodic effect on seed number has been previously associated with increments in the amount of radiation accumulated during the crop cycle because long days extend the duration of the crop cycle. However, evidence of intra-nodal processes independent of the availability of assimilates suggests that photoperiodic effects at the node level might also contribute to pod set. This work aims to identify the main mechanisms responsible for the increase in pod number per node in response to long days; including the dynamics of flowering, pod development, growth and set at the node level. Long days increased pods per node on the main stems, by increasing pods on lateral racemes (usually dominated positions) at some main stem nodes. Long days lengthened the flowering period and thereby increased the number of opened flowers on lateral racemes. The flowering period was prolonged under long days because effective seed filling was delayed on primary racemes (dominant positions). Long days also delayed the development of flowers into pods with filling seeds, delaying the initiation of pod elongation without modifying pod elongation rate. The embryo development matched the external pod length irrespective of the pod’s chronological age. These results suggest that long days during post-flowering enhance pod number per node through a relief of the competition between pods of different hierarchy within the node. The photoperiodic effect on the development of dominant pods, delaying their elongation and therefore postponing their active growth, extends flowering and allows pod set at positions that are usually dominated. PMID:26512057

  1. Phenology and growth adjustments of oil palm (Elaeis guineensis) to photoperiod and climate variability

    PubMed Central

    Legros, S.; Mialet-Serra, I.; Caliman, J.-P.; Siregar, F. A.; Clément-Vidal, A.; Dingkuhn, M.

    2009-01-01

    Background and Aims Oil palm flowering and fruit production show seasonal maxima whose causes are unknown. Drought periods confound these rhythms, making it difficult to analyse or predict dynamics of production. The present work aims to analyse phenological and growth responses of adult oil palms to seasonal and inter-annual climatic variability. Methods Two oil palm genotypes planted in a replicated design at two sites in Indonesia underwent monthly observations during 22 months in 2006–2008. Measurements included growth of vegetative and reproductive organs, morphology and phenology. Drought was estimated from climatic water balance (rainfall – potential evapotranspiration) and simulated fraction of transpirable soil water. Production history of the same plants for 2001–2005 was used for inter-annual analyses. Key Results Drought was absent at the equatorial Kandista site (0°55′N) but the Batu Mulia site (3°12′S) had a dry season with variable severity. Vegetative growth and leaf appearance rate fluctuated with drought level. Yield of fruit, a function of the number of female inflorescences produced, was negatively correlated with photoperiod at Kandista. Dual annual maxima were observed supporting a recent theory of circadian control. The photoperiod-sensitive phases were estimated at 9 (or 9 + 12 × n) months before bunch maturity for a given phytomer. The main sensitive phase for drought effects was estimated at 29 months before bunch maturity, presumably associated with inflorescence sex determination. Conclusion It is assumed that seasonal peaks of flowering in oil palm are controlled even near the equator by photoperiod response within a phytomer. These patterns are confounded with drought effects that affect flowering (yield) with long time-lag. Resulting dynamics are complex, but if the present results are confirmed it will be possible to predict them with models. PMID:19748909

  2. Soybean fruit development and set at the node level under combined photoperiod and radiation conditions.

    PubMed

    Nico, Magalí; Mantese, Anita I; Miralles, Daniel J; Kantolic, Adriana G

    2016-01-01

    In soybean, long days during post-flowering increase seed number. This positive photoperiodic effect on seed number has been previously associated with increments in the amount of radiation accumulated during the crop cycle because long days extend the duration of the crop cycle. However, evidence of intra-nodal processes independent of the availability of assimilates suggests that photoperiodic effects at the node level might also contribute to pod set. This work aims to identify the main mechanisms responsible for the increase in pod number per node in response to long days; including the dynamics of flowering, pod development, growth and set at the node level. Long days increased pods per node on the main stems, by increasing pods on lateral racemes (usually dominated positions) at some main stem nodes. Long days lengthened the flowering period and thereby increased the number of opened flowers on lateral racemes. The flowering period was prolonged under long days because effective seed filling was delayed on primary racemes (dominant positions). Long days also delayed the development of flowers into pods with filling seeds, delaying the initiation of pod elongation without modifying pod elongation rate. The embryo development matched the external pod length irrespective of the pod's chronological age. These results suggest that long days during post-flowering enhance pod number per node through a relief of the competition between pods of different hierarchy within the node. The photoperiodic effect on the development of dominant pods, delaying their elongation and therefore postponing their active growth, extends flowering and allows pod set at positions that are usually dominated. PMID:26512057

  3. Effects of photoperiod and food restriction on the reproductive physiology of female California mice

    PubMed Central

    Steinman, Michael Q.; Knight, Jennifer A.; Trainor, Brian C.

    2012-01-01

    Many temperate-zone animals use changes in photoperiod to time breeding. Shorter term cues, like food availability, are integrated with photoperiod to adjust reproductive timing under unexpected conditions. Many mice of the genus Peromyscus breed in the summer. California mice (Peromyscus californicus), however, can breed year round, but tend to begin breeding in the winter. Glial cells may be involved in transduction of environmental signals that regulate gonadotrophin releasing hormone (GnRH) activity. We examined the effects of diet and photoperiod on reproduction in female California mice. Mice placed on either short days (8L:16D) or long days (16L:8D) were food restricted (80% of normal intake) or fed ad libitum. Short day-food restricted mice showed significant regression of the reproductive system. GnRH-immunoreactivity was increased in the tuberal hypothalamus of long day-food restricted mice. This may be associated with the sparing effect long days have when mice are food restricted. The number of GFAP-immunoreactive fibers in proximity to GnRH nerve terminals correlated negatively with uterine size in ad libitum but not food restricted mice, suggesting diet may alter glial regulation of the reproductive axis. There was a trend towards food restriction increasing uterine expression of c-fos mRNA, an estrogen dependent gene. Similar to other seasonally breeding rodents, short days render the reproductive system of female California mice more susceptible to effects of food restriction. This may be vestigial, or it may have evolved to mitigate consequences of unexpectedly poor winter food supplies. PMID:22245263

  4. Photoperiod regulates growth of male accessory glands through juvenile hormone signaling in the linden bug, Pyrrhocoris apterus.

    PubMed

    Urbanová, Veronika; Bazalová, Olga; Vaněčková, Hanka; Dolezel, David

    2016-03-01

    Adult reproductive diapause is characterized by lower behavioral activity, ceased reproduction and absence of juvenile hormone (JH). The role of JH receptor Methoprene-tolerant (Met) in female reproduction is well established; however, its function in male reproductive development and behavior is unclear. In the bean bug, Riptortus pedestris, circadian genes are essential for mediating photoperiodically-dependent growth of the male accessory glands (MAGs). The present study explores the role of circadian genes and JH receptor in male diapause in the linden bug, Pyrrhocoris apterus. These data indicate that circadian factors Clock, Cycle and Cry2 are responsible for photoperiod measurement, whereas Met and its partner protein Taiman participate in JH reception. Surprisingly, knockdown of the JH receptor neither lowered locomotor activity nor reduced mating behavior of males. These data suggest existence of a parallel, JH-independent or JH-upstream photoperiodic regulation of reproductive behavior. PMID:26826599

  5. CACTA-like transposable element in ZmCCT attenuated photoperiod sensitivity and accelerated the postdomestication spread of maize

    PubMed Central

    Yang, Qin; Li, Zhi; Li, Wenqiang; Ku, Lixia; Wang, Chao; Ye, Jianrong; Li, Kun; Yang, Ning; Li, Yipu; Zhong, Tao; Li, Jiansheng; Chen, Yanhui; Yan, Jianbing; Yang, Xiaohong; Xu, Mingliang

    2013-01-01

    The postdomestication adaptation of maize to longer days required reduced photoperiod sensitivity to optimize flowering time. We performed a genome-wide association study and confirmed that ZmCCT, encoding a CCT domain-containing protein, is associated with the photoperiod response. In early-flowering maize we detected a CACTA-like transposable element (TE) within the ZmCCT promoter that dramatically reduced flowering time. TE insertion likely occurred after domestication and was selected as maize adapted to temperate zones. This process resulted in a strong selective sweep within the TE-related block of linkage disequilibrium. Functional validations indicated that the TE represses ZmCCT expression to reduce photoperiod sensitivity, thus accelerating maize spread to long-day environments. PMID:24089449

  6. Epistasis and the Genetic Divergence of Photoperiodism between Populations of the Pitcher-Plant Mosquito, Wyeomyia Smithii

    PubMed Central

    Hard, J. J.; Bradshaw, W. E.; Holzapfel, C. M.

    1992-01-01

    Parallel crosses between each of two southern (ancestral) and one northern (derived) population of the pitcher-plant mosquito, Wyeomyia smithii, were made to determine the genetic components of population divergence in critical photoperiod, a phenological trait that measures adaptation to seasonality along a climatic gradient. Joint scaling tests were used to analyze means and variances of first- and second-generation hybrids in order to determine whether nonadditive genetic variance, especially epistatic variance, contributed to divergence in critical photoperiod. In both crosses, digenic epistatic effects were highly significant, indicating that genetic divergence cannot have resulted solely from differences in additively acting loci. For one cross that could be tested directly for such effects, higher order epistasis and/or linkage did not contribute to the divergence of critical photoperiod between the constituent populations. PMID:1353737

  7. Epistasis and the genetic divergence of photoperiodism between populations of the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Hard, J J; Bradshaw, W E; Holzapfel, C M

    1992-06-01

    Parallel crosses between each of two southern (ancestral) and one northern (derived) population of the pitcher-plant mosquito, Wyeomyia smithii, were made to determine the genetic components of population divergence in critical photoperiod, a phenological trait that measures adaptation to seasonality along a climatic gradient. Joint scaling tests were used to analyze means and variances of first- and second-generation hybrids in order to determine whether nonadditive genetic variance, especially epistatic variance, contributed to divergence in critical photoperiod. In both crosses, digenic epistatic effects were highly significant, indicating that genetic divergence cannot have resulted solely from differences in additively acting loci. For one cross that could be tested directly for such effects, higher order epistasis and/or linkage did not contribute to the divergence of critical photoperiod between the constituent populations. PMID:1353737

  8. Cloning of quantitative trait genes from rice reveals conservation and divergence of photoperiod flowering pathways in Arabidopsis and rice

    PubMed Central

    Matsubara, Kazuki; Hori, Kiyosumi; Ogiso-Tanaka, Eri; Yano, Masahiro

    2014-01-01

    Flowering time in rice (Oryza sativa L.) is determined primarily by daylength (photoperiod), and natural variation in flowering time is due to quantitative trait loci involved in photoperiodic flowering. To date, genetic analysis of natural variants in rice flowering time has resulted in the positional cloning of at least 12 quantitative trait genes (QTGs), including our recently cloned QTGs, Hd17, and Hd16. The QTGs have been assigned to specific photoperiodic flowering pathways. Among them, 9 have homologs in the Arabidopsis genome, whereas it was evident that there are differences in the pathways between rice and Arabidopsis, such that the rice Ghd7–Ehd1–Hd3a/RFT1 pathway modulated by Hd16 is not present in Arabidopsis. In this review, we describe QTGs underlying natural variation in rice flowering time. Additionally, we discuss the implications of the variation in adaptive divergence and its importance in rice breeding. PMID:24860584

  9. Interaction between photoperiod and an endogenous seasonal factor in influencing the diel locomotor activity of the benthic polychaete Nereis virens Sars.

    PubMed

    Last, Kim S; Olive, Peter J W

    2004-04-01

    The locomotor activity of Nereis virens Sars associated with food prospecting was investigated in response to photoperiod and season using an actograph. Experimental animals which had been reared under natural photoperiods were exposed to two constant photoperiodic treatments, LD 16:8 and LD 8:16, in both the autumn and winter and in the absence of tidal entrainment. Autocorrelation analysis of rhythmicity showed that during the autumn, animals under the LD 16:8 photoperiod displayed a strong nocturnal rhythm of activity, whereas animals under the LD 8:16 photoperiod showed only a weak nocturnal activity rhythm. This is believed to represent an autumn feeding cessation that is triggered when the animals pass through a critical photoperiod LD(crit) <12:>12. Later in the winter, however, animals exposed to both photoperiodic treatments showed strong rhythms of foraging activity irrespective of the imposed photoperiod. It is suggested that the autumn cessation may maximize the fitness of N. virens, a spring-breeding semelparous organism, by reducing risk during gamete maturation, while spontaneous resurgence of activity after the winter solstice permits animals that are not physiologically competent to spawn to accrue further metabolic reserves. This response is believed to be initiated by a seasonal (possibly circannual) endogenous oscillator or interval timer. PMID:15111365

  10. Effects of natural and artificial photoperiods and fluctuating temperature on age of first mating and mating frequency in the navel orangeworm, Amyelois transitella

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We examined the effect of weak illumination during part or all of scotophase on mating frequency of navel orangeworm, Amyelois transitella (Walker), in environmental chambers under long photoperiods and constant warm temperature (colony conditions) or shorter photoperiods and a cooler thermoperiod i...

  11. Geographic Variation of Diapause and Sensitive Stages of Photoperiodic Response in Laodelphax striatellus Fallén (Hemiptera: Delphacidae).

    PubMed

    Hou, Yang-Yang; Xu, Lan-Zhen; Wu, Yan; Wang, Peng; Shi, Jin-Jian; Zhai, Bao-Ping

    2016-01-01

    Large numbers of the small brown planthopper Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae) occur in temperate regions, causing severe losses in rice, wheat, and other economically important crops. The planthoppers enter diapause in the third- or fourth-instar nymph stage, induced by short photoperiods and low temperatures. To investigate the geographic variation in L. striatellus diapause, we compared the incidence of nymphal diapause under various constant temperature (20 and 27 °C) and a photoperiod of 4:20, 8:16, 10:14, 12:12, 14:10, and 16:8 (L:D) h regimes among three populations collected from Hanoi (21.02° N, 105.85° E, northern Vietnam), Jiangyan (32.51° N, 120.15° E, eastern China), and Changchun (43.89° N, 125.32° E, north-eastern China). Our results indicated that there were significant geographic variations in the diapause of L. striatellus. When the original latitude of the populations increased, higher diapause incidence and longer critical photoperiod (CP) were exhibited. The CPs of the Jiangyan and Changchun populations were ∼ 12 hr 30 min and 13 hr at 20 °C, and 11 hr and 11 hr 20 min at 27 °C, respectively. The second- and third-instar nymphs were at the stage most sensitive to the photoperiod. However, when the fourth- and fifth-instar nymphs were transferred to a long photoperiod, the diapause-inducing effect of the short photoperiod on young instars was almost reversed. The considerable geographic variations in the nymphal diapause of L. striatellus reflect their adaptation in response to a variable environment and provide insights to develop effective pest management strategies. PMID:26839318

  12. Geographic Variation of Diapause and Sensitive Stages of Photoperiodic Response in Laodelphax striatellus Fallén (Hemiptera: Delphacidae)

    PubMed Central

    Hou, Yang-Yang; Xu, Lan-Zhen; Wu, Yan; Wang, Peng; Shi, Jin-Jian; Zhai, Bao-Ping

    2016-01-01

    Large numbers of the small brown planthopper Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae) occur in temperate regions, causing severe losses in rice, wheat, and other economically important crops. The planthoppers enter diapause in the third- or fourth-instar nymph stage, induced by short photoperiods and low temperatures. To investigate the geographic variation in L. striatellus diapause, we compared the incidence of nymphal diapause under various constant temperature (20 and 27°C) and a photoperiod of 4:20, 8:16, 10:14, 12:12, 14:10, and 16:8 (L:D) h regimes among three populations collected from Hanoi (21.02° N, 105.85° E, northern Vietnam), Jiangyan (32.51° N, 120.15° E, eastern China), and Changchun (43.89° N, 125.32° E, north-eastern China). Our results indicated that there were significant geographic variations in the diapause of L. striatellus. When the original latitude of the populations increased, higher diapause incidence and longer critical photoperiod (CP) were exhibited. The CPs of the Jiangyan and Changchun populations were ∼12 hr 30 min and 13 hr at 20°C, and 11 hr and 11 hr 20 min at 27°C, respectively. The second- and third-instar nymphs were at the stage most sensitive to the photoperiod. However, when the fourth- and fifth-instar nymphs were transferred to a long photoperiod, the diapause-inducing effect of the short photoperiod on young instars was almost reversed. The considerable geographic variations in the nymphal diapause of L. striatellus reflect their adaptation in response to a variable environment and provide insights to develop effective pest management strategies. PMID:26839318

  13. Photoperiodic regulation of seasonal reproduction, molt and body weight in the migratory male yellow-breasted bunting (Emberiza aureola).

    PubMed

    Dixit, Anand S; Sougrakpam, Ramita

    2013-09-01

    Photoperiod has been shown to be a major source of temporal information regulating reproduction and associated functions in a number of avian species. We studied seasonal cycles of testicular volume, molt and body weight in natural and temperature-controlled conditions and under different artificial photoperiods in the yellow-breasted buntings. Buntings posses seasonal cycles of testicular volume, molt, body weight and fattening with no major difference between natural and temperature-controlled conditions. These cycles follow an annual solar cycle suggesting the possibility of their photoperiodic control. To confirm this, photosensitive birds were studied under 9L/15D (close to shortest day length), 12L/12D (equinox day length) and 14L/10D (close to longest day length) for 18 months. Buntings showed testicular growth followed by regression and development of photorefractoriness; molt and body weight change only under 12L/12D and 14L/10D but not under 9L/15D. Reinitiation of above responses did not occur following initial cycles under stimulatory photoperiods precluding the possibility of circannual rhythm involvement. Birds exhibited an incomplete prenuptial molt of body feathers during gonadal stimulation under long days followed by complete postnuptial molt of body and primary feathers that progressed with gonadal regression. Exposure of photosensitive birds to light-dark cycles constituting 9-16h of light/day suggested that daily photoperiod of about 12h or more is essential in inducing testicular growth and function. These results clearly indicate that buntings are capable of fine discrimination of photoperiodic information and use annual changes in day length as an environmental factor to time their seasonal responses. PMID:23910635

  14. Mortality in the First 3 Months on Antiretroviral Therapy Among HIV-Positive Adults in Low- and Middle-income Countries: A Meta-analysis.

    PubMed

    Brennan, Alana T; Long, Lawrence; Useem, Johanna; Garrison, Lindsey; Fox, Matthew P

    2016-09-01

    Previous meta-analyses reported mortality estimates of 12-month post-antiretroviral therapy (ART) initiation; however, 40%-60% of deaths occur in the first 3 months on ART, a more sensitive measure of averted deaths through early ART initiation. To determine whether early mortality is dropping as treatment thresholds have increased, we reviewed studies of 3 months on ART initiation in low- to middle-income countries. Studies of 3-month mortality from January 2003 to April 2016 were searched in 5 databases. Articles were included that reported 3-month mortality from a low- to middle-income country; nontrial setting and participants were ≥15. We assessed overall mortality and stratified by year using random effects models. Among 58 included studies, although not significant, pooled estimates show a decline in mortality when comparing studies whose enrollment of patients ended before 2010 (7.0%; 95% CI: 6.0 to 8.0) with the studies during or after 2010 (4.0%; 95% CI: 3.0 to 5.0). To continue to reduce early HIV-related mortality at the population level, intensified efforts to increase demand for ART through active testing and facilitated referral should be a priority. Continued financial investments by multinational partners and the implementation of creative interventions to mitigate multidimensional complex barriers of accessing care and treatment for HIV are needed. PMID:27513571

  15. Diet and gender are important factors modulating low frequency EEG activity during processing of language sounds in 3 month old infants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known about how early postnatal diet affects brain processes related to cognitive function in healthy infants. To address this question we examined EEG activity recorded from 3 month old infants [breastfed (BF: n = 104, 55 males), milk-based formula fed (MF: n = 114, 57 males) or soy for...

  16. Complete sternal cleft — A rare congenital malformation and its repair in a 3-month-old boy: A case report

    PubMed Central

    Kothari, Paras; Gupta, Abhaya; Patil, Prashant S.; Kekre, Geeta; Kamble, Ravi; Dikshit, Kiran Vishesh

    2016-01-01

    Complete midline sternal cleft is a rare congenital anomaly resulting from failed midline ventral fusion of the sternal bars. Very few cases of complete sternal cleft have been described in literature. We present a case of complete sternal cleft in a 3-month-old child. The patient underwent primary closure of the defect using stainless steel wires. PMID:27046980

  17. Effects of an extended photoperiod on gonadal function and condition of hair coats in Thoroughbred colts and fillies

    PubMed Central

    KUNII, Hirokazu; NAMBO, Yasuo; OKANO, Atsushi; MATSUI, Akira; ISHIMARU, Mutsuki; ASAI, Yo; SATO, Fumio; FUJII, Kazuki; NAGAOKA, Kentaro; WATANABE, Gen; TAYA, Kazuyoshi

    2015-01-01

    ABSTRACT The effects of an extended photoperiod (EP) in Thoroughbreds colts and fillies from winter at one year old to spring at two years old on the gonadal functions, coat condition, and endocrine changes were investigated. Sixty-two Thoroughbreds (31 colts and 31 fillies) reared in the Hidaka Training and Research Center (Hidaka), Japan Racing Association were used. Thirty of them (15 colts and 15 fillies) were reared under EP conditions from December 20 to April 10, and the remaining 32 horses were reared under natural light alone as a control group. For EP, a 100-watt white bulb was set near the ceilings of stalls, and lighting conditions of 14.5-hr light and 9.5-hr dark periods were established. Blood was collected from the jugular vein once a month from October at one year old to February at two years old in both colts and fillies, and then twice a month in colts and weekly in fillies after March, and the coat condition was evaluated in January and April in 56 horses. To investigate endocrine changes, the plasma concentrations of prolactin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), immunoreactive (ir-) inhibin, testosterone, estradiol-17β and progesterone were measured. No significant difference was noted in the coat condition between the two groups in January, but they changed from winter to summer coats (molting of winter coats) in April in the EP group compared with the control group. Regarding endocrine changes, the plasma concentrations of prolactin, FSH, ir-inhibin and testosterone were significantly higher in the EP colts than in the control group from January to April. The plasma concentrations of LH tended to rise in the EP colts from January to April compared with the control group. In the EP fillies, the plasma concentrations of prolactin, LH, ir-inhibin, estradiol-17β and progesterone were significantly higher during January and April, but a significantly high level of FSH was noted in the control than EP group in January

  18. Effects of an extended photoperiod on gonadal function and condition of hair coats in Thoroughbred colts and fillies.

    PubMed

    Kunii, Hirokazu; Nambo, Yasuo; Okano, Atsushi; Matsui, Akira; Ishimaru, Mutsuki; Asai, Yo; Sato, Fumio; Fujii, Kazuki; Nagaoka, Kentaro; Watanabe, Gen; Taya, Kazuyoshi

    2015-01-01

    The effects of an extended photoperiod (EP) in Thoroughbreds colts and fillies from winter at one year old to spring at two years old on the gonadal functions, coat condition, and endocrine changes were investigated. Sixty-two Thoroughbreds (31 colts and 31 fillies) reared in the Hidaka Training and Research Center (Hidaka), Japan Racing Association were used. Thirty of them (15 colts and 15 fillies) were reared under EP conditions from December 20 to April 10, and the remaining 32 horses were reared under natural light alone as a control group. For EP, a 100-watt white bulb was set near the ceilings of stalls, and lighting conditions of 14.5-hr light and 9.5-hr dark periods were established. Blood was collected from the jugular vein once a month from October at one year old to February at two years old in both colts and fillies, and then twice a month in colts and weekly in fillies after March, and the coat condition was evaluated in January and April in 56 horses. To investigate endocrine changes, the plasma concentrations of prolactin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), immunoreactive (ir-) inhibin, testosterone, estradiol-17β and progesterone were measured. No significant difference was noted in the coat condition between the two groups in January, but they changed from winter to summer coats (molting of winter coats) in April in the EP group compared with the control group. Regarding endocrine changes, the plasma concentrations of prolactin, FSH, ir-inhibin and testosterone were significantly higher in the EP colts than in the control group from January to April. The plasma concentrations of LH tended to rise in the EP colts from January to April compared with the control group. In the EP fillies, the plasma concentrations of prolactin, LH, ir-inhibin, estradiol-17β and progesterone were significantly higher during January and April, but a significantly high level of FSH was noted in the control than EP group in January. The

  19. Leptin inhibits the reproductive axis in adult male Syrian hamsters exposed to long and short photoperiod.

    PubMed

    Boggio, Veronica; Cutrera, Rodolfo; Carbone, Silvia; Scacchi, Pablo; Ponzo, Osvaldo J

    2013-09-01

    The aim of the study was to investigate the effects of acute leptin treatment of adult Syrian hamsters exposed to a long (LP, eugonadal males) and short photoperiod (SP, hypogonadal males). Animals were exposed to LP (L:D 14:10) or SP (L:D 10:14) for 10 weeks. Afterwards, both LP and SP hamsters were allocated to a control (SP-C, LP-C) or leptin-treated group (SP 3, SP 10, SP 30 or LP3, LP 10, LP 30). One hour before sacrifice, a single dose of leptin (3, 10 or 30 μg/kg) or vehicle was administered (i.p.) to the males. Testis weight, serum and pituitary luteinizing hormone (LH) concentrations, as well as the hypothalamic concentration of gonadotropin-releasing hormone (GnRH) were recorded. Histological analysis of the testis was performed and GnRH concentration in the culture medium of hypothalamic explants was examined. A dramatic regression of testicular weight and histological atrophy of seminiferous tubules, as well as a decrease in serum and pituitary LH concentrations were found in SP males. All doses of leptin significantly reduced serum LH levels and medium GnRH concentrations in both photoperiod groups. Pituitary LH and hypothalamic GnRH concentrations were not affected by leptin. In conclusion, we demonstrated that leptin inhibited the reproductive axis of Syrian male hamsters exposed to LP and SP and fed ad libitum. PMID:24011191

  20. The Effect of Different Photoperiods in Circadian Rhythms of Per3 Knockout Mice

    PubMed Central

    Pereira, D. S.; van der Veen, D. R.; Gonçalves, B. S. B.; Tufik, S.; von Schantz, M.; Archer, S. N.; Pedrazzoli, M.

    2014-01-01

    The aim of this study was to analyse the circadian behavioural responses of mice carrying a functional knockout of the Per3 gene (Per3−/−) to different light : dark (L : D) cycles. Male adult wild-type (WT) and Per3−/− mice were kept under 12-hour light : 12-hour dark conditions (12L : 12D) and then transferred to either a short or long photoperiod and subsequently released into total darkness. All mice were exposed to both conditions, and behavioural activity data were acquired through running wheel activity and analysed for circadian characteristics during these conditions. We observed that, during the transition from 12L : 12D to 16L : 8D, Per3−/− mice take approximately one additional day to synchronise to the new L : D cycle compared to WT mice. Under these long photoperiod conditions, Per3−/− mice were more active in the light phase. Our results suggest that Per3−/− mice are less sensitive to light. The data presented here provides further evidence that Per3 is involved in the suppression of behavioural activity in direct response to light. PMID:24982860

  1. The influence of light intensity and photoperiod on duckweed biomass and starch accumulation for bioethanol production.

    PubMed

    Yin, Yehu; Yu, Changjiang; Yu, Li; Zhao, Jinshan; Sun, Changjiang; Ma, Yubin; Zhou, Gongke

    2015-01-01

    Duckweed has been considered as a valuable feedstock for bioethanol production due to its high biomass and starch production. To investigate the effects of light conditions on duckweed biomass and starch production, Lemna aequinoctialis 6000 was cultivated at different photoperiods (12:12, 16:8 and 24:0h) and light intensities (20, 50, 80, 110, 200 and 400μmolm(-2)s(-1)). The results showed that the duckweed biomass and starch production was increased with increasing light intensity and photoperiod except at 200 and 400μmolm(-2)s(-1). Considering the light cost, 110μmolm(-2)s(-1) was optimum light condition for starch accumulation with the highest maximum growth rate, biomass and starch production of 8.90gm(-2)day(-1), 233.25gm(-2) and 98.70gm(-2), respectively. Moreover, the results suggested that high light induction was a promising method for duckweed starch accumulation. This study provides optimized light conditions for future industrial large-scale duckweed cultivation. PMID:25841186

  2. Reproductive responses of male Brandt's voles ( Lasiopodomys brandtii) to 6-methoxybenzoxazolinone (6-MBOA) under short photoperiod

    NASA Astrophysics Data System (ADS)

    Dai, Xin; Jiang, Lian Yu; Han, Mei; Ye, Man Hong; Wang, Ai Qin; Wei, Wan Hong; Yang, Sheng Mei

    2016-04-01

    The plant secondary metabolite 6-methoxybenzoxazolinone (6-MBOA) can stimulate and enhance animal reproduction. This compound has been successfully detected in Leymus chinensis, which is the main diet of Brandt's voles. The aim of this study was to investigate the effect of different 6-MBOA doses on the reproductive physiology of male Brandt's voles under a short photoperiod. The results showed that 6-MBOA administration increased relative testis weight, regardless of the dose, but it had little effect on the body mass. Low and middle doses of 6-MBOA increased the concentrations of luteinizing hormone and testosterone in the serum and the mRNA levels of StAR and CYP11a1 in the testes. However, 6-MBOA did not cause any significant increase in the mRNA levels of KiSS-1, GPR54, and GnRH compared to those in the control group. The mRNA level of KiSS-1 in the arcuate nucleus (ARC) was higher than that in the anteroventral periventricular nucleus (AVPV). Collectively, our results demonstrated that the number of KiSS-1-expressing neurons located in the ARC was the highest, and that 6-MBOA, which might modulate the reproductive activity along the hypothalamic-pituitary-gonadal axis, had a dose-dependent stimulatory effect on the reproductive activity of Brandt's voles under a short photoperiod. Our study provided insights into the mechanism of 6-MBOA action and the factors influencing the onset of reproduction in Brandt's voles.

  3. Photoperiodic Regulation of Cerebral Blood Flow in White-Footed Mice (Peromyscus leucopus).

    PubMed

    Borniger, Jeremy C; Teplitsky, Seth; Gnyawali, Surya; Nelson, Randy J; Rink, Cameron

    2016-01-01

    Individuals living outside the tropics need to adjust their behavioral and physiological repertoires throughout the year to adapt to the changing seasons. White-footed mice (Peromyscus leucopus) reduce hippocampal volumes, hippocampal-dependent memory function, long-term potentiation, and alter neurogenesis in response to short (winter-like) day lengths (photoperiods). During winter, these mice putatively shunt energy away from the brain to maximize peripheral thermogenesis, immune function, and survival. We hypothesized that these changes in brain function are accompanied by alterations in brain vasculature. We maintained white-footed mice in short (8 h light/16 h dark) or long (16 h light/8 h dark) photoperiods for 8-9 weeks. Mice were then perfused with fluorescein isothiocyanate (FITC)-conjugated tomato (Lycopersicon esculentum) lectin to visualize the perfused cerebrovasculature. Short-day mice reduced hippocampal and cortical capillary density (FITC(+) area); vessels isolated from short day-exposed mice expressed higher mRNA levels of the gelatinase matrix metalloproteinase 2 (MMP2). Additionally, short-day mice reduced cerebral blood flow ∼15% compared with their long-day counterparts, as assessed by laser speckle flowmetry. Immunohistochemistry revealed higher levels of MMP2 in the hippocampus of mice maintained in short days compared with long days, potentially contributing to the observed vascular remodeling. These data demonstrate that a discrete environmental signal (i.e., day length) can substantially alter cerebral blood flow in adult mammals. PMID:27570829

  4. Seasonal pelage changes are synchronized by simulated natural photoperiods in Siberian hamsters (Phodopus sungorus).

    PubMed

    Butler, Matthew P; Zucker, Irving

    2009-08-01

    The extent to which changing day lengths (DLs) synchronize the seasonal molt was assessed in nine cohorts of male and female Siberian hamsters (Phodopus sungorus) born into a simulated natural photoperiod (SNP) beginning 4 weeks before and ending 12 weeks after the summer solstice. Hamsters in early cohorts displayed rapid somatic and gonadal growth and early puberty, whereas those in later cohorts delayed puberty until the next spring. Despite the varying birth dates and puberty strategies, the seasonal pattern of change in pelage is much better predicted by calendar date than by age in both sexes. Males born over the course of 16 weeks first made the transition to the winter pelage during a 5-week interval beginning on October 25; the autumn molt, however, was not significantly synchronized by either age or calendar date. The autumn molt of females on the other hand began 2 weeks later, and was significantly synchronized to calendar date with no detectable age effects. In both sexes, the autumn molt lagged gonadal and somatic seasonal changes by many weeks. Date of birth did not affect the timing of the spring molt, which was significantly synchronized by calendar date in both sexes. Incrementally changing photoperiods exert a strong organizing effect on the seasonal molt by providing hamsters with timing cues that are absent in laboratory analyses that employ static DLs and abrupt transitions from summer to winter DLs, thereby extending and validating conclusions derived from previous analyses. PMID:19425044

  5. Seasonal pelage changes are synchronized by simulated natural photoperiods in Siberian hamsters (Phodopus sungorus)

    PubMed Central

    Butler, Matthew P.; Zucker, Irving

    2013-01-01

    The extent to which changing day lengths synchronize the seasonal molt was assessed in nine cohorts of male and female Siberian hamsters (Phodopus sungorus) born into a simulated natural photoperiod (SNP) beginning 4 weeks before and ending 12 weeks after the summer solstice. Hamsters in early cohorts displayed rapid somatic and gonadal growth and early puberty, whereas those in later cohorts delayed puberty until the next spring. Despite the varying birth dates and puberty strategies, the seasonal pattern of change in pelage is much better predicted by calendar date than by age in both sexes. Males born over the course of 16 weeks first made the transition to the winter pelage during a 5 week interval beginning on October 25; the autumn molt, however, was not significantly synchronized by either age or calendar date. The autumn molt of females on the other hand began 2 weeks later, and was significantly synchronized to calendar date with no detectable age effects. In both sexes, the autumn molt lagged gonadal and somatic seasonal changes by many weeks. Date of birth did not affect the timing of the spring molt, which was significantly synchronized by calendar date in both sexes. Incrementally changing photoperiods exert a strong organizing effect on the seasonal molt by providing hamsters with timing cues that are absent in laboratory analyses that employ static day lengths and abrupt transitions from summer to winter day lengths, thereby extending and validating conclusions derived from previous analyses. PMID:19425044

  6. Actions and interactions of temperature and photoperiod on mercury accumulation by Elodea densa from sediment source

    SciTech Connect

    Maury-Brachet, R.; Ribeyre, F.; Boudou, A. )

    1990-10-01

    Actions and interactions of two abiotic parameters--temperature (18, 21, and 24 degrees C) and photoperiod (8, 12, and 16 hr/day)--on mercury bioaccumulation (HgCl2 and CH3HgCl) by a rooted macrophyte species, Elodea densa, from the sediment source were studied using experimental designs. Comparative analysis of shoot growth (weight and length criteria) was made to look for a possible inhibiting action by the metal and to establish quantitative data for the interpretation of accumulation results. Total mercury accumulation by E. densa was quantified using two criteria--concentration and content. The amount of total mercury accumulated in the whole plant after a 28-day exposure was 40 times greater for the organic form, if the two compounds were initially added to the sediment at the same concentration. Temperature and photoperiod had a strong influence on methyl mercury accumulation by the plants, separately and in interaction. The interactions generally represent an amplification of effects produced by each abiotic factor, although this synergy varied according to the two accumulation criteria being considered or to the level of analysis (whole plant, leaves, and stems).

  7. Evolutionary divergence of the genetic architecture underlying photoperiodism in the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Lair, K P; Bradshaw, W E; Holzapfel, C M

    1997-12-01

    We determine the contribution of composite additive, dominance, and epistatic effects to the genetic divergence of photoperiodic response along latitudinal, altitudinal, and longitudinal gradients in the pitcher-plant mosquito, Wyeomyia smithii. Joint scaling tests of crosses between populations showed widespread epistasis as well as additive and dominance differences among populations. There were differences due to epistasis between an alpine population in North Carolina and populations in Florida, lowland North Carolina, and Maine. Longitudinal displacement resulted in differences due to epistasis between Florida and Alabama populations separated by 300 km but not between Maine and Wisconsin populations separated by 2000 km. Genetic differences between New Jersey and Ontario did not involve either dominance or epistasis and we estimated the minimum number of effective factors contributing to a difference in mean critical photoperiod of 5 SD between them as nE = 5. We propose that the genetic similarity of populations within a broad northern region is due to their more recent origin since recession of the Laurentide Ice Sheet and that the unique genetic architecture of each population is the result of both mutation and repeated migration-founder-flush episodes during the dispersal of W. smithii in North America. Our results suggest that differences in composite additive and dominance effects arise early in the genetic divergence of populations while differences due to epistasis accumulate after more prolonged isolation. PMID:9409843

  8. Photoperiod-H1 (Ppd-H1) Controls Leaf Size.

    PubMed

    Digel, Benedikt; Tavakol, Elahe; Verderio, Gabriele; Tondelli, Alessandro; Xu, Xin; Cattivelli, Luigi; Rossini, Laura; von Korff, Maria

    2016-09-01

    Leaf size is a major determinant of plant photosynthetic activity and biomass; however, it is poorly understood how leaf size is genetically controlled in cereal crop plants like barley (Hordeum vulgare). We conducted a genome-wide association scan for flowering time, leaf width, and leaf length in a diverse panel of European winter cultivars grown in the field and genotyped with a single-nucleotide polymorphism array. The genome-wide association scan identified PHOTOPERIOD-H1 (Ppd-H1) as a candidate gene underlying the major quantitative trait loci for flowering time and leaf size in the barley population. Microscopic phenotyping of three independent introgression lines confirmed the effect of Ppd-H1 on leaf size. Differences in the duration of leaf growth and consequent variation in leaf cell number were responsible for the leaf size differences between the Ppd-H1 variants. The Ppd-H1-dependent induction of the BARLEY MADS BOX genes BM3 and BM8 in the leaf correlated with reductions in leaf size and leaf number. Our results indicate that leaf size is controlled by the Ppd-H1- and photoperiod-dependent progression of plant development. The coordination of leaf growth with flowering may be part of a reproductive strategy to optimize resource allocation to the developing inflorescences and seeds. PMID:27457126

  9. Photoperiodic control of soybean /sup 14/C-assimilate partitioning during the seed filling period

    SciTech Connect

    Morandi, E.N.

    1986-04-01

    Photoperiod not only controls the timing of flowering, but also affects later stages of seed development. To study its effect on assimilate partitioning, soybean plants were kept in short days (SD) or night interrupted (NI) during seed filling. The source-sink ratio was fixed to one leaflet-one pod per node. The node was girdle-isolated and its leaflet was pulse labelled with /sup 14/CO/sub 2/. SD plants partitioned more /sup 14/C into seeds, while NI plants showed higher proportions in the petiole, stem and carpel. Seed growth rate and final seed dry weight were increased by 40% in SD. The sugar/starch ratio was increased in cotyledons and decreased in leaves of SD plants. In contrast, NI plants showed more /sup 14/C incorporation into proteins. No changes were detected in carbon exchange ratio, dark respiration and total node dry weight. Thus, photoperiodic induced changes in carbohydrate and protein partitioning occurred without changes in the overall assimilatory process.

  10. Spatio-temporal variation of the diterpene steviol in Stevia rebaudiana grown under different photoperiods.

    PubMed

    Ceunen, Stijn; Geuns, Jan M C

    2013-05-01

    As part of an ongoing study on the effects of photoperiodism on the metabolism of steviol glycosides (SVglys) in Stevia rebaudiana, the spatio-temporal variations of free steviol (SV) have now been evaluated. For its quantitation, an internal standard method was used, based upon a specific fluorometric detection of SV as its methoxycoumarinyl derivative. The level of free SV in leaves did not exceed 30 μg/g dry wt and was at least 1000-fold smaller than that of its glycosidic conjugates. In other organs, free SV was mainly measured in stem tissue and apices, with relatively large amounts measured in the latter. Similarly to SVglys, the content of free SV was influenced by photoperiod and genotype. In plants grown under long-days (LD) of 16 h, more spatial variations were seen compared to those under short-days (SD) of 8h. In the former, upper leaves contained almost four times more free SV compared to lower ones near the end of vegetative growth. In addition, the correlation between SV and its glycosidic conjugates was more linear under SD. Despite the variability of SV levels, a decrease was noted in all conditions after flower opening, which can be related a decreased transcription of the biosynthetic genes involved. PMID:23402803

  11. Evolutionary Divergence of the Genetic Architecture Underlying Photoperiodism in the Pitcher-Plant Mosquito, Wyeomyia Smithii

    PubMed Central

    Lair, K. P.; Bradshaw, W. E.; Holzapfel, C. M.

    1997-01-01

    We determine the contribution of composite additive, dominance, and epistatic effects to the genetic divergence of photoperiodic response along latitudinal, altitudinal, and longitudinal gradients in the pitcher-plant mosquito, Wyeomyia smithii. Joint scaling tests of crosses between populations showed wide-spread epistasis as well as additive and dominance differences among populations. There were differences due to epistasis between an alpine population in North Carolina and populations in Florida, lowland North Carolina, and Maine. Longitudinal displacement resulted in differences due to epistasis between Florida and Alabama populations separated by 300 km but not between Maine and Wisconsin populations separated by 2000 km. Genetic differences between New Jersey and Ontario did not involve either dominance or epistasis and we estimated the minimum number of effective factors contributing to a difference in mean critical photoperiod of 5 SD between them as n(E) = 5. We propose that the genetic similarity of populations within a broad northern region is due to their more recent origin since recession of the Laurentide Ice Sheet and that the unique genetic architecture of each population is the result of both mutation and repeated migration-founder-flush episodes during the dispersal of W. smithii in North America. Our results suggest that differences in composite additive and dominance effects arise early in the genetic divergence of populations while differences due to epistasis accumulate after more prolonged isolation. PMID:9409843

  12. Photoperiodic Regulation of Cerebral Blood Flow in White-Footed Mice (Peromyscus leucopus)

    PubMed Central

    Teplitsky, Seth

    2016-01-01

    Abstract Individuals living outside the tropics need to adjust their behavioral and physiological repertoires throughout the year to adapt to the changing seasons. White-footed mice (Peromyscus leucopus) reduce hippocampal volumes, hippocampal-dependent memory function, long-term potentiation, and alter neurogenesis in response to short (winter-like) day lengths (photoperiods). During winter, these mice putatively shunt energy away from the brain to maximize peripheral thermogenesis, immune function, and survival. We hypothesized that these changes in brain function are accompanied by alterations in brain vasculature. We maintained white-footed mice in short (8 h light/16 h dark) or long (16 h light/8 h dark) photoperiods for 8–9 weeks. Mice were then perfused with fluorescein isothiocyanate (FITC)-conjugated tomato (Lycopersicon esculentum) lectin to visualize the perfused cerebrovasculature. Short-day mice reduced hippocampal and cortical capillary density (FITC+ area); vessels isolated from short day-exposed mice expressed higher mRNA levels of the gelatinase matrix metalloproteinase 2 (MMP2). Additionally, short-day mice reduced cerebral blood flow ∼15% compared with their long-day counterparts, as assessed by laser speckle flowmetry. Immunohistochemistry revealed higher levels of MMP2 in the hippocampus of mice maintained in short days compared with long days, potentially contributing to the observed vascular remodeling. These data demonstrate that a discrete environmental signal (i.e., day length) can substantially alter cerebral blood flow in adult mammals. PMID:27570829

  13. Phenolic Profile of Dark-Grown and Photoperiod-Exposed Hypericum perforatum L. Hairy Root Cultures

    PubMed Central

    Petreska Stanoeva, Jasmina; Stefova, Marina; Simic, Sonja Gadzovska

    2013-01-01

    Hypericum perforatum L. is a medicinal plant considered as an important natural source of secondary metabolites with a wide range of pharmacological attributes. Hairy roots (HR) were induced from root segments of in vitro grown seedlings from H. perforatum after cocultivation with Agrobacterium rhizogenes A4. Investigations have been made to study the production of phenolic compounds in dark-grown (HR1) and photoperiod-exposed (HR2) cultures. The chromatographic analysis of phenolic acids, flavonols, flavan-3-ols, and xanthones revealed marked differences between HR1 and HR2 cultures. The production of quinic acid, kaempferol, and seven identified xanthones was increased in HR2. Moreover, HR2 showed a capability for de novo biosynthesis of two phenolic acids (3-p-coumaroylquinic acid and 3-feruloylquinic acid), three flavonol glycosides (kaempferol hexoside, hyperoside, and quercetin acetylglycoside), and five xanthones (tetrahydroxy-one-methoxyxanthone, 1,3,5-trihydroxy-6-methoxyxanthone, 1,3,5,6-tetrahydroxy-2-prenylxanthone, paxanthone, and banaxanthone E). On the other side, HR1 cultures were better producers of flavan-3-ols (catechin, epicatechin, and proanthocyanidin dimers) than HR2. This is the first comparative study on phenolic profile of H. perforatum HR cultures grown under dark and photoperiod conditions. PMID:24453880

  14. Reproductive responses of male Brandt's voles (Lasiopodomys brandtii) to 6-methoxybenzoxazolinone (6-MBOA) under short photoperiod.

    PubMed

    Dai, Xin; Jiang, Lian Yu; Han, Mei; Ye, Man Hong; Wang, Ai Qin; Wei, Wan Hong; Yang, Sheng Mei

    2016-04-01

    The plant secondary metabolite 6-methoxybenzoxazolinone (6-MBOA) can stimulate and enhance animal reproduction. This compound has been successfully detected in Leymus chinensis, which is the main diet of Brandt's voles. The aim of this study was to investigate the effect of different 6-MBOA doses on the reproductive physiology of male Brandt's voles under a short photoperiod. The results showed that 6-MBOA administration increased relative testis weight, regardless of the dose, but it had little effect on the body mass. Low and middle doses of 6-MBOA increased the concentrations of luteinizing hormone and testosterone in the serum and the mRNA levels of StAR and CYP11a1 in the testes. However, 6-MBOA did not cause any significant increase in the mRNA levels of KiSS-1, GPR54, and GnRH compared to those in the control group. The mRNA level of KiSS-1 in the arcuate nucleus (ARC) was higher than that in the anteroventral periventricular nucleus (AVPV). Collectively, our results demonstrated that the number of KiSS-1-expressing neurons located in the ARC was the highest, and that 6-MBOA, which might modulate the reproductive activity along the hypothalamic-pituitary-gonadal axis, had a dose-dependent stimulatory effect on the reproductive activity of Brandt's voles under a short photoperiod. Our study provided insights into the mechanism of 6-MBOA action and the factors influencing the onset of reproduction in Brandt's voles. PMID:26940061

  15. Photoperiod as a proximate factor in control of seasonality in the subtropical male Tree Sparrow, Passer montanus

    PubMed Central

    2011-01-01

    Background Most species of birds exhibit well-defined seasonality in their various physiological and behavioral functions like reproduction, molt, bill color etc. such that they occur at the most appropriate time of the year. Day length has been shown to be a major source of temporal information regulating seasonal reproduction and associated events in a number of avian species. The present study aims to investigate the role of photoperiod in control of seasonal cycles in the subtropical male tree sparrow (Passer montanus) and to compare its responses at Shillong (Latitude 25°34'N, Longitude 91°53'E) with those exhibited by its conspecifics and related species at other latitudes. Results Initial experiment involving study of seasonal cycles revealed that the wild tree sparrows posses definite seasonal cycles of testicular volume, molt and bill color. These cycles were found remarkably linked to annual solar cycle suggesting the possibility of their photoperiodic control. To confirm this possibility in the next experiment, the photosensitive birds were exposed to three different light-dark regimes that were close to what they experience at this latitude: 9L/15D (close to shortest day length), 12L/12D (equinox day length) and 14L/10D (close to longest day length) for 18 months. Tree sparrows showed testicular growth followed by regression and development of photorefractoriness, molting and bill color changes only under long daily photoperiods (12 L and 14 L) but not under short daily photoperiod (9 L). Birds, under stimulatory photoperiods, did not show reinitiation of the above responses after the completion of initiation regression cycle even after their exposure to these photoperiods for 18 months. This precludes the possibility of circannual rhythm generation and suggests the involvement of photoperiodic mechanism in control of their seasonal cycles. Further, replacement of body and primary feathers progressed with gonadal regression only under long days

  16. Influence of photoperiod, light intensity, and their interaction on growth performance and carcass characteristics of broilers grown to heavy weights

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated the effects of photoperiod, light intensity and their interaction on growth performance and carcass characteristics of broilers in 2 trials. In each trial, 540 1-d-old Ross × Ross 708 chicks were randomly distributed into 9 environmentally controlled rooms (30 males/30 females chicks...

  17. FIELD-BASED EVALUATION OF VERNALIZATION REQUIREMENT, PHOTOPERIOD RESPONSE AND EARLINESS PER SE IN BREAD WHEAT (TRITICUM AESTIVUM L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vernalization requirement, photoperiod response and earliness per se (EPS) of bread wheat cultivars are often determined using controlled environments. However, use of non-field conditions may reduce the applicability of results for predicting field performance as well as increase the cost of evalu...

  18. Melatonin and 6-methoxy-2-benzoxazolinone (6-MBOA) alter the response of the male Syrian hamster to natural photoperiod

    NASA Astrophysics Data System (ADS)

    Vaughan, M. K.; Little, J. C.; Powell, D. C.; Puig-Domingo, M.; Reiter, R. J.

    1988-06-01

    Adult male hamsters bearing either a blank beeswax, 6-methoxy-2-benzoxazolinone (6-MBOA), or melatonin pellet were exposed to 8 weeks (Oct. 6 Dec. 6) of natural autumn decreasing photoperiod (<11 h light) and temperature conditions (mean 10°C for last 4 weeks) or to a 14 h light/10 h dark (14L∶10D) photoperiod and controlled temperature (20°C). Melatonin but not 6-MBOA pellets partially prevented the combined effects of short photoperiod and cold temperatures on the testes and accessory organs. However, both 6-MBOA-and melatonin-treated hamsters maintained outdoors had significantly higher pituitary follicle stimulating hormone (FSH) values compared to their respective indoor-treated controls or to the animals kept outdoors and treated with a blank beeswax pellet. When one compares the various effects of 6-MBOA and melatonin (2 mg/month) on the reproductive system of the male hamster, 6-MBOA is not as effective as melatonin in altering reproductive responses to short photoperiod and cool temperatures at the dose administered.

  19. The synchronization of neuronal oscillators determined by the directed network structure of the suprachiasmatic nucleus under different photoperiods

    PubMed Central

    Gu, Changgui; Tang, Ming; Yang, Huijie

    2016-01-01

    The main function of the principal clock located in the suprachiasmatic nucleus (SCN) of mammals is synchronizing the body rhythms to the 24 h light-dark cycle. Additionally, the SCN is able to adapt to the photoperiod of the cycle which varies among seasons. Under the long photoperiod (LP), the synchronization degree of the SCN neurons is lower than that under the photoperiod (SP). In the present study, a potential explanation is given for this phenomenon. We propose that the asymmetrical coupling between the light-signal-sensitive part (the ventralateral part, abbreviation: VL) and the light-signal-insensitive part (the dorsalmedial part, abbreviation: DM) of the SCN plays a role in the synchronization degree, which is reflected by the ratio of the number of the directed links from the VL neurons to the DM neurons to the total links of both directions between the VL and the DM. The ratio is assumed to characterize the directed network structure under different photoperiods, which is larger under the SP and smaller under the LP. We found that with the larger ratio in the situation of the SP, the synchronization degree is higher. Our finding may shed new light on the asymmetrical coupling between the VL and the DM, and the network structure of the SCN. PMID:27358024

  20. Photoperiod Mediated Changes in Olfactory Bulb Neurogenesis and Olfactory Behavior in Male White-Footed Mice (Peromyscus leucopus)

    PubMed Central

    Weil, Zachary M.; Nelson, Randy J.

    2012-01-01

    Brain plasticity, in relation to new adult mammalian neurons generated in the subgranular zone of the hippocampus, has been well described. However, the functional outcome of new adult olfactory neurons born in the subventricular zone of the lateral ventricles is not clearly defined, as manipulating neurogenesis through various methods has given inconsistent and conflicting results in lab mice. Several small rodent species, including Peromyscus leucopus, display seasonal (photoperiodic) brain plasticity in brain volume, hippocampal function, and hippocampus-dependent behaviors; plasticity in the olfactory system of photoperiodic rodents remains largely uninvestigated. We exposed adult male P. leucopus to long day lengths (LD) and short day lengths (SD) for 10 to 15 weeks and then examined olfactory bulb cell proliferation and survival using the thymidine analog BrdU, olfactory bulb granule cell morphology using Golgi-Cox staining, and behavioral investigation of same-sex conspecific urine. SD mice did not differ from LD counterparts in granular cell morphology of the dendrites or in dendritic spine density. Although there were no differences due to photoperiod in habituation to water odor, SD mice rapidly habituated to male urine, whereas LD mice did not. In addition, short day induced changes in olfactory behavior were associated with increased neurogenesis in the caudal plexiform and granule cell layers of the olfactory bulb, an area known to preferentially respond to water-soluble odorants. Taken together, these data demonstrate that photoperiod, without altering olfactory bulb neuronal morphology, alters olfactory bulb neurogenesis and olfactory behavior in Peromyscus leucopus. PMID:22912730

  1. Long-day effects on the terminal inflorescence development of a photoperiod-sensitive soybean [Glycine max (L.) Merr.] variety

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The type of terminal inflorescence is a key component for identifying soybean type. In this study, a late maturity and photoperiod-sensitive determinate soybean, cv. Zigongdongdou, was used to investigate effects of long-day (LD) on the formation and development of the terminal inflorescence. After ...

  2. Effect of temperature and photoperiod on the development, reproduction, and predation of the predatory ladybird Cheilomenes sexmaculata (Coleoptera: Coccinellidae).

    PubMed

    Wang, Su; Tan, Xiao-Ling; Guo, Xiao-Jun; Zhang, Fan

    2013-12-01

    The polyphagous predatory ladybird Cheilomenes. sexmaculata (F.) (Coleoptera: Coccinellidae) is distributed throughout southern China and has been investigated as a potential biological control agent against herbivorous insects in various agroecosystems. In the current study, we evaluated the preimaginal development, eclosion rate, reproduction, fertility, adult longevity, and prey consumption of C. sexmaculata under five temperature and five photoperiod regimens. The results showed that preadult developmental duration decreased significantly with increasing temperature and amount of daylight. Adult eclosion rate was highest at 35 degrees C and under conditions of complete darkness. Higher temperatures shortened the duration of copulation and preoviposition, prolonged the duration of oviposition, and increased the level of fecundity. Hatchability was highest at 30 degrees C. By contrast, the shortest copulation and oviposition duration and lowest level of fecundity and hatchability occurred with a completely dark photoperiod. Temperature and the gender of C. sexmaculata influenced adult longevity. In addition, there was a significant interaction effect of photoperiod and gender on adult longevity. Furthermore, prey consumption by fourth instar larvae and adult females both increased with increasing temperature and photoperiod. Our results reveal the high thermal and light sensitivities of C. sexmaculata, which highlight the importance of environment regulation in the mass rearing of this natural enemy for application as a biological control in agroecosystems in China. PMID:24498765

  3. The influence of light intensity and photoperiod on the growth and lipid content of microalgae Nannochloropsis sp.

    PubMed

    Wahidin, Suzana; Idris, Ani; Shaleh, Sitti Raehanah Muhamad

    2013-02-01

    Illumination factors such as length of photoperiod and intensity can affect growth of microalgae and lipid content. In order to optimize microalgal growth in mass culture system and lipid content, the effects of light intensity and photoperiod cycle on the growth of the marine microalgae, Nannochloropsis sp. were studied in batch culture. Nannochloropsis sp. was grown aseptically for 9 days at three different light intensities (50, 100 and 200 μmol m(-2) s(-1)) and three different photoperiod cycles (24:0, 18:06 and 12:12 h light:dark) at 23 °C cultivation temperature. Under the light intensity of 100 μmol m(-2) s(-1) and photoperiod of 18 h light: 6 h dark cycle, Nannochloropsis sp. was found to grow favorably with a maximum cell concentration of 6.5×10(7) cells mL(-1), which corresponds to the growth rate of 0.339 d(-1) after 8 day cultivation and the lipid content was found to be 31.3%. PMID:23232218

  4. Seed rescue from photoperiod sensitive American Joint Vetch (Aeschynomene americana L.) accessions using hydroponic cloning and aeroponics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    American joint vetch, Aeschynomene Americana L. is a self-pollinated tropical pasture legume and the USDA, ARS, PGRCU curates 137 accessions from the United States, S. America, Mexico, Central America, and Zambia. Many accessions in this collection are photoperiod sensitive due to their typical flow...

  5. The synchronization of neuronal oscillators determined by the directed network structure of the suprachiasmatic nucleus under different photoperiods.

    PubMed

    Gu, Changgui; Tang, Ming; Yang, Huijie

    2016-01-01

    The main function of the principal clock located in the suprachiasmatic nucleus (SCN) of mammals is synchronizing the body rhythms to the 24 h light-dark cycle. Additionally, the SCN is able to adapt to the photoperiod of the cycle which varies among seasons. Under the long photoperiod (LP), the synchronization degree of the SCN neurons is lower than that under the photoperiod (SP). In the present study, a potential explanation is given for this phenomenon. We propose that the asymmetrical coupling between the light-signal-sensitive part (the ventralateral part, abbreviation: VL) and the light-signal-insensitive part (the dorsalmedial part, abbreviation: DM) of the SCN plays a role in the synchronization degree, which is reflected by the ratio of the number of the directed links from the VL neurons to the DM neurons to the total links of both directions between the VL and the DM. The ratio is assumed to characterize the directed network structure under different photoperiods, which is larger under the SP and smaller under the LP. We found that with the larger ratio in the situation of the SP, the synchronization degree is higher. Our finding may shed new light on the asymmetrical coupling between the VL and the DM, and the network structure of the SCN. PMID:27358024

  6. The genetic basis of photoperiodism and its evolutionary divergence among populations of the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Hard, J J; Bradshaw, W E; Holzapfel, C M

    1993-09-01

    We measured the additive genetic variance within populations and the composite additive, dominance, and epistatic effects contributing to differentiation of photoperiodic response between two southern (ancestral) and each of four progressively more northern (derived) populations of the pitcher-plant mosquito, Wyeomyia smithii. Critical photoperiod and its additive genetic variance but not its heritability increased with latitude. Directional selection on critical photoperiod during the northward divergence of W. smithii has therefore not eroded the additive genetic variance underlying this trait. Joint scaling tests of crosses between populations showed that epistatic effects, especially additive x additive and dominance x dominance interactions, overwhelm composite additive and dominance effects on critical photoperiod. The presence of substantial epistasis suggests that multiple founder events during the northward divergence of W. smithii may have been responsible for the release of progressively greater additive genetic variance in derived populations, despite directional and stabilizing selection to reduce it. If epistasis makes a similar contribution to the genetic differentiation of populations in other species, then current models of adaptive evolution that consider only additive genetic variation and covariation within populations may be of limited value in predicting how natural populations differentiate in life history. PMID:19425986

  7. Performance of photoperiod and light intensity on biogas upgrade and biogas effluent nutrient reduction by the microalgae Chlorella sp.

    PubMed

    Yan, Cheng; Zheng, Zheng

    2013-07-01

    Biogas is an environment-friendly fuel but that must be upgraded before being utilized. The method about removing CO2 from biogas by microalgal culturing using biogas effluent as nutrient medium in this study could effectively upgrade biogas and simultaneously reduce the biogas effluent nutrient. Results showed that the optimum parameters for microalgal growth and biogas effluent nutrient reduction was moderate light intensity with middle photoperiod. While low light intensity with long photoperiod and moderate light intensity with middle photoperiod obtained the best biogas CO2 removal and biogas upgrade effects. Therefore, the optimal parameters were moderate light intensity 350 μmol m(-2)s(-1) with middle photoperiod 14 h light:10h dark. Under this condition, the microalgal dry weight, CH4 concentration, reduction efficiency of chemical oxygen demand, total nitrogen, and total phosphorus was 615.84 ± 33.07 mg L(-1), 92.16 ± 2.83% (v/v), 88.74 ± 3.45%, 83.94 ± 3.51%, and 80.43 ± 4.17%, respectively. PMID:23665690

  8. Interactive effects of photoperiod and light intensity on blood physiological and biochemical reactions of broilers grown to heavy weights

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of photoperiod, light intensity, and their interaction on blood acid-base balance, metabolites, and electrolytes in broiler chickens under environmentally controlled conditions were examined in 2 trials. The experiment was consisted of a factorial arrangement of treatments in a randomize...

  9. Rescue of photoperiod/freeze-sensitive and low seed producing accessions of Lablab purpureus using hydroponic cloning and aeroponics.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyacinth bean, Lablab purpureus is a legume used as a vegetable and the USDA, ARS, PGRCU conserves 137 hyacinth bean accessions from countries worldwide. Many accessions in this collection are photoperiod and freeze-sensitive due to their flower and seed production during November through March in t...

  10. PHYTOCHROME C plays a major role in the acceleration of wheat flowering under long-day photoperiod

    PubMed Central

    Chen, Andrew; Li, Chengxia; Hu, Wei; Lau, Mei Yee; Lin, Huiqiong; Rockwell, Nathan C.; Martin, Shelley S.; Jernstedt, Judith A.; Lagarias, J. Clark; Dubcovsky, Jorge

    2014-01-01

    Phytochromes are dimeric proteins that function as red and far-red light sensors influencing nearly every phase of the plant life cycle. Of the three major phytochrome families found in flowering plants, PHYTOCHROME C (PHYC) is the least understood. In Arabidopsis and rice, PHYC is unstable and functionally inactive unless it heterodimerizes with another phytochrome. However, when expressed in an Arabidopsis phy-null mutant, wheat PHYC forms signaling active homodimers that translocate into the nucleus in red light to mediate photomorphogenic responses. Tetraploid wheat plants homozygous for loss-of-function mutations in all PHYC copies (phyCAB) flower on average 108 d later than wild-type plants under long days but only 19 d later under short days, indicating a strong interaction between PHYC and photoperiod. This interaction is further supported by the drastic down-regulation in the phyCAB mutant of the central photoperiod gene PHOTOPERIOD 1 (PPD1) and its downstream target FLOWERING LOCUS T1, which are required for the promotion of flowering under long days. These results implicate light-dependent, PHYC-mediated activation of PPD1 expression in the acceleration of wheat flowering under inductive long days. Plants homozygous for the phyCAB mutations also show altered profiles of circadian clock and clock-output genes, which may also contribute to the observed differences in heading time. Our results highlight important differences in the photoperiod pathways of the temperate grasses with those of well-studied model plant species. PMID:24961368

  11. Serotonin Transporter Gene (SLC6A4) Methylation Associates With Neonatal Intensive Care Unit Stay and 3-Month-Old Temperament in Preterm Infants.

    PubMed

    Montirosso, Rosario; Provenzi, Livio; Fumagalli, Monica; Sirgiovanni, Ida; Giorda, Roberto; Pozzoli, Uberto; Beri, Silvana; Menozzi, Giorgia; Tronick, Ed; Morandi, Francesco; Mosca, Fabio; Borgatti, Renato

    2016-01-01

    Preterm birth and Neonatal Intensive Care Unit (NICU) stay are early adverse stressful experiences, which may result in an altered temperamental profile. The serotonin transporter gene (SLC6A4), which has been linked to infant temperament, is susceptible to epigenetic regulation associated with early stressful experience. This study examined a moderation model in which the exposure to NICU-related stress and SLC6A4 methylation moderated infant temperament at 3 months of age. SLC6A4 methylation at 20 CpG sites was quantified in preterm infants (N = 48) and full-term infants (N = 30) from Italian middle-class families. Results suggested that in preterm infants NICU-related stress might be associated with alterations of serotonergic tone as a consequence of SLC6A4 methylation, which in turn, might associate with temperamental difficulties assessed at 3 months of age. PMID:26822441

  12. Sensitivity of Syrian hamsters (Mesocricetus auratus) to amplitudes and rates of photoperiodic change typical of the tropics.

    PubMed

    Heideman, P D; Bronson, F H

    1993-01-01

    Empirical data suggest that reproductive photoresponsiveness occurs in some populations of mammals above 13 degrees of latitude, but may be absent in populations from 0 degrees to 10 degrees of latitude. The present experiments examined the degree to which the low amplitude of change in photoperiod in the tropics constrains mammals from using daylength as a seasonal cue. The Syrian hamster, a temperate-zone species, was studied because of its well-documented ability to respond to small changes in photoperiod, and because of the absence of an alternative robustly responding species from the tropics. We subjected adult male hamsters to photoperiods that mimicked the amplitude and rate of photoperiod change of 30 degrees, 20 degrees, 10 degrees, and 5 degrees of latitude, but centered around an estimate of their critical daylength. For comparison, a fifth group was subjected to an abrupt change in daylength of a magnitude equal to the total annual variation occurring at 30 degrees. The two groups experiencing the gradually changing daylengths of 30 degrees and 20 degrees showed less within-group synchrony during testicular regression; in other dimensions of the annual testis cycle, including the degree of synchrony exhibited during recrudescence, they reacted similarly to the hamsters given the abrupt change in daylength. Some of the hamsters exposed to the gradually changing daylengths of 10 degrees responded to this challenge, as did a few in the 5 degrees treatment--in both cases, with poor within-group synchrony and a submaximal decrease in testis size. In an abbreviated second experiment, hamsters given abrupt decreases in daylength of magnitudes equal to those of the 10 degrees and 5 degrees groups responded slightly more frequently, and with maximal decreases in testis size. This suggests that mammals may not be constrained absolutely by an inability to respond to changes in photoperiod at 5 degrees to 10 degrees latitude. Seasonally breeding populations of

  13. Effect of changing from a short-day to long-day photoperiod on the breeding season of the brushtail possum (Trichosurus vulpecula).

    PubMed

    Gemmell, R T; Sernia, C

    1995-10-15

    In Queensland, possums (Trichosurus vulpecula) in the wild and in captivity first give birth during March and April and continue to give birth throughout the year until November. The possum has a gestation length of 17.5 days, gives birth to one young, and lactation continues for approximately 180 days. If the newborn possum is removed during the breeding season, the possum will ovulate approximately 9 days later and give birth approximately 26 days after removal of the pouch young (RPY). Repeated RPY may be used to determine the duration of the breeding season. In this study, the effect on the breeding season of a marked change in photoperiod From a short-day to a long-day was examined by comparing three groups of possums in different photoperiods for 13 months. One group of five female and two mail possums (group A) was housed in a natural photoperiod and a second group (B) was housed in a short-day photoperiod (10 h light: 14 h dark) throughout the study. The third group (C) was housed in a short-day photoperiod until each possum gave birth, the pouch young was removed, and the possum transferred to a long-day photoperiod room (14 h light: 10 h dark) for the remainder of the study. The possums held in a natural photoperiod, group A, gave birth to a total of 27 births in the one breeding season from March to October.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7595285

  14. A randomized controlled trial of brain training with non-action video games in older adults: results of the 3-month follow-up

    PubMed Central

    Ballesteros, Soledad; Mayas, Julia; Prieto, Antonio; Toril, Pilar; Pita, Carmen; Laura, Ponce de León; Reales, José M.; Waterworth, John A.

    2015-01-01

    This randomized controlled study (ClinicalTrials.gov NCT02007616) investigated the maintenance of training effects of 20 1-hr non-action video game training sessions with selected games from a commercial package on several age-declining cognitive functions and subjective wellbeing after a 3-month no-contact period. Two groups of cognitively normal older adults participated in both the post-training (posttest) and the present follow-up study, the experimental group who received training and the control group who attended several meetings with the research team during the study but did not receive training. Groups were similar at baseline on demographics, vocabulary, global cognition, and depression status. Significant improvements in the trained group, and no variation in the control group had been previously found at posttest, in processing speed, attention and visual recognition memory, as well as in two dimensions of subjective wellbeing. In the current study, improvement from baseline to 3 months follow-up was found only in wellbeing (Affection and Assertivity dimensions) in the trained group whereas there was no change in the control group. Previous significant improvements in processing speed, attention and spatial memory become non-significant after the 3-month interval. Training older adults with non-action video games enhanced aspects of cognition just after training but this effect disappeared after a 3-month no-contact follow-up period. Cognitive plasticity can be induced in older adults by training, but to maintain the benefits periodic boosting sessions would be necessary. PMID:25926790

  15. A randomized controlled trial of brain training with non-action video games in older adults: results of the 3-month follow-up.

    PubMed

    Ballesteros, Soledad; Mayas, Julia; Prieto, Antonio; Toril, Pilar; Pita, Carmen; Laura, Ponce de León; Reales, José M; Waterworth, John A

    2015-01-01

    This randomized controlled study (ClinicalTrials.gov NCT02007616) investigated the maintenance of training effects of 20 1-hr non-action video game training sessions with selected games from a commercial package on several age-declining cognitive functions and subjective wellbeing after a 3-month no-contact period. Two groups of cognitively normal older adults participated in both the post-training (posttest) and the present follow-up study, the experimental group who received training and the control group who attended several meetings with the research team during the study but did not receive training. Groups were similar at baseline on demographics, vocabulary, global cognition, and depression status. Significant improvements in the trained group, and no variation in the control group had been previously found at posttest, in processing speed, attention and visual recognition memory, as well as in two dimensions of subjective wellbeing. In the current study, improvement from baseline to 3 months follow-up was found only in wellbeing (Affection and Assertivity dimensions) in the trained group whereas there was no change in the control group. Previous significant improvements in processing speed, attention and spatial memory become non-significant after the 3-month interval. Training older adults with non-action video games enhanced aspects of cognition just after training but this effect disappeared after a 3-month no-contact follow-up period. Cognitive plasticity can be induced in older adults by training, but to maintain the benefits periodic boosting sessions would be necessary. PMID:25926790

  16. High D-dimer level is associated with increased 15-d and 3 months mortality through a more central localization of pulmonary emboli and serious comorbidity.

    PubMed

    Klok, F A; Djurabi, R Karami; Nijkeuter, M; Eikenboom, H C J; Leebeek, F W G; Kramer, M H H; Kaasjager, K; Kamphuisen, P W; Büller, H R; Huisman, M V

    2008-01-01

    High D-dimer levels are predictors of death in patients with pulmonary embolism (PE), as are more proximally located, larger emboli. The direct link between these three has not yet been described. A cohort of 674 consecutive patients with confirmed PE was studied. Patients were followed up for 3 months. D-dimer levels were measured only in patients with an unlikely clinical probability (n = 262). The odds ratio (OR) for death of all variables was calculated. Multivariate analysis was performed to identify independent risk factors for mortality. The best predictive D-dimer cut-off point for mortality was a concentration >3000 ng/ml FEU (OR 7.29). High D-dimer levels were correlated with active malignancy and age over 65 years, both being indicators of 3-month mortality. High D-dimer levels were also correlated with centrally located pulmonary emboli and 15-d mortality. The combination of high D-dimer levels and central emboli increased early mortality risk by 2.2. High D-dimer levels in patients with an unlikely clinical probability were associated with fatal outcome after PE. Centrally located pulmonary emboli were associated with higher D-dimer levels and worse 15-d mortality. Active malignancy, being an inpatient at time of diagnosis and age over 65 years were associated with higher D-dimer levels and worse 3-month survival. PMID:18028485

  17. Quantitative Trait Loci for Thermal Time to Flowering and Photoperiod Responsiveness Discovered in Summer Annual-Type Brassica napus L

    PubMed Central

    Nelson, Matthew N.; Rajasekaran, Ravikesavan; Smith, Alison; Chen, Sheng; Beeck, Cameron P.; Siddique, Kadambot H. M.; Cowling, Wallace A.

    2014-01-01

    Time of flowering is a key adaptive trait in plants and is conditioned by the interaction of genes and environmental cues including length of photoperiod, ambient temperature and vernalisation. Here we investigated the photoperiod responsiveness of summer annual-types of Brassica napus (rapeseed, canola). A population of 131 doubled haploid lines derived from a cross between European and Australian parents was evaluated for days to flowering, thermal time to flowering (measured in degree-days) and the number of leaf nodes at flowering in a compact and efficient glasshouse-based experiment with replicated short and long day treatments. All three traits were under strong genetic control with heritability estimates ranging from 0.85–0.93. There was a very strong photoperiod effect with flowering in the population accelerated by 765 degree-days in the long day versus short day treatments. However, there was a strong genetic correlation of line effects (0.91) between the long and short day treatments and relatively low genotype x treatment interaction indicating that photoperiod had a similar effect across the population. Bivariate analysis of thermal time to flowering in short and long days revealed three main effect quantitative trait loci (QTLs) that accounted for 57.7% of the variation in the population and no significant interaction QTLs. These results provided insight into the contrasting adaptations of Australian and European varieties. Both parents responded to photoperiod and their alleles shifted the population to earlier flowering under long days. In addition, segregation of QTLs in the population caused wide transgressive segregation in thermal time to flowering. Potential candidate flowering time homologues located near QTLs were identified with the aid of the Brassica rapa reference genome sequence. We discuss how these results will help to guide the breeding of summer annual types of B. napus adapted to new and changing environments. PMID:25061822

  18. Simulated Seasonal Photoperiods and Fluctuating Temperatures Have Limited Effects on Blood Feeding and Life History in Aedes triseriatus (Diptera: Culicidae).

    PubMed

    Westby, K M; Juliano, S A

    2015-09-01

    Biotic and abiotic factors change seasonally and impact life history in temperate-zone ectotherms. Temperature and photoperiod are factors that change in predictable ways. Most studies testing for effects of temperature on vectors use constant temperatures and ignore potential correlated effects of photoperiod. In two experiments, we tested for effects of larval rearing environments creating ecologically relevant temperatures and photoperiods simulating early and late season conditions (June and August), or constant temperatures (cool and warm) with the June or August photoperiods, respectively. We determined effects on survivorship, development, size, and a composite performance index in a temperate-zone population of Aedes triseriatus (Say). We followed cohorts of resulting females, all held under the same environmental conditions, to assess carry-over effects of rearing conditions for larvae on longevity, blood feeding, and egg production. Larval survivorship was affected by treatment in one experiment. Development time was greater in the June and cool treatments, but the constant and fluctuating temperatures did not differ. Significantly larger mosquitoes were produced in fluctuating versus constant temperature treatments. There were no significant treatment effects on the composite performance index. Adult female longevity was lower after rearing at constant versus fluctuating temperature, but there was no difference between June and August, nor did size affect longevity. There was no effect of treatments on blood feeding and a limited effect on egg production. We conclude that seasonal temperatures and photoperiods during development have limited effects on this population of A. triseriatus and find little evidence of strong effects of fluctuating versus constant temperatures. PMID:26336255

  19. Photoperiodic Modulation of Circadian Clock and Reproductive Axis Gene Expression in the Pre-Pubertal European Sea Bass Brain

    PubMed Central

    Martins, Rute S. T.; Gomez, Ana; Zanuy, Silvia; Carrillo, Manuel; Canário, Adelino V. M.

    2015-01-01

    The acquisition of reproductive competence requires the activation of the brain-pituitary-gonad (BPG) axis, which in most vertebrates, including fishes, is initiated by changes in photoperiod. In the European sea bass long-term exposure to continuous light (LL) alters the rhythm of reproductive hormones, delays spermatogenesis and reduces the incidence of precocious males. In contrast, an early shift from long to short photoperiod (AP) accelerates spermatogenesis. However, how photoperiod affects key genes in the brain to trigger the onset of puberty is still largely unknown. Here, we investigated if the integration of the light stimulus by clock proteins is sufficient to activate key genes that trigger the BPG axis in the European sea bass. We found that the clock genes clock, npas2, bmal1 and the BPG genes gnrh, kiss and kissr share conserved transcription factor frameworks in their promoters, suggesting co-regulation. Other gene promoters of the BGP axis were also predicted to be co-regulated by the same frameworks. Co-regulation was confirmed through gene expression analysis of brains from males exposed to LL or AP photoperiod compared to natural conditions: LL fish had suppressed gnrh1, kiss2, galr1b and esr1, while AP fish had stimulated npas2, gnrh1, gnrh2, kiss2, kiss1rb and galr1b compared to NP. It is concluded that fish exposed to different photoperiods present significant expression differences in some clock and reproductive axis related genes well before the first detectable endocrine and morphological responses of the BPG axis. PMID:26641263

  20. Effect of photoperiod on development and demographic parameters of Neoseiulus barkeri (Acari: Phytoseiidae) fed on Tyrophagus putrescentiae (Acari: Acaridae).

    PubMed

    Zou, Zhiwen; Min, Qiang; Xiao, Shungen; Xin, Tianrong; Xia, Bin

    2016-09-01

    Effects of five photoperiods (Light:Dark = 4:20, 8:16; 12:12, 16:8, 20:4) on the development, survival and reproduction of Neoseiulus barkeri Hughes fed on storage mite Tyrophagus putrescentiae (Schrank) were examined under laboratory conditions at 85 % relative humidity and 24 °C. Development time of almost all immature stages in N. barkeri was the shortest (5.43 ± 0.12 days) under 12 h of daylight. Total duration of immature stages was as high as 8.55 ± 0.16 days during the longest photoperiod. Photoperiod had no effect on hatching rate, but did affect survival of larvae, protonymphs and deutonymphs. Total survivorship ranged from 20 (4:20) to 60 % (12:12). Under 12 h daylight, female adults had the shortest pre- and post-oviposition period, longest oviposition period and longevity, largest total number of eggs (15.95) and and highest daily egg production (1.43) per female. Under 12 h light, N. barkeri experienced its highest net reproductive rate (R 0  = 11.791), intrinsic rate of increase (r m  = 0.180), and finite rate of increase (λ = 1.197), and lowest mean generation time (t = 13.71 days) and population doubling time (DT = 3.86 days). All demographic parameters displayed a parabolic relationship with photoperiod. The results of the present study indicated that the photoperiod of 12:12 is optimal for the development and reproduction of N. barkeri fed on T. putrescentiae, and that N. barkeri may serve most efficiently as a biological control agent under this regime. PMID:27382980

  1. Discovery, evaluation and distribution of haplotypes and new alleles of the Photoperiod-A1 gene in wheat.

    PubMed

    Muterko, Alexandr; Kalendar, Ruslan; Cockram, James; Balashova, Irina

    2015-05-01

    Photoperiod response in wheat is determined to a large extent by the homoeologous series of Photoperiod 1 (Ppd1) genes. In this study, Ppd-A1 genomic sequences from the 5' UTR and promoter region were analysed in 104 accessions of six tetraploid wheat species (Triticum dicoccoides, T. dicoccum, T. turgidum, T. polonicum, T. carthlicum, T. durum) and 102 accessions of six hexaploid wheat species (T. aestivum, T. compactum, T. sphaerococcum, T. spelta, T. macha, T. vavilovii). This data was supplemented with in silico analysis of publicly available sequences from 46 to 193 accessions of diploid and tetraploid wheat, respectively. Analysis of a region of the Ppd-A1 promoter identified thirteen haplotypes, which were divided in two haplogroups. Distribution of the Ppd-A1 haplogroups and haplotypes in wheat species, and their geographical distributions were analysed. Polymerase chain reaction combined with a heteroduplex mobility assay was subsequently used to efficiently discriminate between Ppd-A1 alleles, allowing identification of the Ppd-A1b haplotypes and haplogroups. The causes of anomalous migration of Ppd-A1 heteroduplexes in gels were found to be the localization of mismatches relative to the center of fragment, the cumulative effect of neighbouring polymorphic sites, and the location of mismatches within A/T-tracts. Analysis of the Ppd-A1 5' UTR in hexaploid wheat revealed a novel mutation within the "photoperiod critical" region in a subset of T. compactum accessions. This putative photoperiod insensitive allele (designated Ppd-A1a.4) includes a 684 bp deletion which spans region in common with deletions previously identified in other photoperiod insensitive Ppd1 alleles. PMID:25851614

  2. Modelling temperature, photoperiod and vernalization responses of Brunonia australis (Goodeniaceae) and Calandrinia sp. (Portulacaceae) to predict flowering time

    PubMed Central

    Cave, Robyn L.; Hammer, Graeme L.; McLean, Greg; Birch, Colin J.; Erwin, John E.; Johnston, Margaret E.

    2013-01-01

    Background and Aims Crop models for herbaceous ornamental species typically include functions for temperature and photoperiod responses, but very few incorporate vernalization, which is a requirement of many traditional crops. This study investigated the development of floriculture crop models, which describe temperature responses, plus photoperiod or vernalization requirements, using Australian native ephemerals Brunonia australis and Calandrinia sp. Methods A novel approach involved the use of a field crop modelling tool, DEVEL2. This optimization program estimates the parameters of selected functions within the development rate models using an iterative process that minimizes sum of squares residual between estimated and observed days for the phenological event. Parameter profiling and jack-knifing are included in DEVEL2 to remove bias from parameter estimates and introduce rigour into the parameter selection process. Key Results Development rate of B. australis from planting to first visible floral bud (VFB) was predicted using a multiplicative approach with a curvilinear function to describe temperature responses and a broken linear function to explain photoperiod responses. A similar model was used to describe the development rate of Calandrinia sp., except the photoperiod function was replaced with an exponential vernalization function, which explained a facultative cold requirement and included a coefficient for determining the vernalization ceiling temperature. Temperature was the main environmental factor influencing development rate for VFB to anthesis of both species and was predicted using a linear model. Conclusions The phenology models for B. australis and Calandrinia sp. described development rate from planting to VFB and from VFB to anthesis in response to temperature and photoperiod or vernalization and may assist modelling efforts of other herbaceous ornamental plants. In addition to crop management, the vernalization function could be used to

  3. Photosynthetic photon flux, photoperiod, and temperature effects on emissions of (Z)-3-hexenal, (Z)-3-hexenol, and (Z)-3-hexenyl acetate from lettuce

    NASA Technical Reports Server (NTRS)

    Charron, C. S.; Cantliffe, D. J.; Wheeler, R. M.; Manukian, A.; Heath, R. R.

    1996-01-01

    To investigate the effects of environment on plant volatile emissions, 'Waldmann's Green' leaf lettuce was cultivated under different levels of photosynthetic photon flux (PPF), photoperiod, and temperature. A modified growth chamber was used to sample plant volatile emissions nondestructively, over time, and under controlled conditions. Total volatile emission rates were significantly higher from lettuce cultivated under PPF of 360 or 200 micromoles m-2 s-1 compared to 105 micromoles m-2 s-1, and significantly higher under a 16-h photoperiod than an 8-h photoperiod. No differences were detected among emission rates from different temperature treatments. In controlled environments, emissions could be regulated by adjusting environmental conditions accordingly.

  4. Biomass and pigments production in photosynthetic bacteria wastewater treatment: Effects of photoperiod.

    PubMed

    Zhou, Qin; Zhang, Panyue; Zhang, Guangming; Peng, Meng

    2015-08-01

    This study aimed at enhancing the bacterial biomass and pigments production in together with pollution removal in photosynthetic bacteria (PSB) wastewater treatment via using different photoperiods. Different light/dark cycles and light/dark cycle frequencies were examined. Results showed that PSB had the highest biomass production, COD removal and biomass yield, and light energy efficiency with light/dark cycle of 2h/1h. The corresponding biomass, COD removal and biomass yield reached 2068mg/L, 90.3%, and 0.38mg-biomass/mg-COD-removal, respectively. PSB showed higher biomass production and biomass yield with higher light/dark cycle frequency. Mechanism analysis showed within a light/dark cycle from 1h/2h to 2h/1h, the carotenoid and bacteriochlorophyll production increased with an increase in light/dark cycle. Moreover, the pigment contents were much higher with lower frequency of 2-4 times/d. PMID:25958142

  5. Establishment of TSH β real-time monitoring system in mammalian photoperiodism

    PubMed Central

    Tsujino, Kaori; Narumi, Ryohei; Masumoto, Koh-hei; Susaki, Etsuo A; Shinohara, Yuta; Abe, Takaya; Iigo, Masayuki; Wada, Atsushi; Nagano, Mamoru; Shigeyoshi, Yasufumi; Ueda, Hiroki R

    2013-01-01

    Organisms have seasonal physiological changes in response to day length. Long-day stimulation induces thyroid-stimulating hormone beta subunit (TSHβ) in the pars tuberalis (PT), which mediates photoperiodic reactions like day-length measurement and physiological adaptation. However, the mechanism of TSHβ induction for day-length measurement is largely unknown. To screen candidate upstream molecules of TSHβ, which convey light information to the PT, we generated Luciferase knock-in mice, which quantitatively report the dynamics of TSHβ expression. We cultured brain slices containing the PT region from adult and neonatal mice and measured the bioluminescence activities from each slice over several days. A decrease in the bioluminescence activities was observed after melatonin treatment in adult and neonatal slices. These observations indicate that the experimental system possesses responsiveness of the TSHβ expression to melatonin. Thus, we concluded that our experimental system monitors TSHβ expression dynamics in response to external stimuli. PMID:23758111

  6. Reproductive seasonality in captive wild ruminants: implications for biogeographical adaptation, photoperiodic control, and life history.

    PubMed

    Zerbe, Philipp; Clauss, Marcus; Codron, Daryl; Bingaman Lackey, Laurie; Rensch, Eberhard; Streich, Jürgen W; Hatt, Jean-Michel; Müller, Dennis W H

    2012-11-01

    Many ruminant species show seasonal patterns of reproduction. Causes for this are widely debated, and include adaptations to seasonal availability of resources (with cues either from body condition in more tropical, or from photoperiodism in higher latitude habitats) and/or defence strategies against predators. Conclusions so far are limited to datasets with less than 30 species. Here, we use a dataset on 110 wild ruminant species kept in captivity in temperate-zone zoos to describe their reproductive patterns quantitatively [determining the birth peak breadth (BPB) as the number of days in which 80% of all births occur]; then we link this pattern to various biological characteristics [latitude of origin, mother-young-relationship (hider/follower), proportion of grass in the natural diet (grazer/browser), sexual size dimorphism/mating system], and compare it with reports for free-ranging animals. When comparing taxonomic subgroups, variance in BPB is highly correlated to the minimum, but not the maximum BPB, suggesting that a high BPB (i.e. an aseasonal reproductive pattern) is the plesiomorphic character in ruminants. Globally, latitude of natural origin is highly correlated to the BPB observed in captivity, supporting an overruling impact of photoperiodism on ruminant reproduction. Feeding type has no additional influence; the hider/follower dichotomy, associated with the anti-predator strategy of 'swamping', has additional influence in the subset of African species only. Sexual size dimorphism and mating system are marginally associated with the BPB, potentially indicating a facilitation of polygamy under seasonal conditions. The difference in the calculated Julian date of conception between captive populations and that reported for free-ranging ones corresponds to the one expected if absolute day length was the main trigger in highly seasonal species: calculated day length at the time of conception between free-ranging and captive populations followed a y = x

  7. Effects of an advanced temperature cycle on smolt development and endocrinology indicate that temperature is not a zeitgeber for smolting in Atlantic salmon

    USGS Publications Warehouse

    McCormick, S.D.; Shrimpton, J.M.; Moriyama, S.; Bjornsson, Bjorn Thrandur

    2002-01-01

    Atlantic salmon (Salmo salar) juveniles were reared under simulated conditions of normal photoperiod (LDN) or short days (LD 9:15) and ambient temperature (AMB: normal temperature increases in April) or an advanced temperature cycle (ADV: temperature increases in February). Under both photoperiod conditions, the timing of increased and peak levels of gill Na+,K+-ATPase activity were not altered by temperature, although the rate of increase was initially greater under ADV. ADV/LD 9:15 resulted in peak gill Na+,K+-ATPase activity that was half of that seen under normal photoperiod and temperature conditions. Plasma growth hormone (GH) levels increased threefold in late March under ADV/LDN, but not under ADV/LD 9:15, indicating that there is a photoperiod-dependent effect of temperature on levels of this hormone. Plasma insulin-like growth factor I (IGF-I) increased in spring in all groups, with increases occurring significantly earlier in the ADV/LDN group. In each photoperiod condition, the advanced temperature cycle resulted in large decreases in plasma thyroxine (T4) levels in March, which subsequently recovered, whereas plasma 3,5,3???-triiodo-L-thyronine (T3) levels were not substantially affected by either photoperiod or temperature. There was no consistent pattern of change in plasma cortisol levels. The results do not provide support for the role of temperature as a zeitgeber, but do indicate that temperature has a role in the timing of smolting by affecting the rate of development and interacting with the photoperiod.

  8. Adaptation to short photoperiods augments circadian food anticipatory activity in Siberian hamsters.

    PubMed

    Bradley, Sean P; Prendergast, Brian J

    2014-06-01

    This article is part of a Special Issue "Energy Balance". Both the light-dark cycle and the timing of food intake can entrain circadian rhythms. Entrainment to food is mediated by a food entrainable circadian oscillator (FEO) that is formally and mechanistically separable from the hypothalamic light-entrainable oscillator. This experiment examined whether seasonal changes in day length affect the function of the FEO in male Siberian hamsters (Phodopus sungorus). Hamsters housed in long (LD; 15 h light/day) or short (SD; 9h light/day) photoperiods were subjected to a timed-feeding schedule for 10 days, during which food was available only during a 5h interval of the light phase. Running wheel activity occurring within a 3h window immediately prior to actual or anticipated food delivery was operationally-defined as food anticipatory activity (FAA). After the timed-feeding interval, hamsters were fed ad libitum, and FAA was assessed 2 and 7 days later via probe trials of total food deprivation. During timed-feeding, all hamsters exhibited increases FAA, but FAA emerged more rapidly in SD; in probe trials, FAA was greater in magnitude and persistence in SD. Gonadectomy in LD did not induce the SD-like FAA phenotype, indicating that withdrawal of gonadal hormones is not sufficient to mediate the effects of photoperiod on FAA. Entrainment of the circadian system to light markedly affects the functional output of the FEO via gonadal hormone-independent mechanisms. Rapid emergence and persistent expression of FAA in SD may reflect a seasonal adaptation that directs behavior toward sources of nutrition with high temporal precision at times of year when food is scarce. PMID:24666779

  9. Non-photoperiodic regulation of reproductive physiology in the flexibly breeding pine siskin (Spinus pinus).

    PubMed

    Watts, Heather E; Hahn, Thomas P

    2012-09-01

    In order to time reproduction to coincide with favorable conditions, animals use environmental cues to up- and down-regulate the reproductive axis appropriately. Although photoperiodic cues are one of the best studied of such environmental cues, animals also attend to others such as temperature, food availability, rainfall and social cues. Such non-photic cues are expected to be particularly important for tropical species and temperate-zone species that exhibit flexible or opportunistic breeding schedules. In this study, we investigate the use of non-photic cues, specifically food availability and social cues, to time the initiation of reproductive development in the pine siskin (Spinus pinus), a temperate-zone songbird with a flexible breeding schedule. Following winter solstice, males were housed on a 12L:12D photoperiod with either access to a preferred food, a potential mate (social cue), or both. Control birds received only maintenance diet and no mate. Access to a preferred food had a significant positive effect on testis size and circulating luteinizing hormone (LH). However, we found no effect of social treatment on reproductive development. The effect of the food treatment on reproductive development did not appear to result from effects on body mass or fat, as neither measure differed across treatments. The food treatment influenced not only reproductive physiology, but also reproductive behavior in this species, as access to seeds had a positive effect on affiliation of pairs. This study demonstrates that food is a potent stimulus for the initiation of reproductive development in pine siskins. PMID:22569115

  10. Non-photoperiodic regulation of reproductive physiology in the flexibly breeding pine siskin (Spinus pinus)

    PubMed Central

    Watts, Heather E.; Hahn, Thomas P.

    2012-01-01

    In order to time reproduction to coincide with favorable conditions, animals use environmental cues to up- and down-regulate the reproductive axis appropriately. Although photoperiodic cues are one of the best studied of such environmental cues, animals also attend to others such as temperature, food availability, rainfall and social cues. Such non-photic cues are expected to be particularly important for tropical species and temperate-zone species that exhibit flexible or opportunistic breeding schedules. In this study, we investigate the use of non-photic cues, specifically food availability and social cues, to time the initiation of reproductive development in the pine siskin (Spinus pinus), a temperate-zone songbird with a flexible breeding schedule. Following winter solstice, males were housed on a 12L:12D photoperiod with either access to a preferred food, a potential mate (social cue), or both. Control birds received only maintenance diet and no mate. Access to a preferred food had a significant positive effect on testis size and circulating luteinizing hormone (LH). However, we found no effect of social treatment on reproductive development. The effect of the food treatment on reproductive development did not appear to result from effects on body mass or fat, as neither measure differed across treatments. The food treatment influenced not only reproductive physiology, but also reproductive behavior in this species, as access to seeds had a positive effect on affiliation of pairs. This study demonstrates that food is a potent stimulus for the initiation of reproductive development in pine siskins. PMID:22569115

  11. Growth rates of North Sea macroalgae in relation to temperature, irradiance and photoperiod

    NASA Astrophysics Data System (ADS)

    Fortes, M. D.; Lüning, K.

    1980-03-01

    Three eulittoral algae (Ulva lactuca, Porphyra umbilicalis, Chondrus crispus) and one sublittoral alga (Laminaria saccharina) from Helgoland (North Sea) were cultivated in a flow-through system at different temperatures, irradiances and daylengths. In regard to temperature there was a broad optimum at 10 15° C, except in P. umbilicalis, which grew fastest at 10 °C. A growth peak at this temperature was also found in four of 17 other North Sea macroalgae, for which the growth/temperature response was studied, whereas 13 of these species exhibited a growth optimum at 15 °C, or a broad optimum at 10 15 °C. Growth was light-saturated in U. lactuca, L. saccharina and C. crispus at photon flux densities above 70 µE m-2s-1, but in P. umbilicalis above 30 µE m-2s-1. Growth rate did not decrease notably in the eulittoral species after one week in relatively strong light (250 µE m-2s-1), but by about 50 % in the case of the sublittoral L. saccharina, as compared with growth under weak light conditions (30 µE m-2s-1). In contrast, chlorophyll content decreased in the sublittoral as well as in the eulittoral species, and the greatest change in pigment content occurred in the range 30 70 µE m-2s-1. Growth rate increased continuously up to photoperiods of 24 h light per day in L. saccharina and C. crispus, whereas daylength saturation occurred at photoperiods of more than 16 h light per day in U. lactuca and P. umbilicalis.

  12. Variability of Phyllochron, Plastochron and Rate of Increase in Height in Photoperiod-sensitive Sorghum Varieties

    PubMed Central

    Clerget, B.; Dingkuhn, M.; Gozé, E.; Rattunde, H. F. W.; Ney, B.

    2008-01-01

    Background and Aims West African sorghum (Sorghum bicolor) varieties are generally highly photoperiod-sensitive, which is a necessary adaptation to the variable onset date of the rainy season and the variable dates of sowing in the savannah zone. Depending on sowing date, plants can produce from 12 to >40 leaves on the main culm, with height varying from 1 m to more than 5 m. The present study aimed to better understand the complex phenology of these variables. Methods A 2-year series of monthly sowings of three West African sorghum varieties was conducted near Bamako, Mali. Drought stress was avoided by supplemental irrigation. Rate of initiation of primordia at the stem apex was recorded, together with rate of leaf emergence and increase in plant height. Key Results Leaf initiation and appearance rates (plastochron−1 and phyllochron−1) were constant for a given sowing date in cases where less than 20 leaves were produced (generally observed with late sowing dates). In contrast, rates were bilinear for early sowing dates, for which plants produced more than 20 leaves. The secondary rates, which occurred from the 20th leaf onwards, were only half of the initial rate. Plastochron and phyllochron showed large variations among sowing dates, and were correlated with the rate of plant height increase. The initial plastochron and phyllochron were positively correlated with soil temperature and negatively correlated with both day length and day-to-day change of day length prevailing at plant emergence, but these factors explained only half of the variation observed. Conclusions Although they belong to different genetic groups and have different height and photoperiod sensitivity, the three varieties studied exhibited similar response patterns of development rates among phenological phases and seasons, with the local landrace showing the greatest variation due to its longer vegetative phase and longer stem internodes. The possible adaptive advantages in African

  13. Photoperiod: Its importance as an impeller of pineal and seasonal reproductive rhythms

    NASA Astrophysics Data System (ADS)

    Reiter, R. J.

    1980-03-01

    A number of long day breeding rodents depend on seasonal changes in photoperiodic length to synchronize their breeding seasons with the appropriate time of the year. These relationships are particularly conspicuous in the Syrian hamster where day length is vitally important in determining periods of sexual activity and inactivity. The organ in the body whose activity is most closely attuned to the photoperiodic environment is the pineal gland. During periods of darkness the biochemical and secretory activity of the pineal is enhanced with the resultant production of antigonadotrophic principles which are strongly suppressive to reproductive physiology. In this manner, decreasing day lengths of the fall are involved with suppressing sexual capability in male and female hamsters. Throughout the winter months darkness (because of the shorter day lengths and the fact that hamsters remain underground in lightless burrows) holds the gonads in an atrophic condition and thereby prevents hamsters from breeding. As spring approaches the neuroendocrine reproductive axis becomes refractory to the inhibitory effects of darkness and the pineal gland and, as a consequence, the gonads recrudesce allowing the animals to successfully reproduce. The long days of the spring and summer serve to interrupt the refractory period so that when winter approaches shortening day lengths will again, by way of the pineal gland, induce gonadalinvolution. In this scheme both light and darkness are critically important in synchronizing the phases of the annual reproductive cycle of the hamster with the appropriate season of the year. Melatonin may be the pineal hormone which mediates the effects of darkness on reproductive physiology.

  14. Adaptation to short photoperiods augments circadian food anticipatory activity in Siberian hamsters

    PubMed Central

    Bradley, Sean P.; Prendergast, Brian J.

    2014-01-01

    Both the light-dark cycle and the timing of food intake can entrain circadian rhythms. Entrainment to food is mediated by a food entrainable circadian oscillator (FEO) that is formally and mechanistically separable from the hypothalamic light-entrainable oscillator. This experiment examined whether seasonal changes in day length affect the function of the FEO in male Siberian hamsters (Phodopus sungorus). Hamsters housed in long (LD; 15 h light/day) or short (SD; 9 h light/day) photoperiods were subjected to a timed-feeding schedule for 10 days, during which food was available only during a 5 h interval of the light phase. Running wheel activity occurring within a 3 h window immediately prior to actual or anticipated food delivery was operationally-defined as food anticipatory activity (FAA). After the timed-feeding interval, hamsters were fed ad libitum, and FAA was assessed 2 and 7 days later via probe trials of total food deprivation. During timed-feeding, all hamsters exhibited increases FAA, but FAA emerged more rapidly in SD; in probe trials, FAA was greater in magnitude and persistence in SD. Gonadectomy in LD did not induce the SD-like FAA phenotype, indicating that withdrawal of gonadal hormones is not sufficient to mediate the effects of photoperiod on FAA. Entrainment of the circadian system to light markedly affects the functional output of the FEO via gonadal hormone-independent mechanisms. Rapid emergence and persistent expression of FAA in SD may reflect a seasonal adaptation that directs behavior toward sources of nutrition with high temporal precision at times of year when food is scarce. PMID:24666779

  15. The influence of season, photoperiod, and pineal melatonin on immune function.

    PubMed

    Nelson, R J; Demas, G E; Klein, S L; Kriegsfeld, L J

    1995-11-01

    In addition to the well-documented seasonal cycles of mating and birth, there are also significant seasonal cycles of illness and death among many animal populations. Challenging winter conditions (i.e., low ambient temperature and decreased food availability) can directly induce death via hypothermia, starvation, or shock. Coping with these challenges can also indirectly increase morbidity and mortality by increasing glucocorticoid secretion, which can compromise immune function. Many environmental challenges are recurrent and thus predictable; animals could enhance survival, and presumably increase fitness, if they could anticipate immunologically challenging conditions in order to cope with these seasonal threats to health. The annual cycle of changing photoperiod provides an accurate indicator of time of year and thus allows immunological adjustments prior to the deterioration of conditions. Pineal melatonin codes day length information. Short day lengths enhance several aspects of immune function in laboratory studies, and melatonin appears to mediate many of the enhanced immunological effects of photoperiod. Generally, field studies report compromised immune function during the short days of autumn and winter. The conflict between laboratory and field data is addressed with a multifactor approach. The evidence for seasonal fluctuations in lymphatic tissue size and structure, as well as immune function and disease processes, is reviewed. The role of pineal melatonin and the hormones regulated by melatonin is discussed from an evolutionary and adaptive functional perspective. Finally, the clinically significance of seasonal fluctuations in immune function is presented. Taken together, it appears that seasonal fluctuations in immune parameters, mediated by melatonin, could have profound effects on the etiology and progression of diseases in humans and nonhuman animals. An adaptive functional perspective is critical to gain insights into the interaction among

  16. Photoperiod-dependent negative feedback effects of thyroid hormones in Fundulus heteroclitus

    SciTech Connect

    Brown, C.L.; Stetson, M.H.

    1985-05-01

    In Fundulus heteroclitus, an annual cycle in the response of the thyroid to ovine thyroid-stimulating hormone (oTSH) is characterized by maximal thyroxin (T4) secretion in mid-winter and minimal T4 secretion in summer. Four daily injections of oTSH, given in winter caused serum T4 to plateau at elevated levels for several days, while in summer fish similar treatment resulted in far more fluctuating titers of serum T4; maximum levels were similar in both groups. The difference in sustenance rather than magnitude of Peak T4 led to an examination of the negative feedback effects of thyroid hormones as they might relate to these seasonal changes. Radioiodine uptake by thyroid follicles served as a simple, but effective bioassay for endogenous TSH. Fish collected in summer were more sensitive to negative feedback of T3 than those collected in winter; feedback effects of T4 in the two groups were not significantly different. The effects of specific photoperiods on negative feedback sensitivity to T3 and T4 were also tested. Exposure of winter fish for one month to long days (LD 14:10) enhanced the degree of reduction of iodine uptake caused by T4 in the aquarium water (10 micrograms/100 ml). Negative feedback in short-day (LD 8:16) winter fish was not demonstrated. It is concluded that long days increase and short days diminish the negative feedback sensitivity of the hypothalamus-pituitary axis to thyroid hormones in F. heteroclitus. Such photoperiodically induced changes may act to aid in the year-round maintenance of T4 levels necessary for seasonal adaptation and survival.

  17. N-acetyltransferase (nat) Is a Critical Conjunct of Photoperiodism between the Circadian System and Endocrine Axis in Antheraea pernyi

    PubMed Central

    Bembenek, Jadwiga; Hiragaki, Susumu; Suzuki, Takeshi; Takeda, Makio

    2014-01-01

    Since its discovery in 1923, the biology of photoperiodism remains a mystery in many ways. We sought the link connecting the circadian system to an endocrine switch, using Antheraea pernyi. PER-, CLK- and CYC-ir were co-expressed in two pairs of dorsolateral neurons of the protocerebrum, suggesting that these are the circadian neurons that also express melatonin-, NAT- and HIOMT-ir. The results suggest that a melatonin pathway is present in the circadian neurons. Melatonin receptor (MT2 or MEL-1B-R)-ir in PTTH-ir neurons juxtaposing clock neurons suggests that melatonin gates PTTH release. RIA showed a melatonin rhythm with a peak four hours after lights off in adult brain both under LD16∶8 (LD) and LD12∶12 (SD), and both the peak and the baseline levels were higher under LD than SD, suggesting a photoperiodic influence. When pupae in diapause were exposed to 10 cycles of LD, or stored at 4°C for 4 months under constant darkness, an increase of NAT activity was observed when PTTH released ecdysone. DNA sequence upstream of nat contained E-boxes to which CYC/CLK could bind, and nat transcription was turned off by clk or cyc dsRNA. dsRNANAT caused dysfunction of photoperiodism. dsRNAPER upregulated nat transcription as anticipated, based on findings in the Drosophila melanogaster circadian system. Transcription of nat, cyc and clk peaked at ZT12. RIA showed that dsRNANAT decreased melatonin while dsRNAPER increased melatonin. Thus nat, a clock controlled gene, is the critical link between the circadian clock and endocrine switch. MT-binding may release PTTH, resulting in termination of diapause. This study thus examined all of the basic functional units from the clock: a photoperiodic counter as an accumulator of mRNANAT, to endocrine switch for photoperiodism in A. pernyi showing this system is self-complete without additional device especially for photoperiodism. PMID:24667367

  18. Induction of flowering by 5-azacytidine in some plant species: relationship between the stability of photoperiodically induced flowering and flower-inducing effect of DNA demethylation.

    PubMed

    Kondo, Hiroshi; Miura, Takashi; Wada, Kaede C; Takeno, Kiyotoshi

    2007-11-01

    The flower-inducing effect of 5-azacytidine, a DNA demethylating reagent, was examined in several plant species with a stable or unstable photoperiodically induced flowering state under non-inductive photoperiodic conditions. The long day plant Silene armeria, whose flowering state is stable and the short day plant Pharbitis nil, whose flowering state is unstable were induced to flower by 5-azacytidine under a non-inductive condition. Thus, the replacement of photoinduction by 5-azacytidine treatment is not specific to Perilla frutescens. On the other hand, 5-azacytidine did not induce flowering in Xanthium strumarium whose flowering state is stable and Lemna paucicostata whose flowering state is unstable. Thus, epigenetics caused by DNA demethylation may be involved in the regulation of photoperiodic flowering irrespective of the stability of the photoperiodically induced flowering state. PMID:18251884

  19. Part 3. Assessment of genotoxicity and oxidative stress after exposure to diesel exhaust from U.S. 2007-compliant diesel engines: report on 1- and 3-month exposures in the ACES bioassay.

    PubMed

    Hallberg, L M; Ward, J B; Hernandez, C; Ameredes, B T; Wickliffe, J K

    2012-09-01

    -exposed animals. Results from the comet assay showed no significant differences in rats between the control and exposed groups (P = 0.53, low exposure; P = 0.92, medium exposure; P = 0.77, high exposure) after 1 month of DE exposure. There were no differences between sexes in the responses of rats to these exposures. Likewise, there were no significant differences found after 3 months of exposure. Similarly, no significant differences were found between the mice exposed for 1 and 3 months to DE, nor were any differences found between sexes. Measurements of 8-OHdG in both mice and rats showed no significant difference among DE exposure groups (P = 0.46, mice; P = 0.86, rats). In mice, measured 8-OHdG was lower in the 3-month group than the 1-month group. In rats, the inverse was true. In mice, no significant differences in the levels of lipid peroxidation, as measured by TBARS, were found between the controls and DE exposure groups (P = 0.92), nor were there any differences between sexes. In rats, comparisons between the control and low-exposure groups approached significance, but no significant differences were found between the other DE exposure groups. Additionally, in rats, there were no significant differences between the 1- and 3-month DE exposure groups. PMID:23156842

  20. Association of blood eosinophils and plasma periostin with FEV1 response after 3-month inhaled corticosteroid and long-acting beta2-agonist treatment in stable COPD patients

    PubMed Central

    Park, Hye Yun; Lee, Hyun; Koh, Won-Jung; Kim, Seonwoo; Jeong, Ina; Koo, Hyeon-Kyoung; Kim, Tae-Hyung; Kim, Jin Woo; Kim, Woo Jin; Oh, Yeon-Mok; Sin, Don D; Lim, Seong Yong; Lee, Sang-Do

    2016-01-01

    Background COPD patients with increased airway eosinophilic inflammation show a favorable response to inhaled corticosteroids (ICS) in combination with a long-acting bronchodilator. Recent studies have demonstrated a significant correlation of sputum eosinophilia with blood eosinophils and periostin. We investigated whether high blood eosinophils and plasma periostin were associated with an improvement in forced expiratory volume in 1 second (FEV1) after 3-month treatment with ICS/long-acting beta2-agonist (LABA) in stable COPD patients. Patients and methods Blood eosinophils and plasma periostin levels were measured in 130 stable COPD subjects selected from the Korean Obstructive Lung Disease cohort. Subjects began a 3-month ICS/LABA treatment after washout period. Results High blood eosinophils (>260/µL, adjusted odds ratio =3.52, P=0.009) and high plasma periostin (>23 ng/mL, adjusted odds ratio =3.52, P=0.013) were significantly associated with FEV1 responders (>12% and 200 mL increase in FEV1 from baseline after treatment). Moreover, the addition of high blood eosinophils to age, baseline positive bronchodilator response, and FEV1 <50% of the predicted value significantly increased the area under the curve for prediction of FEV1 responders (from 0.700 to 0.771; P=0.045). Conclusion High blood eosinophils and high plasma periostin were associated with improved lung function after 3-month ICS/LABA treatment. In particular, high blood eosinophils, in combination with age and baseline lung function parameters, might be a possible biomarker for identification of COPD patients with favorable FEV1 improvement in response to ICS/LABA treatment. PMID:26730185

  1. 3-Month experience in presbyopic correction with bi-aspheric multifocal central presbyLASIK treatments for hyperopia and myopia with or without astigmatism

    PubMed Central

    Luger, Michiel H.A.; Ewering, Tobias; Arba-Mosquera, Samuel

    2012-01-01

    Purpose To analyze simultaneous vision (distance and near) 3-month after bi-aspheric multifocal central presbyLASIK treatments for hyperopia and myopia with or without astigmatism. Methods Retrospective study analyzing patients that had been treated for correcting distance ametropiae and alleviating presbyopic symptoms simultaneously. All patients had been treated in Presby Aspheric mode using FemtoLASIK. No eye had previous corneal refractive surgery. Preoperative corneal curvature ranged between 40 D and 48 D, with pachymetry thicker than 500 μm. Preoperative best distance corrected visual acuity (CDVA) was 0.1 LogMAR or better, with best corrected near vision (CNVA) of 0.2 LogRAD or better. Results 66 patients treated using PresbyMAX software (SCHWIND eye-tech-solutions GmbH and Co. KG, Kleinostheim, Germany) were reviewed. For 24 patients, 3-month follow-up was completed. At 3 months, 71% of patients achieved UDVA 0.1 LogMAR or better, 79% patients obtained UNVA 0.1 LogRAD or better, and 83% of eyes were within 0.75 diopters (D) of defocus. Postoperative mean spherical equivalent refraction was −0.15 ± 0.50 D. Stability was achieved from the 6-week follow-up. 92% of patients achieved UDVA 0.2 LogMAR or better and UNVA 0.2 LogRAD or better. No statistical differences between myopes/hyperopes or between males/females were found. Conclusions Patient selection and expectation management are essential to achieve patient satisfaction. Even though optically the results are quite predictable, some patients find it difficult to adapt to the compromise between far and near vision, and others are dissatisfied by the minor loss of distance VA.

  2. A model to predict 3-month mortality risk of acute-on-chronic hepatitis B liver failure using artificial neural network.

    PubMed

    Zheng, M-H; Shi, K-Q; Lin, X-F; Xiao, D-D; Chen, L-L; Liu, W-Y; Fan, Y-C; Chen, Y-P

    2013-04-01

    Model for end-stage liver disease (MELD) scoring was initiated using traditional statistical technique by assuming a linear relationship between clinical features, but most phenomena in a clinical situation are not linearly related. The aim of this study was to predict 3-month mortality risk of acute-on-chronic hepatitis B liver failure (ACHBLF) on an individual patient level using an artificial neural network (ANN) system. The ANN model was built using data from 402 consecutive patients with ACHBLF. It was trained to predict 3-month mortality by the data of 280 patients and validated by the remaining 122 patients. The area under the curve of receiver operating characteristic (AUROC) was calculated for ANN and MELD-based scoring systems. The following variables age (P < 0.001), prothrombin activity (P < 0.001), serum sodium (P < 0.001), total bilirubin (P = 0.015), hepatitis B e antigen positivity rate (P < 0.001) and haemoglobin (P < 0.001) were significantly related to the prognosis of ACHBLF and were selected to build the ANN. The ANN performed significantly better than MELD-based scoring systems both in the training cohort (AUROC = 0.869 vs 0.667, 0.591, 0.643, 0.571 and 0.577; P < 0.001, respectively) and in the validation cohort (AUROC = 0.765 vs 0.599, 0.563, 0.601, 0.521 and 0.540; P ≤ 0.006, respectively). Thus, the ANN model was shown to be more accurate in predicting 3-month mortality of ACHBLF than MELD-based scoring systems. PMID:23490369

  3. [Fatal outcome during physiotherapy (Vojta's method) in a 3-month old infant. Case report and comments on manual therapy in children].

    PubMed

    Jacobi, G; Riepert, T; Kieslich, M; Bohl, J

    2001-01-01

    Detailed clinical and neuropathological report on a fatal incident during the first manual therapy according to Vojta conducted in a 3 months old baby: during forced active rotation and head retraction the baby suffered from a bleeding into the adventitia of both her vertebral arteries at the level of C1 prompting ischemia of the caudal brainstem with subarachnoid haemorrhage around. It has to be suggested that similar cases already have occurred but have not been reported yet. There might be a time lag between the performance of physiotherapy and the beginning of neurologic symptoms. The risks of manual therapy in children will be discussed. PMID:11305197

  4. Reproductive allochrony in seasonally sympatric populations maintained by differential response to photoperiod: Implications for population divergence and response to climate change

    USGS Publications Warehouse

    Fudickar, A.M.; Grieves, T.J.; Atwell, Jonathan W.; Stricker, Craig A.; Ketterson, Ellen D.

    2016-01-01

    Reproductive allochrony presents a potential barrier to gene flow and is common in seasonally sympatric migratory and sedentary birds. Mechanisms mediating reproductive allochrony can influence population divergence and the capacity of populations to respond to environmental change. We asked whether reproductive allochrony in seasonally sympatric birds results from a difference in response to supplementary or photoperiodic cues and whether the response varies in relation to the distance separating breeding and wintering locations as measured by stable isotopes. We held seasonally sympatric migratory and sedentary male dark-eyed juncos (Junco hyemalis) in a common garden in early spring under simulated natural changes in photoperiod and made measurements of reproductive and migratory physiology. On the same dates and photoperiods, sedentary juncos had higher testosterone (initial and gonadotropin-releasing hormone induced), more developed cloacal protuberances, and larger testes than migrants. In contrast, migratory juncos had larger fat reserves (fuel for migration). We found a negative relationship between testis mass and feather hydrogen isotope ratios, indicating that testis growth was more delayed in migrants making longer migrations. We conclude that reproductive allochrony in seasonally sympatric migratory and sedentary birds can result from a differential response to photoperiodic cues in a common garden, and as a result, gene flow between migrants and residents may be reduced by photoperiodic control of reproductive development. Further, earlier breeding in response to future climate change may currently be constrained by differential response to photoperiodic cues.

  5. Reproductive Allochrony in Seasonally Sympatric Populations Maintained by Differential Response to Photoperiod: Implications for Population Divergence and Response to Climate Change.

    PubMed

    Fudickar, Adam M; Greives, Timothy J; Atwell, Jonathan W; Stricker, Craig A; Ketterson, Ellen D

    2016-04-01

    Reproductive allochrony presents a potential barrier to gene flow and is common in seasonally sympatric migratory and sedentary birds. Mechanisms mediating reproductive allochrony can influence population divergence and the capacity of populations to respond to environmental change. We asked whether reproductive allochrony in seasonally sympatric birds results from a difference in response to supplementary or photoperiodic cues and whether the response varies in relation to the distance separating breeding and wintering locations as measured by stable isotopes. We held seasonally sympatric migratory and sedentary male dark-eyed juncos (Junco hyemalis) in a common garden in early spring under simulated natural changes in photoperiod and made measurements of reproductive and migratory physiology. On the same dates and photoperiods, sedentary juncos had higher testosterone (initial and gonadotropin-releasing hormone induced), more developed cloacal protuberances, and larger testes than migrants. In contrast, migratory juncos had larger fat reserves (fuel for migration). We found a negative relationship between testis mass and feather hydrogen isotope ratios, indicating that testis growth was more delayed in migrants making longer migrations. We conclude that reproductive allochrony in seasonally sympatric migratory and sedentary birds can result from a differential response to photoperiodic cues in a common garden, and as a result, gene flow between migrants and residents may be reduced by photoperiodic control of reproductive development. Further, earlier breeding in response to future climate change may currently be constrained by differential response to photoperiodic cues. PMID:27028072

  6. The effect of an extended artificial photoperiod and gonadotrophin-releasing hormone infusions in inducing fertile oestrus in anoestrous mares.

    PubMed

    Lowis, T C; Hyland, J H

    1991-12-01

    The occurrence of fertile oestrus early in the breeding season is of paramount importance to the Thoroughbred industry to facilitate early conception. This paper compares 2 techniques for inducing fertile oestrus in anoestrous mares using either an extended photoperiod alone or together with gonadotrophin-releasing hormone (GnRH) infusions. Eleven mares were placed under conditions of 16 h light and 8 h darkness and 5 of these were implanted with osmotic minipumps delivering approximately 100 ng GnRH/kg/h for 28 days (treated mares). The treated mares ovulated 27.7 days earlier than and conceived 32 days earlier than the 6 mares not given GnRH. GnRH-induced ovulations were followed by a competent luteal phase. The combination of GnRH pumps implanted 2 weeks before commencement of service together with extended photoperiod from July 1 has promise in assisting the stud breeder to improve reproductive efficiency on commercial stud farms. PMID:1807248

  7. Distortion product otoacoustic emission (2f1-f2) suppression in 3-month-old infants: Evidence for postnatal maturation of human cochlear function?

    NASA Astrophysics Data System (ADS)

    Abdala, Carolina

    2004-12-01

    The complete timeline for maturation of human cochlear function has not been defined. Distortion product otoacoustic emission (DPOAE)-based measures of cochlear function show non-adult-like responses from premature and term-born neonates at high f2 frequencies; however, older infants were not included in these studies. In the present experiment, previously collected DPOAE ipsilateral suppression data from premature neonates were combined with new data collected from adults, term-born neonates, and 3-month-old infants to further examine the time course for maturation of cochlear function. DPOAE suppression tuning curves (STC) and suppression growth patterns were measured in the three age groups at f2=6000 Hz, L1=65, L2=55 dB SPL, with an f2/f1 of 1.2. Results indicate that term-born neonates and 3-month-old infants have non-adult-like STC width, slope on the low-frequency flank, and tip features. However, the two infant groups are not significantly different from one another. Suppression growth patterns for low-frequency suppressor tones show a clear developmental progression. In general, the younger the infant, the more shallow and compressive the suppression growth for the lowest suppressor frequencies. These findings suggest a high-frequency postnatal immaturity in cochlear function as measured by DPOAE suppression. Results may have been influenced by noncochlear factors, such as middle-ear immaturity. These factors are reviewed and considered. .

  8. Pharmacokinetics, safety, and tolerability of paliperidone palmitate 3-month formulation in patients with schizophrenia: A phase-1, single-dose, randomized, open-label study.

    PubMed

    Ravenstijn, Paulien; Remmerie, Bart; Savitz, Adam; Samtani, Mahesh N; Nuamah, Isaac; Chang, Cheng-Tao; De Meulder, Marc; Hough, David; Gopal, Srihari

    2016-03-01

    This multicenter, randomized, open-label, parallel-group, phase-1 study assessed the pharmacokinetics (PK), safety, and tolerability of the investigational intramuscular paliperidone palmitate 3-month (PP3M) formulation in patients with schizophrenia or schizoaffective disorder. A total of 328 patients (men or women, aged 18-65 years) were enrolled in 1 of 4 separately conducted panels (A to D). Each panel had 2 single-dose treatment periods (period 1, 1 mg intramuscular paliperidone immediate release [IR]; period 2, intramuscular PP3M 75-525 mg eq) separated by a washout of 7-21 days. Overall, 245 of 308 (79.5%) PP3M-dosed patients completed the study. Because the PK studies of panels A and C were compromised by incomplete injection in some patients, PK data from only panels B and D are presented. Safety data from all panels are presented. Peak paliperidone plasma concentration was achieved between 23 and 34 days, and apparent half-life was ∼2-4 months. Mean plasma AUC∞ and Cmax of paliperidone appeared to be dose-proportional. Relative bioavailability in comparison with paliperidone was ∼100% independent of the dose and injection site. Headache and nasopharyngitis were the most common (>7%) treatment-emergent adverse events. Overall, safety and tolerability were similar to those of the 1-month formulation. Results support a once-every-3-months dosing interval in patients with schizophrenia or schizoaffective disorder. PMID:26189570

  9. Pulmonary embolism and 3-month outcomes in 4036 patients with venous thromboembolism and chronic obstructive pulmonary disease: data from the RIETE registry

    PubMed Central

    2013-01-01

    Background Patients with chronic obstructive pulmonary disease (COPD) have a modified clinical presentation of venous thromboembolism (VTE) but also a worse prognosis than non-COPD patients with VTE. As it may induce therapeutic modifications, we evaluated the influence of the initial VTE presentation on the 3-month outcomes in COPD patients. Methods COPD patients included in the on-going world-wide RIETE Registry were studied. The rate of pulmonary embolism (PE), major bleeding and death during the first 3 months in COPD patients were compared according to their initial clinical presentation (acute PE or deep vein thrombosis (DVT)). Results Of the 4036 COPD patients included, 2452 (61%; 95% CI: 59.2-62.3) initially presented with PE. PE as the first VTE recurrence occurred in 116 patients, major bleeding in 101 patients and mortality in 443 patients (Fatal PE: first cause of death). Multivariate analysis confirmed that presenting with PE was associated with higher risk of VTE recurrence as PE (OR, 2.04; 95% CI: 1.11-3.72) and higher risk of fatal PE (OR, 7.77; 95% CI: 2.92-15.7). Conclusions COPD patients presenting with PE have an increased risk for PE recurrences and fatal PE compared with those presenting with DVT alone. More efficient therapy is needed in this subtype of patients. PMID:23865769

  10. Five-day inhalation toxicity study of three types of synthetic amorphous silicas in Wistar rats and post-exposure evaluations for up to 3 months.

    PubMed

    Arts, Josje H E; Muijser, Hans; Duistermaat, Evert; Junker, Karin; Kuper, C Frieke

    2007-10-01

    Evidence suggests that short-term animal exposures to synthetic amorphous silicas (SAS) and crystalline silica can provide comparable prediction of toxicity to those of 90-day studies, therefore providing the opportunity to screen these types of substances using short-term rather than 90-day studies. To investigate this hypothesis, the inhalation toxicity of three SAS, precipitated silica Zeosil 45, silica gel Syloid 74, and pyrogenic silica Cab-O-Sil M5 was studied in Wistar rats. Rats were exposed nose-only to concentrations of 1, 5 or 25mg/m(3) of one of the SAS 6h a day for five consecutive days. Positive controls were exposed to 25mg/m(3) crystalline silica (quartz dust), negative controls to clean air. Animals were necropsied the day after the last exposure or 1 or 3 months later. All exposures were tolerated without serious clinical effects, changes in body weight or food intake. Differences in the effects associated with exposure to the three types of SAS were limited and almost exclusively confined to the 1-day post-exposure time point. Silicon levels in tracheobronchial lymph nodes were below the detection limit in all groups at all time points. Silicon was found in the lungs of all high concentration SAS groups 1-day post-exposure, and was cleared 3 months later. Exposure to all three SAS at 25mg/m(3) induced elevations in biomarkers of cytotoxicity in bronchoalveolar lavage fluid (BALf), increases in lung and tracheobronchial lymph node weight and histopathological lung changes 1-day post-exposure. Exposure to all three SAS at 5mg/m(3) induced histopathological changes and changes in BALf only. With all three SAS these effects were transient and, with the exception of slight histopathological lung changes at the higher exposure levels, were reversible during the 3-month recovery period. No adverse changes were observed in animals exposed to any of the SAS at 1mg/m(3). In contrast, with quartz-exposed animals the presence of silicon in the lungs was

  11. Inheritance of photoperiodic control of larval diapause in the Asian corn borer Ostrinia furnacalis (Guenée).

    PubMed

    Xiao, L; He, H M; Zhong, P S; Fu, S; Chen, C; Xue, F S

    2015-06-01

    The Asian corn borer, Ostrinia furnacalis enters diapause as fully grown larvae. Owing to geographical variation in photoperiodic control of diapause, the subtropical strain from Hefei city (HF) enters diapause in response to short daylengths, whereas the tropical strain from Ledong county (LD) exhibits almost no diapause under the same conditions. The two strains were used in crosses to study the inheritance of diapause. The HF strain showed a typical long-day response with a critical daylength of approximately 14.97 h at 22 °C, 14.60 h at 25 °C and 13.68 h at 28 °C. The LD strain showed weak photoperiodic responses at 22 and 25 °C; and the F1 progeny also showed a long-day response with significantly shorter critical daylength compared with the HF strain. However, the LD × HF (F × M) crosses had significantly longer critical daylengths than HF × LD crosses, indicating a sexual bias in the inheritance of diapause induction, with the male parent having more influence on the F1 progeny. The critical daylength in a backcross to HF was significantly longer than a backcross to LD. Whether the inheritance of diapause fits an additive hypothesis or not depended on photoperiod, with results from different photoperiods showing additive inheritance or incomplete dominance of either diapause or non-diapause. Unlike diapause induction, the duration of diapause for reciprocal crosses was equally influenced by each parent, suggesting that diapause incidence and maintenance are controlled by separate systems in O. furnacalis. PMID:25779483

  12. Bird eyes distinguish summer from winter: Retinal response to acute photoperiod change in the night-migratory redheaded bunting.

    PubMed

    Majumdar, Gaurav; Yadav, Garima; Rani, Sangeeta; Kumar, Vinod

    2015-10-01

    Eyes are the part of the circadian timekeeping system but not involved in the photoperiod regulated seasonal physiology in songbirds. Here, two experiments tested whether eyes detect and respond to seasonal change in the photoperiod environment, by examining gene and protein expressions in the retinas of redheaded buntings exposed to a single long day (LD, 16L:8D), with controls on short days (SD, 8L:16D). In the first experiment, mRNA expression of genes implicated in the light perception (opsins, rhodopsin, neuropsin, melanopsin, peropsin) and photoperiod induction (eya3, tsh-β, dio2, dio3) was measured at hours 15 and 19 (hour 0 = light on) on the first long day. There was a significant increase in the eya3, tsh-β and dio2 mRNA expression, albeit with a temporal difference, and decrease in the neuropsin mRNA expression in buntings on the first long day. There was no change in the dio3, rhodopsin, melanopsin and peropsin mRNA expressions on exposure to long days. The second experiment immunohistochemically examined the eya3, tsh-β and rhodopsin peptide expressions. eya3 was expressed in both light conditions, but with a significant higher levels in the retinal photoreceptor layer (PRL) under LD, as compared to SD. Similarly, tsh-β was expressed in the PRL of LD retinas only. Rhodopsin levels were not significantly different between SD and LD conditions, however. These results for the first time show photoperiod-dependent molecular switches in the bunting retina, similar to the well documented thyroid hormone response genes based molecular cascades in the avian hypothalamus. PMID:26219493

  13. Do photoperiod and endocrine disruptor 4-tert-octylphenol effect on spermatozoa of bank vole (Clethrionomys glareolus)?

    PubMed

    Kotula-Balak, Malgorzata; Grzmil, Pawel; Chojnacka, Katarzyna; Andryka, Katarzyna; Bilinska, Barbara

    2014-05-15

    Photoperiod is an environmental signal that controls physiology and behavior of all organisms. Bank voles, which are seasonal breeders, are stimulated to reproduce by the long photoperiod associated with spring and summer. To date, physiology of bank vole spermatozoa has not been explored, although they constitute an interesting model for examining the relationship between photoperiod and xenoestrogen on spermatozoa function. In an attempt to evaluate the acute effect of 4-tert-octylphenol (OP) an in vitro system was used. Spermatozoa isolated from the cauda epididymidies of long-day (LD; 18 h light: 6 h darkness) and short-day (SD; 6 h light: 18 h darkness) bank voles were treated with two OP concentrations (10(-4) M and 10(-8)M, respectively). OP-treated spermatozoa were used for the examination of motility parameters (computer-assisted semen analyzer CEROS), acrosome integrity (Commassie blue staining), cAMP production (immunoenzymatic assay) and cell viability (flow-cytometry analysis). The study revealed the photoperiod-dependent effect of short OP-treatment on motility parameters of vole spermatozoa. In LD spermatozoa, an increase of velocities: (curvilinear velocity [VCL], average path velocity [VAP] straight line velocity [VSL]) and head activity (amplitude of the lateral head displacement, [ALH]) was found. Interestingly, in SD spermatozoa opposite effect on VCL, VAP, VSL and ALH was observed, however only after treatment with 10(-4)M OP. The dose-dependent influence of OP upon acrosome integrity, as well as cAMP levels, in relation to the reproductive status of voles was observed. Moreover, OP exposure affected spermatozoa morphology rather than spermatozoa viability. PMID:24698786

  14. Interacting effects of photoperiod and photosynthetic photon flux on net carbon assimilation and starch accumulation in potato leaves

    NASA Technical Reports Server (NTRS)

    Stutte, G. W.; Yorio, N. C.; Wheeler, R. M.

    1996-01-01

    The effect of photoperiod (PP) on net carbon assimilation rate (Anet) and starch accumulation in newly mature canopy leaves of 'Norland' potato (Solanum tuberosum L.) was determined under high (412 varies as mol m-2s-1) and low (263 varies as mol m-2s-1) photosynthetic photon flux (PPF) conditions. The Anet decreased from 13.9 to 11.6 and 9.3 micromoles m-2s-1, and leaf starch increased from 70 to 129 and 118 mg g-1 drymass (DM) as photoperiod (PP) was increased from 12/12 to 18/6, and 24/0, respectively. Longer PP had a greater effect with high PPF conditions than with low PPF treatments, with high PPF showing greater decline in Anet. Photoperiod did not affect either the CO2 compensation point (50 micromoles mol-1) or CO2 saturation point (1100-1200 micromoles mol-1) for Anet. These results show an apparent limit to the amount of starch that can be stored (approximately 15% DM) in potato leaves. An apparent feedback mechanism exists for regulating Anet under high PPF, high CO2, and long PP, but there was no correlation between Anet and starch concentration in individual leaves. This suggests that maximum Anet cannot be sustained with elevated CO2 conditions under long PP (> or = 12 hours) and high PPF conditions. If a physiological limit exists for the fixation and transport of carbon,then increasing photoperiod and light intensity under high CO2 conditions is not the most appropriate means to maximize the yield of potatoes.

  15. Circadian photosensitive phase and photoperiodic control of testis activity in the mink, a short-day mammal

    SciTech Connect

    Boissin-Agasse, L.; Boissin, J.; Ortavant, R.

    1982-02-01

    Evidence of a circadian photosensitive phase in male mink, whose annual reproductive cycle is characterized by the recrudescence of testicular development in autumn, was based on the study of testicular response after interrupting the dark period by light breaks offered at various times. In this mammal, the experimental short days 4L:20D and 8L:16D stimulated testicular growth. Short photoperiods, including a main light period of 3.5 h and an additional 0.5 h light break 7.5 h after the beginning of the main photoperiod, were as effective as 8L:16D in stimulating testicular development. On the other hand, when a 0.5 h light break occurred 11.5 or 15.5 h after the beginning of the main photoperiod, the same inhibiting effect on testicular activity was obtained as for long photoperiods. However, when 0.5 h light breaks were given 19.5 after the beginning of the main light period, some minks recognized, as, the onset of the shorter of the two light periods offered. Thus our results proved the existence of a special phase in the day cycle in which light inhibited testicular development in the mink which appears to be a short-day animal. One explanation of the difference between long-day and short-day animals would be the following: if for long-day animals exposure to light during the photosensitive phase led to gonadostimulation, in short-day mammals, like mink, it exerted an inhibiting influence on testicular growth.

  16. Dual role of tree florigen activation complex component FD in photoperiodic growth control and adaptive response pathways.

    PubMed

    Tylewicz, Szymon; Tsuji, Hiroyuki; Miskolczi, Pál; Petterle, Anna; Azeez, Abdul; Jonsson, Kristoffer; Shimamoto, Ko; Bhalerao, Rishikesh P

    2015-03-10

    A complex consisting of evolutionarily conserved FD, flowering locus T (FT) proteins is a regulator of floral transition. Intriguingly, FT orthologs are also implicated in developmental transitions distinct from flowering, such as photoperiodic control of bulbing in onions, potato tuberization, and growth cessation in trees. However, whether an FT-FD complex participates in these transitions and, if so, its mode of action, are unknown. We identified two closely related FD homologs, FD-like 1 (FDL1) and FD-like 2 (FDL2), in the model tree hybrid aspen. Using gain of function and RNAi-suppressed FDL1 and FDL2 transgenic plants, we show that FDL1 and FDL2 have distinct functions and a complex consisting of FT and FDL1 mediates in photoperiodic control of seasonal growth. The downstream target of the FT-FD complex in photoperiodic control of growth is Like AP1 (LAP1), a tree ortholog of the floral meristem identity gene APETALA1. Intriguingly, FDL1 also participates in the transcriptional control of adaptive response and bud maturation pathways, independent of its interaction with FT, presumably via interaction with abscisic acid insensitive 3 (ABI3) transcription factor, a component of abscisic acid (ABA) signaling. Our data reveal that in contrast to its primary role in flowering, FD has dual roles in the photoperiodic control of seasonal growth and stress tolerance in trees. Thus, the functions of FT and FD have diversified during evolution, and FD homologs have acquired roles that are independent of their interaction with FT. PMID:25713384

  17. Evolution of CONSTANS Regulation and Function after Gene Duplication Produced a Photoperiodic Flowering Switch in the Brassicaceae.

    PubMed

    Simon, Samson; Rühl, Mark; de Montaigu, Amaury; Wötzel, Stefan; Coupland, George

    2015-09-01

    Environmental control of flowering allows plant reproduction to occur under optimal conditions and facilitates adaptation to different locations. At high latitude, flowering of many plants is controlled by seasonal changes in day length. The photoperiodic flowering pathway confers this response in the Brassicaceae, which colonized temperate latitudes after divergence from the Cleomaceae, their subtropical sister family. The CONSTANS (CO) transcription factor of Arabidopsis thaliana, a member of the Brassicaceae, is central to the photoperiodic flowering response and shows characteristic patterns of transcription required for day-length sensing. CO is believed to be widely conserved among flowering plants; however, we show that it arose after gene duplication at the root of the Brassicaceae followed by divergence of transcriptional regulation and protein function. CO has two close homologs, CONSTANS-LIKE1 (COL1) and COL2, which are related to CO by tandem duplication and whole-genome duplication, respectively. The single CO homolog present in the Cleomaceae shows transcriptional and functional features similar to those of COL1 and COL2, suggesting that these were ancestral. We detect cis-regulatory and codon changes characteristic of CO and use transgenic assays to demonstrate their significance in the day-length-dependent activation of the CO target gene FLOWERING LOCUS T. Thus, the function of CO as a potent photoperiodic flowering switch evolved in the Brassicaceae after gene duplication. The origin of CO may have contributed to the range expansion of the Brassicaceae and suggests that in other families CO genes involved in photoperiodic flowering arose by convergent evolution. PMID:25972346

  18. Effect of photoperiod on characteristics of semen obtained by electroejaculation in stump-tailed macaques (Macaca arctoides).

    PubMed

    García Granados, Mónica Dafne; Hernández López, Leonor Estela; Córdoba Aguilar, Alejandro; Cerda Molina, Ana Lilia; Pérez-Ramírez, Olivia; Mondragón-Ceballos, Ricardo

    2014-07-01

    Some environmental variables determining seasonal reproduction in mammals are temperature, humidity, food availability, and photoperiod. Among these, photoperiod is considered the main regulator of primates' seasonal reproduction, thus the latitudinal distribution of primate populations is a key factor determining the appearance of seasonal reproduction. The present work presents supporting discrete seasonality in male stump-tailed macaques (Macaca arctoides). We investigated whether semen quality and testosterone covaried with Mexico City's photoperiod and relative humidity by analyzing variations in the portions that form the ejaculate: the seminal liquid, the seminal coagulum, and the copulatory plug. Five male adult stump-tailed macaques were electroejaculated once a month, obtaining three semen samples per male, from August 2011 to July 2012 (except for December 2011) (n = 165). Our results showed that stump-tailed macaque sperm counts were significantly different between the portions of the ejaculate. The seminal coagulum contained the significantly largest number of spermatozoids, followed by the copulatory plug and the seminal fluid. Photoperiod and relative humidity had major influence on the sperm count in the seminal coagulum and the testosterone concentrations. Testosterone reached its highest values around the time when days and nights lasted the same hours, decreasing when days either grew longer or became shorter. Concerning relative humidity, sperm counts in the seminal coagulum were highly variable on dry days, but decreased as the relative humidity increased. We conclude that stump-tailed macaques have a discrete seasonality, occurring in spring and fall when macaques' reproductive condition and readiness for postcopulatory intrasexual competition increase. PMID:24585247

  19. Evolution of CONSTANS Regulation and Function after Gene Duplication Produced a Photoperiodic Flowering Switch in the Brassicaceae

    PubMed Central

    Simon, Samson; Rühl, Mark; de Montaigu, Amaury; Wötzel, Stefan; Coupland, George

    2015-01-01

    Environmental control of flowering allows plant reproduction to occur under optimal conditions and facilitates adaptation to different locations. At high latitude, flowering of many plants is controlled by seasonal changes in day length. The photoperiodic flowering pathway confers this response in the Brassicaceae, which colonized temperate latitudes after divergence from the Cleomaceae, their subtropical sister family. The CONSTANS (CO) transcription factor of Arabidopsis thaliana, a member of the Brassicaceae, is central to the photoperiodic flowering response and shows characteristic patterns of transcription required for day-length sensing. CO is believed to be widely conserved among flowering plants; however, we show that it arose after gene duplication at the root of the Brassicaceae followed by divergence of transcriptional regulation and protein function. CO has two close homologs, CONSTANS-LIKE1 (COL1) and COL2, which are related to CO by tandem duplication and whole-genome duplication, respectively. The single CO homolog present in the Cleomaceae shows transcriptional and functional features similar to those of COL1 and COL2, suggesting that these were ancestral. We detect cis-regulatory and codon changes characteristic of CO and use transgenic assays to demonstrate their significance in the day-length-dependent activation of the CO target gene FLOWERING LOCUS T. Thus, the function of CO as a potent photoperiodic flowering switch evolved in the Brassicaceae after gene duplication. The origin of CO may have contributed to the range expansion of the Brassicaceae and suggests that in other families CO genes involved in photoperiodic flowering arose by convergent evolution. PMID:25972346

  20. Quantification of the rates of resynchronization of heart rate with body temperature rhythms in man following a photoperiod shift

    NASA Technical Reports Server (NTRS)

    Hetherington, N. W.; Rosenblatt, L. S.; Higgins, E. A.; Winget, C. M.

    1973-01-01

    A mathematical model previously presented by Rosenblatt et al. (1973) for estimating the rates of resynchronization of individual biorhythms following transmeridian flights or photoperiod shifts is extended to estimation of rates at which two biorythms resynchronize with respect to each other. Such quantification of the rate of restoration of the initial phase relationship of the two biorhythms is pointed out as a valuable tool in the study of internal desynchronosis.

  1. Photoperiod affects the cerebrospinal fluid proteome: a comparison between short day- and long day-treated ewes.

    PubMed

    Teixeira-Gomes, A-P; Harichaux, G; Gennetay, D; Skipor, J; Thiery, J-C; Labas, V; Dufourny, L

    2015-10-01

    Photoperiod is the main physical synchronizer of seasonal functions and a key factor in the modulation of molecule access to cerebrospinal fluid (CSF) in animals. Previous work has shown that photoperiod affects the transfer rate of steroids and protein hormones from blood to CSF and modulates choroid plexus tight junction protein content. We hypothesized that the CSF proteome would also be modified by photoperiod. We tested this hypothesis by comparing CSF obtained from the third ventricle of mature, ovariectomized, estradiol-replaced ewes exposed to long day length (LD) or short day length (SD). Variations in CSF protein expression between SD- or LD-treated ewes were studied in pools of CSF collected for 48 h. Proteins were precipitated, concentrated, and included in a polyacrylamide gel without protein fractionation. After in-gel tryptic digestion of total protein samples, we analyzed the resulting peptides by nanoliquid chromatography coupled with high-resolution tandem mass spectrometry (GeLC-MS/MS). Quantitative analysis was performed using 2 methods based on spectral counting and extracted ion chromatograms. Among 103 identified proteins, 41 were differentially expressed between LD and SD ewes (with P < 0.05 and at least a 1.5-fold difference). Of the 41 differentially expressed proteins, 22 were identified by both methods and 19 using extracted ion chromatograms only. Eighteen proteins were more abundant in LD ewes and 23 were more abundant in SD ewes. These proteins are involved in numerous functions including hormone transport, immune system activity, metabolism, and angiogenesis. To confirm proteomic results, 2 proteins, pigment epithelium-derived factor (PEDF) and gelsolin, for each individual sample of CSF collected under SD or LD were analyzed with Western blots. These results suggest an important photoperiod-dependent change in CSF proteome composition. Nevertheless, additional studies are required to assess the role of each protein in seasonal

  2. Regulation of UVR8 photoreceptor dimer/monomer photo-equilibrium in Arabidopsis plants grown under photoperiodic conditions.

    PubMed

    Findlay, Kirsten M W; Jenkins, Gareth I

    2016-08-01

    The UV RESISTANCE LOCUS 8 (UVR8) photoreceptor specifically mediates photomorphogenic responses to UV-B. Photoreception induces dissociation of dimeric UVR8 into monomers to initiate responses. However, the regulation of dimer/monomer status in plants growing under photoperiodic conditions has not been examined. Here we show that UVR8 establishes a dimer/monomer photo-equilibrium in plants growing in diurnal photoperiods in both controlled environments and natural daylight. The photo-equilibrium is determined by the relative rates of photoreception and dark-reversion to the dimer. Experiments with mutants in REPRESSOR OF UV-B PHOTOMORPHOGENESIS 1 (RUP1) and RUP2 show that these proteins are crucial in regulating the photo-equilibrium because they promote reversion to the dimer. In plants growing in daylight, the UVR8 photo-equilibrium is most strongly correlated with low ambient fluence rates of UV-B (up to 1.5 μmol m(-2) s(-1) ), rather than higher fluence rates or the amount of photosynthetically active radiation. In addition, the rate of reversion of monomer to dimer is reduced at lower temperatures, promoting an increase in the relative level of monomer at approximately 8-10 °C. Thus, UVR8 does not behave like a simple UV-B switch under photoperiodic growth conditions but establishes a dimer/monomer photo-equilibrium that is regulated by UV-B and also influenced by temperature. PMID:26864532

  3. Interspecific hybridization in Cucumis leads to the divergence of phenotypes in response to low light and extended photoperiods

    PubMed Central

    Yu, Xiaqing; Hyldgaard, Benita; Rosenqvist, Eva; Ottosen, Carl-Otto; Chen, Jinfeng

    2015-01-01

    With the aim of improving shade tolerance of cucumber, Cucumis × hytivus, a newly synthesized allotetraploid, was obtained by crossing a shade tolerant wild relative, Cucumis hystrix, with a cultivated cucumber, Cucumis sativus L. ‘BejingJietou.’ The results show that the new C. × hytivus only partly is an intermediate hybrid and it has not only chlorophyll deficiency, which recovers during leaf development, but also lower carotenoid content. Three light conditions with the combination of different light intensities and photoperiods were employed to investigate the photosynthetic response of these three Cucumis species to low light and long photoperiod. The consistent order of Pmax and DWS being lowest in C. hystrix, medium in C. × hytivus and highest in ‘BejingJietou’ suggests the three species to have genetically different photosynthetic efficiency, which relates well with the natural habitats of the parent species and the hybrid as intermediate. C. × hytivus appears to be inhibited by the low light levels to the same extent as the cultivated ‘BeijingJietou,’ which indicates neither improvement of shade tolerance nor hypothetical heterosis effect in C. × hytivus. However, unexpectedly, the PSII of C. hystrix was affected by the long photoperiod in the long term, suggested by the decrease of Fv/Fm. This sensitivity toward day length has not been passed on to C. × hytivus. PMID:26483817

  4. Reproductive phenology of the American Bullfrog in subtropical Brazil: photoperiod as a main determinant of seasonal activity.

    PubMed

    Medeiros, Camila I; Both, Camila; Kaefer, Igor L; Cechin, Sonia Z

    2016-07-11

    The North American bullfrog Lithobates catesbeianus continues to invade ecosystems worldwide, potentially causing population declines and even extinctions. Within its native distribution, bullfrogs show prolonged reproductive seasons and high fertility. However, data on breeding biology of bullfrogs ex-situ in invaded localities mainly comes from anecdotal reports. Understanding how invasive species are adjusting their life histories to new colonized environments is important for conservation purposes. Here we describe temporal and spatial abundance, calling activity, spawning and tadpole distribution of bullfrogs in southern Brazil. Eighteen samplings occurred during one year. The abundance of individuals was positively related to longer photoperiods and higher temperatures. Reproductive activity was also positively associated with longer photoperiods. Calling sites, spawning and tadpoles were associated with microhabitats presenting hydrophytes, which may provide shelter and thermal stability to bullfrogs. The reproductive seasonal activity of bullfrogs can be highly variable across its growing geographical range, but in subtropical Brazil it is associated with photoperiod, a highly predictable abiotic determinant. In our study area, bullfrogs presented a breeding season twice as long as that observed in some native localities. We suggest that management strategies directed to bullfrog populations must consider the habitat structures and seasonal regimes determined by each invaded environment. PMID:27411069

  5. PCH1 integrates circadian and light-signaling pathways to control photoperiod-responsive growth in Arabidopsis

    PubMed Central

    Huang, He; Yoo, Chan Yul; Bindbeutel, Rebecca; Goldsworthy, Jessica; Tielking, Allison; Alvarez, Sophie; Naldrett, Michael J; Evans, Bradley S; Chen, Meng; Nusinow, Dmitri A

    2016-01-01

    Plants react to seasonal change in day length through altering physiology and development. Factors that function to harmonize growth with photoperiod are poorly understood. Here we characterize a new protein that associates with both circadian clock and photoreceptor components, named PHOTOPERIODIC CONTROL OF HYPOCOTYL1 (PCH1). pch1 seedlings have overly elongated hypocotyls specifically under short days while constitutive expression of PCH1 shortens hypocotyls independent of day length. PCH1 peaks at dusk, binds phytochrome B (phyB) in a red light-dependent manner, and co-localizes with phyB into photobodies. PCH1 is necessary and sufficient to promote the biogenesis of large photobodies to maintain an active phyB pool after light exposure, potentiating red-light signaling and prolonging memory of prior illumination. Manipulating PCH1 alters PHYTOCHROME INTERACTING FACTOR 4 levels and regulates light-responsive gene expression. Thus, PCH1 is a new factor that regulates photoperiod-responsive growth by integrating the clock with light perception pathways through modulating daily phyB-signaling. DOI: http://dx.doi.org/10.7554/eLife.13292.001 PMID:26839287

  6. Photoperiod-Dependent Effects of 4-tert-Octylphenol on Adherens and Gap Junction Proteins in Bank Vole Seminiferous Tubules

    PubMed Central

    Kuras, Paulina; Lydka-Zarzycka, Marta; Bilinska, Barbara

    2013-01-01

    In the present study we evaluated in vivo and in vitro effects of 4-tert-octylphenol (OP) on the expression and distribution of adherens and gap junction proteins, N-cadherin, β-catenin, and connexin 43 (Cx43), in testes of seasonally breeding rodents, bank voles. We found that in bank vole testes expression and distribution of N-cadherin, β-catenin, and Cx43 were photoperiod dependent. Long-term treatment with OP (200 mg/kg b.w.) resulted in the reduction of junction proteins expressions (P < 0.05, P < 0.01) and their delocalization in the testes of males kept in long photoperiod, whereas in short-day animals slight increase of Cx43 (P < 0.05), N-cadherin, and β-catenin (statistically nonsignificant) levels was observed. Effects of OP appeared to be independent of FSH and were maintained during in vitro organ culture, indicating that OP acts directly on adherens and gap junction proteins in the testes. An experiment performed using an antiestrogen ICI 182,780 demonstrated that the biological effects of OP on β-catenin and Cx43 involve an estrogen receptor-mediated response. Taken together, in bank vole organization of adherens and gap junctions and their susceptibility to OP are related to the length of photoperiod. Alterations in cadherin/catenin and Cx43-based junction may partially result from activation of estrogen receptor α and/or β signaling pathway. PMID:23737770

  7. Electrical Responses and Spontaneous Activity of Human iPS-Derived Neuronal Networks Characterized for 3-month Culture with 4096-Electrode Arrays

    PubMed Central

    Amin, Hayder; Maccione, Alessandro; Marinaro, Federica; Zordan, Stefano; Nieus, Thierry; Berdondini, Luca

    2016-01-01

    The recent availability of human induced pluripotent stem cells (hiPSCs) holds great promise as a novel source of human-derived neurons for cell and tissue therapies as well as for in vitro drug screenings that might replace the use of animal models. However, there is still a considerable lack of knowledge on the functional properties of hiPSC-derived neuronal networks, thus limiting their application. Here, upon optimization of cell culture protocols, we demonstrate that both spontaneous and evoked electrical spiking activities of these networks can be characterized on-chip by taking advantage of the resolution provided by CMOS multielectrode arrays (CMOS-MEAs). These devices feature a large and closely-spaced array of 4096 simultaneously recording electrodes and multi-site on-chip electrical stimulation. Our results show that networks of human-derived neurons can respond to electrical stimulation with a physiological repertoire of spike waveforms after 3 months of cell culture, a period of time during which the network undergoes the expression of developing patterns of spontaneous spiking activity. To achieve this, we have investigated the impact on the network formation and on the emerging network-wide functional properties induced by different biochemical substrates, i.e., poly-dl-ornithine (PDLO), poly-l-ornithine (PLO), and polyethylenimine (PEI), that were used as adhesion promoters for the cell culture. Interestingly, we found that neuronal networks grown on PDLO coated substrates show significantly higher spontaneous firing activity, reliable responses to low-frequency electrical stimuli, and an appropriate level of PSD-95 that may denote a physiological neuronal maturation profile and synapse stabilization. However, our results also suggest that even 3-month culture might not be sufficient for human-derived neuronal network maturation. Taken together, our results highlight the tight relationship existing between substrate coatings and emerging network

  8. Effects of CO2 Concentration on Leaf Photosynthesis and Stomatal Conductance of Potatoes Grown Under Different Irradiance Levels and Photoperiods

    NASA Technical Reports Server (NTRS)

    Wheeler, R. M.; Fitzpatrick, A. H.; Tibbitts, T. W.

    2012-01-01

    Potato (Solanum tuberosum L.) cvs. Russet Burbank, Denali, and Norland, were grown in environmental rooms controlled at approx 350 micro mol/mol (ambient during years 1987/1988) and 1000 micro mol/mol (enriched) CO2 concentrations. Plants and electric lamps were arranged to provide two irradiance zones, 400 and 800 micro mol/mol/square m/S PPF and studies were repeated using two photoperiods (12-h light / 12-h dark and continuous light). Leaf photosynthetic rates and leaf stomatal conductance were measured using fully expanded, upper canopy leaves at weekly intervals throughout growth (21 through 84 days after transplanting). Increasing the CO2 from approx 350 to 1000 micro mol/mol under the 12-h photoperiod increased leaf photosynthetic rates by 39% at 400 micro mol/mol/square m/S PPF and 27% at 800 micro mol/mol/square m/S PPF. Increasing the CO2 from approx 350 to 1000 micro mol/mol under continuous light decreased leaf photosynthetic rates by 7% at 400 micro mol/mol/square m/S PPF and 13% at 800 micro mol/mol/square m/S PPF. Increasing the CO2 from approx 350 to 1000 micro mol/mol under the 12-h photoperiod plants decreased stomatal conductance by an average of 26% at 400 micro mol/mol/square m/S PPF and 42% at 800 micro mol/mol/square m/S PPF. Under continuous light, CO2 enrichment resulted in a small increase (2%) of stomatal conductance at 400 micro mol/mol/square m/S PPF, and a small decrease (3%) at 800 micro mol/mol/square m/S PPF. Results indicate that CO2 enrichment under the 12-h photoperiod showed the expected increase in photosynthesis and decrease in stomatal conductance for a C3 species like potato, but the decreases in leaf photosynthetic rates and minimal effect on conductance from CO2 enrichment under continuous light were not expected. The plant leaves under continuous light showed more chlorosis and some rusty flecking versus plants under the 12-h photoperiod, suggesting the continuous light was more stressful on the plants. The increased

  9. Fine structure and photoperiodical seasonal changes in Pars tuberalis of hibernating bats.

    PubMed

    Azzali, Giacomo; Arcari, Maria Luisa; Cacchioli, Antonio; Toni, Roberto

    2003-01-01

    In Pars tuberalis (PT) of pituitary gland of hibernating bats, extending cranially along the ventral face of the hypothalamic median eminence, around the hypophyseal stalk, and caudally continuing in the Pars distalis (PD), pt specific cells, follicular cells and gonadotropic cells were distinguished. Pt specific cells contain peculiar secretory granules positive to lectin WGA and negative to lectins LFA and PNA, positive to S-100 protein labeling and to PD hormones antisera. During hibernation they present a low numerical density of both secretory granules and melatonin binding sites. After light exposure, on the other hand, the latter increase in density and are associated with marked secretion synthetic activity and exocytosis. These aspects result to be more balanced in animals sacrificed during summer. These changes seem to support the hypothesis of marked annual changes even in animal species with seasonal rhythmicity of metabolisms and gonads. Follicular cells, organized in closed follicles, have slightly developed RER and Golgi apparatus during hibernation, whereas they seem to show an increased secretory activity after light exposure and during summer. In perinuclear and supranuclear cytoplasm, glycogen particles clusters (peculiar of hibernation), cilia 9+2 and multivesicular bodies were identified. Concerning FSH cells, a reduced numerical density during hibernation, the secretory granules morphological characteristics and their probable involvement in photoperiod-linked reproductive functions are investigated. PMID:12737515

  10. Demand-feeding rhythm in rainbow trout and European catfish. Synchronisation by photoperiod and food availability.

    PubMed

    Bolliet, V; Aranda, A; Boujard, T

    2001-07-01

    The effect of light-dark (LD) cycle and food availability was tested on the demand-feeding rhythm of single and groups of rainbow trout and European catfish. Under LD and free food access, most trout and catfish displayed, respectively, a diurnal and a nocturnal pattern of demand-feeding activity, whereas a few fish or groups of fish switched from diurnalism to nocturnalism or vice versa. In both species held under constant lighting conditions and a restricted feeding (RF) cycle (RF 20:4), the demand-feeding rhythm rapidly synchronised to food availability. The demand-feeding rhythm was under endogenous control and, in rainbow trout, periodogram analysis suggested the existence of two oscillators, one synchronised by photoperiod (LEO) and the other by food (FEO). When submitted to both LD and RF cycles, LD was, at least in the rainbow trout, the dominant zeitgeber synchronising the demand-feeding rhythm. In catfish, food availability rapidly synchronised demand-feeding rhythm. Finally, in both species, the synchronisation of single fish to LD or feed availability appeared slower than that of groups of fish, supporting the idea that social organisation affects the circadian activity in fish. PMID:11495668

  11. Effect of Photoperiod on the Metabolism of Deuterium-Labeled Gibberellin A53 in Spinach 1

    PubMed Central

    Gianfagna, Thomas; Zeevaart, Jan A. D.; Lusk, William J.

    1983-01-01

    Application of gibberellin A53 (GA53) to short-day (SD)-grown spinach (Spinacia oleracea L.) plants caused an increase in petiole length and leaf angle similar to that found in plants transferred to long days (LD). [2H] GA53 was fed to plants in SD, LD, and in a SD to LD transition experiment, and the metabolites were identified by gas chromatography with selected ion monitoring. After 2, 4, or 6 SD, [2H]GA53 was converted to [2H]GA19 and [2H]GA44. No other metabolites were detected. After 2 LD, only [2H] GA20 was identified. In the transition experiment in which plants were given 4 SD followed by 2 LD, all three metabolites were found. The results demonstrate unequivocally that GA19, GA20, and GA44 are metabolic products of GA53, and strongly suggest that photoperiod regulates GA metabolism, in part, by controlling the conversion of GA19 to GA20. PMID:16662988

  12. Water stress, CO2 and photoperiod influence hormone levels in wheat

    NASA Technical Reports Server (NTRS)

    Nan, Rubin; Carman, John G.; Salisbury, Frank B.; Campbell, W. F. (Principal Investigator)

    2002-01-01

    'Super Dwarf' wheat (Triticum aestivum L.) plants have been grown from seed to maturity in the Mir space station where they were periodically exposed, because of microgravity and other constraints, to water deficit, waterlogging, high CO2 levels, and low light intensities. The plants produced many tillers, but none of them produced viable seed. Studies have been initiated to determine why the plants responded in these ways. In the present study, effects of the listed stresses on abscisic acid (ABA), indole-3-acetic acid (IAA) and isopentenyl adenosine ([9R]iP) levels in roots and leaves of plants grown under otherwise near optimal conditions on earth were measured. Hormones were extracted, purified by HPLC, and quantified by noncompetitive indirect ELISA. In response to water deficit, ABA levels increased in roots and leaves, IAA levels decreased in roots and leaves, and [9R]iP levels increased in leaves but decreased in roots. In response to waterlogging, ABA, IAA and [9R]iP levels briefly increased in roots and leaves and then decreased. When portions of the root system were exposed to waterlogging and/or water deficit, ABA levels in leaves increased while [9R]iP and IAA levels decreased. These responses were correlated with the percentage of the root system stressed. At a low photosynthetic photon flux (100 micromoles m-2 s-1), plants grown in continuous light had higher leaf ABA levels than plants grown using an 18 or 21 h photoperiod.

  13. Diurnal temperature fluctuation effects on potatoes grown with 12 hr photoperiods

    NASA Technical Reports Server (NTRS)

    Bennett, S. M.; Tibbitts, T. W.; Cao, W.

    1991-01-01

    This study was designed to characterize the growth responses of potato (Solanum tuberosum L.) to diurnal temperature fluctuations. Potato plants of two cultivars, Norland and Denali, were grown for 90 days under 12 hr photoperiod in walk-in growth rooms at the University of Wisconsin Biotron. The alternating temperature was 22 C light/14 C dark and compared to a constant 18 C as control. At all temperature regimes vapor pressure deficit was maintained at 0.62 kPa (70% relative humidity [correction of humdidity] at 18 C). Plant height, plant dry weight, tuber dry weight, and harvest index were overall greater under the warm light/cool dark alternating temperatures than under the constant temperature. The differences between temperature treatments were greater for Denali than for Norland. Alternating temperatures increased Denali tuber weights by 25%, but no significant increase was found with Norland. Also the total plant weight was increased over 20% with Denali, but increased with Norland in only one of the two replications of the experiment. This study documents that alternating temperatures are a benefit to some cultivars but may not be of benefit to all cultivars.

  14. Development of photoperiod- and thermo-sensitive male sterility rice expressing transgene Bacillus thuringiensis

    PubMed Central

    Liu, Xin; Zhang, Jiwen; Zhang, Cuicui; Wang, Liangchao; Chen, Hao; Zhu, Zengrong; Tu, Jumin

    2015-01-01

    Stem borers and leaffolders are the main pests that cause severe damage in rice (Oryza sativa L.) production worldwide. We developed the first photoperiod- and thermo-sensitive male sterility (PTSMS) rice 208S with the cry1Ab/1Ac Bacillus thuringiensis (Bt) gene, through sexual crossing with Huahui 1 (elite line with the cry1Ab/1Ac gene). The novel 208S and its hybrids presented high and stable resistance to stem borers and leaffolders, and the content of Cry1Ab/1Ac protein in chlorophyllous tissues achieved the identical level as donor and showed little accumulation in non-chlorophyllous tissue. No dominant dosage effect in the Bt gene was observed in 208S and its derived hybrids. An analysis of fertility transition traits indicated that 208S was completely sterile under long day length/high temperature, but partially fertile under short day length/low temperature. With fine grain quality and favorable combining ability, 208S had no observed negative effects on fertility and agronomic traits from Bt (cry1Ab/1Ac). Additionally, 208S as a male sterile line showed no fertility decrease caused by Bt transgenic process, as it is the case in Huahui 1. Thus, 208S has great application value in two-line hybrid production for insect resistance, and can also be used as a bridge material in rice Bt transgenic breeding. PMID:26366116

  15. Sulfuric Acid Pretreatment and Enzymatic Hydrolysis of Photoperiod Sensitvie Sorghum for Ethanol Production

    SciTech Connect

    F Xu; Y Shi; X Wu

    2011-12-31

    Photoperiod sensitive (PS) sorghum, with high soluble sugar content, high mass yield and high drought tolerance in dryland environments, has great potential for bioethanol production. The effect of diluted sulfuric acid pretreatment on enzymatic hydrolysis was investigated. Hydrolysis efficiency increased from 78.9 to 94.4% as the acid concentration increased from 0.5 to 1.5%. However, the highest total glucose yield (80.3%) occurred at the 1.0% acid condition because of the significant cellulose degradation at the 1.5% concentration. Synchrotron wide-angle X-ray diffraction was used to study changes of the degree of crystallinity. With comparison of cellulosic crystallinity and adjusted cellulosic crystallinity, the crystalline cellulose decreased after low acidic concentration (0.5%) applied, but did not change significantly, as the acid concentration increased. Scanning electron microscopy was also employed to understand how the morphological structure of PS sorghum changed after pretreatment. Under current processing conditions, the total ethanol yield is 74.5% (about 0.2 g ethanol from 1 g PS sorghum). A detail mass balance was also provided.

  16. Photoperiodic versus metabolic signals as determinants of seasonal anestrus in the mare.

    PubMed

    Fitzgerald, B P; McManus, C J

    2000-07-01

    The objectives of this study were to compare the timing and mechanisms controlling the onset of anestrus in young and mature mares treated either continuously with melatonin and in those that remained untreated. Changes in body weight, subcutaneous body fat measured to provide an estimate of total body fat, and circulating concentrations of leptin were compared throughout the 1-yr experimental period. The results demonstrate that in young mares the timing of anestrus occurs significantly earlier in the year than in mature mares and that mature mares are more likely to exhibit continuous reproductive activity during the nonbreeding season. The propensity of mature mares to exhibit this phenomenon is not modified by continuous treatment with melatonin but is associated with higher mean circulating concentrations of leptin, body weight, and estimated percent of body fat. In both young and mature mares, body weight, percent of body fat, and circulating concentrations of leptin are higher during summer than winter months. We conclude that, in the mare, the reproductive response to a decrease in photoperiod or a presumptive inhibitory melatonin signal is modified by energy availability, which may be signaled to the hypothalamus-pituitary axis via a change in the circulating concentration of leptin. An additional observation confirmed that the prolactin axis is responsive to continuous treatment with melatonin but that a suppression of prolactin secretion is limited to the spring months. PMID:10859276

  17. Linked circadian outputs control elongation growth and flowering in response to photoperiod and temperature

    PubMed Central

    Seaton, Daniel D; Smith, Robert W; Song, Young Hun; MacGregor, Dana R; Stewart, Kelly; Steel, Gavin; Foreman, Julia; Penfield, Steven; Imaizumi, Takato; Millar, Andrew J; Halliday, Karen J

    2015-01-01

    Clock-regulated pathways coordinate the response of many developmental processes to changes in photoperiod and temperature. We model two of the best-understood clock output pathways in Arabidopsis, which control key regulators of flowering and elongation growth. In flowering, the model predicted regulatory links from the clock to CYCLING DOF FACTOR 1 (CDF1) and FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 (FKF1) transcription. Physical interaction data support these links, which create threefold feed-forward motifs from two clock components to the floral regulator FT. In hypocotyl growth, the model described clock-regulated transcription of PHYTOCHROME-INTERACTING FACTOR 4 and 5 (PIF4, PIF5), interacting with post-translational regulation of PIF proteins by phytochrome B (phyB) and other light-activated pathways. The model predicted bimodal and end-of-day PIF activity profiles that are observed across hundreds of PIF-regulated target genes. In the response to temperature, warmth-enhanced PIF4 activity explained the observed hypocotyl growth dynamics but additional, temperature-dependent regulators were implicated in the flowering response. Integrating these two pathways with the clock model highlights the molecular mechanisms that coordinate plant development across changing conditions. PMID:25600997

  18. The sorghum photoperiod sensitivity gene, Ma3, encodes a phytochrome B.

    PubMed Central

    Childs, K L; Miller, F R; Cordonnier-Pratt, M M; Pratt, L H; Morgan, P W; Mullet, J E

    1997-01-01

    The Ma3 gene is one of six genes that regulate the photoperiodic sensitivity of flowering in sorghum (Sorghum bicolor [L.] Moench). The ma3R mutation of this gene causes a phenotype that is similar to plants that are known to lack phytochrome B, and ma3 sorghum lacks a 123-KD phytochrome that predominates in light-grown plants and that is present in non-ma3 plants. A population segregating for Ma3 and ma3 was created and used to identify two randomly amplified polymorphic DNA markers linked to Ma3. These two markers were cloned and mapped in a recombinant inbred population as restriction fragment length polymorphisms. cDNA clones of PHYA and PHYC were cloned and sequenced from a cDNA library prepared from green sorghum leaves. Using a genome-walking technique, a 7941-bp partial sequence of PHYB, was determined from genomic DNA from ma3 sorghum. PHYA, PHYB, and PHYC all mapped to the same linkage group. The Ma3-linked markers mapped with PHYB more than 121 centimorgans from PHYA and PHYC. A frameshift mutation resulting in a premature stop codon was found in the PHYB sequence from ma3 sorghum. Therefore, we conclude that the Ma3 locus in sorghum is a PHYB gene that encodes a 123-kD phytochrome. PMID:9046599

  19. Differential responses of silver birch (Betula pendula) ecotypes to short-day photoperiod and low temperature.

    PubMed

    Li, Chunyang; Welling, Annikki; Puhakainen, Tuula; Viherä-Aarnio, Anneli; Ernstsen, Arild; Junttila, Olavi; Heino, Pekka; Palva, E Tapio

    2005-12-01

    We investigated interrelations of dormancy and freezing tolerance and the role of endogenous abscisic acid (ABA) in the development of silver birch (Betula pendula Roth) ecotypes in controlled environments. Short-day treatment induced growth cessation, bud set and dormancy development, as well as initiation of cold acclimation and an increase in freezing tolerance. Subsequent low temperature and short days (12-h photoperiod) resulted in a significant increase in freezing tolerance, whereas bud dormancy was gradually released. The concentration of ABA increased in response to short days and then remained high, but ABA concentrations fluctuated irregularly when the dormant plants were subsequently exposed to low temperature during short days. Although there was a parallel development of freezing tolerance and bud dormancy in response to short days, subsequent exposure to low temperature had opposite effects on these processes, enhancing freezing tolerance and releasing dormancy. Compared with the southern ecotype, the northern ecotype was more responsive to short days and low temperature, exhibiting earlier initiation of cold acclimation, growth cessation and an increase in ABA concentrations in short days, and higher freezing tolerance, faster dormancy release and greater alteration in ABA concentrations when subsequently exposed to low temperature during short days. The rates and extent of the increases in ABA concentration may be related to increases in freezing tolerance and dormancy development during short days, whereas the extent of the fluctuations in ABA concentration may play an important role in enhancing freezing tolerance and releasing dormancy during a subsequent exposure to low temperature during short days. PMID:16137942

  20. Follow-up of Ascaris lumbricoides and Trichuris trichiura infections in children living in a community treated with ivermectin at 3-monthly intervals.

    PubMed

    Ranque, S; Chippaux, J P; Garcia, A; Boussinesq, M

    2001-06-01

    Ivermectin treatment was administered every 3 months over a 1-year period (April 1993-April 1994) to the whole eligible population of a village in South Cameroon where both Ascaris lumbricoides and Trichuris trichiura were hyper-endemic. A parasitological stool examination was performed before each treatment. Thirty children, aged 5-15 years, were not only found egg-positive for A. lumbricoides and/or T. trichiura before the first treatment but were also each treated and examined in each treatment round. Among these children, the intensity of infection with A. lumbricoides decreased significantly following the first treatment but thereafter remained steady. In contrast, the repeated ivermectin treatments had no significant impact on the intensity of the T. trichiura infections or on the prevalence of infection with T. trichiura or A. lumbricoides among the 30 children. PMID:11454248

  1. Effects of structured vocational services on job-search success in ex-offender veterans with mental illness: 3-month follow-up.

    PubMed

    LePage, James P; Washington, Edward L; Lewis, Avery A; Johnson, Kim E; Garcia-Rea, Elizabeth A

    2011-01-01

    With the high number of incarcerated veterans with mental illness and substance dependence returning to the community annually, a significant need exists for technologies that will help them return to employment. This study evaluates three methods of assistance: (1) basic vocational services, (2) self-study of a vocational manual designed for formerly incarcerated veterans, and (3) a group led by vocational staff using the vocational manual. We evaluated 69 veterans to determine the number finding employment within 3 months after enrollment in the study. The group format was expected to be superior to self-study, and self-study was expected to be superior to basic services. Though the group format was found to be superior to both self-study and basic services, the results for self-study and basic services were statistically similar. Limitations and directions for future refinement are discussed. PMID:21480102

  2. [Two cases of meningitis caused by the same Haemophilus influenzae type B strain in a nursery at a 3-month interval].

    PubMed

    Abe, Katsuaki A; Ishiwada, Naruhiko; Hoshino, Tadashi; Kohno, Yoichi

    2007-01-01

    We present 2 cases of meningitis caused by the same Haemophilus influenzae type b (Hib) strain in a nursery at a 3-month interval. Causative agents isolated showed good susceptibility to beta-lactams and both patients recovered without any sequelae. Survey culture at each occurrence of meningitis showed 10 asymptomatic nasopharyngeal carriers. Oral rifampin was administrated to all staff and infants, but 2 carriers were found a month later from chemoprophylaxis. Pulsed-field gel electrophoresis analysis showed that the two strains isolated from meningitis patients and 12 from asymptomatic carriers were apparently identical. When systemic Hib infection occurs in a nursery, other infants may be at high risk for secondary disease. It is difficult, however, to eliminate Hib carriage by chemoprophylaxis, indicating that Hib vaccination to prevent systemic Hib infection is necessary in Japan. PMID:17338320

  3. Artificial long-day photoperiod in the subtropics increases milk production in goats giving birth in late autumn.

    PubMed

    Flores, M J; Flores, J A; Elizundia, J M; Mejía, A; Delgadillo, J A; Hernández, H

    2011-03-01

    Two experiments were conducted to determine whether exposure to a photoperiod of artificial long days in autumn increased milk yield in subtropical goats milked once (Exp. I) or twice daily (Exp. II). In Exp. I, starting at d 10 of lactation, 1 group of does was kept under naturally decreasing photoperiod (DD1X; n = 8), whereas the other group was submitted to an artificial photoperiod of long days (LD1X; n = 8; 16 h light:8 h darkness). The kids were weaned 28 d after parturition, and dams were manually milked once daily. Milk yield and milk components (fat, protein, and lactose) were assessed up to 140 d of lactation. From d 0 to 28 of lactation (suckling phase), mean daily milk yield did not differ between DD1X and LD1X goats (2.3 ± 0.2 kg vs. 2.4 ± 0.2 kg; P = 0.717). However, between d 29 and 84 (early milking phase), mean daily milk yield was greater in LD1X does than in DD1X does (2.6 ± 0.1 kg vs. 2.1 ± 0.1 kg; P = 0.001). Finally, between d 85 and 140 (late milking phase), mean daily milk yield was greater in LD1X goats than in DD1X goats (P ≤ 0.05) only during the first 2 wk. In Exp. II, one group of goats was exposed to a photoperiod of naturally decreasing days (DD2X; n = 8) and another group was submitted to an artificial photoperiod of long days (LD2X; n = 7). In both groups, kids were weaned on d 28 of lactation and the dams were manually milked twice daily. During the nursing phase, mean daily milk yield did not differ between the DD2X and LD2X groups (2.5 ± 0.3 kg vs. 2.6 ± 0.2 kg; P = 0.767). In the early milking phase, mean daily milk yield was greater in LD2X than in DD2X goats (3.3 ± 0.2 kg vs. 2.8 ± 0.2 kg; P = 0.022), whereas during the late milking phase, milk yield did not differ between the 2 groups (P = 0.946). In both experiments, milk composition was not significantly influenced by exposure to long-day photoperiod. We conclude that, in subtropical female goats that start lactation in late autumn, exposure to an artificial long

  4. Microbiological and biochemical effectiveness of an antiseptic gel on the bacterial contamination of the inner space of dental implants: a 3-month human longitudinal study.

    PubMed

    D'Ercole, S; Tetè, S; Catamo, G; Sammartino, G; Femminella, B; Tripodi, D; Spoto, G; Paolantonio, M

    2009-01-01

    Microbial penetration inside the implants internal cavity produces a bacterial reservoir that is associated with an area of inflamed connective tissue facing the fixture-abutment junction. The aim of this clinical trial is to evaluate the effectiveness of a 1 percent chlorhexidine gel on the internal bacterial contamination of implants with screw-retained abutments and on the level of AST secreted in peri-implant crevicular fluid. Twenty-five patients (aged 29 to 58 years) each received one implant. Three months after the end of the restorative treatment, and immediately after a clinical and radiographic examination and the abutment removal, microbiological samples were obtained from the internal part of each fixture and biochemical samples were collected by peri-implant sulci. The patients were then divided into two groups: the control (CG; n=10) and test (TG; n=15) groups. The CG had the abutment screwed into place and the crown cemented without any further intervention. In contrast, before the abutment placement and screw tightening, the TG had the internal part of the fixture filled with a 1 percent chlorhexidine gel. Three months later, the same clinical, microbiological and biochemical procedures were repeated in both groups. Total bacterial count, specific pathogens and AST activity were detected. The clinical parameters remained stable throughout the study. From baseline to the 3-month examination, the total bacterial counts underwent a significant reduction only in the TG. In contrast, the AST activity showed a significant increase in the CG. The administration of a 1% chlorhexidine gel appears to be an effective method for the reduction of bacterial colonization of the implant cavity and for safeguarding the health status of peri-implant tissue over a 3-month administration period. PMID:20074465

  5. Reduction in systemic and VLDL triacylglycerol concentration after a 3-month Mediterranean-style diet in high-cardiovascular-risk subjects.

    PubMed

    Perona, Javier S; Covas, María-Isabel; Fitó, Montserrat; Cabello-Moruno, Rosana; Aros, Fernando; Corella, Dolores; Ros, Emilio; Garcia, Maria; Estruch, Ramon; Martinez-Gonzalez, Miguel A; Ruiz-Gutierrez, Valentina

    2010-09-01

    The first results of the PREDIMED (PREvencion con Dieta MEDiterranea) randomized trial, after 3-month intervention, showed that the Mediterranean Diet (MD), supplemented with either virgin olive oil (VOO) or nuts, reduced systolic blood pressure, serum cholesterol and triacylglycerol (TG) concentrations and increased high-density lipoprotein (HDL)-cholesterol when compared to a control (low-fat diet) group. Serum TG levels are an independent risk factor for coronary heart disease and are strongly determined by very low-density lipoprotein (VLDL) composition, which can be specifically modified by dietary lipid source. Within the context of the PREDIMED study, we assessed the VLDL composition in 50 participants after 3 months of intake of two MD, supplemented with VOO or nuts, compared with a low-fat diet. Total and low-density lipoprotein cholesterol concentrations were reduced in subjects on the MD+nuts, whereas HDL-cholesterol increased after consumption of the MD+VOO. Serum TG concentrations were significantly lowered in both intervention groups (either the MD+nuts or MD+VOO). However, only the MD+VOO reduced the VLDL-cholesterol and VLDL-TG content and the TG/apolipoprotein B ratio in VLDL, which was used to estimate particle size. Although VLDL-TG fatty acids were very slightly modified, VLDL-TG molecular species in VLDL after consumption of the MD+nuts were characterized by a higher presence of linoleic acid (18:2, n-6), whereas after the intake of MD+VOO, they were rich in oleic acid (18:1, n-9). Therefore, we conclude that the reduction in systemic TG concentrations observed after consumption of the MD may be explained by reduction of the lipid core of VLDL and a selective modification of the molecular species composition in the particle. PMID:19962297

  6. Daily rhythm of cortisol, and evidence for a photo-inducible phase for prolactin secretion in nonpregnant mares housed under non-interrupted and skeleton photoperiods.

    PubMed

    Johnson, A L; Malinowski, K

    1986-07-01

    Studies were conducted in anestrous mares to characterize daily rhythms of cortisol in non-interrupted [ambient and 16 h light (L): 8 h dark (D)] and skeleton (10L:4D:2L:8D, 10L:6D:2L:6D and 10L:8D:2L:4D) photoperiods, and to determine if there exists a photosensitive phase for the secretion of prolactin. Neither peak or nadir concentrations of cortisol, nor the time of peak or nadir concentrations differed among photoperiod treatments. Highest concentrations (66 +/- 4.4 ng/ml, mean +/- SE) occurred between 0700 and 0900, whereas lowest concentrations (31 +/- 3.6 ng/ml) were found from 1900 to 2300. Mean daily concentrations of serum prolactin were significantly higher in mares housed under the 16L:8D and the 10L:8D:2L:4D photoperiods as compared with the remaining photoperiod treatments, and were lowest in the ambient photoperiod treatment. The mean daily concentration of prolactin in February among photoperiod treatments was inversely related to the number of days (from December 1) to first seasonal ovulation (r = -.92, P = .027). The results were interpreted to: 1) suggest that mares in the 10L:8D:2L:4D skeleton photoperiod do not phase-shift to interpret the 2-h light pulse as the beginning of their subjective day; and 2) provide further evidence that the photo-inducible phase for both prolactin secretion and the stimulation of seasonal reproductive activity occurs 8 to 10 h following the onset of the dark period (scotophase). PMID:3733571

  7. Effects of spectral composition, photoperiod and light intensity on the gonadal development of Atlantic salmon Salmo salar in recirculating aquaculture systems (RAS)

    NASA Astrophysics Data System (ADS)

    Qiu, Denggao; Xu, Shihong; Song, Changbin; Chi, Liang; Li, Xian; Sun, Guoxiang; Liu, Baoliang; Liu, Ying

    2015-01-01

    Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement. However, when these operations are applied in commercial recirculating aquaculture systems (RAS) using standard lighting technology, sexual maturation is not suppressed. In this study, an L9 (33) orthogonal design was used to determine the effects of three factors (spectral composition, photoperiod, and light intensity) on the gonadal development of Atlantic salmon in RAS. We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity. The photoperiod had a significant effect on the secretion of sex steroids and melatonin ( P<0.05), and a short photoperiod delayed sex steroid and melatonin level increases. The three test factors had no significant effects on the survival rate, specific growth rate, relative weight gain, and male Fulton condition factor ( P>0.05). The optimum lighting levels in female and male Atlantic salmon were LD 8:16, 455 nm (or 625 nm), 8.60 W/m2; and LD 8:16, 8.60 W/m2, 455 nm respectively. These conditions not only delayed gonadal development, but also had no negative effects on Atlantic salmon growth in RAS. These results demonstrate that a combination of spectral composition, photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.

  8. Hd3a, RFT1 and Ehd1 integrate photoperiodic and drought stress signals to delay the floral transition in rice.

    PubMed

    Galbiati, Francesca; Chiozzotto, Remo; Locatelli, Franca; Spada, Alberto; Genga, Annamaria; Fornara, Fabio

    2016-09-01

    Plants show a high degree of developmental plasticity in response to external cues, including day length and environmental stress. Water scarcity in particular can interfere with photoperiodic flowering, resulting in the acceleration of the switch to reproductive growth in several species, a process called drought escape. However, other strategies are possible and drought stress can also delay flowering, albeit the underlying mechanisms have never been addressed at the molecular level. We investigated these interactions in rice, a short day species in which drought stress delays flowering. A protocol that allows the synchronization of drought with the floral transition was set up to profile the transcriptome of leaves subjected to stress under distinct photoperiods. We identified clusters of genes that responded to drought differently depending on day length. Exposure to drought stress under floral-inductive photoperiods strongly reduced transcription of EARLY HEADING DATE 1 (Ehd1), HEADING DATE 3a (Hd3a) and RICE FLOWERING LOCUS T 1 (RFT1), primary integrators of day length signals, providing a molecular connection between stress and the photoperiodic pathway. However, phenotypic and transcriptional analyses suggested that OsGIGANTEA (OsGI) does not integrate drought and photoperiodic signals as in Arabidopsis, highlighting molecular differences between long and short day model species. PMID:27111837

  9. Genetic correlations and the evolution of photoperiodic time measurement within a local population of the pitcher-plant mosquito, Wyeomyia smithii

    PubMed Central

    Bradshaw, W E; Emerson, K J; Holzapfel, C M

    2012-01-01

    The genetic relationship between the daily circadian clock and the seasonal photoperiodic timer remains a subject of intense controversy. In Wyeomyia smithii, the critical photoperiod (an overt expression of the photoperiodic timer) evolves independently of the rhythmic response to the Nanda–Hamner protocol (an overt expression of the daily circadian clock) over a wide geographical range in North America. Herein, we focus on these two processes within a single local population in which there is a negative genetic correlation between them. We show that antagonistic selection against this genetic correlation rapidly breaks it down and, in fact, reverses its sign, showing that the genetic correlation is due primarily to linkage and not to pleiotropy. This rapid reversal of the genetic correlation within a small, single population means that it is difficult to argue that circadian rhythmicity forms the necessary, causal basis for the adaptive divergence of photoperiodic time measurement within populations or for the evolution of photoperiodic time measurement among populations over a broad geographical gradient of seasonal selection. PMID:22072069

  10. Genetic correlations and the evolution of photoperiodic time measurement within a local population of the pitcher-plant mosquito, Wyeomyia smithii.

    PubMed

    Bradshaw, W E; Emerson, K J; Holzapfel, C M

    2012-05-01

    The genetic relationship between the daily circadian clock and the seasonal photoperiodic timer remains a subject of intense controversy. In Wyeomyia smithii, the critical photoperiod (an overt expression of the photoperiodic timer) evolves independently of the rhythmic response to the Nanda-Hamner protocol (an overt expression of the daily circadian clock) over a wide geographical range in North America. Herein, we focus on these two processes within a single local population in which there is a negative genetic correlation between them. We show that antagonistic selection against this genetic correlation rapidly breaks it down and, in fact, reverses its sign, showing that the genetic correlation is due primarily to linkage and not to pleiotropy. This rapid reversal of the genetic correlation within a small, single population means that it is difficult to argue that circadian rhythmicity forms the necessary, causal basis for the adaptive divergence of photoperiodic time measurement within populations or for the evolution of photoperiodic time measurement among populations over a broad geographical gradient of seasonal selection. PMID:22072069

  11. Conserved CO-FT regulons contribute to the photoperiod flowering control in soybean

    PubMed Central

    2014-01-01

    Background CO and FT orthologs, belonging to the BBX and PEBP family, respectively, have important and conserved roles in the photoperiod regulation of flowering time in plants. Soybean genome experienced at least three rounds of whole genome duplications (WGDs), which resulted in multiple copies of about 75% of genes. Subsequent subfunctionalization is the main fate for paralogous gene pairs during the evolutionary process. Results The phylogenic relationships revealed that CO orthologs were widespread in the plant kingdom while FT orthologs were present only in angiosperms. Twenty-eight CO homologous genes and twenty-four FT homologous genes were gained in the soybean genome. Based on the collinear relationship, the soybean ancestral CO ortholog experienced three WGD events, but only two paralogous gene pairs (GmCOL1/2 and GmCOL5/13) survived in the modern soybean. The paralogous gene pairs, GmCOL1/2 or GmCOL5/13, showed similar expression patterns in pair but different between pairs, indicating that they functionally diverged. GmFTL1 to 7 were derived from the same ancestor prior to the whole genome triplication (WGT) event, and after the Legume WGD event the ancestor diverged into two branches, GmFTL3/5/7 and GmFTL1/2/4/6. GmFTL7 were truncated in the N-terminus compared to other FT-lineage genes, but ubiquitously expressed. Expressions of GmFTL1 to 6 were higher in leaves at the flowering stage than that at the seedling stage. GmFTL3 was expressed at the highest level in all tissues except roots at the seedling stage, and its circadian pattern was different from the other five ones. The transcript of GmFTL6 was highly accumulated in seedling roots. The circadian rhythms of GmCOL5/13 and GmFT1/2/4/5/6 were synchronized in a day, demonstrating the complicate relationship of CO-FT regulons in soybean leaves. Over-expression of GmCOL2 did not rescue the flowering phenotype of the Arabidopsis co mutant. However, ectopic expression of GmCOL5 did rescue the co mutant

  12. Optical coherence tomography analysis of the stent strut and prediction of resolved strut malapposition at 3 months after 2nd-generation drug-eluting stent implantation.

    PubMed

    Izumi, Daisuke; Miyahara, Masatoshi; Fujimoto, Naoki; Fukuoka, Shusuke; Sakai, Masataka; Dohi, Kaoru; Ito, Masaaki

    2016-08-01

    Our objective was to clarify whether thrombogenic problems with stent struts are resolved at 3 months after 2nd-generation drug-eluting stent implantation. Twenty-one patients with stable angina pectoris having 28 (22 zotarolimus-eluting, 6 everolimus-eluting) stents with optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) were evaluated. Stent strut coverage and malapposition were evaluated by OCT immediately after PCI and at 3-month follow-up. Acute strut malapposition was observed in 26 out of 28 analyzed stents (92.9 %). At 3-month follow-up, 7 (26.9 %) of those 26 stents with strut malapposition were completely resolved, and the mean percentages of uncovered struts and malapposed struts were 8.3 and 2.0 % when analyzed by each individual stent. When analyzing a total of 30,060 struts, 807 struts (2.7 %) demonstrated acute strut malapposition. Among these, 219 struts (27.1 %) demonstrated persistent strut malapposition. On the basis of receiver-operating characteristic curve analysis, a strut-to-vessel (S-V) distance ≤160 µm on post-stenting OCT images was the corresponding cutoff point for resolved malapposed struts (sensitivity 78.1 %, specificity 62.8 %, area under the curve 0.758). The S-V distance of persistent malapposed struts on post-stenting OCT images was longer than that of resolved malapposed struts (235 ± 112 vs. 176 ± 93 µm, p < 0.01). At 3 months after PCI, the prevalence rates of uncovered and malapposed struts were relatively low in 2nd-generation drug-eluting stent. Our results suggest that OCT-guide PCI with an S-V distance ≤160 µm may be recommended especially in patients with planed short-term DAPT. PMID:26334709

  13. Efficacy and Safety of Paliperidone Palmitate 3-Month Formulation for Patients with Schizophrenia: A Randomized, Multicenter, Double-Blind, Noninferiority Study

    PubMed Central

    Xu, Haiyan; Gopal, Srihari; Nuamah, Isaac; Ravenstijn, Paulien; Janik, Adam; Schotte, Alain; Hough, David; Fleischhacker, Wolfgang W.

    2016-01-01

    Background: This double-blind, parallel-group, multicenter, phase-3 study was designed to test the noninferiority of paliperidone palmitate 3-month formulation (PP3M) to the currently marketed 1-month formulation (PP1M) in patients (age 18–70 years) with schizophrenia, previously stabilized on PP1M. Methods: After screening (≤3 weeks) and a 17-week, flexible-dosed, open-label phase (PP1M: day 1 [150mg eq. deltoid], day 8 [100mg eq. deltoid.], weeks 5, 9, and 13 [50, 75, 100, or 150mg eq., deltoid/gluteal]), clinically stable patients were randomized (1:1) to PP3M (fixed-dose, 175, 263, 350, or 525mg eq. deltoid/gluteal) or PP1M (fixed-dose, 50, 75, 100, or 150mg eq. deltoid/gluteal) for a 48-week double-blind phase. Results: Overall, 1016/1429 open-label patients entered the double-blind phase (PP3M: n=504; PP1M: n=512) and 842 completed it (including patients with relapse). PP3M was noninferior to PP1M: relapse rates were similar in both groups (PP3M: n=37, 8%; PP1M: n=45, 9%; difference in relapse-free rate: 1.2% [95% CI:-2.7%; 5.1%]) based on Kaplan-Meier estimates (primary efficacy). Secondary endpoint results (changes from double-blind baseline in positive and negative symptom score total and subscale scores, Clinical Global Impression-Severity, and Personal and Social Performance scores) were consistent with primary endpoint results. No clinically relevant differences were observed in pharmacokinetic exposures between PP3M and PP1M. Both groups had similar tolerability profiles; increased weight was the most common treatment-emergent adverse event (double-blind phase; 21% each). No new safety signals were detected. Conclusion: Taken together, PP3M with its 3-month dosing interval is a unique option for relapse prevention in schizophrenia. PMID:26902950

  14. Spontaneous "regression" of enhanced immune function in a photoperiodic rodent Peromyscus maniculatus.

    PubMed Central

    Prendergast, B. J.; Nelson, R. J.

    2001-01-01

    Short days inhibit reproduction and enhance immune function in deer mice (Peromyscus maniculatus). Their reproductive inhibition is sustained by an endogenous timing mechanism: after ca. 20 weeks in short days, reproductive photorefractoriness develops, followed by spontaneous recrudescence of the reproductive system. It is unknown whether analogous seasonal timing mechanisms regulate their immune function or whether enhanced immune function is sustained indefinitely under short days. In order to test this hypothesis, we housed adult male deer mice under long (16 h light day(-1)) or short (8 h light day(-1)) day conditions for 32 weeks or under long day conditions for 20 weeks followed by 12 weeks of short days. Mice under the long day conditions remained photostimulated over the 32 weeks, whereas mice housed under the short day conditions exhibited gonadal regression followed by photorefractoriness and spontaneous recrudescence. Mice transferred to short days at week 20 were reproductively photoregressed at week 32. Total splenocytes, relative splenic mass and mitogen-activated splenocyte proliferation were greater in those mice transferred to short days at week 20 than in those mice housed under either long or short day conditions for 32 consecutive weeks, and immune function in mice exposed to short days for 32 weeks was comparable with that of long day animals. These data suggest that short day enhancement of immune function is not indefinite. With prolonged (< or = 32 weeks) exposure to short days, several measures of immune function exhibit "spontaneous" regression, restoring long day-like immunocompetence. The results suggest that formal similarities and, possibly, common substrates exist among the photoperiodic timekeeping mechanisms that regulate seasonal transitions in reproductive and immune function. PMID:11674869

  15. The Evolution of Photoperiod-Insensitive Flowering in Sorghum, A Genomic Model for Panicoid Grasses.

    PubMed

    Cuevas, Hugo E; Zhou, Chengbo; Tang, Haibao; Khadke, Prashant P; Das, Sayan; Lin, Yann-Rong; Ge, Zhengxiang; Clemente, Thomas; Upadhyaya, Hari D; Hash, C Thomas; Paterson, Andrew H

    2016-09-01

    Of central importance in adapting plants of tropical origin to temperate cultivation has been selection of daylength-neutral genotypes that flower early in the temperate summer and take full advantage of its long days. A cross between tropical and temperate sorghums [Sorghum propinquum (Kunth) Hitchc.×S. bicolor (L.) Moench], revealed a quantitative trait locus (QTL), FlrAvgD1, accounting for 85.7% of variation in flowering time under long days. Fine-scale genetic mapping placed FlrAvgD1 on chromosome 6 within the physically largest centiMorgan in the genome. Forward genetic data from "converted" sorghums validated the QTL. Association genetic evidence from a diversity panel delineated the QTL to a 10-kb interval containing only one annotated gene, Sb06g012260, that was shown by reverse genetics to complement a recessive allele. Sb06g012260 (SbFT12) contains a phosphatidylethanolamine-binding (PEBP) protein domain characteristic of members of the "FT" family of flowering genes acting as a floral suppressor. Sb06g012260 appears to have evolved ∼40 Ma in a panicoid ancestor after divergence from oryzoid and pooid lineages. A species-specific Sb06g012260 mutation may have contributed to spread to temperate regions by S. halepense ("Johnsongrass"), one of the world's most widespread invasives. Alternative alleles for another family member, Sb02g029725 (SbFT6), mapping near another flowering QTL, also showed highly significant association with photoperiod response index (P = 1.53×10 (-)  (6)). The evolution of Sb06g012260 adds to evidence that single gene duplicates play large roles in important environmental adaptations. Increased knowledge of Sb06g012260 opens new doors to improvement of sorghum and other grain and cellulosic biomass crops. PMID:27335143

  16. Chrysanthemum stunt viroid disturbs the photoperiodic response for flowering of chrysanthemum plants.

    PubMed

    Hosokawa, Munetaka; Ueda, Emi; Ohishi, Kazushi; Otake, Ayaka; Yazawa, Susumu

    2004-11-01

    Chrysanthemum ( Dendranthema grandiflorum Kitam.) is one of the qualitative short-day flowering plants. Therefore, the flowering of chrysanthemum can usually be controlled by photoperiod. However, it was noted that 'Piato' plants infected by the chrysanthemum stunt viroid (CSVd) flowered autonomously even under long-day conditions. In this study, CSVd-free and CSVd-infected plants were prepared by culturing different-sized dissected shoot apical meristems (SAMs) of 'Piato'. Using these CSVd-free and CSVd-infected plants, we clarified the relationship between CSVd infection and the autonomous flowering of 'Piato'. Under natural short-day conditions, the flowering of plants regenerated from SAMs containing leaf primordia (LPs) was 1 month earlier than plants regenerated from LP-free SAMs. CSVd was detected from these early flowering plants by reverse transcription-polymerase chain reaction. On the other hand, CSVd was not detected in plants regenerated from LP-free SAMs. CSVd-infected and CSVd-free plants were grown under long-day conditions simulated by night-break lighting at 22:00 p.m. to 2:00 a.m. All CSVd-infected plants flowered autonomously even under long-day conditions; on the other hand, CSVd-free chrysanthemum plants maintained their vegetative growth. When the CSVd-free plants were inoculated with CSVd by grafting them to CSVd-infected rootstocks, they flowered autonomously even under night-break lighting. In this study, the results suggest that CSVd may control the qualitative development process, flowering, i.e. CSVd can induce the autonomous flowering of chrysanthemum. PMID:15549375

  17. Cyclic Colour Change in the Bearded Dragon Pogona vitticeps under Different Photoperiods

    PubMed Central

    Fan, Marie; Stuart-Fox, Devi; Cadena, Viviana

    2014-01-01

    The ability to change colour rapidly is widespread among ectotherms and has various functions including camouflage, communication and thermoregulation. The process of colour change can occur as an aperiodic event or be rhythmic, induced by cyclic environmental factors or regulated by internal oscillators. Despite the importance of colour change in reptile ecology, few studies have investigated the occurrence of a circadian rhythm in lizard pigmentation. Additionally, although colour change also entails changes in near-infrared reflectance, which may affect thermoregulation, little research has examined this part of the spectrum. We tested whether the bearded dragon lizard, Pogona vitticeps, displays an endogenous circadian rhythm in pigmentation changes that could be entrained by light/dark (LD) cycles and how light affected the relative change in reflectance in both ultraviolet-visible and near-infrared spectra. We subjected 11 lizards to four photoperiodic regimens: LD 12∶12; LD 6∶18; LD 18∶6 and DD; and measured their dorsal skin reflectance at 3-hour intervals for 72 hours after a habituation period. A proportion of lizards displayed a significant rhythm under constant darkness, with maximum reflectance occurring in the subjective night. This endogenous rhythm synchronised to the different artificial LD cycles, with maximum reflectance occurring during dark phases, but did not vary in amplitude. In addition, the total ultraviolet-visible reflectance in relation to the total near-infrared reflectance was significantly higher during dark phases than during light phases. We conclude that P. vitticeps exhibits a circadian pigmentation rhythm of constant amplitude, regulated by internal oscillators and that can be entrained by light/dark cycles. PMID:25354192

  18. Cyclic colour change in the bearded dragon Pogona vitticeps under different photoperiods.

    PubMed

    Fan, Marie; Stuart-Fox, Devi; Cadena, Viviana

    2014-01-01

    The ability to change colour rapidly is widespread among ectotherms and has various functions including camouflage, communication and thermoregulation. The process of colour change can occur as an aperiodic event or be rhythmic, induced by cyclic environmental factors or regulated by internal oscillators. Despite the importance of colour change in reptile ecology, few studies have investigated the occurrence of a circadian rhythm in lizard pigmentation. Additionally, although colour change also entails changes in near-infrared reflectance, which may affect thermoregulation, little research has examined this part of the spectrum. We tested whether the bearded dragon lizard, Pogona vitticeps, displays an endogenous circadian rhythm in pigmentation changes that could be entrained by light/dark (LD) cycles and how light affected the relative change in reflectance in both ultraviolet-visible and near-infrared spectra. We subjected 11 lizards to four photoperiodic regimens: LD 12:12; LD 6:18; LD 18:6 and DD; and measured their dorsal skin reflectance at 3-hour intervals for 72 hours after a habituation period. A proportion of lizards displayed a significant rhythm under constant darkness, with maximum reflectance occurring in the subjective night. This endogenous rhythm synchronised to the different artificial LD cycles, with maximum reflectance occurring during dark phases, but did not vary in amplitude. In addition, the total ultraviolet-visible reflectance in relation to the total near-infrared reflectance was significantly higher during dark phases than during light phases. We conclude that P. vitticeps exhibits a circadian pigmentation rhythm of constant amplitude, regulated by internal oscillators and that can be entrained by light/dark cycles. PMID:25354192

  19. Ehd4 Encodes a Novel and Oryza-Genus-Specific Regulator of Photoperiodic Flowering in Rice

    PubMed Central

    Gao, He; Zheng, Xiao-Ming; Fei, Guilin; Chen, Jun; Jin, Mingna; Ren, Yulong; Wu, Weixun; Zhou, Kunneng; Sheng, Peike; Zhou, Feng; Jiang, Ling; Wang, Jie; Zhang, Xin; Guo, Xiuping; Wang, Jiu-Lin; Cheng, Zhijun; Wu, Chuanyin; Wang, Haiyang; Wan, Jian-Min

    2013-01-01

    Land plants have evolved increasingly complex regulatory modes of their flowering time (or heading date in crops). Rice (Oryza sativa L.) is a short-day plant that flowers more rapidly in short-day but delays under long-day conditions. Previous studies have shown that the CO-FT module initially identified in long-day plants (Arabidopsis) is evolutionary conserved in short-day plants (Hd1-Hd3a in rice). However, in rice, there is a unique Ehd1-dependent flowering pathway that is Hd1-independent. Here, we report isolation and characterization of a positive regulator of Ehd1, Early heading date 4 (Ehd4). ehd4 mutants showed a never flowering phenotype under natural long-day conditions. Map-based cloning revealed that Ehd4 encodes a novel CCCH-type zinc finger protein, which is localized to the nucleus and is able to bind to nucleic acids in vitro and transactivate transcription in yeast, suggesting that it likely functions as a transcriptional regulator. Ehd4 expression is most active in young leaves with a diurnal expression pattern similar to that of Ehd1 under both short-day and long-day conditions. We show that Ehd4 up-regulates the expression of the “florigen” genes Hd3a and RFT1 through Ehd1, but it acts independently of other known Ehd1 regulators. Strikingly, Ehd4 is highly conserved in the Oryza genus including wild and cultivated rice, but has no homologs in other species, suggesting that Ehd4 is originated along with the diversification of the Oryza genus from the grass family during evolution. We conclude that Ehd4 is a novel Oryza-genus-specific regulator of Ehd1, and it plays an essential role in photoperiodic control of flowering time in rice. PMID:23437005

  20. Regulatory mechanisms for the development of the migratory phenotype: roles for photoperiod and the gonad.

    PubMed

    Ramenofsky, Marilyn; Németh, Zoltán

    2014-06-01

    This article is part of a Special Issue "Energy Balance". Male white-crowned sparrows, Zonotrichia leucophrys gambelii, were studied to investigate roles of natural day length and the testes in regulating development and expression of the vernal migration phenotype. Previous work suggested that a pulse of androgen during winter months followed by the vernal increase in photoperiod promotes fueling (fat deposition) to support long distance flight; however, other traits required for successful migration remain untested. To investigate these points, birds were captured on their wintering grounds and castrated prior to winter solstice following Mattocks (1976). A subset of the castrates received 8mm Silastic implants of testosterone (T-castrates) and others blank implants (Blank-castrates) for 16 days in February. Shams were surgical controls. Migratory traits measured were as follows: 24h locomotor activity, prenuptial molt, body mass, fat score, flight muscle profile, cloacal protuberance (CPL) and plasma androgens measured over 28 weeks divided into 3 experimental periods (pre-implant, implant, and post-implant). Under short day lengths, castration increased diurnal locomotor activity over Shams. Testosterone implants temporarily enhanced CPL, plasma androgens and flight muscle enlargement, but failed to induce migratory restlessness. Whereas all groups exhibited seasonal increases in mass, fat score and muscle profile, only Shams showed timely onset and completion of prenuptial molt and migratory restlessness. Thus, for castrated males exposed to naturally increasing day lengths, the organizational effects of a transient testosterone surge were not sufficient to actuate a timely spring molt and migratory behavior. A fully functional testis that can organize central processes is required for the entire expression of the spring migratory phenotype. PMID:24780144

  1. Diurnal variation in hepatic expression of the rat S14 gene is synchronized by the photoperiod

    SciTech Connect

    Kinlaw, W.B.; Fish, L.H.; Schwartz, H.L.; Oppenheimer, J.H.

    1987-04-01

    We have analyzed the factors responsible for the circadian variation in rat hepatic mRNA-S14. Regulation of this sequence, which is found in lipogenic tissues and encodes a protein (S14) believed to be associated with fatty acid synthesis, is an excellent model of the interaction of thyroid hormone and dietary factors at the hepatocellular level. The mRNA exhibits a 3-fold diurnal variation (peak, approximately 2000 h; nadir, 0800 h) in ad libitum feeding rats on a 12-h light, 12-h dark photoschedule. We studied the effects of the photoschedule, periodic food intake, hypophysectomy, and induction by thyroid hormone (T3) on the mRNA-S14 rhythm. Adaptation to feeding restricted to either light or dark periods for 15 days did not greatly affect the diurnal rhythm. Photoreversal resulted in a 180 degrees phase shift, whereas the rhythm persisted in the presence of constant light. Oscillation continued around a higher baseline after a receptor-saturating dose of T3 in both normal and hypophysectomized rats. Our results indicate primary entrainment of the mRNA-S14 diurnal rhythm to the photoperiod, rather than to periodic food intake. Moreover, the circadian regulatory signal, which probably originates in the central nervous system, appears capable of antagonizing a maximal T3-inductive stimulus and does not originate in the pituitary gland. Persistence of the oscillation in constant light rules out circulating melatonin as the mediator. Synchronization of the rhythm by the photoschedule suggests that neuroendocrine factors are important determinants of rhythmic changes in hepatic gene expression.

  2. The Evolution of Photoperiod-Insensitive Flowering in Sorghum, A Genomic Model for Panicoid Grasses

    PubMed Central

    Cuevas, Hugo E.; Zhou, Chengbo; Tang, Haibao; Khadke, Prashant P.; Das, Sayan; Lin, Yann-Rong; Ge, Zhengxiang; Clemente, Thomas; Upadhyaya, Hari D.; Hash, C. Thomas; Paterson, Andrew H.

    2016-01-01

    Of central importance in adapting plants of tropical origin to temperate cultivation has been selection of daylength-neutral genotypes that flower early in the temperate summer and take full advantage of its long days. A cross between tropical and temperate sorghums [Sorghum propinquum (Kunth) Hitchc.×S. bicolor (L.) Moench], revealed a quantitative trait locus (QTL), FlrAvgD1, accounting for 85.7% of variation in flowering time under long days. Fine-scale genetic mapping placed FlrAvgD1 on chromosome 6 within the physically largest centiMorgan in the genome. Forward genetic data from “converted” sorghums validated the QTL. Association genetic evidence from a diversity panel delineated the QTL to a 10-kb interval containing only one annotated gene, Sb06g012260, that was shown by reverse genetics to complement a recessive allele. Sb06g012260 (SbFT12) contains a phosphatidylethanolamine-binding (PEBP) protein domain characteristic of members of the “FT” family of flowering genes acting as a floral suppressor. Sb06g012260 appears to have evolved ∼40 Ma in a panicoid ancestor after divergence from oryzoid and pooid lineages. A species-specific Sb06g012260 mutation may have contributed to spread to temperate regions by S. halepense (“Johnsongrass”), one of the world’s most widespread invasives. Alternative alleles for another family member, Sb02g029725 (SbFT6), mapping near another flowering QTL, also showed highly significant association with photoperiod response index (P = 1.53×10 − 6). The evolution of Sb06g012260 adds to evidence that single gene duplicates play large roles in important environmental adaptations. Increased knowledge of Sb06g012260 opens new doors to improvement of sorghum and other grain and cellulosic biomass crops. PMID:27335143

  3. An intact dorsomedial posterior arcuate nucleus is not necessary for photoperiodic responses in Siberian hamsters.

    PubMed

    Teubner, Brett J W; Leitner, Claudia; Thomas, Michael A; Ryu, Vitaly; Bartness, Timothy J

    2015-04-01

    Seasonal responses of many animal species are triggered by changes in daylength and its transduction into a neuroendocrine signal by the pineal gland through the nocturnal duration of melatonin (MEL) release. The precise central sites necessary to receive, transduce, and relay the short day (SD) fall-winter MEL signals into seasonal responses and changes in physiology and behavior are unclear. In Siberian hamsters, SDs trigger decreases in body and lipid mass, testicular regression and pelage color changes. Several candidate genes and their central sites of expression have been proposed as components of the MEL transduction system with considerable recent focus on the arcuate nucleus (ARC) and its component, the dorsomedial posterior arcuate nucleus (dmpARC). This site has been postulated as a critical relay of SD information through the modulation of a variety of neurochemicals/receptors important for the control of energy balance. Here the necessity of an intact dmpARC for SD responses was tested by making electrolytic lesions of the Siberian hamster dmpARC and then exposing them to either long days (LD) or SDs for 12wks. The SD typical decreases in body and fat mass, food intake, testicular volume, serum testosterone concentrations, pelage color change and increased UCP-1 protein expression (a proxy for brown adipose tissue thermogenesis) all occurred despite the lack of an intact dmpARC. Although the Siberian hamster dmpARC contains photoperiod-modulated constituents, these data demonstrate that an intact dmpARC is not necessary for SD responses and not integral to the seasonal energy- and reproductive-related responses measured here. PMID:25647158

  4. Thermal acclimation, growth, and burst swimming of threespine stickleback: enzymatic correlates and influence of photoperiod.

    PubMed

    Guderley, H; Leroy, P H; Gagné, A

    2001-01-01

    Threespine sticklebacks (Gasterosteus aculeatus) that had been reared in the laboratory under natural photoperiods were acclimated to 23 degrees and 8 degrees C in late spring under increasing day lengths and again in late fall under decreasing day lengths. The parents of these fish were from the anadromous Isle Verte population. In the spring, cold- and warm-acclimated fish grew at the same rates and attained similar condition factors (mass L(-3)), although food intake was considerably higher at 23 degrees C. As both groups had similar increases in mass and condition, the higher axial muscle activities of citrate synthase and phosphofructokinase (measured at 20 degrees C) after cold acclimation were likely a direct response to temperature. Multiple regression analysis showed that axial muscle levels of cytochrome C oxidase and citrate synthase were correlated with the burst swimming speeds of the spring sticklebacks, while growth rates were positively correlated with lactate dehydrogenase levels in pectoral and axial muscles and creatine kinase levels in the axial muscle. In the fall, the fish in both acclimation groups grew little, although they fed at similar rates as in the spring experiment. Overall, the sticklebacks showed lower burst swimming speeds in the fall. In both spring and fall, the burst speeds of cold- and warm-acclimated sticklebacks only differed at warm temperatures. In the spring experiment, the cold-acclimated fish swam faster, whereas in the fall experiment the warm-acclimated fish swam faster despite their lower percentage of axial muscle. Swimming speeds were measured both at a fish's acclimation temperature and after 12 h at the other temperature. Cold-acclimated sticklebacks seem to have more facility in rapidly adjusting to warm temperatures when they have experienced increasing rather than decreasing day lengths, perhaps as a result of the requirements of the spring migration to the intertidal breeding grounds. PMID:11226015

  5. Functional and evolutionary characterization of the CONSTANS gene family in short-day photoperiodic flowering in soybean.

    PubMed

    Wu, Faqiang; Price, Brian William; Haider, Waseem; Seufferheld, Gabriela; Nelson, Randall; Hanzawa, Yoshie

    2014-01-01

    CONSTANS (CO) plays a central role in photoperiodic flowering control of plants. However, much remains unknown about the function of the CO gene family in soybean and the molecular mechanisms underlying short-day photoperiodic flowering of soybean. We identified 26 CO homologs (GmCOLs) in the soybean genome, many of them previously unreported. Phylogenic analysis classified GmCOLs into three clades conserved among flowering plants. Two homeologous pairs in Clade I, GmCOL1a/GmCOL1b and GmCOL2a/GmCOL2b, showed the highest sequence similarity to Arabidopsis CO. The mRNA abundance of GmCOL1a and GmCOL1b exhibited a strong diurnal rhythm under flowering-inductive short days and peaked at dawn, which coincided with the rise of GmFT5a expression. In contrast, the mRNA abundance of GmCOL2a and GmCOL2b was extremely low. Our transgenic study demonstrated that GmCOL1a, GmCOL1b, GmCOL2a and GmCOL2b fully complemented the late flowering effect of the co-1 mutant in Arabidopsis. Together, these results indicate that GmCOL1a and GmCOL1b are potential inducers of flowering in soybean. Our data also indicate rapid regulatory divergence between GmCOL1a/GmCOL1b and GmCOL2a/GmCOL2b but conservation of their protein function. Dynamic evolution of GmCOL regulatory mechanisms may underlie the evolution of photoperiodic signaling in soybean. PMID:24465684

  6. Photoperiod- and Triiodothyronine-dependent Regulation of Reproductive Neuropeptides, Proinflammatory Cytokines, and Peripheral Physiology in Siberian Hamsters (Phodopus sungorus).

    PubMed

    Banks, Ruth; Delibegovic, Mirela; Stevenson, Tyler J

    2016-06-01

    Seasonal trade-offs in reproduction and immunity are ubiquitous in nature. The mechanisms that govern transitions across seasonal physiological states appear to involve reciprocal switches in the local synthesis of thyroid hormone. In long-day (LD) summer-like conditions, increased hypothalamic triiodothyronine (T3) stimulates gonadal development. Alternatively, short-day (SD) winter-like conditions increase peripheral leukocytes and enhance multiple aspects of immune function. These data indicate that the localized effects of T3 in the hypothalamus and leukocytes are photoperiod dependent. We tested the hypothesis that increased peripheral T3 in SD conditions would increase aspects of reproductive physiology and inhibit immune function, whereas T3 injections in LD conditions would facilitate aspects of immune function (i.e., leukocytes). In addition, we also examined whether T3 regulates hypothalamic neuropeptide expression as well as hypothalamic and splenic proinflammatory cytokine expression. Adult male Siberian hamsters were maintained in LD (15L:9D) or transferred to SD (9L:15D) for 8 weeks. A subset of LD and SD hamsters was treated daily with 5 µg T3 for 2 weeks. LD and SD controls were injected with saline. Daily T3 administration in SD hamsters (SD+T3) resulted in a rapid and substantial decrease in peripheral leukocyte concentrations and stimulated gonadal development. T3 treatment in LD (LD+T3) had no effect on testicular volumes but significantly increased leukocyte concentrations. Molecular analyses revealed that T3 stimulated interleukin 1β messenger RNA (mRNA) expression in the spleen and inhibited RFamide Related Peptide-3 mRNA expression in the hypothalamus. Moreover, there was a photoperiod-dependent decrease in splenic tumor necrosis factor-α mRNA expression. These findings reveal that T3 has tissue-specific and photoperiod-dependent regulation of seasonal rhythms in reproduction and immune function. PMID:26984896

  7. Pituitary gonadotropin and testicular gonadotropin receptor expression in Atlantic cod (Gadusmorhua L.) during the first reproductive season: Effects of photoperiod modulation.

    PubMed

    de Almeida, Fernanda Ferreira Loureiro; Andersson, Eva; Mittelholzer, Christian; Karlsen, Orjan; Taranger, Geir Lasse; Schulz, Rüdiger W

    2011-08-01

    Pituitary mRNA levels of gonadotropin β-subunits and of their cognate receptors in the testis were studied during puberty in Atlantic cod under normal and experimental photoperiod conditions that suppressed, delayed or accelerated testis maturation. Results are discussed in context with changes in testicular histology and plasma androgen levels, considered as end points of gonadotropic regulation. Up-regulation of fshb was closely associated with the onset of puberty, decreased when spermatogenesis was completed and reached minimum levels after spawning. These results demonstrate, for the first time using an experimental approach, that activation of Fsh-dependent signaling is associated with spermatogonial proliferation and formation of spermatogenic cysts. Changes in fshr expression were less prominent and could be explained by changes in the cellular composition and RNA content of cod testis tissue. At more advanced stages of development (spermiogenesis, spermiation and spawning), lhb and, one month later, lhcgr transcript levels increased and reached peak values in spawning fish, in a positive feedback loop involving plasma androgens and Lh/Lhcgr-dependent signaling. This loop was broken by a loss of lhb expression at the end of the spawning season. Continuous light (LL) from summer solstice, ~8 months prior to spawning, suppressed the start of testis maturation and the changes in gonadotropin and receptor mRNA levels, while LL from winter solstice initially up-regulated lhb and lhcgr expression, before resulting in a precocious termination of the spawning season and low expression of all four genes. Our studies provide experimental evidence for a clear functional discrimination of cod gonadotropins. PMID:21605561

  8. Different effects of an extended photoperiod treatment on growth, gonadal function, and condition of hair coats in Thoroughbred yearlings reared under different climate conditions

    PubMed Central

    SUZUKI, Tsuyoshi; MIZUKAMI, Hirotoshi; NAMBO, Yasuo; ISHIMARU, Mutsuki; MIYATA, Kenji; AKIYAMA, Kentaro; KOROSUE, Kenji; NAITO, Hiroshi; NAGAOKA, Kentaro; WATANABE, Gen; TAYA, Kazuyoshi

    2016-01-01

    ABSTRACT One- to two-year-old Thoroughbred colts and fillies being reared in Miyazaki (warm climate) and Hidaka (cold climate), Japan, were administered extended photoperiod (EP) treatment between December 20 and the following April 10, and its effect on growth, endocrine changes, gonadal activation, and hair coat condition was investigated. In colts reared in Miyazaki, no effect of EP treatment was noted on the growth indices, including body weight (BW), height at withers (HW), girth, and cannon circumference (CC), whereas the BWs and CCs of fillies were significantly higher in the EP treatment group than the control. In Hidaka, the BWs and HWs of colts and HWs of fillies were significantly higher in the EP treatment group. Gonadal activation characterized by an increase in circulating hormone concentrations was earlier in the EP treatment group for fillies reared in Miyazaki [luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone (P4), and estradiol-17β (E2)] and in colts (LH, testosterone, and E2) and fillies (LH, FSH, P4, and E2) reared in Hidaka. Regardless of sex and climate, prolactin was significantly higher in the EP treatment group, whereas insulin-like growth factor (IGF-I) was not. Initial ovulation occurred before April in more of the EP treatment group than the control regardless of the climate. Molting of the hair coat, examined in March, was advanced in the EP treatment group regardless of sex and climate. These results suggest that EP treatment may promote growth and gonadal activation in fillies reared in Miyazaki and in colts and fillies reared in Hidaka and that the effect may be mediated by prolactin. PMID:26858576

  9. Different effects of an extended photoperiod treatment on growth, gonadal function, and condition of hair coats in Thoroughbred yearlings reared under different climate conditions.

    PubMed

    Suzuki, Tsuyoshi; Mizukami, Hirotoshi; Nambo, Yasuo; Ishimaru, Mutsuki; Miyata, Kenji; Akiyama, Kentaro; Korosue, Kenji; Naito, Hiroshi; Nagaoka, Kentaro; Watanabe, Gen; Taya, Kazuyoshi

    2015-01-01

    One- to two-year-old Thoroughbred colts and fillies being reared in Miyazaki (warm climate) and Hidaka (cold climate), Japan, were administered extended photoperiod (EP) treatment between December 20 and the following April 10, and its effect on growth, endocrine changes, gonadal activation, and hair coat condition was investigated. In colts reared in Miyazaki, no effect of EP treatment was noted on the growth indices, including body weight (BW), height at withers (HW), girth, and cannon circumference (CC), whereas the BWs and CCs of fillies were significantly higher in the EP treatment group than the control. In Hidaka, the BWs and HWs of colts and HWs of fillies were significantly higher in the EP treatment group. Gonadal activation characterized by an increase in circulating hormone concentrations was earlier in the EP treatment group for fillies reared in Miyazaki [luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone (P4), and estradiol-17β (E2)] and in colts (LH, testosterone, and E2) and fillies (LH, FSH, P4, and E2) reared in Hidaka. Regardless of sex and climate, prolactin was significantly higher in the EP treatment group, whereas insulin-like growth factor (IGF-I) was not. Initial ovulation occurred before April in more of the EP treatment group than the control regardless of the climate. Molting of the hair coat, examined in March, was advanced in the EP treatment group regardless of sex and climate. These results suggest that EP treatment may promote growth and gonadal activation in fillies reared in Miyazaki and in colts and fillies reared in Hidaka and that the effect may be mediated by prolactin. PMID:26858576

  10. Effect of a low glycaemic index diet in gestational diabetes mellitus on post-natal outcomes after 3 months of birth: a pilot follow-up study.

    PubMed

    Louie, Jimmy Chun Yu; Markovic, Tania P; Ross, Glynis P; Foote, Deborah; Brand-Miller, Jennie C

    2015-07-01

    A low glycaemic index (LGI) diet during pregnancy complicated by gestational diabetes mellitus (GDM) may offer benefits to the mother and infant pair beyond those during pregnancy. We aimed to investigate the effect of an LGI diet during pregnancy complicated with GDM on early post-natal outcomes. Fifty-eight women (age: 23-41 years; mean ± SD pre-pregnancy body mass index: 24.5 ± 5.6 kg m(-2) ) who had GDM and followed either an LGI diet (n = 33) or a conventional high-fibre diet (HF; n = 25) during pregnancy had a 75-g oral glucose tolerance test and blood lipid tests at 3 months post-partum. Anthropometric assessments were conducted for 55 mother-infant pairs. The glycaemic index of the antenatal diets differed modestly (mean ± SD: 46.8 ± 5.4 vs. 52.4 ± 4.4; P < 0.001), but there were no significant differences in any of the post-natal outcomes. In conclusion, an LGI diet during pregnancy complicated by GDM has outcomes similar to those of a conventional healthy diet. Adequately powered studies should explore the potential beneficial effects of LGI diet on risk factors for chronic disease. PMID:23638904

  11. Safety of purified decolorized (low anthraquinone) whole leaf Aloe vera (L) Burm. f. juice in a 3-month drinking water toxicity study in F344 rats.

    PubMed

    Shao, A; Broadmeadow, A; Goddard, G; Bejar, E; Frankos, V

    2013-07-01

    Decolorized (purified, low anthraquinone) whole leaf Aloe vera (L.) Burm. f. juice was administered at concentrations of 0%, 0.5%, 1% and 2% in the drinking water of F344Du rats for 3 months without any adverse effect. The no-observed-adverse-effect level (NOAEL) in this study was considered to be >2%w/v (>1845 mg/kg bodyweight/day for males and >2920 mg/kg bodyweight for females). The test material contained total anthraquinones at <0.1 parts per million. In the present study there was a complete absence of any histological alteration in samples from the cecum, colon (proximal, mid and distal regions). Similar concentrations of non-decolorized (unpurified, high anthraquinone) Aloe vera extracts tested in other studies have resulted in an increased incidence and severity of diarrhea and colon adenomas and carcinomas. The results of this study supports the assertion that the high levels of anthraquinone present in orally administered, non-purified whole leaf Aloe vera extract may be responsible for the adverse effects observed on the colon. PMID:23500775

  12. Exposure to milk or water at preschool lunch for 3 months influences children's choice of elementary school lunch drink 4 months later.

    PubMed

    Koivisto, U K; Edlund, B; Sjödén, P O

    1994-12-01

    The purpose was to study if serving milk or water with the lunch at preschool influenced 6- to 7-year-old children's preferences for and later choice between milk and water at lunch in elementary school later. Children (n = 147) at 12 daycare centres were usually served water at lunch but, for 3 months, six randomly chosen centres served milk at lunch (Intervention group) and six matched centres continued serving water (Control group). The groups did not differ with respect to preferences for seven types of beverages (including water and four varieties of milk) either before or after the intervention. Four and 12 months later, their choice of lunch drink (milk or water) at school was studied for two 5-week periods. At the 4-month assessment, the children in the Intervention group chose milk at lunch significantly more often than did those in the Control group (92% vs. 81% of the days), while there were no significant differences at 12 months (85% vs. 81%). Since there were no demonstrable effects on preferences, one interpretation of the results is that children tend to associate the type of drink regularly served at a meal with that specific meal. PMID:7726544

  13. Infants with complex congenital heart diseases show poor short-term memory in the mobile paradigm at 3 months of age.

    PubMed

    Chen, Chao-Ying; Harrison, Tondi; Heathcock, Jill

    2015-08-01

    The purpose of this study was to examine learning, short-term memory and general development including cognitive, motor, and language domains in infants with Complex Congenital Heart Defects (CCDH). Ten infants with CCHD (4 males, 6 females) and 14 infants with typical development (TD) were examined at 3 months of age. The mobile paradigm, where an infant's leg is tethered to an overhead mobile, was used to evaluate learning and short-term memory. The Bayley Scales of Infant Development 3rd edition (Bayley-III) was used to evaluate general development in cognitive, motor, and language domains. Infants with CCHD and infants with TD both showed learning with significant increase in kicking rate (p<0.001) across periods of the mobile paradigm, but only infants with TD demonstrated short-term memory (p=0.017) in the mobile paradigm. There were no differences on cognitive, motor, and language development between infants with CCHD and infants with TD on the Bayley-III. Early assessment is necessary to guide targeted treatment in infants with CCHD. One-time assessment may fail to detect potential cognitive impairments during early infancy in infants with CCHD. Supportive intervention programs for infants with CCHD that focuses on enhancing short-term memory are recommended. PMID:25919428

  14. Influence of long-bright and increasing-dim photoperiods on live and processing performance of two broiler strains.

    PubMed

    Lien, R J; Hooie, L B; Hess, J B

    2009-05-01

    The influence of long-bright and increasing-dim photoperiods on live and processing performance was investigated in 2 broiler strains. Fifty males of moderate (M) and high (H) yield strains were placed by strain in 2 pens in each of 12 rooms. Six rooms were provided a long-bright photoperiod (LB treatment) of 23L:1D with 2 footcandles of intensity. The other 6 rooms were provided an increasing-dim photoperiod (ID treatment) of 20L:4D from 1 to 10 d, 12L:12D from 10 to 21 d, 15L:9D from 21 to 28 d, 18L:6D from 28 to 35 d, and 20L:4D from 35 to 54 d, with 0.1 foot-candle throughout. Relative to LB, the ID treatment had lower BW from 7 to 28 d, feed consumption from 7 to 35 d, and feed conversion from 7 to 42 d; however, these variables did not differ between treatments at 54 d. The M strain had consistently greater BW and feed consumption than the H strain. However, M strain feed conversion was only greater from 7 to 35 d. Mortality was unaffected by treatment or strain. Total breast weights and yields were 42 g or 5.1% greater, respectively, in the LB than the ID treatment. Fillet weights and yields, and tender yields, were greater in the LB than ID treatment. Leg weights and yields, and wing yields, were greater in the ID than LB treatment. Total breast weights of M and H strains were similar; however, yield was 3.3% greater in the H than M strain. Fillet yields were greater in the H than M strain. Wing and leg weights and yields were greater in the M than H strain. There was an interaction effect on fat pad weights and yields, which were greater in H strain subjected to ID treatment than other strain and treatment combinations. These results indicate that increasing photoperiods and dim intensities, which often improve broiler live performance, may have a greater negative effect on breast meat production than differences in strains. PMID:19359674

  15. Neuromedin U partly mimics thyroid-stimulating hormone and triggers Wnt/β-catenin signalling in the photoperiodic response of F344 rats.

    PubMed

    Helfer, G; Ross, A W; Morgan, P J

    2013-12-01

    In seasonal animals, photoperiod exerts profound effects on physiology, such as growth, energy balance and reproduction, via changes in the neuroendocrine axes. A key element of the photoperiodic response is the thyroid hormone level in the hypothalamus, which is controlled via retrograde transport of thyroid-stimulating hormone (TSH) from the pars tuberalis of the pituitary. TSH regulates type II deiodinase (Dio2) expression, which transforms inactive thyroid hormone to its active form, via TSH receptors expressed in the ependymal cells of the hypothalamus. In the present study, we hypothesised that a second peptide hormone, neuromedin U (NMU), may play a role in the photoperiodic response alongside TSH because the gene for NMU is also expressed in a strongly photoperiod-dependent manner in the pars tuberalis and its receptor NMU2 is expressed in the ependymal layer of the third ventricle in photoperiod-sensitive F344 rats. Consistent with other studies conducted in nonseasonal mammals, we found that acute i.c.v. injections of NMU into the hypothalamus negatively regulated food intake and body weight and increased core body temperature in F344 rats. At the same time, NMU increased Dio2 mRNA expression in the ependymal region of the hypothalamus similar to the effects of TSH. These data suggest that NMU may affect acute and photoperiodically controlled energy balance through distinct pathways. We also showed that TSH inhibits the expression of type III deiodinase (Dio3) in F344 rats, a response not mimicked by NMU. Furthermore, NMU also increased the expression of genes from the Wnt/β-catenin pathway within the ependymal layer of the third ventricle. This effect was not influenced by TSH. These data indicate that, although NMU acts with some similarities to TSH, it also has completely distinct signalling functions that do not overlap. In summary, the present study of NMU signalling reveals the potential for a new player in the control of seasonal biology. PMID

  16. Neuromedin U Partly Mimics Thyroid-Stimulating Hormone and Triggers Wnt/β-Catenin Signalling in the Photoperiodic Response of F344 Rats

    PubMed Central

    Helfer, G; Ross, A W; Morgan, P J

    2013-01-01

    In seasonal animals, photoperiod exerts profound effects on physiology, such as growth, energy balance and reproduction, via changes in the neuroendocrine axes. A key element of the photoperiodic response is the thyroid hormone level in the hypothalamus, which is controlled via retrograde transport of thyroid-stimulating hormone (TSH) from the pars tuberalis of the pituitary. TSH regulates type II deiodinase (Dio2) expression, which transforms inactive thyroid hormone to its active form, via TSH receptors expressed in the ependymal cells of the hypothalamus. In the present study, we hypothesised that a second peptide hormone, neuromedin U (NMU), may play a role in the photoperiodic response alongside TSH because the gene for NMU is also expressed in a strongly photoperiod-dependent manner in the pars tuberalis and its receptor NMU2 is expressed in the ependymal layer of the third ventricle in photoperiod-sensitive F344 rats. Consistent with other studies conducted in nonseasonal mammals, we found that acute i.c.v. injections of NMU into the hypothalamus negatively regulated food intake and body weight and increased core body temperature in F344 rats. At the same time, NMU increased Dio2 mRNA expression in the ependymal region of the hypothalamus similar to the effects of TSH. These data suggest that NMU may affect acute and photoperiodically controlled energy balance through distinct pathways. We also showed that TSH inhibits the expression of type III deiodinase (Dio3) in F344 rats, a response not mimicked by NMU. Furthermore, NMU also increased the expression of genes from the Wnt/β-catenin pathway within the ependymal layer of the third ventricle. This effect was not influenced by TSH. These data indicate that, although NMU acts with some similarities to TSH, it also has completely distinct signalling functions that do not overlap. In summary, the present study of NMU signalling reveals the potential for a new player in the control of seasonal biology. PMID

  17. The importance of light and photoperiod in sexual reproduction and geographical distribution in the green snow alga, Chloromonas sp.-D (Chlorophyceae, Volvocales)

    NASA Astrophysics Data System (ADS)

    Hoham, Ronald W.; Marcarelli, Amy M.; Rogers, Haldre S.; Ragan, Michael D.; Petre, Benjamin M.; Ungerer, Michael D.; Barnes, Joseph M.; Francis, David O.

    2000-12-01

    The effects of premating light regimes on sexual reproduction and the production of spherical cells in Chloromonas sp.-D, a unicellular green snow alga, were studied using cross-mating strains 582C and 582D isolated from snowpacks associated with mixed hardwood- softwood forests in Whetstone Gulf State Park, Tughill Plateau, NY. Two pre-acclimation regimes were used, Vita-Lite as controls (530- 700 nm peak) and blue light as experimentals (430- 460 nm peak) prior to the mating experiments. In blue light, an increase in the number of matings and spherical cells (spheres) produced in the life cycle was observed as the photoperiod increased. This implies that longer photoperiods of blue light are more optimal for sexual reproduction in Chloromonas sp.-D than shorter ones. Under Vita-Lite, there was a significant increase in the number of matings and spheres with the extended 20 : 4 photoperiod compared with the shorter 14 : 10 photoperiod. Under blue light, significantly more matings and spheres occurred than under Vita-Lite using the same irradiance level of 95µmol photons m-2 s-1 (photosynthetically active radiation [PAR] of 400- 700 nm) for the 14 : 10 and 20 : 4 photoperiods. The results of these experiments suggest that Chloromonas sp.-D, known only from the Tughill Plateau, NY, is not reproducing optimally at this site where it grows and reproduces under an approximate 14 : 10 photoperiod in early April. However, in the upper 10 cm of snow in the Tughill Plateau, a blue light irradiance level of 95µmol photons m-2 s-1 occurs, which is optimal for this species. When these conditions are combined with a 14 : 10 photoperiod, the Tughill Plateau appears to be sub-optimal for mating and production of spherical cells. Since Chloromonas sp.-D does not appear to have a dependence on a dark cycle, this would allow it to expand its geographical distribution. It may reproduce more optimally under blue light (95µmol photons m-2 s-1) with an extended photoperiod (>20 : 4

  18. Factors influencing quality of anticoagulation control and warfarin dosage in patients after aortic valve replacement within the 3 months of follow up.

    PubMed

    Wypasek, E; Mazur, P; Bochenek, M; Awsiuk, M; Grudzien, G; Plincer, D; Undas, A

    2016-06-01

    Warfarin dosage estimation using the pharmacogenetic algorithms has been shown to improve the quality of anticoagulation control in patients with atrial fibrillation. We sought to assess the genetic, demographic and clinical factors that determine the quality of anticoagulation in patients following aortic valve replacement (AVR). We studied 200 consecutive patients (130 men) aged 63 ± 12.3 years, undergoing AVR, in whom warfarin dose was established using a pharmacogenetic algorithm. The quality of anticoagulation within the first 3 months since surgery was expressed as the time of international normalized ratio (INR) in the therapeutic range (TTR). The median TTR in the entire cohort was 59.6% (interquartile range, 38.7 - 82.7). Ninety-nine (49.5%) patients with TTR ≥ 60% did not differ from those with poor anticoagulation control (TTR < 60%) with regard to demographic and cardiovascular risk factors. Coronary artery disease (n = 84, 42%) and previous stroke (n = 5, 2.5%) predicted higher TTR, while possession of CYP2C9*2 variant allele (n = 49, 25%) was associated with lower TTR (P = 0.01). In turn, VKORC1 c.-1639A, CYP2C9*2 and *3 variants were independently associated with actual warfarin dose (P < 0.0001). In AVR patients better anticoagulation control is observed in patients with coronary artery disease and history of stroke, which might result in part from previous lifestyle modification and therapy. Possession of CYP2C9*2 and/or CYP2C9*3 allele variants is associated with lower TTR values and warfarin dose variations in AVR patients, the latter affected also by VKORC1 c.-1693G>A polymorphism. PMID:27511999

  19. Prevalence and risk factors of posttraumatic stress disorder among teachers 3 months after the Lushan earthquake: A cross-sectional study.

    PubMed

    Zhang, Jun; Zhang, Ye; Du, Changhui; Zhu, Shenyue; Huang, Yalin; Tian, Yulian; Chen, Decao; Li, Haimin; Gong, Yao; Zhang, Mengmeng; Gu, Bo

    2016-07-01

    Teachers and students often suffer from the same disaster. The prevalence of PTSD in students has been given great attention. However, in acting as mentors to students and their families, teachers are more likely to have vicarious an