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Sample records for activity declined sharply

  1. Auditory cortical local subnetworks are characterized by sharply synchronous activity.

    PubMed

    Atencio, Craig A; Schreiner, Christoph E

    2013-11-20

    In primary auditory cortex (AI), broadly correlated firing has been commonly observed. In contrast, sharply synchronous firing has rarely been seen and has not been well characterized. Therefore, we examined cat AI local subnetworks using cross-correlation and spectrotemporal receptive field (STRF) analysis for neighboring neurons. Sharply synchronous firing responses were observed predominantly for neurons separated by <150 μm. This high synchrony was independent of layers and was present between all distinguishable cell types. The sharpest synchrony was seen in supragranular layers and between regular spiking units. Synchronous spikes conveyed more stimulus information than nonsynchronous spikes. Neighboring neurons in all layers had similar best frequencies and similar STRFs, with the highest similarity in supragranular and granular layers. Spectral tuning selectivity and latency were only moderately conserved in these local, high-synchrony AI subnetworks. Overall, sharp synchrony is a specific characteristic of fine-scale networks within the AI and local functional processing is well ordered and similar, but not identical, for neighboring neurons of all cell types.

  2. Cost leveling continues; planned activity drops sharply in US gas pipeline cnstruction

    SciTech Connect

    Morgan, J.M.

    1986-02-01

    Natural gas pipeline construction costs, as measured by the OGJ-Morgan Pipeline cost index for US gas-pipeline construction, barely crept up in the second quarter 1985. Construction activity for lines and compressor stations was down.

  3. Effect of sharply lowered muscular activity on the thyroid gland of the white rat

    NASA Technical Reports Server (NTRS)

    Bekishev, K.

    1980-01-01

    The effect of hypokinesia on the thyroid gland of 200 white rats was studied. The rats were kept in 16x6x6 cm cages for 90 days. The functional activity of the thyroids increased after 24 hrs of partial immobilization and peaked after 15 days. After 30 days of immobilization, the functional activity returned to normal in one third of the test animals and after 60 days in all animals. After 15 days of immobilization, the test animals began to lose weight (in comparison to the controls) and remained underweight for the rest of the test period (up to 90 days). When returned to normal conditions, they caught up with and even overtook in weight the control animals after about 1 month. All changes produced by hypokinesia were reversible after 1 month.

  4. Physical activity and motor decline in older persons.

    PubMed

    Buchman, A S; Boyle, P A; Wilson, R S; Bienias, Julia L; Bennett, D A

    2007-03-01

    We tested the hypothesis that physical activity modifies the course of age-related motor decline. More than 850 older participants of the Rush Memory and Aging Project underwent baseline assessment of physical activity and annual motor testing for up to 8 years. Nine strength measures and nine motor performance measures were summarized into composite measures of motor function. In generalized estimating equation models, global motor function declined during follow-up (estimate, -0.072; SE, 0.008; P < 0.001). Each additional hour of physical activity at baseline was associated with about a 5% decrease in the rate of global motor function decline (estimate, 0.004; SE, 0.001; P = 0.007). Secondary analyses suggested that the association of physical activity with motor decline was mostly due to the effect of physical activity on the rate of motor performance decline. Thus, higher levels of physical activity are associated with a slower rate of motor decline in older persons.

  5. Late Life Leisure Activities and Risk of Cognitive Decline

    PubMed Central

    2013-01-01

    Background. Studies concerning the effect of different types of leisure activities on various cognitive domains are limited. This study tests the hypothesis that mental, physical, and social activities have a domain-specific protection against cognitive decline. Methods. A cohort of a geographically defined population in China was examined in 2003–2005 and followed for an average of 2.4 years. Leisure activities were assessed in 1,463 adults aged 65 years and older without cognitive or physical impairment at baseline, and their cognitive performances were tested at baseline and follow-up examinations. Results. High level of mental activity was related to less decline in global cognition (β = −.23, p < .01), language (β = −.11, p < .05), and executive function (β = −.13, p < .05) in ANCOVA models adjusting for age, gender, education, history of stroke, body mass index, Apolipoprotein E genotype, and baseline cognition. High level of physical activity was related to less decline in episodic memory (β = −.08, p < .05) and language (β = −.15, p < .01). High level of social activity was associated with less decline in global cognition (β = −.11, p < .05). Further, a dose-response pattern was observed: although participants who did not engage in any of the three activities experienced a significant global cognitive decline, those who engaged in any one of the activities maintained their cognition, and those who engaged in two or three activities improved their cognition. The same pattern was observed in men and in women. Conclusions. Leisure activities in old age may protect against cognitive decline for both women and men, and different types of activities seem to benefit different cognitive domains. PMID:22879456

  6. Magnetic observations during the recent declining phase of solar activity

    NASA Astrophysics Data System (ADS)

    Smith, E. J.

    Changes in the heliospheric magnetic field during the recent declining phase in solar activity are reviewed and compared with observations during past sunspot cycles. The study is based principally on data obtained by IMP-8 and Ulysses. The field magnitude is found to have increased during the declining phase until it reached a maximum value of 11.5nT in approximately 1991.5, approximately two years after sunspot maximum. The field of the sun's south pole became negative after a reversal in early 1990. The sector structure disappeared at Ulysses in April 1993 when the latitude of the spacecraft was -30 deg revealing a low inclination of the heliospheric current sheet. A large outburst of solar activity in March 1991 caused four Coronal Mass Ejections (CMEs) and numerious shocks at the location of Ulysses. Following a delay of more than a year, a series of recurrent high speed streams and Corotating Interaction Regions commenced in July 1992 which were observed by IMP-8, Ulysses and Voyager 2. In all these respects, the behavior of the magnetic field mimics that seen in the two earlier sunspot cycles. The comprehensive data set suggests a correlation between the absolute value of B and sunspot number. The major solar cycle variations in the radial component (and magnitude) of the field have been successfully reproduced by a recent model consisting of a tilted solar dipole, whose strength and tilt undergo characteristic changes over the sunspot cycle, and the heliospheric current sheet. The large outbursts of activity in mid-1972, mid-1982 and the first quarter of 1991 may represent a characteristic last 'gasp' of solar activity before the sun evolves to a different state. The recurrent high speed streams in 1973, 1984 and 1992 accompany the developemnt of large asymetrical polar coronal holes and the growth in intensity of the polar cap fields. After they endure for about one year, the polar coronal holes recede and the high speed streams are replaced by weaker

  7. The argon-induced decline in nitrogenase activity commences before the beginning of a decline in nodule oxygen uptake.

    PubMed

    Fischinger, Stephanie A; Schulze, Joachim

    2010-09-01

    Replacement of N(2) by argon in the air around nodules directs nitrogenase electron flow in its total onto H(+) resulting in increased nodule H(2) evolution (total nitrogenase activity (TNA)). However, argon application induces a so-called argon-induced decline in nitrogenase activity (Ar-ID) connected with decreased nodule oxygen permeability. Consequently, TNA measurements tend to underestimate total nitrogenase activity. It is unclear whether the decline in oxygen diffusion into nodules induces the Ar-ID, or whether a decline in nitrogenase activity is followed by lower nodule O(2) uptake. The objective of the present work was to examine the time sequence of the decline in nodule H(2) evolution and O(2) uptake after argon application. In addition, the reliability of TNA values, taken as quickly as possible after the switch to Ar/O(2), was tested through comparative measurement of (15)N(2) uptake of the same plants. Short-term TNA measurements in an optimized gas exchange measurement system yielded reliable results, verified by parallel determination of (15)N(2) uptake. A five min application of Ar/O(2) was without effect on the subsequent H(2) evolution in ambient air. A parallel experiment on control plants revealed that a decrease in nodule oxygen uptake began several minutes after the onset of the decline in H(2) evolution. We conclude that the primary effect of the replacement of N(2) by argon differs from oxygen diffusion control. A gas exchange system allowing an immediate taking of TNA yields reliable results and does not disturb nodule activity. Gas exchange measurements provide a powerful tool for studying nodule physiology and should be combined with material from molecular studies.

  8. Sharply rising prevalence of HIV infection in Bali: a critical assessment of the surveillance data.

    PubMed

    Januraga, P P; Wulandari, L P L; Muliawan, P; Sawitri, S; Causer, L; Wirawan, D N; Kaldor, J M

    2013-08-01

    This study critically examines serological survey data for HIV infection in selected populations in Bali, Indonesia. Sero-survey data reported by the Bali Health Office between 2000 and 2010 were collated, and provincial health staff were interviewed to gain a detailed understanding of survey methods. Analysis of time series restricted to districts that have used the same sampling methods and sites each year indicates that there has been a steady decline in HIV prevalence among prisoners, from 18.7% in 2000 to 4.3% in 2010. In contrast, HIV prevalence among women engaged in sex work increased sharply: from 0.62% in 2000 to 20.2% in 2010 (brothel based), and from 0% in 2000 to 7.2% in 2010 (non-brothel based). The highest prevalence was recorded among people who injected drugs. Recent surveys of gay men and transvestites also found high prevalences, at 18.7% and 40.9%, respectively. Review of the methodology used in the surveys identified inconsistencies in the sampling technique, sample numbers and sites over time, and incomplete recording of individual information about survey participants. Attention to methodological aspects and incorporation of additional information on behavioural factors will ensure that the surveillance system is in the best position to support prevention activities.

  9. Changes in physical activity and cognitive decline in older adults living in the community.

    PubMed

    Lee, Yunhwan; Kim, Jinhee; Han, Eun Sook; Chae, Songi; Ryu, Mikyung; Ahn, Kwang Ho; Park, Eun Ju

    2015-01-01

    Accumulating evidence suggests that physical activity may be beneficial in preserving cognition in late life. This study examined the association between baseline and changes in physical activity and cognitive decline in community-dwelling older people. Data were from the Korean Longitudinal Study of Aging, with 2605 aged 65 years and older subjects interviewed in 2006 and followed up for 2 years. Cognitive decline was defined by calculating the Reliable Change Index using the Mini-Mental State Examination. Physical activity levels were categorized as sedentary, low, or high. Changes in physical activity were classified as inactive, decreaser, increaser, or active. Logistic regression analysis of baseline and changes in physical activity with cognitive decline was performed. Compared with the sedentary group at baseline, both the low and high activity groups were less likely to experience cognitive decline. The active (odds ratio [OR] = 0.40, 95 % confidence interval [CI] 0.23-0.68) and increaser (OR = 0.45, 95 % CI 0.27-0.74) group, compared with the inactive counterpart, demonstrated a significantly lower likelihood of cognitive decline. Older adults who remained active or increased activity over time had a reduced risk of cognitive decline. Engagement in physical activity in late life may have cognitive health benefits.

  10. Biological mechanisms of physical activity in preventing cognitive decline.

    PubMed

    Lista, I; Sorrentino, G

    2010-05-01

    In order to guarantee better conditions for competition, the nervous system has developed not only mechanisms controlling muscle effectors, but also retrograde systems that, starting from peripheral structures, may influence brain functions. Under such perspective, physical activity could play an important role in influencing cognitive brain functions including learning and memory. The results of epidemiological studies (cross-sectional, prospective and retrospective) support a positive relationship between cognition and physical activities. Recent meta-analysis confirmed a significant effect of exercise on cognitive functions. However, the biological mechanisms that underlie such beneficial effects are still to be completely elucidated. They include supramolecular mechanisms (e.g. neurogenesis, synaptogenesis, and angiogenesis) which, in turn, are controlled by molecular mechanisms, such as BDNF, IGF-1, hormone and second messengers.

  11. Recent progress on the mechanics of sharply bent DNA

    NASA Astrophysics Data System (ADS)

    Cong, PeiWen; Yan, Jie

    2016-08-01

    Despite extensive studies on the mechanics of DNA under external constrains, such as tension, torsion, and bending, several important aspects have remained poorly understood. One biologically important example is the mechanics of DNA under sharp bending conditions, which has been debated for a decade without thorough comprehension. The debate is about the interesting phenomenon raised from a series of different experiments: sharply bent DNA has a surprisingly high apparent bending flexibility that deviates from the canonical bending elasticity of DNA. This finding has motivated various theoretical models, which mainly incorporate the excitation of mechanical defects inside severely bent DNA molecules. Here, we review the recent progress on the understanding of the mechanics of sharply bent DNA and provide our view on this important question by interrogating the theoretical foundation of these experimental measurements.

  12. Transient Decline in Hippocampal Theta Activity during the Acquisition Process of the Negative Patterning Task

    PubMed Central

    Sakimoto, Yuya; Okada, Kana; Takeda, Kozue; Sakata, Shogo

    2013-01-01

    Hippocampal function is important in the acquisition of negative patterning but not of simple discrimination. This study examined rat hippocampal theta activity during the acquisition stages (early, middle, and late) of the negative patterning task (A+, B+, AB-). The results showed that hippocampal theta activity began to decline transiently (for 500 ms after non-reinforced stimulus presentation) during the late stage of learning in the negative patterning task. In addition, this transient decline in hippocampal theta activity in the late stage was lower in the negative patterning task than in the simple discrimination task. This transient decline during the late stage of task acquisition may be related to a learning process distinctive of the negative patterning task but not the simple discrimination task. We propose that the transient decline of hippocampal theta activity reflects inhibitory learning and/or response inhibition after the presentation of a compound stimulus specific to the negative patterning task. PMID:23936249

  13. The Decline of Physical Activity? Why Are So Many Kids Out of Shape?

    ERIC Educational Resources Information Center

    Villaire, Ted

    2001-01-01

    The problem of childhood obesity and inadequate physical activity is growing, with the biggest physical activity decline occurring in high school. This paper discusses the need to promote physical activity at school and home and get children in shape. Two sidebars describe: National Physical Fitness and Sports Month and how to determine a school'…

  14. Declining rates of physical activity in the United States: what are the contributors?

    PubMed

    Brownson, Ross C; Boehmer, Tegan K; Luke, Douglas A

    2005-01-01

    This review describes current patterns and long-term trends (up to 50 years when possible) related to (a) physical activity, (b) employment and occupation, (c) travel behavior, (d) land use, and (e) related behaviors (e.g., television watching). On the basis of available data, the following trends were observed according to type of physical activity: relatively stable or slightly increasing levels of leisure-time physical activity, declining work-related activity, declining transportation activity, declining activity in the home, and increasing sedentary activity. These result in an overall trend of declining total physical activity. Large differences were noted in the rates of walking for transportation across metropolitan statistical areas. A strong linear increase existed in vehicle miles traveled per person over the past half century, coupled with a strong and consistent trend toward Americans living in suburbs. Although it is difficult to precisely quantify owing to the lack of long-term data, it is apparent that a combination of changes to the built environment and increases in the proportion of the population engaging in sedentary activities put the majority of the American population at high risk of physical inactivity. PMID:15760296

  15. Telmisartan prevented cognitive decline partly due to PPAR-{gamma} activation

    SciTech Connect

    Mogi, Masaki; Li Jianmei; Tsukuda, Kana; Iwanami, Jun; Min, Li-Juan; Sakata, Akiko; Fujita, Teppei; Iwai, Masaru; Horiuchi, Masatsugu

    2008-10-24

    Telmisartan is a unique angiotensin receptor blocker (ARB) and partial agonist of peroxisome proliferator-activated receptor (PPAR)-{gamma}. Here, we investigated the preventive effect of telmisartan on cognitive decline in Alzheimer disease. In ddY mice, intracerebroventricular injection of A{beta} 1-40 significantly attenuated their cognitive function evaluated by shuttle avoidance test. Pretreatment with a non-hypotensive dose of telmisartan significantly inhibited such cognitive decline. Interestingly, co-treatment with GW9662, a PPAR-{gamma} antagonist, partially inhibited this improvement of cognitive decline. Another ARB, losartan, which has less PPAR-{gamma} agonistic effect, also inhibited A{beta}-injection-induced cognitive decline; however the effect was smaller than that of telmisartan and was not affected by GW9662. Immunohistochemical staining for A{beta} showed the reduced A{beta} deposition in telmisartan-treated mice. However, this reduction was not observed in mice co-administered GW9662. These findings suggest that ARB has a preventive effect on cognitive impairment in Alzheimer disease, and telmisartan, with PPAR-{gamma} activation, could exert a stronger effect.

  16. Risk of decline in functional activities in dementia with Lewy bodies and Alzheimer disease.

    PubMed

    Gill, Dawn P; Koepsell, Thomas D; Hubbard, Rebecca A; Kukull, Walter A

    2011-01-01

    We examined the risk of 1-year decline in 4 everyday activities in patients with dementia with Lewy bodies (DLB), relative to patients with Alzheimer disease (AD). Data were from the National Alzheimer's Coordinating Center, gathered from 32 Alzheimer's Disease Centers. Participants (n=1880) were: aged 60+ years, demented with a primary clinical diagnosis of probable AD or DLB, and had a global Clinical Dementia Rating of 0.5 to 2. The activities were measured with the Functional Activities Questionnaire. In modified Poisson regression models adjusted for demographics, baseline activity, years from symptom onset, cognitive impairment, and comorbidities; DLB participants aged 67 to 81 years had 1.5 to 2 times increased risk of decline in performing basic kitchen tasks, engaging in games/hobbies, and paying attention/understanding, relative to AD participants of the same age (P<0.05). There was no significant difference between AD and DLB participants beyond this age range. For decline in ability to go shopping alone, there was also no significant difference between AD and DLB participants. In summary, the functional course of DLB, relative to AD, may depend on the age of the patient. These findings may provide anticipatory guidance to families and healthcare providers, which may be useful in the planning of care strategies.

  17. Does a physically active lifestyle attenuate decline in all cognitive functions in old age?

    PubMed

    Ballesteros, Soledad; Mayas, Julia; Reales, Jose Manuel

    2013-07-01

    In this study, the performance of a group of 20 physically active older adults was compared with that of a group of 20 sedentary healthy older adults while performing a series of cognitive tasks. These tasks were designed to assess processes that deteriorate most with age, namely executive control (assessed with the Wisconsin Card Sorting Task) and processing speed (simple and choice reaction time tasks). A repetition priming task that does not decline with age, involving attended and unattended picture outlines at encoding, was also included as a control task. The results show that a physically active lifestyle has a positive influence on executive control, processing speed, and controlled processing. As expected, a physically active lifestyle did not enhance repetition priming for attended stimuli, nor did it produce priming for unattended stimuli at encoding. Both groups exhibited robust priming for attended stimuli and no priming for unattended ones. Executive control functions are of vital importance for independent living in old age. These results have practical implications for enhancing the cognitive processes that decline most in old age. Promoting a physically active lifestyle throughout adulthood could significantly reduce the decline of effortful executive control functions in old age.

  18. Role of physical activity in reducing cognitive decline in older Mexican-American adults.

    PubMed

    Ottenbacher, Allison J; Snih, Soham Al; Bindawas, Saad M; Markides, Kyriakos S; Graham, James E; Samper-Ternent, Rafael; Raji, Mukaila; Ottenbacher, Kenneth J

    2014-09-01

    The effect of physical activity on cognitive function in older adults from minority and disadvantaged populations is not well understood. This study examined the longitudinal association between physical activity and cognition in older Mexican Americans. The study methodology included a prospective cohort with longitudinal analysis of data from the Hispanic Established Populations for the Epidemiologic Study of the Elderly. General linear mixed models were used to assess the associations and interactions between physical activity and cognitive function over 14 years. Community-based assessments were performed in participants' homes. Physical activity was recorded for 1,669 older Mexican Americans using the Physical Activity Scale for the Elderly. Cognition was measured using the Mini-Mental State Examination (MMSE) and separated into memory and nonmemory components. A statistically significant positive association was observed between levels of physical activity and cognitive function after adjusting for age, sex, marital status, education, and comorbid health conditions. There was a statistically significant difference in MMSE scores over time between participants in the third (β = 0.11, standard error (SE) = 0.05) and fourth (β = 0.10, SE = 0.2) quartiles of physical activity and those in the first. The protective effect of physical activity on cognitive decline was evident for the memory component of the MMSE but not the nonmemory component after adjusting for covariates. Greater physical activity at baseline was associated with less cognitive decline over 14 years in older Mexican Americans. The reduction in cognitive decline appeared to be related to the memory components of cognitive function.

  19. Decline of rubisco activity and net photosynthesis in ozone-treated potato foliage. [Solanum tuberosum

    SciTech Connect

    Dann, M.S.; Pell, E.J.

    1987-04-01

    The effect of O/sub 3/ on rubisco activity in Solanum tuberosum L. cv Norland foliage was studied as related to oxidant-induced premature senescence. Plants, 25 days old, were exposed to O/sub 3/ increasing from 0.06 to 0.08 ..mu..1/L for 6 h/day for 4 days in a controlled environment chamber. On day 5 plants were exposed to a 6 h simulated inversion in which O/sub 3/ peaked at 0.12 /sup +/1/L. The authors measured initial and total rubisco activities and net photosynthesis of leaves at full expansion on days 0,3,5,6,9 and 12. These parameters declined in both ozone and control plants throughout the course of the experiment. O/sub 3/ exacerbated the decline and produced a significantly greater decrease following the inversion. The enhanced reduction in rubisco activity over time may be an important characteristics of ozone-induced premature senescence. Rubisco activation (initial/total activity) did not change with the treatment. The decrease in activity is most likely due to a decrease in available protein rather than a decrease in the percentage of rubisco activated in vivo.

  20. NK cell activating receptor ligand expression in lymphangioleiomyomatosis is associated with lung function decline

    PubMed Central

    Osterburg, Andrew R.; Nelson, Rebecca L.; Yaniv, Benyamin Z.; Foot, Rachel; Donica, Walter R.F.; Nashu, Madison A.; Liu, Huan; Wikenheiser-Brokamp, Kathryn A.; Moss, Joel; McCormack, Francis X.; Borchers, Michael T.

    2016-01-01

    Lymphangioleiomyomatosis (LAM) is a rare lung disease of women that leads to progressive cyst formation and accelerated loss of pulmonary function. Neoplastic smooth muscle cells from an unknown source metastasize to the lung and drive destructive remodeling. Given the role of NK cells in immune surveillance, we postulated that NK cell activating receptors and their cognate ligands are involved in LAM pathogenesis. We found that ligands for the NKG2D activating receptor UL-16 binding protein 2 (ULBP2) and ULBP3 are localized in cystic LAM lesions and pulmonary nodules. We found elevated soluble serum ULBP2 (mean = 575 pg/ml ± 142) in 50 of 100 subjects and ULBP3 in 30 of 100 (mean = 8,300 pg/ml ± 1,515) subjects. LAM patients had fewer circulating NKG2D+ NK cells and decreased NKG2D surface expression. Lung function decline was associated with soluble NKG2D ligand (sNKG2DL) detection. The greatest rate of decline forced expiratory volume in 1 second (FEV1, –124 ± 30 ml/year) in the 48 months after enrollment (NHLBI LAM Registry) occurred in patients expressing both ULBP2 and ULBP3, whereas patients with undetectable sNKG2DL levels had the lowest rate of FEV1 decline (–32.7 ± 10 ml/year). These data suggest a role for NK cells, sNKG2DL, and the innate immune system in LAM pathogenesis. PMID:27734028

  1. Parenchyma cell respiration and survival in secondary xylem: does metabolic activity decline with cell age?

    PubMed

    Spicer, R; Holbrook, N M

    2007-08-01

    Sapwood respiration often declines towards the sapwood/heartwood boundary, but it is not known if parenchyma metabolic activity declines with cell age. We measured sapwood respiration in five temperate species (sapwood age range of 5-64 years) and expressed respiration on a live cell basis by quantifying living parenchyma. We found no effect of parenchyma age on respiration in two conifers (Pinus strobus, Tsuga canadensis), both of which had significant amounts of dead parenchyma in the sapwood. In angiosperms (Acer rubrum, Fraxinus americana, Quercus rubra), both bulk tissue and live cell respiration were reduced by about one-half in the oldest relative to the youngest sapwood, and all sapwood parenchyma remained alive. Conifers and angiosperms had similar bulk tissue respiration despite a smaller proportion of parenchyma in conifers (5% versus 15-25% in angiosperms), such that conifer parenchyma respired at rates about three times those of angiosperms. The fact that 5-year-old parenchyma cells respired at the same rate as 25-year-old cells in conifers suggests that there is no inherent or intrinsic decline in respiration as a result of cellular ageing. In contrast, it is not known whether differences observed in cellular respiration rates of angiosperms are a function of age per se, or whether active regulation of metabolic rate or positional effects (e.g. proximity to resources and/or hormones) could be the cause of reduced respiration in older sapwood.

  2. Summer declines in activity and body temperature offer polar bears limited energy savings

    USGS Publications Warehouse

    Whiteman, J.P.; Harlow, H.J.; Durner, George M.; Anderson-Sprecher, R.; Albeke, Shannon E.; Regehr, Eric V.; Amstrup, Steven C.; Ben-David, M.

    2015-01-01

    Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of “ice” bears in summer is unknown, “shore” bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of on-ice foraging opportunities caused by climate change. However, here we report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, nonhibernating mammals. Also, we found that to avoid unsustainable heat loss while swimming, bears employed unusual heterothermy of the body core. Thus, although well adapted to seasonal ice melt, polar bears appear susceptible to deleterious declines in body condition during the lengthening period of summer food deprivation.

  3. Animal physiology. Summer declines in activity and body temperature offer polar bears limited energy savings.

    PubMed

    Whiteman, J P; Harlow, H J; Durner, G M; Anderson-Sprecher, R; Albeke, S E; Regehr, E V; Amstrup, S C; Ben-David, M

    2015-07-17

    Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of "ice" bears in summer is unknown, "shore" bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of on-ice foraging opportunities caused by climate change. However, here we report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, nonhibernating mammals. Also, we found that to avoid unsustainable heat loss while swimming, bears employed unusual heterothermy of the body core. Thus, although well adapted to seasonal ice melt, polar bears appear susceptible to deleterious declines in body condition during the lengthening period of summer food deprivation.

  4. Animal physiology. Summer declines in activity and body temperature offer polar bears limited energy savings.

    PubMed

    Whiteman, J P; Harlow, H J; Durner, G M; Anderson-Sprecher, R; Albeke, S E; Regehr, E V; Amstrup, S C; Ben-David, M

    2015-07-17

    Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of "ice" bears in summer is unknown, "shore" bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of on-ice foraging opportunities caused by climate change. However, here we report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, nonhibernating mammals. Also, we found that to avoid unsustainable heat loss while swimming, bears employed unusual heterothermy of the body core. Thus, although well adapted to seasonal ice melt, polar bears appear susceptible to deleterious declines in body condition during the lengthening period of summer food deprivation. PMID:26185248

  5. Physical activity and inflammation: effects on gray-matter volume and cognitive decline in aging.

    PubMed

    Papenberg, Goran; Ferencz, Beata; Mangialasche, Francesca; Mecocci, Patrizia; Cecchetti, Roberta; Kalpouzos, Grégoria; Fratiglioni, Laura; Bäckman, Lars

    2016-10-01

    Physical activity has been positively associated with gray-matter integrity. In contrast, pro-inflammatory cytokines seem to have negative effects on the aging brain and have been related to dementia. It was investigated whether an inactive lifestyle and high levels of inflammation resulted in smaller gray-matter volumes and predicted cognitive decline across 6 years in a population-based study of older adults (n = 414). Self-reported physical activity (fitness-enhancing, health-enhancing, inadequate) was linked to gray-matter volume, such that individuals with inadequate physical activity had the least gray matter. There were no overall associations between different pro-and anti-inflammatory markers (IL-1β, IL-6, IL-10, IL-12p40, IL-12p70, G-CSF, and TNF-α) and gray-matter integrity. However, persons with inadequate activity and high levels of the pro-inflammatory marker IL-12p40 had smaller volumes of lateral prefrontal cortex and hippocampus and declined more on the Mini-Mental State Examination test over 6 years compared with physically inactive individuals with low levels of IL-12p40 and to more physically active persons, irrespective of their levels of IL-12p40. These patterns of data suggested that inflammation was particularly detrimental in inactive older adults and may exacerbate the negative effects of physical inactivity on brain and cognition in old age. Hum Brain Mapp 37:3462-3473, 2016. © 2016 Wiley Periodicals, Inc.

  6. Declining sand dune activity in the southern Canadian prairies: Historical context, controls and ecosystem implications

    NASA Astrophysics Data System (ADS)

    Hugenholtz, Chris H.; Bender, Darren; Wolfe, Stephen A.

    2010-11-01

    Sandhills are islands of biodiversity in the southern Canadian prairies that sustain habitat for many rare and endangered species. These unique areas consist of large expanses of dune fields now mostly stabilized by grassland vegetation. Historically, the number of active dunes has decreased significantly due to vegetation stabilization, resulting in a dramatic decline of open-sand habitat for a variety of dune-dependent species. Without a certain level of wind erosion, opportunities for establishment of early-stage, species-rich vegetation types are diminished and open-sand habitat decreases by encroachment of the surrounding grassland vegetation. The current trend of dune stabilization, however, implies that wind erosion is decreasing, thereby threatening the continued existence of a variety of dune-dependent plants, arthropods and vertebrates, as well as other less-specialized species that benefit indirectly from these habitats. By reviewing factors contributing to the historical decline of active dunes, as well as the ecological implications of dune stabilization, the aim of this paper is to establish the biophysical context for new land management strategies that conserve valued landscape components, such as active dunes, and the processes therein. As dune stabilization continues management interventions will be required to sustain or re-establish open sand and the species that rely on these habitats.

  7. Ventral striatum activation to prosocial rewards predicts longitudinal declines in adolescent risk taking.

    PubMed

    Telzer, Eva H; Fuligni, Andrew J; Lieberman, Matthew D; Galván, Adriana

    2013-01-01

    Adolescence is a period of intensified emotions and an increase in motivated behaviors and passions. Evidence from developmental neuroscience suggests that this heightened emotionality occurs, in part, due to a peak in functional reactivity to rewarding stimuli, which renders adolescents more oriented toward reward-seeking behaviors. Most prior work has focused on how reward sensitivity may create vulnerabilities, leading to increases in risk taking. Here, we test whether heightened reward sensitivity may potentially be an asset for adolescents when engaged in prosocial activities. Thirty-two adolescents were followed over a one-year period to examine whether ventral striatum activation to prosocial rewards predicts decreases in risk taking over a year. Results show that heightened ventral striatum activation to prosocial stimuli relates to longitudinal declines in risk taking. Therefore, the very same neural region that has conferred vulnerability for adolescent risk taking may also be protective against risk taking. PMID:23245219

  8. Why have physical activity levels declined among Chinese adults? Findings from the 1991 - 2006 China Health and Nutrition Surveys

    PubMed Central

    Ng, Shu Wen; Norton, Edward C; Popkin, Barry M

    2009-01-01

    Between 1991 and 2006, average weekly physical activity among adults in China fell by 32%. This paper discusses why total and occupational physical activity levels have fallen, and models the association between the rapid decline and various dimensions of exogenous community urbanization. We hypothesize that a) physical activity levels are negatively associated with urbanization; b) urbanization domains that affect job functions and opportunities will contribute most to changes in physical activity levels; and c) these urbanization domains will be more strongly associated for men than for women because home activities account for a larger proportion of physical activity for women. To test these hypotheses, we used longitudinal data from individuals aged 18 to 55 in the 1991-2006 China Health and Nutrition Surveys. We find that physical activity declines were strongly associated with greater availability of higher educational institutions, housing infrastructure, sanitation improvements and the economic well-being of the community in which people function. These urbanization factors predict more than four-fifths of the decline in occupational physical activity over the 1991-2006 period for men and nearly two-thirds of the decline for women. They are also associated with 57% of the decline in total physical activity for men and 40% of the decline for women. Intervention strategies to promote physical activity in the workplace, at home, for transit and via exercise should be considered a major health priority in China. PMID:19232811

  9. Physical activity and inflammation: effects on gray-matter volume and cognitive decline in aging.

    PubMed

    Papenberg, Goran; Ferencz, Beata; Mangialasche, Francesca; Mecocci, Patrizia; Cecchetti, Roberta; Kalpouzos, Grégoria; Fratiglioni, Laura; Bäckman, Lars

    2016-10-01

    Physical activity has been positively associated with gray-matter integrity. In contrast, pro-inflammatory cytokines seem to have negative effects on the aging brain and have been related to dementia. It was investigated whether an inactive lifestyle and high levels of inflammation resulted in smaller gray-matter volumes and predicted cognitive decline across 6 years in a population-based study of older adults (n = 414). Self-reported physical activity (fitness-enhancing, health-enhancing, inadequate) was linked to gray-matter volume, such that individuals with inadequate physical activity had the least gray matter. There were no overall associations between different pro-and anti-inflammatory markers (IL-1β, IL-6, IL-10, IL-12p40, IL-12p70, G-CSF, and TNF-α) and gray-matter integrity. However, persons with inadequate activity and high levels of the pro-inflammatory marker IL-12p40 had smaller volumes of lateral prefrontal cortex and hippocampus and declined more on the Mini-Mental State Examination test over 6 years compared with physically inactive individuals with low levels of IL-12p40 and to more physically active persons, irrespective of their levels of IL-12p40. These patterns of data suggested that inflammation was particularly detrimental in inactive older adults and may exacerbate the negative effects of physical inactivity on brain and cognition in old age. Hum Brain Mapp 37:3462-3473, 2016. © 2016 Wiley Periodicals, Inc. PMID:27159568

  10. Effect of estrogen on post-heparin lipolytic activity. Selective decline in hepatic triglyceride lipase.

    PubMed Central

    Applebaum, D M; Goldberg, A P; Pykälistö, O J; Brunzell, J D; Hazzard, W R

    1977-01-01

    The rise in plasma triglyceride (TG) levels associated with estrogen administration has been thought to arise from impaired clearance because of the uniform suppression of post-heparin lipolytic activity (PHLA). Recently PHLA has been shown to consist of two activities: hepatic TG lipase and extrahepatic lipoprotein lipase (LPL). To determine whether estrogen might induce a selective decline in one of these activities, both hepatic TG lipase and extrahepatic LPL were measured in post-heparin plasma from 13 normal women before and after 2 wk of treatment with ethinyl estradiol (1 mug/kg per day). Hepatic TG lipase and extrahepatic LPL were determined by two techniques: (a) separation by heparin-Sepharose column chromatography, and (b) selective inhibition with specific antibodies to post-heparin hepatic TG lipase and milk LPL. Estrogen uniformly depressed hepatic TG lipase as measured by affinity column (-68 +/- 12%, mean +/- SD, P less than 0.001) or antibody inhibition (-63 +/- 11%, P less than 0.001). Extrahepatic LPL was not significantly changed by affinity column (-22 +/- 40%) or antibody inhibition (-3 +/- 42%). Direct measurement of adipose tissue LPL from buttock fat biopsies also showed no systematic change in the activated form of LPL measured as heparin-elutable LPL (+64 +/- 164%) or in the tissue form of LPL measured in extracts of acetone-ether powders (+21 +/- 77%). The change in hepatic TG lipase correlated with the change in PHLA (r = 0.969, P less than 0.01). However, neither the change in PHLA nor hepatic TG lipase correlated with the increase in TG during estrogen. The decrease in PHLA during estrogen thus results from a selective decline in hepatic TG lipase. PMID:845252

  11. Temporal Relationship Between Insulin Sensitivity and the Pubertal Decline in Physical Activity in Peripubertal Hispanic and African American Females

    PubMed Central

    Spruijt-Metz, Donna; Belcher, Britni R.; Hsu, Ya-Wen; McClain, Arianna D.; Chou, Chih-Ping; Nguyen-Rodriguez, Selena; Weigensberg, Marc J.; Goran, Michael I.

    2013-01-01

    OBJECTIVE Little attention has been paid to possible intrinsic biological mechanisms for the decline in physical activity that occurs during puberty. This longitudinal observational study examined the association between baseline insulin sensitivity (SI) and declines in physical activity and increases in sedentary behavior in peripubertal minority females over a year. RESEARCH DESIGN AND METHODS Participants were Hispanic and African American girls (n = 55; 76% Hispanic; mean age 9.4 years; 36% obese). SI and other insulin indices were measured at baseline using the frequently sampled intravenous glucose tolerance test. Physical activity was measured on a quarterly basis by accelerometry and self-report. RESULTS Physical activity declined by 25% and time spent in sedentary behaviors increased by ∼13% over 1 year. Lower baseline SI predicted the decline in physical activity measured by accelerometry, whereas higher baseline acute insulin response to glucose predicted the decline in physical activity measured by self-report. Time spent in sedentary behavior increased by ~13% over 1 year, and this was predicted by lower baseline SI. All models controlled for adiposity, age, pubertal stage, and ethnicity. CONCLUSIONS When evaluated using a longitudinal design with strong outcome measures, this study suggests that lower baseline SI predicts a greater decline in physical activity in peripubertal minority females. PMID:23846812

  12. Decline of cell viability and mitochondrial activity in mouse skeletal muscle cell in a hypomagnetic field.

    PubMed

    Fu, Jing-Peng; Mo, Wei-Chuan; Liu, Ying; He, Rong-Qiao

    2016-05-01

    Hypomagnetic field (HMF), one of the key environmental risk factors for astronauts traveling in outer space, has previously been shown to repress locomotion of mammalians. However, underlying mechanisms of how HMF affects the motor system remains poorly understood. In this study, we created an HMF (<3 μT) by eliminating geomagnetic field (GMF, ∼50 μT) and exposed primary mouse skeletal muscle cells to this low magnetic field condition for a period of three days. HMF-exposed cells showed a decline in cell viability relative to GMF control, even though cells appeared normal in terms of morphology and survival rate. After a 3-day HMF-exposure, glucose consumption of skeletal muscle cells was significantly lower than GMF control, accompanied by less adenosine triphosphate (ATP) and adenosine diphosphate (ADP) content and higher ADP/ATP ratio. In agreement with these findings, mitochondrial membrane potential of HMF-exposed cells was also lower, whereas levels of cellular Reactive Oxygen Species were higher. Moreover, viability and membrane potential of isolated mitochondria were reduced after 1 h HMF-exposure in vitro. Our results indicate that mitochondria can directly respond to HMF at functional level, and suggest that HMF-induced decline in cell functionality results from a reduction in energy production and mitochondrial activity. PMID:27003876

  13. Decline in HIV infectivity following the introduction of highly active antiretroviral therapy

    PubMed Central

    Porco, Travis C.; Martin, Jeffrey N.; Page-Shafer, Kimberly A.; Cheng, Amber; Charlebois, Edwin; Grant, Robert M.; Osmond, Dennis H.

    2008-01-01

    Objective Little is known about the degree to which widespread use of antiretroviral therapy in a community reduces uninfected individuals’ risk of acquiring HIV. We estimated the degree to which the probability of HIV infection from an infected partner (the infectivity) declined following the introduction of highly active antiretroviral therapy (HAART) in San Francisco. Design Homosexual men from the San Francisco Young Men’s Health Study, who were initially uninfected with HIV, were asked about sexual practices, and tested for HIV antibodies at each of four follow-up visits during a 6-year period spanning the advent of widespread use of HAART (1994 to 1999). Methods We estimated the infectivity of HIV (per-partnership probability of transmission from an infected partner) using a probabilistic risk model based on observed incident infections and self-reported sexual risk behavior, and tested the hypothesis that infectivity was the same before and after HAART was introduced. Results A total of 534 homosexual men were evaluated. Decreasing trends in HIV seroincidence were observed despite increases in reported number of unprotected receptive anal intercourse partners. Conservatively assuming a constant prevalence of HIV infection between 1994 and 1999, HIV infectivity decreased from 0.120 prior to widespread use of HAART, to 0.048 after the widespread use of HAART – a decline of 60% (P = 0.028). Conclusions Use of HAART by infected persons in a community appears to reduce their infectiousness and therefore may provide an important HIV prevention tool. PMID:15090833

  14. Normal Weight with Central Obesity, Physical Activity, and Functional Decline: Data from the Osteoarthritis Initiative

    PubMed Central

    Batsis, John A.; Zbehlik, Alicia J.; Scherer, Emily A.; Barre, Laura K.; Bartels, Stephen J.

    2015-01-01

    OBJECTIVES To identify the risks of the combination of normal body mass index (BMI) and central obesity (normal weight and central obesity (NWCO)) on physical activity and function. DESIGN Longitudinal Osteoarthritis Initiative Study. SETTING Community based. PARTICIPANTS Adults aged 60 and older at risk of osteoarthritis (N= 2,210; mean age 68, range 67.1–69.0) were grouped according to BMI (normal 18.5–24.9 kg/m2, overweight 25.0–29.9 kg/m2, obese ≥30.0 kg/m2). High waist circumference (WC) was defined as greater than 88 cm for women and greater than 102 cm for men. Subjects were subcategorized according to WC (five categories). Subjects with normal BMI and a large WC were considered to have NWCO (n=280, 12.7%). MEASUREMENTS Six-year changes in the Physical Component Summary of the Medical Outcomes Study 12-item Short Form Survey (PCS), Physical Activity Scale for the Elderly (PASE), and Late-Life Function and Disability Index (LL-FDI) were examined. The association between BMI and WC over 6 years was assessed (reference normal BMI, normal WC). Stratified analyses were performed according to age (60–69; ≥70). RESULTS Physical component scores, PASE, and LL-FDI declined with time. Mean PASE scores at 6 years differed between the NWCO group and the group with normal BMI and WC (117.7 vs 141.5), but rate of change from baseline to 6 years was not significantly different (p=.35). In adjusted models, those with NWCO had greater decline in PCS over time, particularly those aged 70 and older than those with normal BMI and WC (time interaction β=–0.37, 95% confidence interval=–0.68 to –0.06). CONCLUSION NWCO in older adults at risk of osteoarthritis may be a risk factor for declining function and physical activity, particularly in those aged 70 and older, suggesting the value of targeting those with NWCO who would otherwise be labeled as low risk. PMID:26173812

  15. Functional aging in the nervous system contributes to age-dependent motor activity decline in C. elegans.

    PubMed

    Liu, Jie; Zhang, Bi; Lei, Haoyun; Feng, Zhaoyang; Liu, Jianfeng; Hsu, Ao-Lin; Xu, X Z Shawn

    2013-09-01

    Aging is characterized by a progressive decline in multiple physiological functions (i.e., functional aging). As animals age, they exhibit a gradual loss in motor activity, but the underlying mechanisms remain unclear. Here we approach this question in C. elegans by functionally characterizing its aging nervous system and muscles. We find that motor neurons exhibit a progressive functional decline, beginning in early life. Surprisingly, body-wall muscles, which were previously thought to undergo functional aging, do not manifest such a decline until mid-late life. Notably, motor neurons first develop a deficit in synaptic vesicle fusion followed by that in quantal size and vesicle docking/priming, revealing specific functional deteriorations in synaptic transmission. Pharmacological stimulation of synaptic transmission can improve motor activity in aged animals. These results uncover a critical role for the nervous system in age-dependent motor activity decline in C. elegans and provide insights into how functional aging occurs in this organism.

  16. Default Mode Network Activity Predicts Early Memory Decline in Healthy Young Adults Aged 18-31.

    PubMed

    Nelson, Steven M; Savalia, Neil K; Fishell, Andrew K; Gilmore, Adrian W; Zou, Fan; Balota, David A; McDermott, Kathleen B

    2016-08-01

    Functional magnetic resonance imaging (fMRI) research conducted in healthy young adults is typically done with the assumption that this sample is largely homogeneous. However, studies from cognitive psychology suggest that long-term memory and attentional control begin to diminish in the third decade of life. Here, 100 participants between the ages of 18 and 31 learned Lithuanian translations of English words in an individual differences study using fMRI. Long-term memory ability was operationalized for each participant by deriving a memory score from 3 convergent measures. Age of participant predicted memory score in this cohort. In addition, degree of deactivation during initial encoding in a set of regions occurring largely in the default mode network (DMN) predicted both age and memory score. The current study demonstrates that early memory decline may partially be accounted for by failure to modulate activity in the DMN.

  17. Impact of decline-board squat exercises and knee joint angles on the muscle activity of the lower limbs

    PubMed Central

    Lee, Daehee; Lee, Sangyong; Park, Jungseo

    2015-01-01

    [Purpose] This study aims to investigate how squat exercises on a decline board and how the knee joint angles affect the muscle activity of the lower limbs. [Subjects] The subjects were 26 normal adults. [Methods] A Tumble Forms wedge device was used as the decline board, and the knee joint angles were measured with a goniometer. To examine the muscle activity of the biceps femoris, rectus femoris, gastrocnemius lateralis, and tibialis anterior of the lower limbs, a comparison analysis with electromyography was conducted. [Results] The muscle activity of the biceps femoris, rectus femoris, gastrocnemius lateralis, and tibialis anterior increased with increased knee joint angles, both for squat exercises on the decline board and on a flat floor. When the knee joint angle was 45°, 60°, and 90°, the muscle activity of the rectus femoris was significantly higher and that of the tibialis anterior was significantly lower during squat exercises on the decline board than on the flat floor. When the knee joint angle was 90°, the muscle activity of the gastrocnemius lateralis was significantly lower. [Conclusion] Squat exercises on a decline board are an effective intervention to increase the muscle activity of the rectus femoris with increased knee joint angles. PMID:26357447

  18. Resting spontaneous activity in the default mode network predicts performance decline during prolonged attention workload.

    PubMed

    Gui, Danyang; Xu, Sihua; Zhu, Senhua; Fang, Zhuo; Spaeth, Andrea M; Xin, Yuanyuan; Feng, Tingyong; Rao, Hengyi

    2015-10-15

    After continuous and prolonged cognitive workload, people typically show reduced behavioral performance and increased feelings of fatigue, which are known as "time-on-task (TOT) effects". Although TOT effects are pervasive in modern life, their underlying neural mechanisms remain elusive. In this study, we induced TOT effects by administering a 20-min continuous psychomotor vigilance test (PVT) to a group of 16 healthy adults and used resting-state blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to examine spontaneous brain activity changes associated with fatigue and performance. Behaviorally, subjects displayed robust TOT effects, as reflected by increasingly slower reaction times as the test progressed and higher self-reported mental fatigue ratings after the 20-min PVT. Compared to pre-test measurements, subjects exhibited reduced amplitudes of low-frequency fluctuation (ALFF) in the default mode network (DMN) and increased ALFF in the thalamus after the test. Subjects also exhibited reduced anti-correlations between the posterior cingulate cortex (PCC) and right middle prefrontal cortex after the test. Moreover, pre-test resting ALFF in the PCC and medial prefrontal cortex (MePFC) predicted subjects' subsequent performance decline; individuals with higher ALFF in these regions exhibited more stable reaction times throughout the 20-min PVT. These results support the important role of both task-positive and task-negative networks in mediating TOT effects and suggest that spontaneous activity measured by resting-state BOLD fMRI may be a marker of mental fatigue.

  19. Triclosan causes spontaneous abortion accompanied by decline of estrogen sulfotransferase activity in humans and mice.

    PubMed

    Wang, Xiaoli; Chen, Xiaojiao; Feng, Xuejiao; Chang, Fei; Chen, Minjian; Xia, Yankai; Chen, Ling

    2015-12-15

    Triclosan (TCS), an antibacterial agent, is identified in serum and urine of humans. Here, we show that the level of urinary TCS in 28.3% patients who had spontaneous abortion in mid-gestation were increased by 11.3-fold (high-TCS) compared with normal pregnancies. Oral administration of TCS (10 mg/kg/day) in mice (TCS mice) caused an equivalent urinary TCS level as those in the high-TCS abortion patients. The TCS-exposure from gestation day (GD) 5.5 caused dose-dependently fetal death during GD12.5-16.5 with decline of live fetal weight. GD15.5 TCS mice appeared placental thrombus and tissue necrosis with enhancement of platelet aggregation. The levels of placenta and plasma estrogen sulfotransferase (EST) mRNA and protein in TCS mice or high-TCS abortion patients were not altered, but their EST activities were significantly reduced compared to controls. Although the levels of serum estrogen (E2) in TCS mice and high-TCS abortion patients had no difference from controls, their ratio of sulfo-conjugated E2 and unconjugated E2 was reduced. The estrogen receptor antagonist ICI-182,780 prevented the enhanced platelet aggregation and placental thrombosis and attenuated the fetal death in TCS mice. The findings indicate that TCS-exposure might cause spontaneous abortion probably through inhibition of EST activity to produce placental thrombosis.

  20. Cool temperatures reduce antifungal activity of symbiotic bacteria of threatened amphibians--implications for disease management and patterns of decline.

    PubMed

    Daskin, Joshua H; Bell, Sara C; Schwarzkopf, Lin; Alford, Ross A

    2014-01-01

    Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), is a widespread disease of amphibians responsible for population declines and extinctions. Some bacteria from amphibians' skins produce antimicrobial substances active against Bd. Supplementing populations of these cutaneous antifungal bacteria might help manage chytridiomycosis in wild amphibians. However, the activity of protective bacteria may depend upon environmental conditions. Biocontrol of Bd in nature thus requires knowledge of how environmental conditions affect their anti-Bd activity. For example, Bd-driven amphibian declines have often occurred at temperatures below Bd's optimum range. It is possible these declines occurred due to reduced anti-Bd activity of bacterial symbionts at cool temperatures. Better understanding of the effects of temperature on chytridiomycosis development could also improve risk evaluation for amphibian populations yet to encounter Bd. We characterized, at a range of temperatures approximating natural seasonal variation, the anti-Bd activity of bacterial symbionts from the skins of three species of rainforest tree frogs (Litoria nannotis, Litoria rheocola, and Litoria serrata). All three species declined during chytridiomycosis outbreaks in the late 1980s and early 1990s and have subsequently recovered to differing extents. We collected anti-Bd bacterial symbionts from frogs and cultured the bacteria at constant temperatures from 8 °C to 33 °C. Using a spectrophotometric assay, we monitored Bd growth in cell-free supernatants (CFSs) from each temperature treatment. CFSs from 11 of 24 bacteria showed reduced anti-Bd activity in vitro when they were produced at cool temperatures similar to those encountered by the host species during population declines. Reduced anti-Bd activity of metabolites produced at low temperatures may, therefore, partially explain the association between Bd-driven declines and cool temperatures. We show that to avoid

  1. Cool Temperatures Reduce Antifungal Activity of Symbiotic Bacteria of Threatened Amphibians – Implications for Disease Management and Patterns of Decline

    PubMed Central

    Daskin, Joshua H.; Bell, Sara C.; Schwarzkopf, Lin; Alford, Ross A.

    2014-01-01

    Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), is a widespread disease of amphibians responsible for population declines and extinctions. Some bacteria from amphibians’ skins produce antimicrobial substances active against Bd. Supplementing populations of these cutaneous antifungal bacteria might help manage chytridiomycosis in wild amphibians. However, the activity of protective bacteria may depend upon environmental conditions. Biocontrol of Bd in nature thus requires knowledge of how environmental conditions affect their anti-Bd activity. For example, Bd-driven amphibian declines have often occurred at temperatures below Bd’s optimum range. It is possible these declines occurred due to reduced anti-Bd activity of bacterial symbionts at cool temperatures. Better understanding of the effects of temperature on chytridiomycosis development could also improve risk evaluation for amphibian populations yet to encounter Bd. We characterized, at a range of temperatures approximating natural seasonal variation, the anti-Bd activity of bacterial symbionts from the skins of three species of rainforest tree frogs (Litoria nannotis, Litoria rheocola, and Litoria serrata). All three species declined during chytridiomycosis outbreaks in the late 1980s and early 1990s and have subsequently recovered to differing extents. We collected anti-Bd bacterial symbionts from frogs and cultured the bacteria at constant temperatures from 8°C to 33°C. Using a spectrophotometric assay, we monitored Bd growth in cell-free supernatants (CFSs) from each temperature treatment. CFSs from 11 of 24 bacteria showed reduced anti-Bd activity in vitro when they were produced at cool temperatures similar to those encountered by the host species during population declines. Reduced anti-Bd activity of metabolites produced at low temperatures may, therefore, partially explain the association between Bd-driven declines and cool temperatures. We show that to avoid

  2. Active cognitive lifestyle associates with cognitive recovery and a reduced risk of cognitive decline.

    PubMed

    Marioni, Riccardo E; van den Hout, Ardo; Valenzuela, Michael J; Brayne, Carol; Matthews, Fiona E

    2012-01-01

    Education and lifestyle factors linked with complex mental activity are thought to affect the progression of cognitive decline. Collectively, these factors can be combined to create a cognitive reserve or cognitive lifestyle score. This study tested the association between cognitive lifestyle score and cognitive change in a population-based cohort of older persons from five sites across England and Wales. Data came from 13,004 participants of the Medical Research Council Cognitive Function and Ageing Study who were aged 65 years and over. Cognition was assessed at multiple waves over 16 years using the Mini-Mental State Examination. Subjects were grouped into four cognitive states (no impairment, slight impairment, moderate impairment, severe impairment) and cognitive lifestyle score was assessed as a composite measure of education, mid-life occupation, and current social engagement. A multi-state model was used to test the effect of cognitive lifestyle score on cognitive transitions. Hazard ratios for cognitive lifestyle score showed significant differences between those in the upper compared to the lower tertile with a more active cognitive lifestyle associating with: a decreased risk of moving from no to slight impairment (0.58, 95% CI (0.45, 0.74)); recovery from a slightly impaired state back to a non-impaired state (2.93 (1.35, 6.38)); but an increased mortality risk from a severely impaired state (1.28 (1.12, 1.45)). An active cognitive lifestyle is associated with a more favorable cognitive trajectory in older persons. Future studies would ideally incorporate neuroradiological and neuropathological data to determine if there is causal evidence for these associations. PMID:21971400

  3. Leg strength declines with advancing age despite habitual endurance exercise in active older adults.

    PubMed

    Marcell, Taylor J; Hawkins, Steven A; Wiswell, Robert A

    2014-02-01

    Age-associated loss of muscle mass (sarcopenia) and strength (dynapenia) is associated with a loss of independence that contributes to falls, fractures, and nursing home admissions, whereas regular physical activity has been suggested to offset these losses. The purpose of this study was to evaluate the effect of habitual endurance exercise on muscle mass and strength in active older adults. A longitudinal analysis of muscle strength (≈4.8 years apart) was performed on 59 men (age at start of study: 58.6 ± 7.3 years) and 35 women (56.9 ± 8.2 years) who used endurance running as their primary mode of exercise. There were no changes in fat-free mass although body fat increased minimally (1.0-1.5%). Training volume (km·wk, d·wk) decreased in both the men and women. There was a significant loss of both isometric knee extension (≈5% per year) and knee flexion (≈3.6% per year) strength in both the men and women. However, there was no significant change in either isokinetic concentric or eccentric torque of the knee extensors. Our data demonstrated a significant decline in isometric knee extensor and knee flexor strength although there were no changes in body mass in this group of very active older men and women. Our data support newer exercise guidelines for older Americans suggesting resistance training be an integral component of a fitness program and that running alone was not sufficient to prevent the loss in muscle strength (dynapenia) with aging.

  4. Activity patterns and time budgets of the declining sea otter population at Amchitka Island, Alaska

    USGS Publications Warehouse

    Gelatt, Thomas S.; Siniff, Donald B.; Estes, James A.

    2002-01-01

    Time budgets of predators may reflect population status if time spent foraging varies with local prey abun- dance. We assumed that the sea otter (Enhydra lutris) population at Amchitka Island, Alaska, USA, had been at equilibrium since the early 1960s and collected time budgets of otters to be used to represent future conditions of currently expanding sea otter populations. We used radiotelemetry to monitor activity-time budgets of otters from August 1992 to March 1994. Sea otter activity was directly linked to sex, age, weather condition, season, and time of day. Sea otters differed in percent time foraging among cohorts but not within cohorts. Percent time foraging ranged from 21% for females with very young (≤ 3weeks of age) dependent pups to 52% for females with old (≥10 weeks of age) pups. Otters foraged more and hauled out more as local sea conditions worsened. Adult males spent less time foraging during winter and spring, consistent with seasonal changes in prey selection. Time spent for- aging was similar to that reported for otters in California and an established population in Prince William Sound, Alaska, but greater than that of otters in recently established populations in Oregon and Alaska. Despite current evidence indicating that the population was in decline during our study, we were unable to recognize this change using time budgets. Our results illustrate the importance of stratifying analyses of activity patterns by age and sex cohorts and the complexity inherent in comparisons of behavioral data between different populations relying on distinct prey bases.

  5. Does decreased orographic enhancement explain declining annual streamflows and recent increases in wildfire fire activity in the Pacific Northwestern US?

    NASA Astrophysics Data System (ADS)

    Holden, Z. A.; Luce, C.; Morgan, P.; Crimmins, M.; Abatzoglou, J. T.

    2013-12-01

    The influences of changing snowpack on the hydrology of the western US have been well noted, with trends in snowpack declines, early streamflow timing and associated fire activity attributed primarily to warming temperatures. We present several lines of evidence suggesting that historical declines in high elevation precipitation have contributed to early snowmelt timing, reduced annual streamflow, and increased annual area burned in the Pacific Northwest. Using satellite-derived estimates of area burned and area burned severely, we show that annual flow, an integrator of basin-wide precipitation, explains three times as much of the variability in interannual wildfire activity as does the center of timing of annual flow absent the influence of flow variability. Precipitation and snowpack are fundamentally connected to the timing of snowmelt. Thus, while annual wildfire area burned is correlated with snowmelt timing, precipitation quantity and distribution provide a more direct mechanistic explanation of recent wildfire activity in this region. The magnitude of streamflow declines cannot be explained by either increased evapotranspiration or decreases in precipitation at low elevation weather stations, implicating declining orographic enhancement as a possible mechanism for the substantial declines in streamflow observed in recent decades.

  6. Resting Spontaneous Activity in the Default Mode Network Predicts Performance Decline during Prolonged Attention Workload

    PubMed Central

    Zhu, Senhua; Fang, Zhuo; Spaeth, Andrea M.; Xin, Yuanyuan; Feng, Tingyong; Rao, Hengyi

    2015-01-01

    After continuous and prolonged cognitive workload, people typically show reduced behavioral performance and increased feelings of fatigue, which are known as “time-on-task (TOT) effects”. Although TOT effects are pervasive in modern life, their underlying neural mechanisms remain elusive. In this study, we induced TOT effects by administering a 20-minute continuous psychomotor vigilance test (PVT) to a group of 16 healthy adults and used resting-state blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to examine spontaneous brain activity changes associated with fatigue and performance. Behaviorally, subjects displayed robust TOT effects, as reflected by increasingly slower reaction times as the test progressed and higher self-reported mental fatigue ratings after the 20-minute PVT. Compared to pre-test measurements, subjects exhibited reduced amplitudes of low-frequency fluctuation (ALFF) in the default mode network (DMN) and increased ALFF in the thalamus after the test. Subjects also exhibited reduced anti-correlations between the posterior cingulate cortex (PCC) and right middle prefrontal cortex after the test. Moreover, pre-test resting ALFF in the PCC and medial prefrontal cortex (MePFC) predicted subjects’ subsequent performance decline; individuals with higher ALFF in these regions exhibited more stable reaction times throughout the 20-minute PVT. These results support the important role of both task-positive and task-negative networks in mediating TOT effects and suggest that spontaneous activity measured by resting-state BOLD fMRI may be a marker of mental fatigue. PMID:26196666

  7. Running out of time: the decline of channel activity and nucleotide activation in adenosine triphosphate-sensitive K-channels

    PubMed Central

    Proks, Peter; Puljung, Michael C.; Vedovato, Natascia; Sachse, Gregor; Mulvaney, Rachel; Ashcroft, Frances M.

    2016-01-01

    KATP channels act as key regulators of electrical excitability by coupling metabolic cues—mainly intracellular adenine nucleotide concentrations—to cellular potassium ion efflux. However, their study has been hindered by their rapid loss of activity in excised membrane patches (rundown), and by a second phenomenon, the decline of activation by Mg-nucleotides (DAMN). Degradation of PI(4,5)P2 and other phosphoinositides is the strongest candidate for the molecular cause of rundown. Broad evidence indicates that most other determinants of rundown (e.g. phosphorylation, intracellular calcium, channel mutations that affect rundown) also act by influencing KATP channel regulation by phosphoinositides. Unfortunately, experimental conditions that reproducibly prevent rundown have remained elusive, necessitating post hoc data compensation. Rundown is clearly distinct from DAMN. While the former is associated with pore-forming Kir6.2 subunits, DAMN is generally a slower process involving the regulatory sulfonylurea receptor (SUR) subunits. We speculate that it arises when SUR subunits enter non-physiological conformational states associated with the loss of SUR nucleotide-binding domain dimerization following prolonged exposure to nucleotide-free conditions. This review presents new information on both rundown and DAMN, summarizes our current understanding of these processes and considers their physiological roles. This article is part of the themed issue ‘Evolution brings Ca2+ and ATP together to control life and death’. PMID:27377720

  8. Inhibition of Phosphatase Activity Follows Decline in Sulfatase Activity and Leads to Transcriptional Effects through Sustained Phosphorylation of Transcription Factor MITF

    PubMed Central

    Bhattacharyya, Sumit; Feferman, Leo; Tobacman, Joanne K.

    2016-01-01

    Arylsulfatase B (B-acetylgalactosamine 4-sulfatase; ARSB) is the enzyme that removes 4-sulfate groups from the non-reducing end of the glycosaminoglycans chondroitin 4-sulfate and dermatan sulfate. Decline in ARSB has been shown in malignant prostate, colonic, and mammary cells and tissues, and decline in ARSB leads to transcriptional events mediated by galectin-3 with AP-1 and Sp1. Increased mRNA expression of GPNMB (transmembrane glycoprotein NMB) in HepG2 cells and in hepatic tissue from ARSB-deficient mice followed decline in expression of ARSB and was mediated by the microphthalmia-associated transcription factor (MITF), but was unaffected by silencing galectin-3. Since GPNMB is increased in multiple malignancies, studies were performed to determine how decline in ARSB increased GPNMB expression. The mechanism by which decline in ARSB increased nuclear phospho-MITF was due to reduced activity of SHP2, a protein tyrosine phosphatase with Src homology (SH2) domains that regulates multiple cellular processes. SHP2 activity declined due to increased binding with chondroitin 4-sulfate when ARSB was reduced. When SHP2 activity was inhibited, phosphorylations of p38 mitogen-associated phosphokinase (MAPK) and of MITF increased, leading to GPNMB promoter activation. A dominant negative SHP2 construct, the SHP2 inhibitor PHSP1, and silencing of ARSB increased phospho-p38, nuclear MITF, and GPNMB. In contrast, constitutively active SHP2 and overexpression of ARSB inhibited GPNMB expression. The interaction between chondroitin 4-sulfate and SHP2 is a novel intersection between sulfation and phosphorylation, by which decline in ARSB and increased chondroitin 4-sulfation can inhibit SHP2, thereby regulating downstream tyrosine phosphorylations by sustained phosphorylations with associated activation of signaling and transcriptional events. PMID:27078017

  9. How is post-industrial decline associated with the geography of physical activity? Evidence from the Health Survey for England.

    PubMed

    Rind, Esther; Jones, Andy; Southall, Humphrey

    2014-03-01

    In recent decades, the prevalence of physical activity has declined considerably in many developed countries, which has been related to rising levels of obesity and several weight-related medical conditions, such as coronary heart disease. There is evidence that areas exhibiting particularly low levels of physical activity have undergone a strong transition away from employment in physically demanding occupations. It is proposed that such processes of deindustrialisation may be causally linked to unexplained geographical disparities in physical activity. This study investigates how geographical variations in deindustrialisation are associated with current levels of physical activity across different activity domains and relevant macro-economic time periods in England. The analysis includes data on 27,414 adults from the Health Survey for England 2006 and 2008 who reported total, occupational, domestic, recreational and walking activity. Based on employment change in industries associated with heavy manual work, a local measurement of industrial decline was developed, covering the period 1841-2001. We applied a multilevel modelling approach to study associations between industrial decline and physical activity. Results indicate that the process of deindustrialisation appears to be associated with patterns of physical activity and that this is independent of household income. The effects observed were generally similar for men and women. However, the nature of the association differed across areas, time periods and employment types; in particular, residents of districts characterised by a history of manufacturing and mining employment had increased odds of reporting low activity levels. We conclude that post-industrial change may be a factor in explaining present-day variations in physical activity, emphasising the plausible impact of inherited cultures and regional identities on health related behaviours.

  10. Decline of activity and quantity of ribulose bisphosphate carboxylase/oxygenase and net photosynthesis in ozone-treated potato foliage

    SciTech Connect

    Dann, M.S.; Pell, E.J. )

    1989-09-01

    The effect of ozone (O{sub 3}) on ribulose bisphosphate carboxylase/oxygenase (Rubisco) activity and quantity and net photosynthesis in greenhouse-grown Solanum tuberosum L. cv Norland foliage was studied in relation to oxidant-induced premature senescence. Plants, 26 days old, were exposed to 0.06 to 0.08 microliters per liter O{sub 3} from 1,000 to 1,600 hours for 4 days in a controlled environment chamber. On day 5, plants were exposed to a 6-hour simulated inversion in which O{sub 3} peaked at 0.12 microliters per liter. Net photosynthesis declined in response to O{sub 3} but recovered to near control levels 3 days after the exposure ended. Rubisco activity and quantity in control potato foliage increased and then decreased during the 12-day interval of the study. In some experiments foliage studied was physiologically mature and Rubisco activity had peaked when O{sub 3} exposure commenced. In those cases, O{sub 3} accelerated the decline in Rubisco activity. When less mature foliage was treated with O{sub 3}, the leaves never achieved the maximal level of Rubisco activity observed in control foliage and also exhibited more rapid decline in initial and total activity. Percent activation of Rubisco (initial/total activity) was not affected significantly by treatment. Quantity of Rubisco decreased in concert with activity. The reduction in the quantity of Rubisco, an important foliage storage protein, could contribute to premature senescence associated with toxicity of this air pollutant.

  11. Intellectual Decline.

    ERIC Educational Resources Information Center

    Guilford, J.P.

    In investigations of decline of intellectual status with age, cross-sectional and longitudinal studies give divergent results--the former show almost universal declines in test performances among older groups while the latter often show gains. Although few structure-of-intellect (SI) factors have been explored in relation to adult ages, two kinds…

  12. A Qualitative Study: African-American Girls' Perceptions of Why Physical Activity Declines in High School.

    PubMed

    Williams, Wanda M; Berry, Diane C

    2015-12-01

    African-American adolescent girls are less physically active than any other U.S. racial/ethnic group. The school environment may contribute to physical inactivity in this group. The purpose of this study was to explore African-American girls' perceptions offactors that contribute to girls being less physically active in high school. Interpretative Phenomenological Analysis (IPA) was used to identify individual perceptions of girls regarding physical activity. This resulted in four themes: personal appearances, scheduling/timing of classes, environmental/facilities issues, and lack of variety of activities in PE classes. Thefindings from this study indicated that African-American adolescent girls did not feel the physical or social school environment encouraged or supported them to be physically active. PMID:27045158

  13. Neuroprotective and nootropic activity of Clitorea ternatea Linn.(Fabaceae) leaves on diabetes induced cognitive decline in experimental animals

    PubMed Central

    Talpate, Karuna A.; Bhosale, Uma A.; Zambare, Mandar R.; Somani, Rahul S

    2014-01-01

    Purpose: Ethanol extract of Clitorea ternatea (EECT) was evaluated in diabetes-induced cognitive decline rat model for its nootropic and neuroprotective activity. Materials and Methods: Effect on spatial working memory, spatial reference memory and spatial working-reference memory was evaluated by Y maze, Morris water maze and Radial arm maze respectively. Neuroprotective effects of EECT was studied by assaying acetylcholinesterase, lipid peroxide, superoxide dismutase (SOD), total nitric oxide (NO), catalase (CAT) and glutathione (GSH) levels in the brain of diabetic rats. Results: The EECT (200 and 400 mg/kg) was found to cause significant increase in spatial working memory (P < 0.05), spatial reference memory (P < 0.001) and spatial working-reference (P < 0.001) in retention trials on Y maze, Morris water maze and Radial arm maze respectively. Whereas significant decrease in acetylcholinesterase activity (P < 0.05), lipid peroxide (P < 0.001), total NO (P < 0.001) and significant increase in SOD, CAT and GSH levels was observed in animals treated with EECT (200 and 400 mg/kg) compared to diabetic control group. Conclusions: The present data indicates that Clitorea ternatea tenders protection against diabetes induced cognitive decline and merits the need for further studies to elucidate its mode of action. PMID:24459404

  14. The declining prevalence of overweight among Russian children: income, diet, and physical activity behavior changes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Household income has been shown to be positively associated with overweight among post-Soviet Russian adults. The aim of this study is to examine the relationships among income, diet, physical activity behaviors and overweight among Russian children during a period of economic upheaval. Subjects inc...

  15. Declining Physical Activity Levels as an Unintended Consequence of Abolishing Mandatory Campus Service Fees

    ERIC Educational Resources Information Center

    Jones, Sandra C.; Barrie, Lance

    2011-01-01

    Objective: This study investigates the effect of the introduction of voluntary student unionism and subsequent increase in campus facility fees on engagement in physical activity on campus. Participants: Participants were 1,904 students from a large regional NSW (Australia) university across 3 time periods (926 in 2005, 504 in 2006, and 474 in…

  16. Scattering of sharply focused beams by arbitrarily shaped dielectric particles: an exact solution.

    PubMed

    Yeh, C; Colak, S; Barber, P

    1982-12-15

    By expanding the incident focused beam field in terms of its plane wave spectrum and by using the technique we developed earlier to treat the problem of the scattering of plane waves by arbitrarily shaped dielectric obstacles, we have been successful in solving the problem of the scattering of sharply focused beams by arbitrarily shaped dielectric particles. It was found that the presence of the curvature of the incident wave front and the nonuniformity of the incident wave intensity affect greatly the scattering characteristics.

  17. The Decline of Play and the Rise of Psychopathology in Children and Adolescents

    ERIC Educational Resources Information Center

    Gray, Peter

    2011-01-01

    Over the past half century, in the United States and other developed nations, children's free play with other children has declined sharply. Over the same period, anxiety, depression, suicide, feelings of helplessness, and narcissism have increased sharply in children, adolescents, and young adults. This article documents these historical changes…

  18. Modulation of Mitochondrial Complex I Activity Averts Cognitive Decline in Multiple Animal Models of Familial Alzheimer's Disease

    PubMed Central

    Zhang, Liang; Zhang, Song; Maezawa, Izumi; Trushin, Sergey; Minhas, Paras; Pinto, Matthew; Jin, Lee-Way; Prasain, Keshar; Nguyen, Thi D.T.; Yamazaki, Yu; Kanekiyo, Takahisa; Bu, Guojun; Gateno, Benjamin; Chang, Kyeong-Ok; Nath, Karl A.; Nemutlu, Emirhan; Dzeja, Petras; Pang, Yuan-Ping; Hua, Duy H.; Trushina, Eugenia

    2015-01-01

    Development of therapeutic strategies to prevent Alzheimer's disease (AD) is of great importance. We show that mild inhibition of mitochondrial complex I with small molecule CP2 reduces levels of amyloid beta and phospho-Tau and averts cognitive decline in three animal models of familial AD. Low-mass molecular dynamics simulations and biochemical studies confirmed that CP2 competes with flavin mononucleotide for binding to the redox center of complex I leading to elevated AMP/ATP ratio and activation of AMP-activated protein kinase in neurons and mouse brain without inducing oxidative damage or inflammation. Furthermore, modulation of complex I activity augmented mitochondrial bioenergetics increasing coupling efficiency of respiratory chain and neuronal resistance to stress. Concomitant reduction of glycogen synthase kinase 3β activity and restoration of axonal trafficking resulted in elevated levels of neurotrophic factors and synaptic proteins in adult AD mice. Our results suggest that metabolic reprogramming induced by modulation of mitochondrial complex I activity represents promising therapeutic strategy for AD. PMID:26086035

  19. [Economic activity of Third World women and perspectives on the decline of their fertility].

    PubMed

    Samman, M L

    1983-01-01

    Despite recent efforts to achieve a better understanding of the economic roles of women throughout the world, progress has been impeded by the lack of available statistical material concerning their employment. The importance of women's productive activity remains unrecognized in most of the Third World because it is largely accomplished outside the cash sector and is not included in any statistics. 72% of women in developing countries live in rural zones, where they are occupied in production, processing, storage, and preparation of foodstuffs. Many also assist the family budget by selling foodstuffs and craft products. The role of women in agriculture and commerce varies in different regions; it is estimated that 60-80% of agricultural labor in Africa and about 40% in Latin America is female. Third World women have also found employment in labor intensive industries such as electronics and textiles. The active female population grew from 1950-75 at 2.5%/1year in Asia, 1.9% in Africa, and 3.2% in Latin America. Major variations are seen in the female participation rates of countries within the same regions. The number of women working in the nonorganized sector is not known. Particularly in cities, most new jobs have been in the service sector. Prior to the spread of the capitalist mode of production, the productive and reproductive roles of women were equally significant and compatible, and women had a greater weight in family and community. With the separation of the cash and subsistence sectors, women were increasingly relegated to the least prestigious and least remunerative sectors. When forced to seek work in the modern sector, their lack of education and the persistence of traditional sexist practices allowed them to find only the least qualified, most poorly paid, and least secure jobs in the primary, secondary, or tertiary sectors. The introduction of technical development into Third World countries benefitted women very little, since it was usually

  20. Age-related decline of myelin proteins is highly correlated with activation of astrocytes and microglia in the rat CNS.

    PubMed

    Xie, Fang; Zhang, Jiu-Cong; Fu, Han; Chen, Jun

    2013-11-01

    It has been shown that aging can greatly influence the integrity and ultrastructure of white matter and the myelin sheath; however, studies regarding the effects of aging on the expression of myelin proteins are still limited. In the present study, immunohistochemical mapping was used to investigate the overall expression of myelin basic protein (Mbp) and myelin oligodendrocyte glycoprotein (Mog) in the central nervous system (CNS) of rats in postnatal months 2, 5, 18 and 26. Astrocyte and microglia activation was also detected by glial fibrillary acidic protein (GFAP) or ionized calcium-binding adaptor molecule 1 (Iba1) staining and western blotting. A significant decline of Mbp and Mog was identified as a universal alteration in the CNS of aged rats. Aging also induced significant astrocyte and microglial activation. Correlation analysis indicated a negative correlation between the reduction of age‑related myelin proteins and glial activation in aging. This correlation of myelin breakdown and glial activation in aging may reveal new evidence in connecting the inflammation and myelin breakdown mechanism of age‑related neurodegenerative diseases.

  1. Diffraction from sharply peaked waves as an ocean surface scattering mechanism

    NASA Technical Reports Server (NTRS)

    Jensen, Glenn A.; Vesecky, John F.; Glazman, Roman E.

    1992-01-01

    The role of sharply peaked waves as a major ocean scattering mechanism for radar is investigated. A prototype three-dimensional wedgelike wave shape was constructed, and its scattering properties were analyzed. Using results from the theory of the statistical geometry of the ocean surface, it is estimated how many such wedges there are per unit area, as a function of sea conditions. Taking into account a directional distribution of the wedges, the total radar cross section due to wedge diffraction effects is estimated. At large incidence angles, wedge diffraction appears to account for a significant amount of the radar cross section on the ocean surface. The wedgelike wave shape used is a more realistic representation of sharplypeaked waves. The scale-size and spatial density of the wedgelike waves are computed directly from the wave-height spectrum.

  2. Loss of SYNJ1 dual phosphatase activity leads to early onset refractory seizures and progressive neurological decline.

    PubMed

    Hardies, Katia; Cai, Yiying; Jardel, Claude; Jansen, Anna C; Cao, Mian; May, Patrick; Djémié, Tania; Hachon Le Camus, Caroline; Keymolen, Kathelijn; Deconinck, Tine; Bhambhani, Vikas; Long, Catherine; Sajan, Samin A; Helbig, Katherine L; Suls, Arvid; Balling, Rudi; Helbig, Ingo; De Jonghe, Peter; Depienne, Christel; De Camilli, Pietro; Weckhuysen, Sarah

    2016-09-01

    SYNJ1 encodes a polyphosphoinositide phosphatase, synaptojanin 1, which contains two consecutive phosphatase domains and plays a prominent role in synaptic vesicle dynamics. Autosomal recessive inherited variants in SYNJ1 have previously been associated with two different neurological diseases: a recurrent homozygous missense variant (p.Arg258Gln) that abolishes Sac1 phosphatase activity was identified in three independent families with early onset parkinsonism, whereas a homozygous nonsense variant (p.Arg136*) causing a severe decrease of mRNA transcript was found in a single patient with intractable epilepsy and tau pathology. We performed whole exome or genome sequencing in three independent sib pairs with early onset refractory seizures and progressive neurological decline, and identified novel segregating recessive SYNJ1 defects. A homozygous missense variant resulting in an amino acid substitution (p.Tyr888Cys) was found to impair, but not abolish, the dual phosphatase activity of SYNJ1, whereas three premature stop variants (homozygote p.Trp843* and compound heterozygote p.Gln647Argfs*6/p.Ser1122Thrfs*3) almost completely abolished mRNA transcript production. A genetic follow-up screening in a large cohort of 543 patients with a wide phenotypical range of epilepsies and intellectual disability revealed no additional pathogenic variants, showing that SYNJ1 deficiency is rare and probably linked to a specific phenotype. While variants leading to early onset parkinsonism selectively abolish Sac1 function, our results provide evidence that a critical reduction of the dual phosphatase activity of SYNJ1 underlies a severe disorder with neonatal refractory epilepsy and a neurodegenerative disease course. These findings further expand the clinical spectrum of synaptic dysregulation in patients with severe epilepsy, and emphasize the importance of this biological pathway in seizure pathophysiology. PMID:27435091

  3. Stickiness in Hamiltonian systems: from sharply divided to hierarchical phase space.

    PubMed

    Altmann, Eduardo G; Motter, Adilson E; Kantz, Holger

    2006-02-01

    We investigate the dynamics of chaotic trajectories in simple yet physically important Hamiltonian systems with nonhierarchical borders between regular and chaotic regions with positive measures. We show that the stickiness to the border of the regular regions in systems with such a sharply divided phase space occurs through one-parameter families of marginally unstable periodic orbits and is characterized by an exponent gamma=2 for the asymptotic power-law decay of the distribution of recurrence times. Generic perturbations lead to systems with hierarchical phase space, where the stickiness is apparently enhanced due to the presence of infinitely many regular islands and Cantori. In this case, we show that the distribution of recurrence times can be composed of a sum of exponentials or a sum of power laws, depending on the relative contribution of the primary and secondary structures of the hierarchy. Numerical verification of our main results are provided for area-preserving maps, mushroom billiards, and the newly defined magnetic mushroom billiards. PMID:16605429

  4. Effect of fast pH decline during the early postmortem period on calpain activity and cytoskeletal protein degradation of broiler M. pectoralis major.

    PubMed

    Huang, J C; Yang, J; Huang, F; Huang, M; Chen, K J; Xu, X L; Zhou, G H

    2016-10-01

    The objective of this study was to determine the effects of fast pH decline during the early postmortem period on calpain activity and the degradation of cytoskeletal proteins in broilers. Eighty broilers were randomly categorized into two groups: physical restraint (PR) and free struggle (FS). M. pectoralis major (PM) was used for determination of calpain activity, shear value, ultrastructure of myofibrils, and the degradation of desmin, titin, nebulin, and troponin-T. The pH (6.05) of FS group is significantly low than PR group (6.38) at 0.3 h postmortem. Fast pH decline during the early postmortem period led to a decrease of μ/m-calpain activities at 0.3 and 3 h postmortem (P < 0.05), but did not affect the ultimate μ/m-calpain activity. An initial fast decrease in pH increased the degradation of desmin, titin, nebulin, and increased the 30 kDa degradation fragments of troponin-T. Therefore, the fast pH decline during the early postmortem period decreased the μ/m-calpain activity and increased the degradation of cytoskeletal proteins in broiler muscle. It is possible that the fast pH decline experienced an earlier activation of calpains that resulted in earlier protein degradation and ultimately lower shear force.

  5. Digestive enzyme activities in larvae of sharpsnout seabream (Diplodus puntazzo).

    PubMed

    Suzer, Cüneyt; Aktülün, Sevim; Coban, Deniz; Okan Kamaci, H; Saka, Sahin; Firat, Kürşat; Alpbaz, Atilla

    2007-10-01

    The ontogenesis and specific activities of pancreatic and intestinal enzymes were investigated in sharpsnout sea bream, Diplodus puntazzo, during larval development until the end of weaning on day 50. The green-water technique was carried out for larval rearing in triplicate. Trypsin was first detected as early as hatching and sharply increased related to age and exogenous feeding until day 25, but a sharp decrease was observed towards the end of the experiment. Amylase was determined 2 days after hatching (DAH) and sharply increased to 10 DAH. Afterwards, slight decreases were found between 10 and 20 DAH and then slow alterations were continued until end of the experiment. Lipase was measured for the first time on day 4, and then slight increase was found to 25 DAH. After this date, slow variations were maintained until end of the experiment. Pepsin was firstly assayed 32 DAH related with stomach formation and sharply increased to 40 DAH. Then it was fluctuated until end of the experiment. Enzymes of brush border membranes, alkaline phosphatase and aminopeptidase N, showed similar pattern on specific activities during the first 10 days. Thereafter, while specific activity of alkaline phosphatase slightly decreased to 15 DAH and fluctuated until 20 DAH, aminopeptidase N activity slowly declined to 20 DAH. Afterwards, activity of alkaline phosphatase and aminopeptidase N were sharply increased to 30 DAH, showing maturation of the intestinal digestive process and also these activities continued to slight increase until end of the experiment. The specific activity of cytosolic peptidase, leucine-alanine peptidase sharply increased to on day 8, then suddenly declined to 12 DAH and further decreased until 20 DAH. After this date, in contrast to enzymes of brush border membranes, it sharply decreased to 25 DAH and continued to gradually decline until the end of the experiment. These converse expressions were indicative of a maturation of enterocytes and the transition to

  6. Digestive enzyme activities in larvae of sharpsnout seabream (Diplodus puntazzo).

    PubMed

    Suzer, Cüneyt; Aktülün, Sevim; Coban, Deniz; Okan Kamaci, H; Saka, Sahin; Firat, Kürşat; Alpbaz, Atilla

    2007-10-01

    The ontogenesis and specific activities of pancreatic and intestinal enzymes were investigated in sharpsnout sea bream, Diplodus puntazzo, during larval development until the end of weaning on day 50. The green-water technique was carried out for larval rearing in triplicate. Trypsin was first detected as early as hatching and sharply increased related to age and exogenous feeding until day 25, but a sharp decrease was observed towards the end of the experiment. Amylase was determined 2 days after hatching (DAH) and sharply increased to 10 DAH. Afterwards, slight decreases were found between 10 and 20 DAH and then slow alterations were continued until end of the experiment. Lipase was measured for the first time on day 4, and then slight increase was found to 25 DAH. After this date, slow variations were maintained until end of the experiment. Pepsin was firstly assayed 32 DAH related with stomach formation and sharply increased to 40 DAH. Then it was fluctuated until end of the experiment. Enzymes of brush border membranes, alkaline phosphatase and aminopeptidase N, showed similar pattern on specific activities during the first 10 days. Thereafter, while specific activity of alkaline phosphatase slightly decreased to 15 DAH and fluctuated until 20 DAH, aminopeptidase N activity slowly declined to 20 DAH. Afterwards, activity of alkaline phosphatase and aminopeptidase N were sharply increased to 30 DAH, showing maturation of the intestinal digestive process and also these activities continued to slight increase until end of the experiment. The specific activity of cytosolic peptidase, leucine-alanine peptidase sharply increased to on day 8, then suddenly declined to 12 DAH and further decreased until 20 DAH. After this date, in contrast to enzymes of brush border membranes, it sharply decreased to 25 DAH and continued to gradually decline until the end of the experiment. These converse expressions were indicative of a maturation of enterocytes and the transition to

  7. Systemic lupus erythematosus in a multiethnic U.S. cohort (LUMINA) XXVII: factors predictive of a decline to low levels of disease activity.

    PubMed

    Bertoli, A M; Alarcón, G S; McGwin, G; Fernández, M; Bastian, H M; Fessler, B J; Vilá, L M; Reveille, J D

    2006-01-01

    The objective of this study was to examine factors predictive of a decline to low levels of disease activity in a cohort of systemic lupus erythematosus (SLE) patients. Patients with SLE of Hispanic (from Texas or Puerto Rico), African-American or Caucasian ethnicity from a multiethnic cohort were included. A decline to low levels of disease activity was defined as a score < or =5 as per the Systemic Lupus Activity Measure-Revised (SLAM-R) at any annual study visit if preceded by a SLAM-R > or =8. Using Generalized Estimating Equation (GEE), socioeconomic-demographic, behavioral, function, psychological, laboratory and clinical data [disease manifestations, number of ACR criteria accrued at diagnosis and damage accrual as per the Systemic Lupus International Collaborating Clinics (SLICC) Damage Index (SDI)] from the visit preceding that meeting the definition were examined as predictors of decline to low levels of disease activity. Two-hundred and eighty-seven patients (67 Hispanics from Texas, 32 Hispanics form Puerto Rico, 120 African-Americans and 68 Caucasians), accounting for 632 visits were analyzed. In the GEE multivariable analysis, higher degrees of social support (OR = 1.208, 95% CI 1.059-1.379; P = 0.005) were predictive of a decline to low levels of disease activity, while the number of ACR criteria accrued at diagnosis (OR = 0.765, 95% CI 0.631-0.927; P = 0.006) and damage (OR = 0.850, 95% CI 0.743-0.972, P = 0.018) were negatively associated. These data suggest that a decline to low levels of disease activity in lupus patients seems to be multifactorial; this study also underscores the importance of social support for lupus patients.

  8. Implementing Change to Arrest the Decline in Moderate to Vigorous Physical Activity (MVPA) for Adolescent Girls in Two Rural and Regional High Schools: A Case Study Approach

    ERIC Educational Resources Information Center

    Miller, Judith; Puglisi, Lauren; Perry, Janine

    2012-01-01

    Inactivity has been linked to a range of lifestyle conditions such as hypertension, type II diabetes and cardiovascular disease (World Health Organisation, 2009). Engagement in physical activity and in sport has been consistently reported to decline as the general population ages (Telama et al., 2005). In particular, the age of adolescence has…

  9. Does Increasing Reliance on Student Debt Explain Declines in Entrepreneurial Activity? Posing the Question, Gathering Evidence, Considering Policy Options. Research Report

    ERIC Educational Resources Information Center

    Baum, Sandy

    2015-01-01

    In recent years, concerns have emerged both about declines in entrepreneurial activity, and about increases in the amount students borrow to finance postsecondary education--in the aggregate as well as on average. Because the financial obligations associated with student debt could limit access to credit for individuals seeking to start…

  10. Brief light stimulation during the mouse nocturnal activity phase simultaneously induces a decline in core temperature and locomotor activity followed by EEG-determined sleep

    PubMed Central

    Studholme, Keith M.; Gompf, Heinrich S.

    2013-01-01

    Light exerts a variety of effects on mammals. Unexpectedly, one of these effects is the cessation of nocturnal locomotion and the induction of behavioral sleep (photosomnolence). Here, we extend the initial observations in several ways, including the fundamental demonstration that core body temperature (Tc) drops substantially (about 1.5°C) in response to the light stimulation at CT15 or CT18 in a manner suggesting that the change is a direct response to light rather than simply a result of the locomotor suppression. The results show that 1) the decline of locomotion and Tc begin soon after nocturnal light stimulation; 2) the variability in the magnitude and onset of light-induced locomotor suppression is very large, whereas the variability in Tc is very small; 3) Tc recovers from the light-induced decline in advance of the recovery of locomotion; 4) under entrained and freerunning conditions, the daily late afternoon Tc increase occurs in advance of the corresponding increase in wheel running; and 5) toward the end of the subjective night, the nocturnally elevated Tc persists longer than does locomotor activity. Finally, EEG measurements confirm light-induced sleep and, when Tc or locomotion was measured, show their temporal association with sleep onset. Both EEG- and immobility-based sleep detection methods confirm rapid induction of light-induced sleep. The similarities between light-induced loss of locomotion and drop in Tc suggest a common cause for parallel responses. The photosomnolence response may be contingent upon both the absence of locomotion and a simultaneous low Tc. PMID:23364525

  11. Decline of Activity and Quantity of Ribulose Bisphosphate Carboxylase/Oxygenase and Net Photosynthesis in Ozone-Treated Potato Foliage 1

    PubMed Central

    Dann, Michael S.; Pell, Eva J.

    1989-01-01

    The effect of ozone (O3) on ribulose bisphosphate carboxylase/oxygenase (Rubisco) activity and quantity and net photosynthesis in greenhouse-grown Solanum tuberosum L. cv `Norland' foliage was studied in relation to oxidant-induced premature senescence. Plants, 26 days old, were exposed to 0.06 to 0.08 microliters per liter O3 from 1000 to 1600 hours for 4 days in a controlled environment chamber. On day 5, plants were exposed to a 6-hour simulated inversion in which O3 peaked at 0.12 microliters per liter. Net photosynthesis declined in response to O3 but recovered to near control levels 3 days after the exposure ended. Rubisco activity and quantity in control potato foliage increased and then decreased during the 12-day interval of the study. In some experiments foliage studied was physiologically mature and Rubisco activity had peaked when O3 exposure commenced. In those cases, O3 accelerated the decline in Rubisco activity. When less mature foliage was treated with O3, the leaves never achieved the maximal level of Rubisco activity observed in control foliage and also exhibited more rapid decline in initial and total activity. Percent activation of Rubisco (initial/total activity) was not affected significantly by treatment. Quantity of Rubisco decreased in concert with activity. The decrease in activities is most likely due to a decrease in available protein rather than a decrease in the percentage of Rubisco activated in vivo. The reduction in the quantity of Rubisco, an important foliar storage protein, could contribute to premature senescence associated with toxicity of this air pollutant. PMID:16667037

  12. The Aftermath of Decline.

    ERIC Educational Resources Information Center

    Cameron, Kim S.; Chaffee, Ellen Earle

    Differences between declining colleges and colleges not experiencing decline were investigated, along with dysfunctional organizational consequences that may be associated with decline. Attention is directed to 12 negative attributes resulting from conditions of decline, seven of which were found to be significant: no innovation, scapegoating,…

  13. DNA twisting flexibility and the formation of sharply looped protein-DNA complexes

    NASA Astrophysics Data System (ADS)

    Cloutier, T. E.; Widom, J.

    2005-03-01

    Gene-regulatory complexes often require that pairs of DNA-bound proteins interact by looping-out short (often 100-bp) stretches of DNA. The loops can vary in detailed length and sequence and, thus, in total helical twist, which radically alters their geometry. How this variability is accommodated structurally is not known. Here we show that the inherent twistability of 89- to 105-bp DNA circles exceeds theoretical expectation by up to 400-fold. These results can be explained only by greatly enhanced DNA flexibility, not by permanent bends. They invalidate the use of classic theories of flexibility for understanding sharp DNA looping but support predictions of two recent theories. Our findings imply an active role for DNA flexibility in loop formation and suggest that variability in the detailed helical twist of regulatory loops is accommodated naturally by the inherent twistability of the DNA. activation | gene regulation | repression

  14. Declines in the Lethality of Suicide Attempts Explain the Decline in Suicide Deaths in Australia

    PubMed Central

    Spittal, Matthew J.; Pirkis, Jane; Miller, Matthew; Studdert, David M.

    2012-01-01

    Background To investigate the epidemiology of a steep decrease in the incidence of suicide deaths in Australia. Methods National data on suicide deaths and deliberate self-harm for the period 1994–2007 were obtained from the Australian Institute of Health and Welfare. We calculated attempt and death rates for five major methods and the lethality of these methods. Negative binomial regression was used to estimate the size and significance of method-specific time-trends in attempts and lethality. Results Hanging, motor vehicle exhaust and firearms were the most lethal methods, and together accounted for 72% of all deaths. The lethality of motor vehicle exhaust attempts decreased sharply (RR = 0.94 per year, 95% CI 0.93–0.95) while the motor vehicle exhaust attempt rate changed little; this combination of motor vehicle exhaust trends explained nearly half of the overall decline in suicide deaths. Hanging lethality also decreased sharply (RR = 0.96 per year, 95% CI 0.956–0.965) but large increases in hanging attempts negated the effect on death rates. Firearm lethality changed little while attempts decreased. Conclusion Declines in the lethality of suicide attempts–especially attempts by motor vehicle exhaust and hanging–explain the remarkable decline in deaths by suicide in Australia since 1997. PMID:22957084

  15. 30 CFR 203.54 - How does my relief arrangement for an oil and gas lease operate if prices rise sharply?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false How does my relief arrangement for an oil and gas lease operate if prices rise sharply? 203.54 Section 203.54 Mineral Resources BUREAU OF SAFETY AND... operate if prices rise sharply? In those months when your current reference price rises by at least...

  16. 30 CFR 203.54 - How does my relief arrangement for an oil and gas lease operate if prices rise sharply?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false How does my relief arrangement for an oil and gas lease operate if prices rise sharply? 203.54 Section 203.54 Mineral Resources BUREAU OF SAFETY AND... operate if prices rise sharply? In those months when your current reference price rises by at least...

  17. 30 CFR 203.54 - How does my relief arrangement for an oil and gas lease operate if prices rise sharply?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false How does my relief arrangement for an oil and gas lease operate if prices rise sharply? 203.54 Section 203.54 Mineral Resources BUREAU OF SAFETY AND... operate if prices rise sharply? In those months when your current reference price rises by at least...

  18. 30 CFR 203.54 - How does my relief arrangement for an oil and gas lease operate if prices rise sharply?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... gas lease operate if prices rise sharply? 203.54 Section 203.54 Mineral Resources BUREAU OF OCEAN... Leases § 203.54 How does my relief arrangement for an oil and gas lease operate if prices rise sharply? In those months when your current reference price rises by at least 25 percent above your...

  19. Age-Related Declines in General Cognitive Abilities of Balb/C Mice and General Activity Are Associated with Disparities in Working Memory, Body Weight, and General Activity

    ERIC Educational Resources Information Center

    Matzel, Louis D.; Grossman, Henya; Light, Kenneth; Townsend, David; Kolata, Stefan

    2008-01-01

    A defining characteristic of age-related cognitive decline is a deficit in general cognitive performance. Here we use a testing and analysis regimen that allows us to characterize the general learning abilities of young (3-5 mo old) and aged (19-21 mo old) male and female Balb/C mice. Animals' performance was assessed on a battery of seven diverse…

  20. Postnatal growth hormone deficiency in growing rats causes marked decline in the activity of spinal cord acetylcholinesterase but not butyrylcholinesterase.

    PubMed

    Koohestani, Faezeh; Brown, Chester M; Meisami, Esmail

    2012-11-01

    The effects of growth hormone (GH) deficiency on the developmental changes in the abundance and activity of cholinesterase enzymes were studied in the developing spinal cord (SC) of postnatal rats by measuring the specific activity of acetylcholinesterase (AChE), a marker for cholinergic neurons and their synaptic compartments, and butyrylcholinesterase (BuChE), a marker for glial cells and neurovascular cells. Specific activities of these two enzymes were measured in SC tissue of 21- and 90 day-old (P21, weaning age; P90, young adulthood) GH deficient spontaneous dwarf (SpDwf) mutant rats which lack anterior pituitary and circulating plasma GH, and were compared with SC tissue of normal age-matched control animals. Assays were carried out for AChE and BuChE activity in the presence of their specific chemical inhibitors, BW284C51 and iso-OMPA, respectively. Results revealed that mean AChE activity was markedly and significantly reduced [28% at P21, 49% at P90, (p<0.01)] in the SC of GH deficient rats compared to age-matched controls. GH deficiency had a higher and more significant effect on AChE activity of the older (P90) rats than the younger ones (P21) ones. In contrast, BuChE activity in SC showed no significant changes in GH deficient rats at either of the two ages studied. Results imply that, in the absence of pituitary GH, the postnatal proliferation of cholinergic synapses in the rat SC, a CNS structure, where AChE activity is abundant, is markedly reduced during both the pre- and postweaning periods; more so in the postweaning than preweaning ages. In contrast, the absence of any effects on BuChE activity implies that GH does not affect the development of non-neuronal elements, e.g., glia, as much as the neuronal and synaptic compartments of the developing rat SC. PMID:22922167

  1. Postnatal growth hormone deficiency in growing rats causes marked decline in the activity of spinal cord acetylcholinesterase but not butyrylcholinesterase.

    PubMed

    Koohestani, Faezeh; Brown, Chester M; Meisami, Esmail

    2012-11-01

    The effects of growth hormone (GH) deficiency on the developmental changes in the abundance and activity of cholinesterase enzymes were studied in the developing spinal cord (SC) of postnatal rats by measuring the specific activity of acetylcholinesterase (AChE), a marker for cholinergic neurons and their synaptic compartments, and butyrylcholinesterase (BuChE), a marker for glial cells and neurovascular cells. Specific activities of these two enzymes were measured in SC tissue of 21- and 90 day-old (P21, weaning age; P90, young adulthood) GH deficient spontaneous dwarf (SpDwf) mutant rats which lack anterior pituitary and circulating plasma GH, and were compared with SC tissue of normal age-matched control animals. Assays were carried out for AChE and BuChE activity in the presence of their specific chemical inhibitors, BW284C51 and iso-OMPA, respectively. Results revealed that mean AChE activity was markedly and significantly reduced [28% at P21, 49% at P90, (p<0.01)] in the SC of GH deficient rats compared to age-matched controls. GH deficiency had a higher and more significant effect on AChE activity of the older (P90) rats than the younger ones (P21) ones. In contrast, BuChE activity in SC showed no significant changes in GH deficient rats at either of the two ages studied. Results imply that, in the absence of pituitary GH, the postnatal proliferation of cholinergic synapses in the rat SC, a CNS structure, where AChE activity is abundant, is markedly reduced during both the pre- and postweaning periods; more so in the postweaning than preweaning ages. In contrast, the absence of any effects on BuChE activity implies that GH does not affect the development of non-neuronal elements, e.g., glia, as much as the neuronal and synaptic compartments of the developing rat SC.

  2. Computer Simulation for the Crossing Time in a Diploid, Asymmetric, Sharply-Peaked Landscape in the Infinite Population Limit

    NASA Astrophysics Data System (ADS)

    Gill, Wonpyong

    2013-12-01

    This study calculated the crossing time in the diploid mutation-selection model in an infinite population limit for various dominance parameters, h, and selective advantages, by switching on a diploid, asymmetric, sharply-peaked landscape, from an initial state which is the steady state in a diploid, sharply-peaked landscape. The crossing time for h < 1 was found to diverge at the critical fitness parameter, which increased with increasing selective advantage and decreased with increasing sequence length. When the sequence length was increased with a fixed extension parameter, there was no crossing time for h < 1 when the sequence length was longer than the critical sequence length, which increased with increasing selective advantage. The crossing time for h ≤ 1 was found to be an exponentially increasing function of the sequence length, and the crossing time for h > 1 became saturated at a long sequence length. The crossing time decreased with increasing selective advantage, mainly because the larger selective advantage caused the increase in relative density of the reversal allele to grow exponentially at an earlier time.

  3. Adolescence Intellectual Decline.

    ERIC Educational Resources Information Center

    Campbell, Patricia B.

    The purposes of this study were to investigate adolescent intellectual decline, and to attempt to determine some of the sexual differences possibly inherent in the phenomenon. It was hypothesized that (1) girls would decline in greater numbers and to a greater degree than boys; and (2) areas and amounts of sex differences of the decliners would…

  4. The Management of Decline

    ERIC Educational Resources Information Center

    Boulding, Kenneth E.

    1975-01-01

    With the probability of declining enrollments education needs, according to the author, to develop administrators skilled in adjusting to decline. He notes what educators can learn from the decline of agriculture and railroads and points up the need to get out from under the grants economy. (JT)

  5. [Decline of Activity and Shifts in the Methanotrophic Community Structure of an Ombrotrophic Peat Bog after Wildfire].

    PubMed

    Danilova, O V; Belova, S E; Kulichevskaya, I S; Dedysh, S N

    2015-01-01

    This study examined potential disturbances of methanotrophic communities playing a key role in reducing methane emissions from the peat bog Tasin Borskoye, Vladimir oblast, Russia as a result of the 2007 wildfire. The potential activity of the methane-oxidizing filter in the burned peatland site and the abundance of indigenous methanotrophic bacteria were significantly reduced in comparison to the undisturbed site. Molecular analysis of methanotrophic community structure by means of PCR amplification and cloning of the pmoAgene encoding particulate methane monooxygenase revealed the replacement of typical peat-inhabiting, acidophilic type II methanotrophic bacteria with type I methanotrophs, which are less active in acidic environments. In summary, both the structure and the activity of the methane-oxidizing filter in burned peatland sites underwent significant changes, which were clearly pronounced even after 7 years of the natural ecosystem recovery. These results point to the long-term character of the disturbances caused by wildfire in peatlands.

  6. [Decline of Activity and Shifts in the Methanotrophic Community Structure of an Ombrotrophic Peat Bog after Wildfire].

    PubMed

    Danilova, O V; Belova, S E; Kulichevskaya, I S; Dedysh, S N

    2015-01-01

    This study examined potential disturbances of methanotrophic communities playing a key role in reducing methane emissions from the peat bog Tasin Borskoye, Vladimir oblast, Russia as a result of the 2007 wildfire. The potential activity of the methane-oxidizing filter in the burned peatland site and the abundance of indigenous methanotrophic bacteria were significantly reduced in comparison to the undisturbed site. Molecular analysis of methanotrophic community structure by means of PCR amplification and cloning of the pmoAgene encoding particulate methane monooxygenase revealed the replacement of typical peat-inhabiting, acidophilic type II methanotrophic bacteria with type I methanotrophs, which are less active in acidic environments. In summary, both the structure and the activity of the methane-oxidizing filter in burned peatland sites underwent significant changes, which were clearly pronounced even after 7 years of the natural ecosystem recovery. These results point to the long-term character of the disturbances caused by wildfire in peatlands. PMID:27169243

  7. Slowing of Hippocampal Activity Correlates with Cognitive Decline in Early Onset Alzheimer's Disease. An MEG Study with Virtual Electrodes.

    PubMed

    Engels, Marjolein M A; Hillebrand, Arjan; van der Flier, Wiesje M; Stam, Cornelis J; Scheltens, Philip; van Straaten, Elisabeth C W

    2016-01-01

    Pathology in Alzheimer's disease (AD) starts in the entorhinal cortex and hippocampus. Because of their deep location, activity from these areas is difficult to record with conventional electro- or magnetoencephalography (EEG/MEG). The purpose of this study was to explore hippocampal activity in AD patients and healthy controls using "virtual MEG electrodes". We used resting-state MEG recordings from 27 early onset AD patients [age 60.6 ± 5.4, 12 females, mini-mental state examination (MMSE) range: 19-28] and 26 cognitively healthy age- and gender-matched controls (age 61.8 ± 5.5, 14 females). Activity was reconstructed using beamformer-based virtual electrodes for 78 cortical regions and 6 hippocampal regions. Group differences in peak frequency and relative power in six frequency bands were identified using permutation testing. For the patients, spearman correlations between the MMSE scores and peak frequency or relative power were calculated. Moreover, receiver operator characteristic curves were plotted to estimate the diagnostic accuracy. We found a lower hippocampal peak frequency in AD compared to controls, which, in the patients, correlated positively with MMSE [r(25) = 0.61; p < 0.01] whereas hippocampal relative theta power correlated negatively with MMSE [r(25) = -0.54; p < 0.01]. Cortical peak frequency was also lower in AD in association areas. Furthermore, cortical peak frequency correlated positively with MMSE [r(25) = 0.43; p < 0.05]. In line with this finding, relative theta power was higher in AD across the cortex, and relative alpha and beta power was lower in more circumscribed areas. The average cortical relative theta power was the best discriminator between AD and controls (sensitivity 82%; specificity 81%). Using beamformer-based virtual electrodes, we were able to detect hippocampal activity in AD. In AD, this hippocampal activity is slowed, and correlates better with cognition than the (slowed) activity in cortical areas. On the other

  8. Slowing of Hippocampal Activity Correlates with Cognitive Decline in Early Onset Alzheimer's Disease. An MEG Study with Virtual Electrodes.

    PubMed

    Engels, Marjolein M A; Hillebrand, Arjan; van der Flier, Wiesje M; Stam, Cornelis J; Scheltens, Philip; van Straaten, Elisabeth C W

    2016-01-01

    Pathology in Alzheimer's disease (AD) starts in the entorhinal cortex and hippocampus. Because of their deep location, activity from these areas is difficult to record with conventional electro- or magnetoencephalography (EEG/MEG). The purpose of this study was to explore hippocampal activity in AD patients and healthy controls using "virtual MEG electrodes". We used resting-state MEG recordings from 27 early onset AD patients [age 60.6 ± 5.4, 12 females, mini-mental state examination (MMSE) range: 19-28] and 26 cognitively healthy age- and gender-matched controls (age 61.8 ± 5.5, 14 females). Activity was reconstructed using beamformer-based virtual electrodes for 78 cortical regions and 6 hippocampal regions. Group differences in peak frequency and relative power in six frequency bands were identified using permutation testing. For the patients, spearman correlations between the MMSE scores and peak frequency or relative power were calculated. Moreover, receiver operator characteristic curves were plotted to estimate the diagnostic accuracy. We found a lower hippocampal peak frequency in AD compared to controls, which, in the patients, correlated positively with MMSE [r(25) = 0.61; p < 0.01] whereas hippocampal relative theta power correlated negatively with MMSE [r(25) = -0.54; p < 0.01]. Cortical peak frequency was also lower in AD in association areas. Furthermore, cortical peak frequency correlated positively with MMSE [r(25) = 0.43; p < 0.05]. In line with this finding, relative theta power was higher in AD across the cortex, and relative alpha and beta power was lower in more circumscribed areas. The average cortical relative theta power was the best discriminator between AD and controls (sensitivity 82%; specificity 81%). Using beamformer-based virtual electrodes, we were able to detect hippocampal activity in AD. In AD, this hippocampal activity is slowed, and correlates better with cognition than the (slowed) activity in cortical areas. On the other

  9. Declining densities and reproductive activities of the queen conch Strombus gigas (Mesogastropoda: Strombidae) in Banco Chinchorro, eastern Caribbean, Mexico.

    PubMed

    De Jesús-Navarrete, Alberto; Valencia-Hernández, Adriana

    2013-12-01

    Queen conch is a gastropod inhabiting the Caribbean Sea, it represents the second largest fishery after the spiny lobster, but it has been extensively captured in the area. In order to know its population status in Chinchorro Bank, we determined conch density changes and its effects on reproductive activities, between July and November 2009. For this, data on conch density, morphology and reproductive activities were obtained from 15 sites within three fishing zones, and compared with previously collected data (1990, 1992, 1994, and 1997). Data showed that adult density decreased with time, from 10,700 ind./ha in 1990, to 198 ind./h in 2009. Neither egg masses nor spawns were found and mating was only observed once in July 2009. In July, adult (lip>4 mm) density in the Southern zone was 23 ind./ha whereas in the Northern zone and Central zone densities were 15 and 9ind./ha respectively. In November, density was somewhat higher: Southern zone 96 ind./ha; Central zone 39 ind./ha and Northern zone had 38ind./ha. In July, mean shell length was 170.80 +/- 46.28 mm, with a higher median abundance at 180-189 mm. In November, higher frequency was 187.63 +/- 45.14 mm, maximumat 210-219 mm interval. For the last 10 years period, mean adult conch densities have diminished in each zone, which might be the main cause of decreased reproductive activities of the conch at Banco Chinchorro. It is therefore an immediate need to analyse the management plan for this species in this Reserve and perhaps to promote a re-population of queen conch and culture activities.

  10. Declining densities and reproductive activities of the queen conch Strombus gigas (Mesogastropoda: Strombidae) in Banco Chinchorro, eastern Caribbean, Mexico.

    PubMed

    De Jesús-Navarrete, Alberto; Valencia-Hernández, Adriana

    2013-12-01

    Queen conch is a gastropod inhabiting the Caribbean Sea, it represents the second largest fishery after the spiny lobster, but it has been extensively captured in the area. In order to know its population status in Chinchorro Bank, we determined conch density changes and its effects on reproductive activities, between July and November 2009. For this, data on conch density, morphology and reproductive activities were obtained from 15 sites within three fishing zones, and compared with previously collected data (1990, 1992, 1994, and 1997). Data showed that adult density decreased with time, from 10,700 ind./ha in 1990, to 198 ind./h in 2009. Neither egg masses nor spawns were found and mating was only observed once in July 2009. In July, adult (lip>4 mm) density in the Southern zone was 23 ind./ha whereas in the Northern zone and Central zone densities were 15 and 9ind./ha respectively. In November, density was somewhat higher: Southern zone 96 ind./ha; Central zone 39 ind./ha and Northern zone had 38ind./ha. In July, mean shell length was 170.80 +/- 46.28 mm, with a higher median abundance at 180-189 mm. In November, higher frequency was 187.63 +/- 45.14 mm, maximumat 210-219 mm interval. For the last 10 years period, mean adult conch densities have diminished in each zone, which might be the main cause of decreased reproductive activities of the conch at Banco Chinchorro. It is therefore an immediate need to analyse the management plan for this species in this Reserve and perhaps to promote a re-population of queen conch and culture activities. PMID:24432527

  11. Culturable bacterial flora associated with the dinoflagellate green Noctiluca miliaris during active and declining bloom phases in the Northern Arabian Sea.

    PubMed

    Basu, Subhajit; Deobagkar, Deepti D; Matondkar, S G Prabhu; Furtado, Irene

    2013-05-01

    A massive algal bloom of the dinoflagellate Noctiluca miliaris (green) was located in the Northern Arabian Sea by IRS-P4-2 (OCM-II) for microbiological studies, during two consecutive cruises of February-March 2009. Culturable bacterial load during bloom were ≈ 2-3-fold higher in comparison to non-bloom waters and ranged from 3.20 × 10(5) to 6.84 × 10(5) cfu ml(-1). An analysis of the dominant heterotrophs associated with Noctiluca bloom resulted in phylogenetic and a detailed metabolic characterization of 70 bacterial isolates from an overlapping active and declining bloom phase location near north-central Arabian Sea. The active phase flora was dominated by Gram-positive forms (70.59 %), a majority of which belonged to Bacillus (35.29 %) of Firmicutes. As the bloom declined, Gram-negative forms (61.11 %) emerged dominant, and these belonged to a diverse γ-proteobacterial population consisting of Shewanella (16.67 %) and equal fractions of a Cobetia-Pseudomonas-Psychrobacter-Halomonas population (36.11 %). A Unifrac-based principal coordinate analysis of partial 16S rDNA sequences showed significant differences among the active and declining phase flora and also with reported endocytic flora of Noctiluca (red). A nonparametric multidimensional scaling (NMDS) of antibiogram helped differentiation among closely related strains. The organic matter synthesized by N. miliaris appears to be quickly utilized and remineralized as seen from the high efficiency of isolates to metabolize various complex and simple C/N substrates such as carbohydrates, proteins/amino acids, lipids, sulfide production from organic matter, and solubilize phosphates. The ability of a large fraction of these strains (50-41.67 %) to further aerobically denitrify indicates their potential for nitrogen removal from these high-organic microniches of the Noctiluca bloom in the Arabian Sea, also known for high denitrification activity. The results indicate that culturable euphotic bacterial

  12. Culturable bacterial flora associated with the dinoflagellate green Noctiluca miliaris during active and declining bloom phases in the Northern Arabian Sea.

    PubMed

    Basu, Subhajit; Deobagkar, Deepti D; Matondkar, S G Prabhu; Furtado, Irene

    2013-05-01

    A massive algal bloom of the dinoflagellate Noctiluca miliaris (green) was located in the Northern Arabian Sea by IRS-P4-2 (OCM-II) for microbiological studies, during two consecutive cruises of February-March 2009. Culturable bacterial load during bloom were ≈ 2-3-fold higher in comparison to non-bloom waters and ranged from 3.20 × 10(5) to 6.84 × 10(5) cfu ml(-1). An analysis of the dominant heterotrophs associated with Noctiluca bloom resulted in phylogenetic and a detailed metabolic characterization of 70 bacterial isolates from an overlapping active and declining bloom phase location near north-central Arabian Sea. The active phase flora was dominated by Gram-positive forms (70.59 %), a majority of which belonged to Bacillus (35.29 %) of Firmicutes. As the bloom declined, Gram-negative forms (61.11 %) emerged dominant, and these belonged to a diverse γ-proteobacterial population consisting of Shewanella (16.67 %) and equal fractions of a Cobetia-Pseudomonas-Psychrobacter-Halomonas population (36.11 %). A Unifrac-based principal coordinate analysis of partial 16S rDNA sequences showed significant differences among the active and declining phase flora and also with reported endocytic flora of Noctiluca (red). A nonparametric multidimensional scaling (NMDS) of antibiogram helped differentiation among closely related strains. The organic matter synthesized by N. miliaris appears to be quickly utilized and remineralized as seen from the high efficiency of isolates to metabolize various complex and simple C/N substrates such as carbohydrates, proteins/amino acids, lipids, sulfide production from organic matter, and solubilize phosphates. The ability of a large fraction of these strains (50-41.67 %) to further aerobically denitrify indicates their potential for nitrogen removal from these high-organic microniches of the Noctiluca bloom in the Arabian Sea, also known for high denitrification activity. The results indicate that culturable euphotic bacterial

  13. Fun, Flow, and Fitness: Opinions for Making More Effective Active Videogames

    PubMed Central

    Mellecker, Robin; Buday, Richard; Gao, Zan; Hinkley, Trina; Esparza, Laura; Alexander, Shirley

    2015-01-01

    Abstract Despite active videogames' popularity and ability to increase a player's energy expenditure, research indicates their use sharply declines over time, which limits their utility in promoting physical activity. A frequent criticism is that a player's interest is quickly exhausted. At the preconference of the International Society of Behavioral Nutrition and Physical Activity 2014, a group of investigators and videogame developers gathered to share lessons learned from using serious videogames in health behavior change and offer insight to guide future efforts. PMID:26181681

  14. Fun, Flow, and Fitness: Opinions for Making More Effective Active Videogames.

    PubMed

    Maloney, Ann E; Mellecker, Robin; Buday, Richard; Gao, Zan; Hinkley, Trina; Esparza, Laura; Alexander, Shirley

    2015-02-01

    Despite active videogames' popularity and ability to increase a player's energy expenditure, research indicates their use sharply declines over time, which limits their utility in promoting physical activity. A frequent criticism is that a player's interest is quickly exhausted. At the preconference of the International Society of Behavioral Nutrition and Physical Activity 2014, a group of investigators and videogame developers gathered to share lessons learned from using serious videogames in health behavior change and offer insight to guide future efforts.

  15. Declines in Mobility and Changes in Performance in the Instrumental Activities of Daily Living Among Mildly Disabled Community-Dwelling Older Adults

    PubMed Central

    Bear-Lehman, Jane; Anderson, Stewart J.

    2015-01-01

    Background. Gait speed is as an important predictor of mortality, volume of medical care, hospitalization, onset of activities of daily living (ADL) disability, and nursing home placement. We examined associations between change in gait speed and change in observed performance in the instrumental ADL (IADL) in a sample of mild-to-moderately disabled older adults. Methods. Participants in the Sources of Independence in the Elderly project (n = 375) were approached to complete a 4-m gait assessment and a performance test of IADL competency at three points over 2 years. IADL competency was assessed by occupational therapists, who rated participants using the Assessment of Motor and Process Skills (AMPS) and who also made a global rating of need for help or supervision. Linear mixed models were developed to assess change in motor AMPS score relative to baseline status and change in gait speed and AMPS process scores. Results. Baseline gait and change in gait were significant correlates of change in the AMPS motor ability measures in models that adjusted for cognitive status and AMPS process ability. Even respondents with gait speeds of 1 m/s at baseline were at risk of declining AMPS motor ability and an occupational therapist rating of IADL disability if gait speed declined. Conclusions. Slowing in gait speed is an important risk factor for IADL disability in mild to moderately disabled older adults. PMID:24952575

  16. Tissue plasminogen activator and plasminogen mediate stress-induced decline of neuronal and cognitive functions in the mouse hippocampus.

    PubMed

    Pawlak, Robert; Rao, B S Shankaranarayana; Melchor, Jerry P; Chattarji, Sumantra; McEwen, Bruce; Strickland, Sidney

    2005-12-13

    Repeated stress can impair function in the hippocampus, a brain structure essential for learning and memory. Although behavioral evidence suggests that severe stress triggers cognitive impairment, as seen in major depression or posttraumatic stress disorder, little is known about the molecular mediators of these functional deficits in the hippocampus. We report here both pre- and postsynaptic effects of chronic stress, manifested as a reduction in the number of NMDA receptors, dendritic spines, and expression of growth-associated protein-43 in the cornu ammonis 1 region. Strikingly, the stress-induced decrease in NMDA receptors coincides spatially with sites of plasminogen activation, thereby predicting a role for tissue plasminogen activator (tPA) in this form of stress-induced plasticity. Consistent with this possibility, tPA-/- and plasminogen-/- mice are protected from stress-induced decrease in NMDA receptors and reduction in dendritic spines. At the behavioral level, these synaptic and molecular signatures of stress-induced plasticity are accompanied by impaired acquisition, but not retrieval, of hippocampal-dependent spatial learning, a deficit that is not exhibited by the tPA-/- and plasminogen-/- mice. These findings establish the tPA/plasmin system as an important mediator of the debilitating effects of prolonged stress on hippocampal function at multiple levels of neural organization.

  17. South Korean Students, Hit Hard by Currency Decline, Opt to Stay Home

    ERIC Educational Resources Information Center

    McNeill, David

    2009-01-01

    It is too early to predict enrollment numbers for international students in the United States this fall, but universities in Asia are already seeing big declines among South Koreans studying abroad. The value of South Korea's currency has dropped sharply in recent months, almost doubling the cost of living abroad for South Korean students and…

  18. The decline of smoking in British portraiture

    PubMed Central

    Wilson, N; Thomson, G

    2004-01-01

    Methods: A compact disc produced by the National Portrait Gallery in London, UK, was systematically searched for artworks produced in the years 1950 to 1999. A "smoking portrayal" in an artwork was defined as having a cigarette, cigar or pipe in the mouth or hand of a named individual. Results: Out of 1063 artworks included in the analysis, 53 portrayed smoking by identifiable individuals (5.0%). The rate of portrayal was highest in the 1950s (10%) and 1960s (11%) and then declined sharply thereafter (p value for trend < 0.00001). Smoking virtually disappeared from portraiture in the 1990s (at 0.6%). The median age of the smokers portrayed was significantly higher in the 1970 to 1999 period when compared to the 1950 to 1969 period. Conclusions: The decline of smoking in this collection of portraiture is consistent with the decline in smoking in the UK over these decades, but contrasts with trends for increasing smoking portrayal described elsewhere for film and television. PMID:14985574

  19. Continuous Aerobic Training in Individualized Intensity Avoids Spontaneous Physical Activity Decline and Improves MCT1 Expression in Oxidative Muscle of Swimming Rats

    PubMed Central

    Scariot, Pedro P. M.; Manchado-Gobatto, Fúlvia de Barros; Torsoni, Adriana S.; dos Reis, Ivan G. M.; Beck, Wladimir R.; Gobatto, Claudio A.

    2016-01-01

    Although aerobic training has been shown to affect the lactate transport of skeletal muscle, there is no information concerning the effect of continuous aerobic training on spontaneous physical activity (SPA). Because every movement in daily life (i.e., SPA) is generated by skeletal muscle, we think that it is possible that an improvement of SPA could affect the physiological properties of muscle with regard to lactate transport. The aim of this study was to evaluate the effect of 12 weeks of continuous aerobic training in individualized intensity on SPA of rats and their gene expressions of monocarboxylate transporters (MCT) 1 and 4 in soleus (oxidative) and white gastrocnemius (glycolytic) muscles. We also analyzed the effect of continuous aerobic training on aerobic and anaerobic parameters using the lactate minimum test (LMT). Sixty-day-old rats were randomly divided into three groups: a baseline group in which rats were evaluated prior to initiation of the study; a control group (Co) in which rats were kept without any treatment during 12 weeks; and a chronic exercise group (Tr) in which rats swam for 40 min/day, 5 days/week at 80% of anaerobic threshold during 12 weeks. After the experimental period, SPA of rats was measured using a gravimetric method. Rats had their expression of MCTs determined by RT-PCR analysis. In essence, aerobic training is effective in maintaining SPA, but did not prevent the decline of aerobic capacity and anaerobic performance, leading us to propose that the decline of SPA is not fully attributed to a deterioration of physical properties. Changes in SPA were concomitant with changes in MCT1 expression in the soleus muscle of trained rats, suggestive of an additional adaptive response toward increased lactate clearance. This result is in line with our observation showing a better equilibrium on lactate production-remotion during the continuous exercise (LMT). We propose an approach to combat the decline of SPA of rats in their home

  20. Continuous Aerobic Training in Individualized Intensity Avoids Spontaneous Physical Activity Decline and Improves MCT1 Expression in Oxidative Muscle of Swimming Rats.

    PubMed

    Scariot, Pedro P M; Manchado-Gobatto, Fúlvia de Barros; Torsoni, Adriana S; Dos Reis, Ivan G M; Beck, Wladimir R; Gobatto, Claudio A

    2016-01-01

    Although aerobic training has been shown to affect the lactate transport of skeletal muscle, there is no information concerning the effect of continuous aerobic training on spontaneous physical activity (SPA). Because every movement in daily life (i.e., SPA) is generated by skeletal muscle, we think that it is possible that an improvement of SPA could affect the physiological properties of muscle with regard to lactate transport. The aim of this study was to evaluate the effect of 12 weeks of continuous aerobic training in individualized intensity on SPA of rats and their gene expressions of monocarboxylate transporters (MCT) 1 and 4 in soleus (oxidative) and white gastrocnemius (glycolytic) muscles. We also analyzed the effect of continuous aerobic training on aerobic and anaerobic parameters using the lactate minimum test (LMT). Sixty-day-old rats were randomly divided into three groups: a baseline group in which rats were evaluated prior to initiation of the study; a control group (Co) in which rats were kept without any treatment during 12 weeks; and a chronic exercise group (Tr) in which rats swam for 40 min/day, 5 days/week at 80% of anaerobic threshold during 12 weeks. After the experimental period, SPA of rats was measured using a gravimetric method. Rats had their expression of MCTs determined by RT-PCR analysis. In essence, aerobic training is effective in maintaining SPA, but did not prevent the decline of aerobic capacity and anaerobic performance, leading us to propose that the decline of SPA is not fully attributed to a deterioration of physical properties. Changes in SPA were concomitant with changes in MCT1 expression in the soleus muscle of trained rats, suggestive of an additional adaptive response toward increased lactate clearance. This result is in line with our observation showing a better equilibrium on lactate production-remotion during the continuous exercise (LMT). We propose an approach to combat the decline of SPA of rats in their home

  1. Diagnosing School Decline

    ERIC Educational Resources Information Center

    Duke, Daniel L.

    2008-01-01

    One of the most important strategies for stopping school decline is recognizing its signs early on and promptly applying appropriate interventions. In this article, the author identifies 11 indicators of school decline that are associated with inadequate and inappropriate responses to the challenges of budget cuts, state and federal mandates, loss…

  2. Peroxisome proliferator-activated receptor-γ activation with angiotensin II type 1 receptor blockade is pivotal for the prevention of blood-brain barrier impairment and cognitive decline in type 2 diabetic mice.

    PubMed

    Min, Li-Juan; Mogi, Masaki; Shudou, Masachika; Jing, Fei; Tsukuda, Kana; Ohshima, Kousei; Iwanami, Jun; Horiuchi, Masatsugu

    2012-05-01

    We reported previously that an angiotensin II type 1 receptor blocker, telmisartan, improved cognitive decline with peroxisome proliferator-activated receptor-γ activation; however, the detailed mechanisms are unclear. Enhanced blood-brain barrier (BBB) permeability with alteration of tight junctions is suggested to be related to diabetes mellitus. Therefore, we examined the possibility that telmisartan could attenuate BBB impairment with peroxisome proliferator-activated receptor-γ activation to improve diabetes mellitus-induced cognitive decline. Type 2 diabetic mice KKA(y) exhibited impairment of cognitive function, and telmisartan treatment attenuated this. Cotreatment with GW9662, a peroxisome proliferator-activated receptor-γ antagonist, interfered with these protective effects of telmisartan against cognitive function. BBB permeability was increased in both the cortex and hippocampus in KKA(y) mice. Administration of telmisartan attenuated this increased BBB permeability. Coadministration of GW9662 reduced this effect of telmisartan. Significant decreases in expression of tight junction proteins and increases in matrix metalloproteinase expression, oxidative stress, and proinflammatory cytokine production were observed in the brain, and treatment with telmisartan restored these changes. Swollen astroglial end-feet in BBB were observed in KKA(y) mice, and this change in BBB ultrastructure was decreased in telmisartan. These effects of telmisartan were weakened by cotreatment with GW9662. In contrast, administration of another angiotensin II type 1 receptor blocker, losartan, was less effective compared with telmisartan in terms of preventing BBB permeability and astroglial end-foot swelling, and coadministration of GW9662 did not affect the effects of losartan. These findings are consistent with the possibility that, in type 2 diabetic mice, angiotensin II type 1 receptor blockade with peroxisome proliferator-activated receptor-γ activation by telmisartan

  3. Many families may face sharply higher costs if public health insurance for their children is rolled back.

    PubMed

    Selden, Thomas M; Dubay, Lisa; Miller, G Edward; Vistnes, Jessica; Buettgens, Matthew; Kenney, Genevieve M

    2015-04-01

    Millions of US children could lose access to public health care coverage if Congress does not renew federal funding for the Children's Health Insurance Program (CHIP), which is set to expire September 30, 2015—the end of the federal fiscal year. Additional cuts in public coverage for children in families with incomes above 133 percent of the federal poverty level are possible if the Affordable Care Act's "maintenance of effort" provisions regarding Medicaid and CHIP are allowed to expire as scheduled in 2019. The potential for a significant rollback of public coverage for children raises important policy questions regarding alternative pathways to affordable and high-quality coverage for low-income children. For many children at risk of losing eligibility for public coverage, the primary alternative pathway to coverage would be through their parents' employer-sponsored insurance, yet relatively little is known about the cost and quality of that coverage. Our estimates, based on data from the Insurance Component of the 2012 and 2013 Medical Expenditure Panel Surveys, show that many families would face sharply higher costs of covering their children. In many cases, the only employer-sponsored coverage available would be a high-deductible plan. PMID:25809641

  4. Coping with Decline

    ERIC Educational Resources Information Center

    Boulding, Kenneth

    1977-01-01

    A quantitative decline is predicted because of the leveling off of industrial production and exhaustion of resources. Coping with these conditions requires flexibility and adaptability. Delusions of certainty zero in on catastrophe. (Author/MLF)

  5. SENESCENCE-ASSOCIATED DECLINE IN HEPATIC PEROXISOMAL ENZYME ACTIVITIES CORRESPONDS WITH DIMINISHED LEVELS OF RETINOID X RECEPTOR ALPHA, BUT NOT PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ALPHA1

    EPA Science Inventory

    Abstract

    Aging is associated with alterations in hepatic peroxisomal metabolism and susceptibility to hepatocarcinogenecity produced by agonists of peroxisome proliferator-activated receptor alpha (PPARa). Mechanisms involved in these effects are not well understood. Howev...

  6. ‘Physical Activity 4 Everyone’ school-based intervention to prevent decline in adolescent physical activity levels: 12 month (mid-intervention) report on a cluster randomised trial

    PubMed Central

    Sutherland, Rachel; Campbell, Elizabeth; Lubans, David R; Morgan, Philip J; Okely, Anthony D; Nathan, Nicole; Wolfenden, Luke; Wiese, Jarrod; Gillham, Karen; Hollis, Jenna; Wiggers, John

    2016-01-01

    Background Adolescence is a recognised period of physical activity decline, particularly among low-income communities. We report the 12-month (midpoint) effects of a 2-year multicomponent physical activity intervention implemented in disadvantaged secondary schools. Methods A cluster randomised trial was undertaken in 10 secondary schools located in disadvantaged areas in New South Wales, Australia. Students in Grade 7 were recruited, with follow-up in Grade 8. The intervention was guided by socioecological theory and included seven physical activity strategies, and six implementation adoption strategies. The primary outcome was mean minutes of moderate-to-vigorous physical activity (MVPA) per day assessed using Actigraph GT3X accelerometers. Outcome data were analysed using repeated measures linear mixed models. Results At baseline, 1150 (93%) students participated in the data collection (mean age 12 years, 48% boys) and 1050 (79%) students participated at 12-month follow-up. By the 12-month follow-up, the six implementation adoption strategies had been used to support schools to deliver four of the seven physical activity elements. There was a significant group-by-time interaction for mean minutes of MVPA per day in favour of the intervention group (adjusted difference between groups at follow-up=3.85 min, 95% CI (0.79 to 6.91), p≤0.01), including significantly more vigorous physical activity (2.45 min, p≤0.01), equating to 27 min more MVPA per week. Summary At 12-month follow-up, the intervention had reduced the decline in physical activity among adolescents from disadvantaged schools. The intervention may assist students to meet physical activity guidelines. PMID:26359346

  7. Urban Decline and Durable Housing.

    ERIC Educational Resources Information Center

    Glaeser, Edward L.; Gyourko, Joseph

    2005-01-01

    Urban decline is not the mirror image of growth, and durable housing is the primary reason the nature of decline is so different. This paper presents a model of urban decline with durable housing and verifies these implications of the model: (1) city growth rates are skewed so that cities grow more quickly than they decline; (2) urban decline is…

  8. 30 CFR 203.54 - How does my relief arrangement for an oil and gas lease operate if prices rise sharply?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... arrangement for an oil and gas lease operate if prices rise sharply? In those months when your current... closing prices on the NYMEX for light sweet crude oil and natural gas over the most recent full 12... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How does my relief arrangement for an oil...

  9. Decline of Northern Pintails

    USGS Publications Warehouse

    Hestback, Jay B.

    1995-01-01

    Changes in the size of the continental pintail population result from changes in production, survival, or both. Consequently, understanding population changes involves detecting variation in survival and production over time and relating that variation to changes in population size. Once the cause of the decline is determined, appropriate management strategies can be developed to reverse it.

  10. Rising Above Decline.

    ERIC Educational Resources Information Center

    Wachtel, Betsy; Powers, Brian

    This volume attempts to document ways in which several communities have dealt with the problems of declining school enrollments. Each case study outlines some type of public participation in the task of adjusting to population changes and fiscal pressures. The first chapter supplies an introductory overview of issues related to declining…

  11. Declining Resources, Targeted Strategies

    ERIC Educational Resources Information Center

    Levenson, Nathan

    2011-01-01

    As resources shrink, the need to do more with less becomes critical. As a business CEO turned superintendent, this author has seen firsthand that many options exist, but none are fun, easy, or politically rewarding. He contends that the challenge of managing declining resources is not the choice between doing less for children or discovering new…

  12. [Fertility decline in Spain].

    PubMed

    Arango, J

    1987-01-01

    The historical processes of secular fertility decline in Spain and Portugal are not well understood. Very few microdemographic studies of small geographic regions or particular social strata have been done. A contribution by David Reher to the First Spanish-Portuguese-Italian Historical Demography Conference on the fertility decline in the interior province of Cuenca, Spain, uses the own-children method to analyze changes in marital fertility in the 19th and 20th centuries. Reher discovered a slight fertility decline of perhaps 15% which occurred between the end of the 18th century and 1860-75. The fertility decline did not resume until after the Spanish Civil War, and then it was a very gradual and continuous process. When instead of the total female population, women aged 35-39 were studied, unequivocal signs of fertility control appeared. Conscious fertility control thus appears to have begun among older women limiting rather than spacing births. Reher's analysis by social groups demonstrates that fertility declined first and more rapidly in the nonagricultural and urban populations and among the higher income groups. The fertility decline in Cuenca was certainly not identical to that in most of Spain, but may have been fairly typical of a large part of the interior. Another contribution to the Historical Demography Conference, by Anna Cabre and Isabel Pujadas, analyzes fertility trends and cyclical fluctuations in 20th century Cataluna, arguing that they must be placed in historical perspective if recent changes are to be understood and plausible projections made. Their work demonstrates the value of selecting a relatively homogeneous geographic unit for analysis. The contribution of Margarita Delgado to the conference analyzed interregional fertility differences in contemporary Spain. The high legitimate fertility of the south of Spain is accentuated by high nuptiality rates. In central Spain, the combination of high legitimate fertility rates and low

  13. Falling Back: The Declining Socioeconomic Status of the Mexican Immigrant Population in the U.S., 1980-1990.

    ERIC Educational Resources Information Center

    Rivera-Batiz, Francisco L.

    This report presents data showing that the socioeconomic status of Mexican immigrants in the United States fell sharply behind that of the total native-born population during the 1980s and also declined relative to that of Mexican Americans. Data from the 1980 and 1990 censuses demonstrate that during the 1980s, the earnings and per capita income…

  14. [Fertility decline and consequences of the National Family Planning Program: an analysis of the achievements of family planning activities in Chiang Mai and Lamphun provinces].

    PubMed

    Pardthaisong, T

    1988-07-01

    Based on the census data of 1970 and 1980 for each province of Thailand, the present study has revealed that between 1960-1980, a rapid fertility decline took place in 17 northern provinces and 26 central provinces of Thailand. A similar rapid fertility decline also took place starting in 1975 in the 16 northeast provinces and in the 14 southern provinces. Levels and trends of fertility found in this study suggest that most of the districts in the northern and the central regions reached the replacement level or below by 1985, and that similar levels will be attained by 1990 for almost every district in Thailand. This paper also stresses the impact of the rapid fertility decline on development in Thailand during the past 20 years, and its consequences. Lastly, the present study suggests that, for the future, the most important step is to understand well the consequences of this astonishing rapid fertility decline. This knowledge will be vital for the country and its people.

  15. Normal cognitive decline or dementia?

    PubMed

    Ebmeier, Klaus P

    2010-01-01

    Cognitive speed, inhibitory function, and memory decline with age while crystallised, particularly verbal, abilities remain largely intact. Poor health, fewer years of education, lower activity, the presence of the APOE E4 allele, and high BP appear to predict faster cognitive decline. Dementia is diagnosed in the presence of objective cognitive impairment, both long- and short-term memory, plus at least one additional (cortical) cognitive deficit, such as dysphasia, dyspraxia, agnosia, or disturbance in executive functioning. In addition, patients have to show significant impairment in social or occupational functioning and a significant decline from previous levels. Both smoking and diabetes increase the risk of all types of dementia, not smoking or even stopping smoking reduces this risk, but better control of type 2 diabetes does not appear to have a measurable effect. Drinking small to moderate amounts of alcohol appears to confer some benefit in ameliorating cognitive decline. There is some evidence that HRT, DHEA, BP lowering in patients without prior cerebrovascular disease, statins, vitamin B6 and procaine are NOT helpful. There is insufficient evidence to establish or refute a beneficial effect for exercise, treatment of type 2 diabetes, omega-3 fatty acids, folic acid with/without vitamin B12, antioxidant vitamins, or ginkgo biloba. Depressive symptoms are more prevalent than dementia. Clinical (major) depression can present with cognitive deterioration, often associated with subjective complaints. Patients with subjective or objective memory impairment, but without functional deterioration, can be referred to the local memory clinic, while demented patients eligible for acetylcholinesterase inhibitor treatment, patients whose diagnosis is unclear and who may need some specific investigations, as well as patients who may benefit from a combined approach with psychotropic drugs and behavioural support should be referred to the local mental health team.

  16. Functional changes in digestive enzyme activities of meagre (Argyrosomus regius; Asso, 1801) during early ontogeny.

    PubMed

    Suzer, Cüneyt; Kamacı, H Okan; Çoban, Deniz; Yıldırım, Şükrü; Fırat, Kürşat; Saka, Şahin

    2013-08-01

    The ontogenesis of main pancreatic and intestinal enzymes was investigated in the recent promising Mediterranean candidate species of meagre, Argyrosomus regius, during larval development until 40 days after hatching (DAH). The green-water technique was carried out for larval rearing. Whole-body homogenates were used for enzymatic analysis in larvae younger than 15 DAH; after this date, older larvae were dissected into two segments as pancreatic and intestinal segment. Trypsin was detected as early as hatching and sharply increased concurrently with age and exogenous feeding 15 DAH, but constant decline was observed until the end of experiment. Amylase was determined at 2 DAH and sharply increased 10 DAH. Then, slight decreases were found between 10 and 15 DAH, and then slow alterations were continued until the end of the experiment. Lipase was firstly measured on day 3; then, sudden decline was observed between 20 and 25 DAH. After this date, slow fluctuations were maintained until the end of the experiment. Pepsin was firstly assayed 15 DAH related to gastric gland secretion and sharply increased 30 DAH. Then, it slowly varied until end of the experiment. Enzymes of brush border membranes, alkaline phosphatase and aminopeptidase N showed similar pattern on specific activities during the first 10 days. Thereafter, while specific activity of alkaline phosphatase slightly decreased 15 and fluctuated until 20 DAH, aminopeptidase N activity slowly increased 20 DAH. Then, activity of alkaline phosphatase and aminopeptidase N constantly increased 30 DAH, indicating maturation of the intestinal digestive process, and also, these activities continued to slowly increase until the end of the experiment. The specific activity of cytosolic peptidase, leucine-alanine peptidase, smoothly increased on day 8, then fluctuated until 15 DAH. After this date, in contrast to enzymes of brush border membranes, it sharply decreased 25 DAH and continued to gradually decline until the end

  17. [Functional decline in older people].

    PubMed

    Wada, Taizo

    2013-10-01

    World Health Organization(WHO) proposed to be used as an index of the health of elderly independence of functioning. Basic activities of daily living (BADL), such as bathing, dressing, toileting, transferring, continence, and feeding are well known as the functioning of the elderly. However, not only BADL, there are a variety of levels, such as the ability to play a social role, intellectual activities and instrumental activities of daily living (IADL), which are components of the Tokyo Metropolitan Institute of Gerontology Index of Competence(TMIG-IC). Functional decline in older people is associated with age, gender, depression, up and go test and manual dexterity. Smoking, body-mass index, and exercise patterns in midlife and late adulthood are predictors of subsequent disability. PMID:24261199

  18. Fertility decline in Paraguay.

    PubMed

    Ishida, Kanako; Stupp, Paul; Melian, Mercedes

    2009-09-01

    Recent reproductive health surveys show that the fertility rate in Paraguay decreased precipitously from 4.3 lifetime births per woman in 1995-98 to 2.9 births in 2001-04. In this study, we establish data consistency between the 1998 and 2004 surveys by comparing a series of cohort-specific period rates and use the Bongaarts framework of proximate determinants of fertility to demonstrate that an increase in the contraceptive prevalence rate (CPR) between 1998 and 2004 fully accounts for the fertility decline. Decomposition of rates shows that changes in group-specific CPRs explain a greater proportion of the change in the overall CPR than do changes in population composition by educational attainment, urban residence, region, and language spoken at home. Finally, we show that younger cohorts of women in 2004 reported ideal completed fertility desires of less than 2.9 births, suggesting that the fertility rate is likely to continue to decrease.

  19. Physical fitness is predictive for a decline in the ability to perform instrumental activities of daily living in older adults with intellectual disabilities: Results of the HA-ID study.

    PubMed

    Oppewal, Alyt; Hilgenkamp, Thessa I M; van Wijck, Ruud; Schoufour, Josje D; Evenhuis, Heleen M

    2015-01-01

    The ability to perform instrumental activities of daily living (IADL) is important for one's level of independence. A high incidence of limitations in IADL is seen in older adults with intellectual disabilities (ID), which is an important determinant for the amount of support one needs. The aim of this study was to assess the predictive value of physical fitness for the ability to perform IADL, over a 3-year follow-up period, in 601 older adults with ID. At baseline, an extensive physical fitness assessment was performed. In addition, professional caregivers completed the Lawton IADL scale, both at baseline and at follow-up. The average ability to perform IADL declined significantly over the 3-year follow-up period. A decline in the ability to perform IADL was seen in 44.3% of the participants. The percentage of participants being completely independent in IADL declined from 2.7% to 1.3%. Manual dexterity, balance, comfortable and fast gait speed, muscular endurance, and cardiorespiratory fitness were significant predictors for a decline in IADL after correcting for baseline IADL and personal characteristics (age, gender, level of ID, and Down syndrome). This can be interpreted as representing the predictive validity of the physical tests for a decline in IADL. This study shows that even though older adults with ID experience dependency on others due to cognitive limitations, physical fitness also is an important aspect for IADL, which stresses the importance of using physical fitness tests and physical fitness enhancing programs in the care for older adults with ID.

  20. Physical fitness is predictive for a decline in the ability to perform instrumental activities of daily living in older adults with intellectual disabilities: Results of the HA-ID study.

    PubMed

    Oppewal, Alyt; Hilgenkamp, Thessa I M; van Wijck, Ruud; Schoufour, Josje D; Evenhuis, Heleen M

    2015-01-01

    The ability to perform instrumental activities of daily living (IADL) is important for one's level of independence. A high incidence of limitations in IADL is seen in older adults with intellectual disabilities (ID), which is an important determinant for the amount of support one needs. The aim of this study was to assess the predictive value of physical fitness for the ability to perform IADL, over a 3-year follow-up period, in 601 older adults with ID. At baseline, an extensive physical fitness assessment was performed. In addition, professional caregivers completed the Lawton IADL scale, both at baseline and at follow-up. The average ability to perform IADL declined significantly over the 3-year follow-up period. A decline in the ability to perform IADL was seen in 44.3% of the participants. The percentage of participants being completely independent in IADL declined from 2.7% to 1.3%. Manual dexterity, balance, comfortable and fast gait speed, muscular endurance, and cardiorespiratory fitness were significant predictors for a decline in IADL after correcting for baseline IADL and personal characteristics (age, gender, level of ID, and Down syndrome). This can be interpreted as representing the predictive validity of the physical tests for a decline in IADL. This study shows that even though older adults with ID experience dependency on others due to cognitive limitations, physical fitness also is an important aspect for IADL, which stresses the importance of using physical fitness tests and physical fitness enhancing programs in the care for older adults with ID. PMID:26079525

  1. [Diabetes mellitus and cognitive decline].

    PubMed

    Iglseder, Bernhard

    2011-11-01

    From large epidemiological studies, it has been demonstrated that diabetes mellitus is a risk factor for cognitive decline: Compared to healthy controls, patients with diabetes perform worse on cognitive tests, they experience a pronounced cognitive decline over time and have a higher incidence of dementia. Mechanisms contributing to cognitive decline include vascular damage, negative consequences of hypo- and hyperglycemia, and various dysfunctions in insulin action, summarized as insulin resistance. Possible targets for prevention and treatment of cognitive decline have attracted scientific attention.

  2. Problems Associated with Declining National Oil Production

    NASA Astrophysics Data System (ADS)

    Jackson, J. S.

    2009-12-01

    Forecasts of peak oil production have focussed on the global impacts of declining production. Meanwhile, national oil production has declined in 20 countries, leading to local problems that receive little comment outside of the effected regions. Two problems deserve wider recognition: declining state revenues and fuel substitution. Most oil producing countries with large reserves adopted licensing practices that provide significant revenues to the host governments such that oil revenues generate from 40 to 80 percent of total government funds. Typically these governments allocate a fraction of this revenue to their state oil companies, utilizing the remainder for other activities. As oil revenues decline with falling production, host governments face a dilemma: either to increase state oil company budgets in order to stem the decline, or to starve the state oil company while maintaining other government programs. The declining oil revenues in these states can significantly reduce the government's ability to address important national issues. Mexico, Indonesia, and Yemen illustrate this situation in its early phases. Fuel substitution occurs whenever one fuel proves less expensive than another. The substitution of coal for wood in the eighteenth century and oil for coal in the twentieth century are classic examples. China and India appear to be at peak oil production, while their economies generate increasing demand for energy. Both countries are substituting coal and natural gas for oil with attendant environmental impacts. Coal-to-liquids projects are proposed in in both China, which will require significant water resources if they are executed. These examples suggest that forecasting the impact of peak oil at a regional level requires more than an assessment of proven-probable-possible reserves and a forecast of supply-demand scenarios. A range of government responses to declining oil income scenarios must also be considered, together with scenarios describing

  3. Three decades of recurrent declines and recoveries in corals belie ongoing change in fish assemblages

    NASA Astrophysics Data System (ADS)

    Lamy, T.; Galzin, R.; Kulbicki, M.; Lison de Loma, T.; Claudet, J.

    2016-03-01

    Coral reefs are increasingly being altered by a myriad of anthropogenic activities and natural disturbances. Long-term studies offer unique opportunities to understand how multiple and recurrent disturbances can influence coral reef resilience and long-term dynamics. While the long-term dynamics of coral assemblages have been extensively documented, the long-term dynamics of coral reef fish assemblages have received less attention. Here, we describe the changes in fish assemblages on Tiahura reef, Moorea, from 1979 to 2011. During this 33-yr period, Tiahura was exposed to multiple disturbances (crown-of-thorns seastar outbreaks and cyclones) that caused recurrent declines and recoveries of coral cover and changes in the dominant coral genera. These shifts in coral composition were associated with long-term cascading effects on fish assemblages. The composition and trophic structure of fish assemblages continuously shifted without returning to their initial composition, whereas fish species richness remained stable, albeit with a small increase over time. We detected nonlinear responses of fish density when corals were most degraded. When coral cover dropped below 10 % following a severe crown-of-thorns sea star outbreak, the density of most fish trophic groups sharply decreased. Our study shows that historical contingency may potentially be an important but largely underestimated factor explaining the contemporary structure of reef fish assemblages and suggests that temporal stability in their structure and function should not necessarily be the target of management strategies that aim at increasing or maintaining coral reef resilience.

  4. Growth behavior of additional offspring with a beneficial reversal allele in the asymmetric sharply-peaked landscape in the coupled discrete-time mutation-selection model

    NASA Astrophysics Data System (ADS)

    Gill, Wonpyong

    2013-01-01

    The probability of additional offspring with a beneficial reversal allele for growing to a size NC for a range of population sizes N, sequence lengths L, selective advantages s, and measuring parameters C was calculated for a haploid, asexual population in the coupled discrete-time mutation-selection model in an asymmetric sharply-peaked landscape with a positive selective advantage of the reversal allele over the optimal allele. The growing probability in the stochastic region was inversely proportional to the measuring parameter when C < 1 /Ns, bent when C ≈ 1/ Ns and saturated when C > 1/ Ns. The crossing time and the time dependence of the increase in relative density of the reversal allele in the coupled discrete-time mutation-selection model was approximated using the Wright-Fisher two-allele model with the same selective advantage and corresponding effective mutation rate. The growth behavior of additional offspring with the reversal allele in the asymmetric sharply-peaked landscape in the coupled discrete-time mutation-selection model was controlled by the selective advantage of the reversal allele compared to the optimal allele and could be described by using the Wright-Fisher two-allele model, in spite of there being many other alleles with lower fitness, and in spite of there being two alleles, the optimal and reversal allele, separated by a low-fitness valley with a tunable depth and width.

  5. Decomposing the seasonal fitness decline.

    PubMed

    Öberg, Meit; Pärt, Tomas; Arlt, Debora; Laugen, Ane T; Low, Matthew

    2014-01-01

    Seasonal fitness declines are common, but the relative contribution of different reproductive components to the seasonal change in the production of reproductive young, and the component-specific drivers of this change is generally poorly known. We used long-term data (17 years) on breeding time (i.e. date of first egg laid) in northern wheatears (Oenanthe oenanthe) to investigate seasonal reproductive patterns and estimate the relative contributions of reproductive components to the overall decline in reproduction, while accounting for factors potentially linked to seasonal declines, i.e. individual and habitat quality. All reproductive components-nest success (reflecting nest predation rate), clutch size, fledging success and recruitment success-showed a clear decline with breeding time whereas subsequent adult survival did not. A non-linear increase in nest predation rate caused nest success to decline rapidly early in the season and level off at ~80% success late in the breeding season. The combined seasonal decline in all reproductive components caused the mean production of recruits per nest to drop from around 0.7-0.2; with the relative contribution greatest for recruitment success which accounted for ~50% of the decline. Our data suggest that changing environmental conditions together with effects of nest predation have strong effects on the seasonal decline in fitness. Our demonstration of the combined effects of all reproductive components and their relative contribution shows that omitting data from later stages of breeding (recruitment) can greatly underestimate seasonal fitness declines. PMID:24013387

  6. Increasing metabolic rate despite declining body weight in an adult parasitoid wasp.

    PubMed

    Casas, Jérôme; Body, Mélanie; Gutzwiller, Florence; Giron, David; Lazzari, Claudio R; Pincebourde, Sylvain; Richard, Romain; Llandres, Ana L

    2015-08-01

    Metabolic rate is a positive function of body weight, a rule valid for most organisms and the basis of several theories of metabolic ecology. For adult insects, however, the diversity of relationships between body mass and respiration remains unexplained. The aim of this study is to relate the respiratory metabolism of a parasitoid with body weight and foraging activity. We compared the metabolic rate of groups of starving and host-fed females of the parasitoid Eupelmus vuilleti recorded with respirometry for 7days, corresponding to the mean lifetime of starving females and over half of the lifetime of foraging females. The dynamics of carbohydrate, lipid and protein in the body of foraging females were quantified with biochemical techniques. Body mass and all body nutrients declined sharply from the first day onwards. By contrast, the CO2 produced and the O2 consumed increased steadily. Starving females showed the opposite trend, identifying foraging as the reason for the respiration increase of feeding females. Two complementary physiological processes explain the unexpected relationship between increasing metabolic rate and declining body weight. First, host hemolymph is a highly unbalanced food, and the excess nutrients (protein and carbohydrate) need to be voided, partially through excretion and partially through respiration. Second, a foraging young female produces eggs at an increasing rate during the first half of its lifetime, a process that also increases respiration. We posit that the time-varying metabolic rate contributions of the feeding and reproductive processes supplements the contribution of the structural mass and lead to the observed trend. We extend our explanations to other insect groups and discuss the potential for unification using Dynamic Energy Budget theory.

  7. IUSSP activities. Committee on Anthropological Demography. Report: Seminar on Fertility and the Male Life Cycle in the Era of Fertility Decline, Zacatecas, Mexico, 13-16 November 1995.

    PubMed

    Infesta Dominquez, G

    1996-05-01

    This article gives an overview of a conference on Fertility and the Male Life Cycle held in Mexico on November 13-16, 1995. The seminars, organized by anthropological demographers, were based on the view that differences in men's life course events affect how many children are produced, when children are produced, and the kind of support given to children. Little research has focused on male fertility. Two overview papers addressed the issues of men's changing sexual and reproductive intentions as a response to economic changes (Jane Guyer) and theories of male fertility trends in industrialized countries (David Coleman). Other papers were presented on the following topics: changes in male fertility, sexuality and the male life cycle, polygyny and fertility, men's notions of sexuality and reproductive health, masculinity and reproduction, and future research directions. Laurent Toulemon and Evelyne Lapierre-Adamcyk and Katarina Pohl presented papers on gender differences in fertility. Philip Setel presented an analysis of the social construction of parenthood among Coastal Boiken in Papua New Guinea. Paul Miret discussed men's role in the sharp decline in Spanish fertility. Nosa Orobaton contrasted African men's changing roles over the life course. Differences in fertility among polygynous populations in Africa and in China were analyzed by Ann Blanc and Anastasia Gage, and James Lee and Wang Feng. Other papers were prepared by Juan Gillermo Figueroa Perea, John Anarfi and Clara Korkor, Frances L. Goldscheider et al., Benno de Keijzer, and Mario Humberto Ruz, Ondina Fachel Leal and Jandyra M.G. Fachel, and Kamran Asdar Ali. Seminar papers were expected to be published in several collections.

  8. Feminine Intellectual Decline During Adolescence.

    ERIC Educational Resources Information Center

    Campbell, Patricia B.

    The purpose of this study was to investigate further the relationship between sex and a decline of intellectual abilities during adolescence and to examine some personality differences between young women who declined in intellectual abilities during adolescence and those who did not. Differences examined were: need to be included, need to be…

  9. Slowing of Hippocampal Activity Correlates with Cognitive Decline in Early Onset Alzheimer’s Disease. An MEG Study with Virtual Electrodes

    PubMed Central

    Engels, Marjolein M. A.; Hillebrand, Arjan; van der Flier, Wiesje M.; Stam, Cornelis J.; Scheltens, Philip; van Straaten, Elisabeth C. W.

    2016-01-01

    Pathology in Alzheimer’s disease (AD) starts in the entorhinal cortex and hippocampus. Because of their deep location, activity from these areas is difficult to record with conventional electro- or magnetoencephalography (EEG/MEG). The purpose of this study was to explore hippocampal activity in AD patients and healthy controls using “virtual MEG electrodes”. We used resting-state MEG recordings from 27 early onset AD patients [age 60.6 ± 5.4, 12 females, mini-mental state examination (MMSE) range: 19–28] and 26 cognitively healthy age- and gender-matched controls (age 61.8 ± 5.5, 14 females). Activity was reconstructed using beamformer-based virtual electrodes for 78 cortical regions and 6 hippocampal regions. Group differences in peak frequency and relative power in six frequency bands were identified using permutation testing. For the patients, spearman correlations between the MMSE scores and peak frequency or relative power were calculated. Moreover, receiver operator characteristic curves were plotted to estimate the diagnostic accuracy. We found a lower hippocampal peak frequency in AD compared to controls, which, in the patients, correlated positively with MMSE [r(25) = 0.61; p < 0.01] whereas hippocampal relative theta power correlated negatively with MMSE [r(25) = -0.54; p < 0.01]. Cortical peak frequency was also lower in AD in association areas. Furthermore, cortical peak frequency correlated positively with MMSE [r(25) = 0.43; p < 0.05]. In line with this finding, relative theta power was higher in AD across the cortex, and relative alpha and beta power was lower in more circumscribed areas. The average cortical relative theta power was the best discriminator between AD and controls (sensitivity 82%; specificity 81%). Using beamformer-based virtual electrodes, we were able to detect hippocampal activity in AD. In AD, this hippocampal activity is slowed, and correlates better with cognition than the (slowed) activity in cortical areas. On the

  10. Age-dependent changes of the antioxidant system in rat livers are accompanied by altered MAPK activation and a decline in motor signaling

    PubMed Central

    Yang, Wei; Burkhardt, Britta; Fischer, Luise; Beirow, Maja; Bork, Nadja; Wönne, Eva C.; Wagner, Cornelia; Husen, Bettina; Zeilinger, Katrin; Liu, Liegang; Nussler, Andreas K.

    2015-01-01

    Aging is characterized by a progressive decrease of cellular functions, because cells gradually lose their capacity to respond to injury. Increased oxidative stress is considered to be one of the major contributors to age-related changes in all organs including the liver. Our study has focused on elucidating whether important antioxidative enzymes, the mTOR pathway, and MAPKs exhibit age-dependent changes in the liver of rats during aging. We found an age-dependent increase of GSH in the cytosol and mitochondria. The aged liver showed an increased SOD enzyme activity, while the CAT enzyme activity decreased. HO-1 and NOS-2 gene expression was lower in adult rats, but up-regulated in aged rats. Western blot analysis revealed that SOD1, SOD2, GPx, GR, γ-GCL, and GSS were age-dependent up-regulated, while CAT remained constant. We also demonstrated that the phosphorylation of Akt, JNK, p38, and TSC2Ser1254 decreased while ERK1/2 and TSC2Thr1462 increased age-dependently. Furthermore, our data show that the mTOR pathway seems to be activated in livers of aged rats, and hence stimulating cell proliferation/regeneration, as confirmed by an age-dependent increase of PCNA and p-eIF4ESer209 protein expression. Our data may help to explain the fact that liver cells only proliferate in cases of necessity, like injury and damage. In summary, we have demonstrated that, age-dependent changes of the antioxidant system and stress-related signaling pathways occur in the livers of rats, which may help to better understand organ aging. PMID:27004051

  11. Parasitic driven heliostat mirror declinator

    SciTech Connect

    Rhodes, W.A.

    1983-09-06

    An automatic parasitically driven declinator is disclosed for changing the tilt angle of the mirror of a heliostat to provide solar declination tracking by the heliostat. The declinator includes an axial gear drive train coupled to the polar axial shaft of the heliostat, which shaft is rotated. A pendulum arrangement coupled via an input shaft to the axial gear drive train is substantially held in plumb position by gravity wherein the gear drive train is driven as it is rotated about the polar axis by the polar axial shaft. An output shaft coupled to the gear train is rotated to drive a skew bar linkage assembly that is connected to the mirror mounting assembly of the heliostat. The gear ratio of the gear drive train assembly is made 365:1 so that the mirror angle is annually nutated a predetermined number of degrees corresponding to the cyclic variations of solar declination.

  12. Growth declines in red spruce

    SciTech Connect

    Zedaker, S.M.; Hyink, D.M.; Smith, D.W.

    1987-01-01

    Over the past two decades second-growth red spruce stands in the Northeast have demonstrated declines in radial increment. Some observers are implicating air pollution as a primary cause of the declines, based on recently acquired increment cores from dominant trees. Various forms of air pollution (O/sub 3/, NO/sub x/, SO/sub 2/, and trace metals) are known to reduce growth and development of tree species, but few studies have provided concrete evidence of regional pollution-caused declines in forest ecosystems. Recently published evidence of a synchronous, consistent, and unprecedented regional decline in red spruce should be weighed against the realization that radial increment in red spruce declines naturally as stands age. Separating anthropogenic stress-caused growth patterns from natural stand dynamics requires an in-depth knowledge of forest growth and yield, tree silvics, and forest ecosystem processes. Detailed analyses of growth by stand characteristics - site index, density, elevation, stand history - will be necessary to implicate air pollution as a primary cause of red spruce decline.

  13. Catalase and superoxide dismutase activities after heat injury of listeria monocytogenes

    SciTech Connect

    Dallmier, A.W.; Martin, S.E.

    1988-02-01

    Four strains of Listeria monocytogenes were examined for catalase (CA) and superoxide dismutase (SOD) activities. The two strains having the highest CA activities (LCDC and Scott A) also possessed the highest SOD activities. The CA activity of heated cell extracts of all four strains examined decreased sharply between 55 and 60/sup 0/C. SOD was more heat labile than CA. Two L. monocytogenes strains demonstrated a decline in SOD activity after heat treatment at 45/sup 0/C, whereas the other two strains demonstrated a decline at 50/sup 0/C. Sublethal heating of the cells at 55/sup 0/C resulted in increased sensitivity to 5.5% NaCl. Exogenous hydrogen peroxide was added to suspensions of L. monocytogenes; strains producing the highest CA levels showed the greatest H/sub 2/O/sub 2/ resistance.

  14. Activation of mTOR signaling leads to orthopedic surgery-induced cognitive decline in mice through β-amyloid accumulation and tau phosphorylation.

    PubMed

    Shen, Wenzhen; Lu, Keliang; Wang, Jiawan; Wu, Anshi; Yue, Yun

    2016-10-01

    Postoperative cognitive dysfunction (POCD) is a serious complication following surgery, however, the mechanism of POCD remains to be elucidated. Previous evidence has revealed that POCD may be associated with the pathogenesis of neurodegenerative processes. The mammalian target of rapamycin (mTOR) signaling pathway has been reported to be crucial in the pathophysiology of neurodegenerative diseases. However, the implications of mTOR in POCD remains to be fully elucidated. In the present study, western blotting and enzyme‑linked immunosorbent assay were used to determine the expression of mTOR and any associated downstream targets; contextual fear conditioning was used to estimate the learning and memory ability of mice. Using an animal model of orthopedic surgery, it was found that surgical injury impaired hippocampal‑dependent memory and enhanced the levels of phosphorylated mTOR at Serine‑2448, phosphorylated 70‑kDa ribosomal protein S6 kinase (p70S6K) at Threonine‑389 with accumulation of β‑amyloid (Aβ) and hyperphosphorylated tau at Serine-396, compared with the control group. Pretreatment with rapamycin, an mTOR inhibitor, restored the abnormal mTOR/p70S6K signaling induced by surgery, attenuated the accumulation of Aβ and reduced the phosphorylation of tau protein. Rapamycin also reversed the surgery‑induced cognitive dysfunction. The results of the present study suggested that the surgical stimulus activated mTOR/p70S6K signaling excessively, and that the inhibition of mTOR signaling with rapamycin may prevent postoperative cognitive deficits, partly through attenuating the accumulation of Aβ and hyperphosphorylation of tau protein. PMID:27599409

  15. Sharply curved turn around duct flow predictions using spectral partitioning of the turbulent kinetic energy and a pressure modified wall law

    NASA Technical Reports Server (NTRS)

    Santi, L. Michael

    1986-01-01

    Computational predictions of turbulent flow in sharply curved 180 degree turn around ducts are presented. The CNS2D computer code is used to solve the equations of motion for two-dimensional incompressible flows transformed to a nonorthogonal body-fitted coordinate system. This procedure incorporates the pressure velocity correction algorithm SIMPLE-C to iteratively solve a discretized form of the transformed equations. A multiple scale turbulence model based on simplified spectral partitioning is employed to obtain closure. Flow field predictions utilizing the multiple scale model are compared to features predicted by the traditional single scale k-epsilon model. Tuning parameter sensitivities of the multiple scale model applied to turn around duct flows are also determined. In addition, a wall function approach based on a wall law suitable for incompressible turbulent boundary layers under strong adverse pressure gradients is tested. Turn around duct flow characteristics utilizing this modified wall law are presented and compared to results based on a standard wall treatment.

  16. Growth declines in red spruce

    SciTech Connect

    McLaughlin, S.B. ); Adams, H.S. )

    1987-10-01

    In this letter, the authors take issue with Zedaker, Hyink, and Smith who have indicated that observed red spruce growth declines can be expected based on growth trends for even-aged stands of red spruce as documented in Meyer (1929). Recently, an examination was made of stand stocking levels at 750 sites where red spruce were cored and neither the rate of growth decline nor the extent of mortality were found to be related to stand stocking levels or previous disturbance history. The authors conclude that the Meyer data do not represent an appropriate model for stand dynamics of old-growth, high-elevation stands and no not adequately explain the growth declines observed at many of those sites.

  17. The rise (and decline?) of biotechnology.

    PubMed

    Kinch, Michael S

    2014-11-01

    Since the 1970s, biotechnology has been a key innovator in drug development. An analysis of FDA-approved therapeutics demonstrates pharmaceutical companies outpace biotechs in terms of new approvals but biotechnology companies are now responsible for earlier-stage activities (patents, INDs or clinical development). The number of biotechnology organizations that contributed to an FDA approval began declining in the 2000s and is at a level not seen since the 1980s. Whereas early biotechnology companies had a decade from first approval until acquisition, the average acquisition of a biotechnology company now occurs months before their first FDA approval. The number of hybrid organizations that arise when pharmaceutical companies acquire biotechnology is likewise declining, raising questions about the sustainability of biotechnology.

  18. Bibliography on Decline and Retrenchment.

    ERIC Educational Resources Information Center

    National Center for Higher Education Management Systems, Boulder, CO.

    A bibliography on decline and retrenchment in higher education is presented that includes publications from the fields of higher education, the organization sciences, and public administration. The objective is to make available the reference tools that have been useful in conducting the National Center for Higher Education Management Systems'…

  19. Impact of Declining Rural Infrastructure.

    ERIC Educational Resources Information Center

    McKenzie, Fiona Haslem

    A study investigated the impact of declining rural community infrastructure on social, environmental, and economic well-being in Western Australia's central wheatbelt. Questionnaires were completed by 398 residents of the central wheatbelt, on-farm interviews were conducted with 68 respondents, and 4 focus groups were held in area towns.…

  20. Chinese culture and fertility decline.

    PubMed

    Wu, C; Jia, S

    1992-01-01

    Coale has suggested that cultural factors exert a significant influence on fertility reduction; countries in the "Chinese cultural circle" would be the first to show fertility decline. In China, the view was that traditional Chinese culture contributed to increased population. This paper examines the nature of the relationship between Chinese culture and fertility. Attention was directed to a comparison of fertility rates of developing countries with strong Chinese cultural influence and of fertility within different regions of China. Discussion was followed by an explanation of the theoretical impact of Chinese culture on fertility and direct and indirect beliefs and practices that might either enhance or hinder fertility decline. Emigration to neighboring countries occurred after the Qing dynasty. Fertility after the 1950s declined markedly in Japan, Singapore, Hong Kong, South Korea, Taiwan, and mainland China: all countries within the Chinese cultural circle. Other countries within the Chinese circle which have higher fertility, yet lower fertility than other non-Chinese cultural countries, are Malaysia, Thailand, and Indonesia. Within China, regions with similar fertility patterns are identified as coastal regions, central plains, and mountainous and plateau regions. The Han ethnic group has lower fertility than that of ethnic minorities; regions with large Han populations have lower fertility. Overseas Chinese in East Asian countries also tend to have lower fertility than their host populations. Chinese culture consisted of the assimilation of other cultures over 5000 years. Fertility decline was dependent on the population's desire to limit reproduction, favorable social mechanisms, and availability of contraception: all factors related to economic development. Chinese culture affects fertility reduction by affecting reproductive views and social mechanisms directly, and indirectly through economics. Confucianism emphasizes collectivism, self

  1. Decline of Birds in a Human Modified Coastal Dune Forest Landscape in South Africa

    PubMed Central

    Trimble, Morgan J.; van Aarde, Rudi J.

    2011-01-01

    Previous studies demonstrate that old-growth forest remnants and vegetation regenerating after anthropogenic disturbance provide habitat for birds in a human modified coastal dune forest landscape in northern KwaZulu-Natal, South Africa. However, occurrence does not ensure persistence. Based on a 13-year monitoring database we calculated population trends for 37 bird species and general trends in overall bird density in different vegetation types. We evaluated species' characteristics as covariates of population trend and assessed changes in rainfall and proportional area and survey coverage per vegetation type. 76% of species assessed have declined, 57% significantly so at an average rate of 13.9% per year. Overall, bird density has fallen at 12.2% per year across old-growth forest and woody regenerating vegetation types. Changes in proportional area and coverage per vegetation type may partly explain trends for a few species but are unlikely to account for most. Below average rainfall may have contributed to bird declines. However, other possibilities warrant further investigation. Species with larger range extents tended to decline more sharply than did others, and these species may be responding to environmental changes on a broader geographical scale. Our results cast doubt on the future persistence of birds in this human modified landscape. More research is needed to elucidate the mechanisms driving population decline in the study area and to investigate whether the declines identified here are more widespread across the region and perhaps the continent. PMID:21249203

  2. Digestive enzyme activities of turbot (Scophthalmus maximus L.) during early developmental stages under culture condition.

    PubMed

    Tong, X H; Xu, S H; Liu, Q H; Li, J; Xiao, Z Z; Ma, D Y

    2012-06-01

    Digestive enzyme activities were analysed in turbot (Scophthalmus maximus) from hatching until 60 days after hatching (DAH). Trypsin sharply increased to the climax at 17 DAH and decreased until 31 DAH followed by a stable level thereafter. Amylase was determined at 4 DAH, reached the maximum value at 19 DAH and declined sharply to 39 DAH and remained at a low level thereafter, suggesting the carbohydrate component should remain at a low level in formulated diets. Pepsin was detected at 9 DAH and increased to 34 DAH and then remained at a stable level. The above results revealed pancreatic enzymes are no longer main enzymes for food digestion after the formation of functional stomach. Leucine-alanine peptidase (Leu-ala) and alkaline phosphatase (AP) and leucine aminopeptidase N (LAP) were found in newly hatched larvae. Both AP and LAP activities markedly increased to 23 DAH, decreased abruptly to 50 DAH and increased gradually to 60 DAH. Leu-ala reached the plateau from 23 to 39 DAH, followed by a decline to 46 DAH and an increase until 60 DAH. The brush border membrane (BBM)-bound enzyme activities increased from 30% at 31 DAH to 81% at 38 DAH of the total activities, indicating the maturation of intestinal tract.

  3. The fertility decline in Kenya.

    PubMed

    Robinson, W C; Harbison, S F

    1995-01-01

    In Sub-Saharan Africa Kenya is a prime example of a country experiencing a rapid decline in fertility and greater contraceptive prevalence. These changes have occurred since 1980 when fertility was high at 8.0 children per woman. In 1993 the total fertility rate (TFR) was 5.4, and the growth rate declined to about 2.0%. This transition is swifter than any country in contemporary Asia or historical Europe. The likely projection for Kenya is attainment of replacement level fertility during the 2020s and a leveling of population at about 100 million persons. Fertility has declined the most in urban areas and central and eastern regions. Bongaarts' proximate determinants (TFR, total marital fertility rate, total natural marital fertility rate, and total fecundity) are reduced to the proportion of currently married women using contraception, the proportion in lactational nonfecund status, and the proportion currently married. Actual fertility change is accounted for by total fertility change of 3.0 children. Lactational infecundability accounts for 0.5 potential births, and changes in marital fertility account for 1.0 reduced births per woman. About 70% of fertility reduction is accounted for by contraception and abortion. During 1977-78 80% of fertility control was due to lactational nonfecundity, 10% to nonmarriage, and 10% to contraception. In 1993 lactational nonfecundity accounted for 50% of the reduction, nonmarriage for 20%, and abortion about 30%. Future fertility is expected to be dependent on contraceptive prevalence. Kenya has experienced the Coale paradigm of preconditions necessary for demographic transition (willing, ready, and able). High fertility in Africa is not intractable. Creating the change in attitudes that leads to readiness is linked to education, health, and exposure to modernizing media and urban lifestyles. The public sector family planning program in Kenya has created the opportunity for access and availability of contraception. The key

  4. Climate change and pollution speed declines in zebrafish populations.

    PubMed

    Brown, A Ross; Owen, Stewart F; Peters, James; Zhang, Yong; Soffker, Marta; Paull, Gregory C; Hosken, David J; Wahab, M Abdul; Tyler, Charles R

    2015-03-17

    Endocrine disrupting chemicals (EDCs) are potent environmental contaminants, and their effects on wildlife populations could be exacerbated by climate change, especially in species with environmental sex determination. Endangered species may be particularly at risk because inbreeding depression and stochastic fluctuations in male and female numbers are often observed in the small populations that typify these taxa. Here, we assessed the interactive effects of water temperature and EDC exposure on sexual development and population viability of inbred and outbred zebrafish (Danio rerio). Water temperatures adopted were 28 °C (current ambient mean spawning temperature) and 33 °C (projected for the year 2100). The EDC selected was clotrimazole (at 2 μg/L and 10 μg/L), a widely used antifungal chemical that inhibits a key steroidogenic enzyme [cytochrome P450(CYP19) aromatase] required for estrogen synthesis in vertebrates. Elevated water temperature and clotrimazole exposure independently induced male-skewed sex ratios, and the effects of clotrimazole were greater at the higher temperature. Male sex ratio skews also occurred for the lower clotrimazole exposure concentration at the higher water temperature in inbred fish but not in outbred fish. Population viability analysis showed that population growth rates declined sharply in response to male skews and declines for inbred populations occurred at lower male skews than for outbred populations. These results indicate that elevated temperature associated with climate change can amplify the effects of EDCs and these effects are likely to be most acute in small, inbred populations exhibiting environmental sex determination and/or differentiation.

  5. Climate change and pollution speed declines in zebrafish populations

    PubMed Central

    Owen, Stewart F.; Peters, James; Zhang, Yong; Soffker, Marta; Paull, Gregory C.; Hosken, David J.; Wahab, M. Abdul; Tyler, Charles R.

    2015-01-01

    Endocrine disrupting chemicals (EDCs) are potent environmental contaminants, and their effects on wildlife populations could be exacerbated by climate change, especially in species with environmental sex determination. Endangered species may be particularly at risk because inbreeding depression and stochastic fluctuations in male and female numbers are often observed in the small populations that typify these taxa. Here, we assessed the interactive effects of water temperature and EDC exposure on sexual development and population viability of inbred and outbred zebrafish (Danio rerio). Water temperatures adopted were 28 °C (current ambient mean spawning temperature) and 33 °C (projected for the year 2100). The EDC selected was clotrimazole (at 2 μg/L and 10 μg/L), a widely used antifungal chemical that inhibits a key steroidogenic enzyme [cytochrome P450(CYP19) aromatase] required for estrogen synthesis in vertebrates. Elevated water temperature and clotrimazole exposure independently induced male-skewed sex ratios, and the effects of clotrimazole were greater at the higher temperature. Male sex ratio skews also occurred for the lower clotrimazole exposure concentration at the higher water temperature in inbred fish but not in outbred fish. Population viability analysis showed that population growth rates declined sharply in response to male skews and declines for inbred populations occurred at lower male skews than for outbred populations. These results indicate that elevated temperature associated with climate change can amplify the effects of EDCs and these effects are likely to be most acute in small, inbred populations exhibiting environmental sex determination and/or differentiation. PMID:25733876

  6. Falling teen pregnancy, birthrates: what's behind the declines?

    PubMed

    Donovan, P

    1998-10-01

    About half of the almost 1 million US teenagers who become pregnant each year carry their pregnancies to term and give birth. However, after years of steady increases, teen birthrates in the US are lower and pregnancy rates have fallen to their lowest level in 20 years. Teenage sexual activity is also declining. Over the period 1991-96, the birthrate in the US among teens declined from the 20-year high of 62.1 births/1000 females aged 15-19 to 54.4/1000. This 12% decline comes after a 24% increase in the birthrate between 1986 and 1991. Declines in the teen birthrate were observed for the nation overall, as well as in each state, ranging from 6% in Alabama to 29% in Alaska. The teen birthrate among Blacks declined 21% to reach a record low of 91.4/1000 in 1996, while the rate for Hispanic teens barely changed during 1991-95, but eventually declined 5% during 1995-96 to 101.8/1000. The birthrate among non-Hispanic White teens declined 9% during the period to 48.1/1000, while the birthrate for teens aged 15-17 fell 13% during the period and 9% for 18-19 year olds. Pregnancy rates among women aged 15-19 years declined 14% between 1990 and 1995, to 101.1/1000, the lowest level since the mid-1970s. Although researchers are unsure why teen pregnancy and birthrates have fallen, recent survey data suggest that the declines have occurred because both fewer teens are having sex and more sexually active adolescents are using contraception.

  7. [Strategic factors in fertility decline].

    PubMed

    Genne, M

    1984-01-01

    This study examines income as an important but not exclusive determinant of demographic evolution, using the theoretical model of the demographic transition. Researches at the Population Center at Princeton and the authors of the Bachue dimulation models among others believe that acceleration of fertility decline can be achieved by a more equitable distribution of income, goods, and knowledge. Among the works of this school of thought, the studies of r. Repetto which give quantitative expression to the correlation are particularly interesting when they are placed in the framework of the demographic transition. Even if the significance of all factors involved in the fertility decline has not been specified, income distribution plays a certain role regardless of the definition given to transition: the classic model, the revised definition of the Princeton group, or the equitable development model. A study of the Hungarian case between 1870-1910 bears out the relationship. It is equally interesting to note that developing countries currently have a demographic configuration similar to that of European countries in general, and of Hungary in particular, as of the beginning of the last century, and that a more equalitarian distribution of land or of income could bring about the same effects over time.

  8. Arctic sea ice decline: Introduction

    NASA Astrophysics Data System (ADS)

    DeWeaver, Eric T.

    By any measure, the loss of Arctic sea ice cover in September 2007 was spectacular. The National Snow and Ice Data Center (NSIDC) called it a loss "the size of Alaska and Texas combined," in comparison to the 1979-2000 September mean. Record-breaking minima in sea ice extent are not unexpected, given the declining trend of the past 30 years and its recent acceleration [e.g., Meier et al., 2007; Deser and Teng, this volume]. But the 2007 minimum was remarkable even compared to the decline, a full four standard deviations below the trend line (H. Stern, quoted by Schweiger et al. [2008]). Kerr [2007] reported an Alaska-sized loss compared to the previous record low in 2005, which was itself an Alaska-sized retreat from the value at the beginning of the satellite era in 1979. Deser and Teng point out that the loss between September 2006 and September 2007 is as large as the entire September extent loss from 1979 to 2006.

  9. Dietary Factors and Cognitive Decline

    PubMed Central

    Smith, P.J.; Blumenthal, J.A.

    2015-01-01

    Cognitive decline is an increasingly important public health problem, with more than 100 million adults worldwide projected to develop dementia by 2050. Accordingly, there has been an increased interest in preventive strategies that diminish this risk. It has been recognized that lifestyle factors including dietary patterns, may be important in the prevention of cognitive decline and dementia in later life. Several dietary components have been examined, including antioxidants, fatty acids, and B vitamins. In addition, whole dietary eating plans, including the Mediterranean diet (MeDi), and the Dietary Approaches to Stop Hypertension (DASH) diet, with and without weight loss, have become areas of increasing interest. Although prospective epidemiological studies have observed that antioxidants, fatty acids, and B vitamins are associated with better cognitive functioning, randomized clinical trials have generally failed to confirm the value of any specific dietary component in improving neurocognition. Several randomized trials have examined the impact of changing ‘whole’ diets on cognitive outcomes. The MeDi and DASH diets offer promising preliminary results, but data are limited and more research in this area is needed. PMID:26900574

  10. Short-term muscle disuse atrophy is not associated with increased intramuscular lipid deposition or a decline in the maximal activity of key mitochondrial enzymes in young and older males.

    PubMed

    Wall, Benjamin T; Dirks, Marlou L; Snijders, Tim; Stephens, Francis B; Senden, Joan M G; Verscheijden, Marie-Louise; van Loon, Luc J C

    2015-01-01

    Aging is generally accompanied by a progressive loss of skeletal muscle mass and impairments in metabolic function. Even a few days of muscle disuse (such as that occurring during injury or illness) leads to considerable loss of muscle mass and strength. It has been speculated that short, successive periods of muscle disuse throughout the lifespan may be largely responsible for the age-related loss of muscle mass. However, it remains unknown whether such short periods of disuse also induce impairments in metabolic function within skeletal muscle. Here, we investigated the effects of a five day period of muscle disuse on intramyocellular triacylglycerol (IMTG) content, muscle oxidative capacity, and the expression of key genes that regulate oxidative metabolism in healthy young and elderly men. Muscle biopsies were collected from healthy, young (n=12; 23±1y) and elderly (n=12; 70±1y) men prior to and immediately after a five day period of one-legged knee immobilization by way of a full leg cast. At baseline, elderly men had a greater IMTG content when compared with the young (56.2±5.1 and 34.8±7.3μmol·g(-1), respectively; P<0.05) with no changes in either group following immobilization (53.4±5.0 and 35.7±5.0μmol·g(-1), respectively; P>0.05). In line, five days of disuse did not lower citrate synthase, β-HAD or cytochrome C oxidase activity in skeletal muscle tissue. Pyruvate dehydrogenase activity increased following immobilization in the older subjects only, from 0.39±0.06 to 0.55 0.05μmol·g(-1)·min(-1) (71±33%; P<0.01). The skeletal muscle mRNA expression of PGC1α and citrate synthase both declined following immobilization in both the young and elderly subjects. We conclude that five days of muscle disuse does not increase intramuscular lipid deposition or reduce the maximal activity of key mitochondrial enzymes within the skeletal muscle of young or older men. PMID:25457674

  11. Ways of Dealing with Enrollment Decline

    ERIC Educational Resources Information Center

    Phi Delta Kappan, 1978

    1978-01-01

    Two consultants and superintendents from Livonia (Michigan), New Orleans, Salt Lake City, and Seattle discuss the impact of declining enrollments on the schools and some of the actions school districts are taking to cope with the decline. (IRT)

  12. Declining Sunshine for Phoenix Lander

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The yellow line on this graphic indicates the number of hours of sunlight each sol, or Martian day, at the Phoenix landing site's far-northern latitude, beginning with the entire Martian day (about 24 hours and 40 minutes) for the first 90 sols, then declining to no sunlight by about sol 300. The blue tick mark indicates that on Sol 124 (Sept. 29, 2008), the sun is above the horizon for about 20 hours.

    The brown vertical bar represents the period from Nov. 18 to Dec. 24, 2008, around the 'solar conjunction,' when the sun is close to the line between Mars and Earth, affecting communications.

    The green vertical rectangle represents the period from February to November 2009 when the Phoenix lander is expected to be encased in carbon-dioxide ice.

  13. Dropping dead: causes and consequences of vulture population declines worldwide.

    PubMed

    Ogada, Darcy L; Keesing, Felicia; Virani, Munir Z

    2012-02-01

    Vultures are nature's most successful scavengers, and they provide an array of ecological, economic, and cultural services. As the only known obligate scavengers, vultures are uniquely adapted to a scavenging lifestyle. Vultures' unique adaptations include soaring flight, keen eyesight, and extremely low pH levels in their stomachs. Presently, 14 of 23 (61%) vulture species worldwide are threatened with extinction, and the most rapid declines have occurred in the vulture-rich regions of Asia and Africa. The reasons for the population declines are varied, but poisoning or human persecution, or both, feature in the list of nearly every declining species. Deliberate poisoning of carnivores is likely the most widespread cause of vulture poisoning. In Asia, Gyps vultures have declined by >95% due to poisoning by the veterinary drug diclofenac, which was banned by regional governments in 2006. Human persecution of vultures has occurred for centuries, and shooting and deliberate poisoning are the most widely practiced activities. Ecological consequences of vulture declines include changes in community composition of scavengers at carcasses and an increased potential for disease transmission between mammalian scavengers at carcasses. There have been cultural and economic costs of vulture declines as well, particularly in Asia. In the wake of catastrophic vulture declines in Asia, regional governments, the international scientific and donor communities, and the media have given the crisis substantial attention. Even though the Asian vulture crisis focused attention on the plight of vultures worldwide, the situation for African vultures has received relatively little attention especially given the similar levels of population decline. While the Asian crisis has been largely linked to poisoning by diclofenac, vulture population declines in Africa have numerous causes, which have made conserving existing populations more difficult. And in Africa there has been little

  14. Arctic sea-ice decline archived by multicentury annual-resolution record from crustose coralline algal proxy.

    PubMed

    Halfar, Jochen; Adey, Walter H; Kronz, Andreas; Hetzinger, Steffen; Edinger, Evan; Fitzhugh, William W

    2013-12-01

    Northern Hemisphere sea ice has been declining sharply over the past decades and 2012 exhibited the lowest Arctic summer sea-ice cover in historic times. Whereas ongoing changes are closely monitored through satellite observations, we have only limited data of past Arctic sea-ice cover derived from short historical records, indirect terrestrial proxies, and low-resolution marine sediment cores. A multicentury time series from extremely long-lived annual increment-forming crustose coralline algal buildups now provides the first high-resolution in situ marine proxy for sea-ice cover. Growth and Mg/Ca ratios of these Arctic-wide occurring calcified algae are sensitive to changes in both temperature and solar radiation. Growth sharply declines with increasing sea-ice blockage of light from the benthic algal habitat. The 646-y multisite record from the Canadian Arctic indicates that during the Little Ice Age, sea ice was extensive but highly variable on subdecadal time scales and coincided with an expansion of ice-dependent Thule/Labrador Inuit sea mammal hunters in the region. The past 150 y instead have been characterized by sea ice exhibiting multidecadal variability with a long-term decline distinctly steeper than at any time since the 14th century.

  15. Arctic sea-ice decline archived by multicentury annual-resolution record from crustose coralline algal proxy

    PubMed Central

    Halfar, Jochen

    2013-01-01

    Northern Hemisphere sea ice has been declining sharply over the past decades and 2012 exhibited the lowest Arctic summer sea-ice cover in historic times. Whereas ongoing changes are closely monitored through satellite observations, we have only limited data of past Arctic sea-ice cover derived from short historical records, indirect terrestrial proxies, and low-resolution marine sediment cores. A multicentury time series from extremely long-lived annual increment-forming crustose coralline algal buildups now provides the first high-resolution in situ marine proxy for sea-ice cover. Growth and Mg/Ca ratios of these Arctic-wide occurring calcified algae are sensitive to changes in both temperature and solar radiation. Growth sharply declines with increasing sea-ice blockage of light from the benthic algal habitat. The 646-y multisite record from the Canadian Arctic indicates that during the Little Ice Age, sea ice was extensive but highly variable on subdecadal time scales and coincided with an expansion of ice-dependent Thule/Labrador Inuit sea mammal hunters in the region. The past 150 y instead have been characterized by sea ice exhibiting multidecadal variability with a long-term decline distinctly steeper than at any time since the 14th century. PMID:24248344

  16. [Ozone decline and UV increase].

    PubMed

    Winkler, P; Trepte, S

    2004-02-01

    The following results have been obtained from long-term observations on the ozone layer and UV at the Meteorological Observatory Hohenpeigenberg:The seasonally varying decline of the ozone layer determines the maximum exposure to UV. Since ozone decline shows the highest rates in the spring months the UV exposure has most strongly increased in this time of the year. This is especially important because in spring the human skin is not adapted to UV exposure. Weather changes from day to day can induce rapid ozone reductions in spring about -30% which in turn is followed by an increase in UV of about 40%. Clouds, especially the transparent cirrus clouds (high clouds consisting of ice particles) have increased in frequency during spring and fall while a decrease is observed in summer. This change in cloudiness reduces the daily UV dose in spring and fall while it is enhanced in summer. With increasing height above sea level UV rises by roughly 10% per 1000 m (rule of thumb). Snow reflects the UV-radiation by up to 80% enhancing the UV-doses at relevant conditions. Strong volcano eruptions destroy ozone in the stratosphere additionally during 1-2 years after the eruption. Therafter the ozone layer recovers. In April 1993, after the eruption of Mt. Pinatubo (1991), the UV burden was still 40% higher than average. Miniholes and streamers can appear unexpected on a short-time scale and cross over Central Europe within 1-2 days, thus enhancing UV irradiation. The human skin reacts to UV exposure depending on the type of skin. The campaign "Sonne(n) mit Verstand" of the Bavarian Ministries for Environment, for Health and for Education informs about the danger of UV radiation (see www.sonne-mit-ver-stand.de). The German Weather Service informs the public on present developments of the ozone layer and relevant topics byits ozone bulletin, which is also available via internet under (www.dwd.de/deFundE/Observator/MOHp/hp2/ozon/bulletin.htm).

  17. [Ozone decline and UV increase].

    PubMed

    Winkler, P; Trepte, S

    2004-02-01

    The following results have been obtained from long-term observations on the ozone layer and UV at the Meteorological Observatory Hohenpeigenberg:The seasonally varying decline of the ozone layer determines the maximum exposure to UV. Since ozone decline shows the highest rates in the spring months the UV exposure has most strongly increased in this time of the year. This is especially important because in spring the human skin is not adapted to UV exposure. Weather changes from day to day can induce rapid ozone reductions in spring about -30% which in turn is followed by an increase in UV of about 40%. Clouds, especially the transparent cirrus clouds (high clouds consisting of ice particles) have increased in frequency during spring and fall while a decrease is observed in summer. This change in cloudiness reduces the daily UV dose in spring and fall while it is enhanced in summer. With increasing height above sea level UV rises by roughly 10% per 1000 m (rule of thumb). Snow reflects the UV-radiation by up to 80% enhancing the UV-doses at relevant conditions. Strong volcano eruptions destroy ozone in the stratosphere additionally during 1-2 years after the eruption. Therafter the ozone layer recovers. In April 1993, after the eruption of Mt. Pinatubo (1991), the UV burden was still 40% higher than average. Miniholes and streamers can appear unexpected on a short-time scale and cross over Central Europe within 1-2 days, thus enhancing UV irradiation. The human skin reacts to UV exposure depending on the type of skin. The campaign "Sonne(n) mit Verstand" of the Bavarian Ministries for Environment, for Health and for Education informs about the danger of UV radiation (see www.sonne-mit-ver-stand.de). The German Weather Service informs the public on present developments of the ozone layer and relevant topics byits ozone bulletin, which is also available via internet under (www.dwd.de/deFundE/Observator/MOHp/hp2/ozon/bulletin.htm). PMID:14770335

  18. Mortality rates decline in Malaysia.

    PubMed

    1991-11-01

    Experiencing remarkable decreases in mortality rates over the past 3 decades, Malaysia currently has one of the lowest mortality rates among developing countries, a rate that compares favorably with those of developed countries. Between 1957 and 1989, the crude death rate dropped from 12.4/1000 population to 4.6. Over the same period, Malaysia recorded even greater decreases in the infant mortality rate, from 75.5/1000 births to 15.2. The Maternal mortality rate also declined from 1.48 in 1970 to 0.24 in 1988. The data indicates that mortality rates vary from state to state, and that rural areas have a higher mortality than urban areas. According to a study by the National Population and Family Development Board, the use of maternal and child health services has played an important role in reducing neonatal, perinatal, infant, child, and maternal mortality rates. Nearly all women in Malaysia receive antenatal services. While the country has achieved great gains on mortality rates, programs focusing on specific age and socioeconomic groups could lead to even greater reductions. The Minister for National Unity and Social Development, Dato Napsiah Omar, has called for the development of programs designed to improve the population's quality of life.

  19. Mortality rates decline in Malaysia.

    PubMed

    1991-11-01

    Experiencing remarkable decreases in mortality rates over the past 3 decades, Malaysia currently has one of the lowest mortality rates among developing countries, a rate that compares favorably with those of developed countries. Between 1957 and 1989, the crude death rate dropped from 12.4/1000 population to 4.6. Over the same period, Malaysia recorded even greater decreases in the infant mortality rate, from 75.5/1000 births to 15.2. The Maternal mortality rate also declined from 1.48 in 1970 to 0.24 in 1988. The data indicates that mortality rates vary from state to state, and that rural areas have a higher mortality than urban areas. According to a study by the National Population and Family Development Board, the use of maternal and child health services has played an important role in reducing neonatal, perinatal, infant, child, and maternal mortality rates. Nearly all women in Malaysia receive antenatal services. While the country has achieved great gains on mortality rates, programs focusing on specific age and socioeconomic groups could lead to even greater reductions. The Minister for National Unity and Social Development, Dato Napsiah Omar, has called for the development of programs designed to improve the population's quality of life. PMID:12284509

  20. Minimal models of growth and decline of microbial populations.

    PubMed

    Juška, Alfonsas

    2011-01-21

    Dynamics of growth and decline of microbial populations were analysed and respective models were developed in this investigation. Analysis of the dynamics was based on general considerations concerning the main properties of microorganisms and their interactions with the environment which was supposed to be affected by the activity of the population. Those considerations were expressed mathematically by differential equations or systems of the equations containing minimal sets of parameters characterizing those properties. It has been found that: (1) the factors leading to the decline of the population have to be considered separately, namely, accumulation of metabolites (toxins) in the medium and the exhaustion of resources; the latter have to be separated again into renewable ('building materials') and non-renewable (sources of energy); (2) decline of the population is caused by the exhaustion of sources of energy but no decline is predicted by the model because of the exhaustion of renewable resources; (3) the model determined by the accumulation of metabolites (toxins) in the medium does not suggest the existence of a separate 'stationary phase'; (4) in the model determined by the exhaustion of energy resources the 'stationary' and 'decline' phases are quite discernible; and (5) there is no symmetry in microbial population dynamics, the decline being slower than the rise. Mathematical models are expected to be useful in getting insight into the process of control of the dynamics of microbial populations. The models are in agreement with the experimental data. PMID:21036180

  1. [Concentration or decline in Puebla?].

    PubMed

    Cabrera Becerra, V

    1993-04-01

    Some doubts have been expressed over whether the slowing pace of urbanization suggested by the 1990 census of Mexico was an accurate reflection of changing conditions, or whether it resulted from some intentional or unintended bias. Comparison of data from succeeding censuses indicates that the growth rate of the city of Puebla declined from 6.32% in 1980 to 2.63% in 1990. This work argues that, in Puebla, a trend to deconcentration of the population within the city of Puebla during the 1980s was accompanied by rapid growth in smaller and medium sized nearby cities, resulting in increased overall concentration in Puebla's metropolitan area. The absolute population of the city of Puebla increased from 772,908 in 1980 to 1,007,170 in 1990. The central area of the state of Puebla, which surrounds the city, increased its share of the state population from 51.67% in 1980 to 52.21% in 1990. The number of places with over 5000 inhabitants in the area surrounding the city of Puebla increased from 27 in 1980 to 39 in 1990. Construction of the Puebla-Atlixco highway will undoubtedly attract growth to the area southwest of Puebla. Small cities to the east of Puebla have shown significant growth although their region remains strongly rural. The same process of deconcentration of population in Puebla and concentration in its surrounding metropolitan regions can probably also be detected in patterns of investment of public funds. The trend is likely to continue through the 1990s.

  2. Perioperative Cognitive Decline in the Aging Population

    PubMed Central

    Terrando, Niccolò; Brzezinski, Marek; Degos, Vincent; Eriksson, Lars I.; Kramer, Joel H.; Leung, Jacqueline M.; Miller, Bruce L.; Seeley, William W.; Vacas, Susana; Weiner, Michael W.; Yaffe, Kristine; Young, William L.; Xie, Zhongcong; Maze, Mervyn

    2011-01-01

    Elderly patients who have an acute illness or who undergo surgery often experience cognitive decline. The pathophysiologic mechanisms that cause neurodegeneration resulting in cognitive decline, including protein deposition and neuroinflammation, also play a role in animal models of surgery-induced cognitive decline. With the aging of the population, surgical candidates of advanced age with underlying neurodegeneration are encountered more often, raising concerns that, in patients with this combination, cognitive function will precipitously decline postoperatively. This special article is based on a symposium that the University of California, San Francisco, convened to explore the contributions of surgery and anesthesia to the development of cognitive decline in the aged patient. A road map to further elucidate the mechanisms, diagnosis, risk factors, mitigation, and treatment of postoperative cognitive decline in the elderly is provided. PMID:21878601

  3. Cognitive Decline and the Default American Lifestyle

    PubMed Central

    2011-01-01

    Objectives. Upward trends in IQ, education, and mental work suggest that cognitive function among seniors should be rising strongly across cohorts. There is little sign of such improvement in recent decades, and some analyses find poorer function in the newer cohorts. This essay explores possible explanations of the anomaly. Methods. Major long-term trends that might increase cognitive impairment are reviewed, and their implications are considered. Results. Physical activity is declining, food is increasingly manufactured, body fat is increasing, diabetes and metabolic syndrome are on the rise, the number of prescription drugs per person is increasing, and the proportion of the population either old or obese is growing. Discussion. Technological and economic development may lower the cognitive function needed for survival. They also lower physical activity in daily life. Sedentary work, transportation, and leisure undermine the aerobic and metabolic fitness required for the brain to perform well. Some prescription drugs impair cognitive function, and others do so when taken for many years or in combination with others. The growing fraction of the population that is either old or obese may further lower physical activity norms and requirements and substitute medical intervention for health, accelerating a trend toward cognitive impairment. PMID:21743052

  4. A Longitudinal Examination of Performance Decline in Champion Golfers

    ERIC Educational Resources Information Center

    Baker, J.; Horton, S.; Pearce, W.; Deakin, J. M.

    2005-01-01

    The maintenance of skilled performance is of increasing interest and importance in our aging society. Bortz and Bortz (1996) suggested that cognitive and physical abilities decline at a rate of 0.5% per year from peak performance. However, examinations of expert performance in cognitive-motor activities suggest that performance in these areas can…

  5. Rock mass response to the decline in underground coal mining

    SciTech Connect

    Holub, K.

    2006-01-15

    Geomechanical problems of mining in the Ostrava-Karvina Coal Basin were studied on the basis of longterm experience gained from seismological observations. They could serve as reasonable models of rock-mass response to temporary reduction and gradual decline in mining activities and mine closure.

  6. An Evidence-Based Construction of the Models of Decline of Functioning. Part 1: Two Major Models of Decline of Functioning

    ERIC Educational Resources Information Center

    Okawa, Yayoi; Nakamura, Shigemi; Kudo, Minako; Ueda, Satoshi

    2009-01-01

    The purpose of this study is to confirm the working hypothesis on two major models of functioning decline and two corresponding models of rehabilitation program in an older population through detailed interviews with the persons who have functioning declines and on-the-spot observations of key activities on home visits. A total of 542…

  7. Ethanol and Isopropanol in Concentrations Present in Hand Sanitizers Sharply Reduce Excystation of Giardia and Entamoeba and Eliminate Oral Infectivity of Giardia Cysts in Gerbils

    PubMed Central

    Chatterjee, Aparajita; Bandini, Giulia; Motari, Edwin

    2015-01-01

    Enteric protozoan parasites, which are spread by the fecal-oral route, are important causes of diarrhea (Giardia duodenalis) and amebic dysentery (Entamoeba histolytica). Cyst walls of Giardia and Entamoeba have a single layer composed of fibrils of β-1,3-linked GalNAc and β-1,4-linked GlcNAc (chitin), respectively. The goal here was to determine whether hand sanitizers that contain ethanol or isopropanol as the active microbicide might reduce transmission of these parasites. We found that treatment with these alcohols with or without drying in a rotary evaporator (to model rapid evaporation of sanitizers on hands) kills 85 to 100% of cysts of G. duodenalis and 90 to 100% of cysts of Entamoeba invadens (a nonpathogenic model for E. histolytica), as shown by nuclear labeling with propidium iodide and failure to excyst in vitro. Alcohols with or without drying collapsed the cyst walls of Giardia but did not collapse the cyst walls of Entamoeba. To validate the in vitro results, we showed that treatment with alcohols eliminated oral infection of gerbils by 1,000 G. duodenalis cysts, while a commercial hand sanitizer (Purell) killed E. invadens cysts that were directly applied to the hands. These results suggest that expanded use of alcohol-based hand sanitizers might reduce the transmission of Giardia and Entamoeba. PMID:26282413

  8. Ethanol and isopropanol in concentrations present in hand sanitizers sharply reduce excystation of Giardia and Entamoeba and eliminate oral infectivity of Giardia cysts in gerbils.

    PubMed

    Chatterjee, Aparajita; Bandini, Giulia; Motari, Edwin; Samuelson, John

    2015-11-01

    Enteric protozoan parasites, which are spread by the fecal-oral route, are important causes of diarrhea (Giardia duodenalis) and amebic dysentery (Entamoeba histolytica). Cyst walls of Giardia and Entamoeba have a single layer composed of fibrils of β-1,3-linked GalNAc and β-1,4-linked GlcNAc (chitin), respectively. The goal here was to determine whether hand sanitizers that contain ethanol or isopropanol as the active microbicide might reduce transmission of these parasites. We found that treatment with these alcohols with or without drying in a rotary evaporator (to model rapid evaporation of sanitizers on hands) kills 85 to 100% of cysts of G. duodenalis and 90 to 100% of cysts of Entamoeba invadens (a nonpathogenic model for E. histolytica), as shown by nuclear labeling with propidium iodide and failure to excyst in vitro. Alcohols with or without drying collapsed the cyst walls of Giardia but did not collapse the cyst walls of Entamoeba. To validate the in vitro results, we showed that treatment with alcohols eliminated oral infection of gerbils by 1,000 G. duodenalis cysts, while a commercial hand sanitizer (Purell) killed E. invadens cysts that were directly applied to the hands. These results suggest that expanded use of alcohol-based hand sanitizers might reduce the transmission of Giardia and Entamoeba. PMID:26282413

  9. Ethanol and isopropanol in concentrations present in hand sanitizers sharply reduce excystation of Giardia and Entamoeba and eliminate oral infectivity of Giardia cysts in gerbils.

    PubMed

    Chatterjee, Aparajita; Bandini, Giulia; Motari, Edwin; Samuelson, John

    2015-11-01

    Enteric protozoan parasites, which are spread by the fecal-oral route, are important causes of diarrhea (Giardia duodenalis) and amebic dysentery (Entamoeba histolytica). Cyst walls of Giardia and Entamoeba have a single layer composed of fibrils of β-1,3-linked GalNAc and β-1,4-linked GlcNAc (chitin), respectively. The goal here was to determine whether hand sanitizers that contain ethanol or isopropanol as the active microbicide might reduce transmission of these parasites. We found that treatment with these alcohols with or without drying in a rotary evaporator (to model rapid evaporation of sanitizers on hands) kills 85 to 100% of cysts of G. duodenalis and 90 to 100% of cysts of Entamoeba invadens (a nonpathogenic model for E. histolytica), as shown by nuclear labeling with propidium iodide and failure to excyst in vitro. Alcohols with or without drying collapsed the cyst walls of Giardia but did not collapse the cyst walls of Entamoeba. To validate the in vitro results, we showed that treatment with alcohols eliminated oral infection of gerbils by 1,000 G. duodenalis cysts, while a commercial hand sanitizer (Purell) killed E. invadens cysts that were directly applied to the hands. These results suggest that expanded use of alcohol-based hand sanitizers might reduce the transmission of Giardia and Entamoeba.

  10. Maintaining Excellence in the Management of Decline.

    ERIC Educational Resources Information Center

    Nyquist, Ewald B.

    Unless educators engage in thorough planning, in making the most efficient use of economic resources, and in interpreting to the public why education deserves high priority, public education is in for a long period of gradual decline. The central thrust of the current administrative era is the management of decline, or decremental planning. The…

  11. The Decline of Black Farming in America.

    ERIC Educational Resources Information Center

    Browning, Pamela; And Others

    The rapid decline in the number of farms operated by blacks in the United States, and the consequences of this decline on the conditions of black farmers are the focus of this report. Chapter 1 compares the rate of agricultural land loss from 1900 to 1978 among blacks and whites. Chapter 2 outlines historical conditions, such as racism, lack of…

  12. 31 CFR 240.7 - Declination protest.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... bank may protest the declination of a check that it has presented to a Federal Reserve Bank for payment... presented for payment and a Federal Reserve Bank has reversed its provisional credit to the presenting bank, the presenting bank may file a protest challenging the factual basis for such declination....

  13. Novelty Seeking in Adulthood: Increases Accompany Decline

    ERIC Educational Resources Information Center

    Reio, Thomas G., Jr.; Choi, Namok

    2004-01-01

    Using stereotypes, researchers have predicted that novelty seeking declines in adulthood. Through this cross-sectional study, the authors revealed that only the external sensational type of novelty seeking declined, whereas the internal sensational and internal and external cognitive types remained stable or increased. A population of 233 adults…

  14. Potential causes for amphibian declines in Puerto Rico

    USGS Publications Warehouse

    Burrowes, P.A.; Joglar, R.L.; Green, David E.

    2004-01-01

    We monitored 11 populations of eight species of Eleutherodactylus in Puerto Rico from 1989 through 2001. We determined relative abundance of active frogs along transects established in the Caribbean National Forest (El Yunque), Carite Forest, San Lorenzo, and in the vicinity of San Juan. Three species (Eleutherodactylus karlschmidti, E. jasperi, and E. eneidae) are presumed to be extinct and eight populations of six different species of endemic Eleutherodactylus are significantly declining at elevations above 400 m. Of the many suspected causes of amphibian declines around the world, we focused on climate change and disease. Temperature and precipitation data from 1970a??2000 were analyzed to determine the general pattern of oscillations and deviations that could be correlated with amphibian declines. We examined a total of 106 tissues taken from museum specimens collected from 1961a??1978 and from live frogs in 2000. We found chytrid fungi in two species collected at El Yunque as early as 1976, this is the first report of chytrid fungus in the Caribbean. Analysis of weather data indicates a significant warming trend and an association between years with extended periods of drought and the decline of amphibians in Puerto Rico. The 1970's and 1990's, which represent the periods of amphibian extirpations and declines, were significantly drier than average. We suggest a possible synergistic interaction between drought and the pathological effect of the chytrid fungus on amphibian populations.

  15. Cognitive Decline in Older Persons Initiating Anticholinergic Medications

    PubMed Central

    Shah, Raj C.; Janos, Alicia L.; Kline, Julia E.; Yu, Lei; Leurgans, Sue E.; Wilson, Robert S.; Wei, Peter; Bennett, David A.; Heilman, Kenneth M.; Tsao, Jack W.

    2013-01-01

    Background This study examines the effect of initiating medications with anticholinergic activity on the cognitive functions of older persons. Methods Participants were 896 older community-dwelling, Catholic clergy without baseline dementia. Medication data was collected annually. The Anticholinergic Cognitive Burden Scale was utilized to identify use of a medication with probable or definite anticholinergic activity. Participants had at least two annual cognitive evaluations. Results Over a mean follow-up of 10 years, the annual rate of global cognitive function decline for never users, prevalent users, and incident users was −0.062 (SE = 0.005), −0.081(SE = 0.011), and −0.096 (SE = 0.007) z-score units/year, respectively. Compared to never users, incident users had a more rapid decline (difference = −0.034 z-score units/year, SE = 0.008, p<0.001) while prevalent users did not have a significantly more rapid decline (p = 0.1). Conclusions Older persons initiating a medication with anticholinergic activity have a steeper annual decline in cognitive functioning than those who are not taking these medications. PMID:23741303

  16. Examining differences between recovered and declining endangered species

    USGS Publications Warehouse

    Abbitt, R.J.F.; Michael, Scott J.

    2001-01-01

    Between 1973 and 1999, 43 species in the United States were reclassified from endangered to threatened or removed entirely from the Endangered Species List. Of these, 23 were identified as recovered. In 1999 the U.S. Fish and Wildlife Service (USFWS) published a list of 33 additional species for possible reclassification and/or delisting. We initiated this study to examine why some endangered species recover but others continue to decline and to identify differences in management activities between these two groups. We defined recovered/recovering species as previously recovered species and the additional recovered/recovering species listed by the USFWS. We defined declining species as those identified as declining in the most recent USFWS Report to Congress. Information on recovered/recovering and declining species was gathered from relevant literature, recovery plans, U.S. Federal Register documents, and individuals responsible for the recovery management of each species. We used this information to examine (1) the percentage of current and historic range covered by management activities; (2) threats affecting the species; (3) population sizes at the time of listing; (4) current versus historic range size; and (5) percentage of recovery management objectives completed. Although few statistical analyses provided significant results, those that did suggest the following differences between recovered/recovering and declining species: (1) recovered/recovering species face threats that are easier to address; (2) recovered/recovering species occupy a greater percentage of their historic range; and (3) recovered/recovering species have a greater percentage of their recovery management objectives completed. Those species with threats easier to address and that occupy a greater percentage of their historic range are recovered/recovering. In contrast, declining species face threats more difficult to address and occupy significantly less of their historic range. If this

  17. Theoretical Analysis of Maximum Flow Declination Rate versus Maximum Area Declination Rate in Phonation

    ERIC Educational Resources Information Center

    Titze, Ingo R.

    2006-01-01

    Purpose: Maximum flow declination rate (MFDR) in the glottis is known to correlate strongly with vocal intensity in voicing. This declination, or negative slope on the glottal airflow waveform, is in part attributable to the maximum area declination rate (MADR) and in part to the overall inertia of the air column of the vocal tract (lungs to…

  18. Dropping dead: causes and consequences of vulture population declines worldwide.

    PubMed

    Ogada, Darcy L; Keesing, Felicia; Virani, Munir Z

    2012-02-01

    Vultures are nature's most successful scavengers, and they provide an array of ecological, economic, and cultural services. As the only known obligate scavengers, vultures are uniquely adapted to a scavenging lifestyle. Vultures' unique adaptations include soaring flight, keen eyesight, and extremely low pH levels in their stomachs. Presently, 14 of 23 (61%) vulture species worldwide are threatened with extinction, and the most rapid declines have occurred in the vulture-rich regions of Asia and Africa. The reasons for the population declines are varied, but poisoning or human persecution, or both, feature in the list of nearly every declining species. Deliberate poisoning of carnivores is likely the most widespread cause of vulture poisoning. In Asia, Gyps vultures have declined by >95% due to poisoning by the veterinary drug diclofenac, which was banned by regional governments in 2006. Human persecution of vultures has occurred for centuries, and shooting and deliberate poisoning are the most widely practiced activities. Ecological consequences of vulture declines include changes in community composition of scavengers at carcasses and an increased potential for disease transmission between mammalian scavengers at carcasses. There have been cultural and economic costs of vulture declines as well, particularly in Asia. In the wake of catastrophic vulture declines in Asia, regional governments, the international scientific and donor communities, and the media have given the crisis substantial attention. Even though the Asian vulture crisis focused attention on the plight of vultures worldwide, the situation for African vultures has received relatively little attention especially given the similar levels of population decline. While the Asian crisis has been largely linked to poisoning by diclofenac, vulture population declines in Africa have numerous causes, which have made conserving existing populations more difficult. And in Africa there has been little

  19. Maryland striped bass: recruitment declining below replacement

    SciTech Connect

    Goodyear, C.P.; Cohen, J.E.; Christensen, S.W.

    1985-01-01

    A mathematical technique was developed to examined interrelationships among first-year survival rates, adult fecundity, and adult survival of striped bass Morone saxatilis based on indices of year-class strength. Application of this technique to striped bass in Maryland waters of the Chesapeake Bay provided evidence for reduced survival in the life cycle. If adult fecundity and survival have remained constant, first-year survival declined significantly from 1969 to 1983, and averaged less than that needed for replacement for the last 10 years. Treatment of the individual spawning grounds separately indicated that the downward trend in survival for the pooled data was the result of declines in the upper bay and, to a lesser extent, in the Choptank River. Alternatively, if first-year survival and adult fecundity were assumed to have remained constant, an annual decline of about 1.9% in adult survival would have been required to produce the observed trend in the pooled year-class data. This would be consistent with increased fishing mortality and implies declining recruitment because of declining stock size. Continuing declines in first-year or adult survival would eliminate the Maryland striped bass stock and the fishery it supports. Conversely, an increase in adult survival could offset of the unknown factor or factors responsible for the apparent decline in first-year survival. 25 references, 1 figure, 1 table.

  20. Asymmetric disassembly and robustness in declining networks

    PubMed Central

    Saavedra, Serguei; Reed-Tsochas, Felix; Uzzi, Brian

    2008-01-01

    Mechanisms that enable declining networks to avert structural collapse and performance degradation are not well understood. This knowledge gap reflects a shortage of data on declining networks and an emphasis on models of network growth. Analyzing >700,000 transactions between firms in the New York garment industry over 19 years, we tracked this network's decline and measured how its topology and global performance evolved. We find that favoring asymmetric (disassortative) links is key to preserving the topology and functionality of the declining network. Based on our findings, we tested a model of network decline that combines an asymmetric disassembly process for contraction with a preferential attachment process for regrowth. Our simulation results indicate that the model can explain robustness under decline even if the total population of nodes contracts by more than an order of magnitude, in line with our observations for the empirical network. These findings suggest that disassembly mechanisms are not simply assembly mechanisms in reverse and that our model is relevant to understanding the process of decline and collapse in a broad range of biological, technological, and financial networks. PMID:18936489

  1. Asymmetric disassembly and robustness in declining networks.

    PubMed

    Saavedra, Serguei; Reed-Tsochas, Felix; Uzzi, Brian

    2008-10-28

    Mechanisms that enable declining networks to avert structural collapse and performance degradation are not well understood. This knowledge gap reflects a shortage of data on declining networks and an emphasis on models of network growth. Analyzing >700,000 transactions between firms in the New York garment industry over 19 years, we tracked this network's decline and measured how its topology and global performance evolved. We find that favoring asymmetric (disassortative) links is key to preserving the topology and functionality of the declining network. Based on our findings, we tested a model of network decline that combines an asymmetric disassembly process for contraction with a preferential attachment process for regrowth. Our simulation results indicate that the model can explain robustness under decline even if the total population of nodes contracts by more than an order of magnitude, in line with our observations for the empirical network. These findings suggest that disassembly mechanisms are not simply assembly mechanisms in reverse and that our model is relevant to understanding the process of decline and collapse in a broad range of biological, technological, and financial networks.

  2. Can exercise prevent cognitive decline?

    PubMed

    Behrman, Sophie; Ebmeier, Klaus P

    2014-01-01

    As the tolerability of pharmacological agents decreases with age, exercise may be particularly helpful as a possible treatment or stabiliser of mood and cognitive function in older age. Exercise has been most commonly evaluated for the treatment of depression. Exercise interventions designed primarily for treatment of physical conditions in the elderly do appear to confer psychological benefits as well, with reduction in depressive symptoms over the course of treatment. The effects of exercise on reducing depressive symptoms are not dissimilar to the effects of antidepressant drugs and cognitive behaviour therapy. Exercise may be a useful low-tech intervention for people with mild to moderate depression. In particular, exercise may be helpful in the elderly and in patients who have had insufficient response to, or are intolerant of, pharmacotherapy. Mastery of a new skill and positive feedback from others may increase feelings of self-esteem and improve mood. Exercise may distract participants from persistent negative thoughts. Exercise has been shown to improve executive function acutely in adults of all ages. It is possible that dance routines or other exercise regimens requiring some cognitive input may confer additional benefit to cognitive function. Exercise has a moderate effect on the ability of people with dementia to perform activities of daily living and may improve cognitive function. Midlife exercise may also have an impact on later cognitive function. PMID:24617099

  3. Species decline: Contaminants and other contributing factors

    USGS Publications Warehouse

    Pattee, O.H.; Rattner, B.A.; Eisler, R.

    1998-01-01

    Members of over 1,200 taxa have been listed as Threatened or Endangered, and over 4,000 additional organisms have been identified as Candidate Species or Species of Concern. Identification of critical limiting factors may result in management actions that stabilize vulnerable populations and insure their perpetuation. Both naturally-occurring and anthropogenic activities (e.g., environmental contaminants and pollution) have been demonstrated to be a significant factor in depressing populations or catalyzing the final crash of some species. The objective of this project is to develop a synthesis document and database that lists and ranks the presumed causes of decline, with special emphasis on contaminants and pollutant-related situations. This will be accomplished by synoptic review of all recovery plans (n=479) with listing packages (n=1134) serving as a secondary source of information, followed by itemization, cross-referencing, enumeration, and ranking of contributing and limiting factors. To date we have analyzed all of the recovery plans for reptiles (n=26) and amphibians (n=6). 188 causes are defined, falling into 6 major categories: habitat alteration/availability (47.8%); exploitation/harvest (19.7%); introduction of exotic species (10.1%); contaminants (9.0%); miscellaneous others (6.9%); pollution (6.4%). The applicability of these data are extensive, including facilitating reviews of Section 7 consultations and Environmental Impact Statements, reviewing permit applications, conducting environmental contaminant risk assessments, identifying specific data gaps and research needs, selecting potential management actions, and establishing priorities for broad-based research on limiting factors applicable to groups of species rather than the current species-by-species approach. However. caution must be exercised in the use of this data because of the speculative nature of the causes; most of the causes (69.7%) are based on poorly documented expert opinion and

  4. The rise and decline in Salmonella enterica serovar Enteritidis outbreaks attributed to egg-containing foods in the United States, 1973-2009.

    PubMed

    Wright, A P; Richardson, L; Mahon, B E; Rothenberg, R; Cole, D J

    2016-03-01

    Salmonella enterica causes an estimated 1 million domestically acquired foodborne illnesses annually. Salmonella enterica serovar Enteritidis (SE) is among the top three serovars of reported cases of Salmonella. We examined trends in SE foodborne outbreaks from 1973 to 2009 using Joinpoint and Poisson regression. The annual number of SE outbreaks increased sharply in the 1970s and 1980s but declined significantly after 1990. Over the study period, SE outbreaks were most frequently attributed to foods containing eggs. The average rate of SE outbreaks attributed to egg-containing foods reported by states began to decline significantly after 1990, and the proportion of SE outbreaks attributed to egg-containing foods began declining after 1997. Our results suggest that interventions initiated in the 1990s to decrease SE contamination of shell eggs may have been integral to preventing SE outbreaks.

  5. Hiring of Science Graduates Up Sharply

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1977

    1977-01-01

    A survey conducted by the College Placement Council indicates that employment for chemical professionals has made solid gains in the Spring of 1977, especially in the hiring of new graduates by industry, schools, and government. The largest hiring increases occurred in the aerospace, electronics, petroleum, and glass/paper packaging categories.…

  6. Atrial Fibrillation, Cognitive Decline And Dementia

    PubMed Central

    Alonso, Alvaro; Arenas de Larriva, Antonio P.

    2016-01-01

    Atrial fibrillation (AF) is a common cardiac arrhythmia. Growing evidence supports a role for AF as a risk factor for cognitive decline and dementia. In this review, we summarize epidemiologic observations linking AF with cognitive outcomes, describe potential mechanisms, and explore the impact of AF treatments on cognitive decline and dementia. Community-based, observational studies show a consistent higher rate of cognitive decline and risk of dementia in persons with AF. These associations are partly due to the increased risk of clinical stroke in AF, but other mechanisms, including incidence of silent cerebral infarcts, microbleeds, and cerebral hypoperfusion, are likely additional contributors. Adequate oral anticoagulation and improved management of the overall cardiovascular risk profile in persons with AF offer the promise of reducing the impact of AF on cognitive decline and dementia. PMID:27547248

  7. Decline and conservation of bumble bees.

    PubMed

    Goulson, D; Lye, G C; Darvill, B

    2008-01-01

    Declines in bumble bee species in the past 60 years are well documented in Europe, where they are driven primarily by habitat loss and declines in floral abundance and diversity resulting from agricultural intensification. Impacts of habitat degradation and fragmentation are likely to be compounded by the social nature of bumble bees and their largely monogamous breeding system, which renders their effective population size low. Hence, populations are susceptible to stochastic extinction events and inbreeding. In North America, catastrophic declines of some bumble bee species since the 1990s are probably attributable to the accidental introduction of a nonnative parasite from Europe, a result of global trade in domesticated bumble bee colonies used for pollination of greenhouse crops. Given the importance of bumble bees as pollinators of crops and wildflowers, steps must be taken to prevent further declines. Suggested measures include tight regulation of commercial bumble bee use and targeted use of environmentally comparable schemes to enhance floristic diversity in agricultural landscapes.

  8. Understanding Amphibian Declines Through Geographic Approaches

    USGS Publications Warehouse

    Gallant, Alisa

    2006-01-01

    Growing concern over worldwide amphibian declines warrants serious examination. Amphibians are important to the proper functioning of ecosystems and provide many direct benefits to humans in the form of pest and disease control, pharmaceutical compounds, and even food. Amphibians have permeable skin and rely on both aquatic and terrestrial ecosystems during different seasons and stages of their lives. Their association with these ecosystems renders them likely to serve as sensitive indicators of environmental change. While much research on amphibian declines has centered on mysterious causes, or on causes that directly affect humans (global warming, chemical pollution, ultraviolet-B radiation), most declines are the result of habitat loss and habitat alteration. Improving our ability to characterize, model, and monitor the interactions between environmental variables and amphibian habitats is key to addressing amphibian conservation. In 2000, the U.S. Geological Survey (USGS) initiated the Amphibian Research and Monitoring Initiative (ARMI) to address issues surrounding amphibian declines.

  9. The continuing fertility decline in Sri Lanka.

    PubMed

    Fernando, D F

    1980-01-01

    The continued decline in fertility in Sri Lanka which began in 1960 is analyzed and documented. Data from recent consuses, the 1st report of the World Fertility Survey, and from vital statistics registration are used. The data are tabulated along with similar data from Taiwan to provide a basis of comparison. The birth rate in Sri Lanka has declined steadily since 1960, reaching an almost static level in 1974-76. During the 1970's there was a dramatic upward move in the age at marriage for women in both Sri Lanka and Taiwan. This factor, combined with a changing female age structure, had been responsible for fertility decline during the 1953-63 period. During 1963-68, female marriage postponement continued to influence fertility decline while the change in the female age structure retarded it. Declines in marital fertility began to have an effect by 1963 in the over 25 age groups. The Sri Lankan Family Planning Program began in 1965. The year 1972 is considered a turning point for the program with increasing use of modern contraceptive methods, especially the IUD and female sterilization. Even male sterilization began to increase substantially in 1974. All the fertility figures are higher for Sri Lanka than for Taiwan, but Sri Lanka is making extremely good progress. The decline in marital fertility is concentrated in the over-30 group, and attributed to increased practice of contraception.

  10. Evaluation of invasions and declines of submersed aquatic macrophytes

    USGS Publications Warehouse

    Chambers, P.A.; Barko, J.W.; Smith, C.S.

    1993-01-01

    During the past 60 yr, sightings of aquatic macrophyte species in geographic regions where they had previously not been found have occurred with increasing frequency, apparently due to both greater dispersal of the plants as a result of human activities as well as better documentation of plant distribution. Intercontinental invasions, such as Myriophyllum spicatum and Hydrilla into North America, Elodea canadensis into Europe and Elodea nuttallii, Egeria densa and Cabomba caroliniana into Japan, have generally been well documented. However, the spread of an exotic species across a continent after its initial introduction (e.g., Potamogeton crispus in North America) or the expansion of a species native to a continent into hitherto unexploited territory (e.g.,the expansion of the North American native Myriophyllum heterophyllum into New England) have received little attention. Natural declines in aquatic macrophyte communities have also received little scientific study although there are many accounts of macrophyte declines. The best-documented example comes from the marine literature where extensive declines of eelgrass (Zostera) occurred in the 1930s along the Atlantic coast due to a pathogenic marine slime mold (''wasting disease''). The aim of this workshop was to identify examples of invasions or natural declines of aquatic macrophyte species throughout the world and assess the importance of environmental factors in their control. Forty-five scientists and aquatic plant managers from ten countries participated in the workshop. Eleven of the participants contributed written evaluations of species invasions and declines in their geo-graphic region. These were distributed to registered participants prior to the meeting and served as the starting-point of workshop discussions. To address the topics raised in the working papers, the participants divided into four working groups to evaluate: 1. Environmental controls of species invasions. 2. Biotic controls of species

  11. Decline in Cardiorespiratory Fitness and Odds of Incident Sleep Complaints

    PubMed Central

    Dishman, Rodney K.; Sui, Xuemei; Church, Timothy S.; Kline, Christopher E.; Youngstedt, Shawn D.; Blair, Steven N.

    2014-01-01

    Purpose To examine longitudinal change in cardiorespiratory fitness and odds of incident sleep problems. Methods A cohort of 7368 men and 1155 women, aged 20–85 years, from the Aerobics Center Longitudinal Study. The cohort did not complain of sleep problems, depression, or anxiety at their first clinic visit. Cardiorespiratory fitness assessed at 4 clinic visits between 1971–2006, each separated by an average of 2–3 years, was used as a proxy measure of cumulative physical activity exposure. Sleep complaints were made to a physician during follow-up. Results Across visits, there were 784 incident cases of sleep complaints in men and 207 cases in women. After adjustment for age, time between visits, body mass index, smoking, alcohol use, chronic medical conditions, complaints of depression or anxiety at each visit, and fitness at Visit 1, each minute decline in treadmill endurance (i.e., a decline in cardiorespiratory fitness of approximately one-half MET) between ages 51 to 56 increased the odds of incident sleep complaints by 1.7% (1.0–2.4%) in men and 1.3% (0.0–2.8%) in women. Odds were ~8% higher per minute decline in people with sleep complaints at 2 or 3 visits. Conclusion The results indicate that maintenance of cardiorespiratory fitness during middle-age, when decline in fitness typically accelerates and risk of sleep problems is elevated, helps protect against the onset of sleep complaints made to a physician. PMID:25207930

  12. Pesticides and amphibian population declines in California, USA

    USGS Publications Warehouse

    Sparling, Donald W.; Fellers, Gary M.; McConnell, Laura L.

    2001-01-01

    Several species of anuran amphibians have undergone drastic population declines in the western United States over the last 10 to 15 years. In California, the most severe declines are in the Sierra Mountains east of the Central Valley and downwind of the intensely agricultural San Joaquin Valley. In contrast, coastal and more northern populations across from the less agrarian Sacramento Valley are stable or declining less precipitously. In this article, we provide evidence that pesticides are instrumental in declines of these species. Using Hyla regilla as a sentinel species, we found that cholinesterase (ChE) activity in tadpoles was depressed in mountainous areas east of the Central Valley compared with sites along the coast or north of the Valley. Cholinesterase was also lower in areas where ranid population status was poor or moderate compared with areas with good ranid status. Up to 50% of the sampled population in areas with reduced ChE had detectable organophosphorus residues, with concentrations as high as 190 ppb wet weight. In addition, up to 86% of some populations had measurable endosulfan concentrations and 40% had detectable 4,4'- dichlorodiphenyldichloroethylene, 4,4'-DDT, and 2,4'-DDT residues.

  13. The decline of fertility in Peninsular Malaysia.

    PubMed

    Hirschman, C; Fernandez, D

    1980-01-01

    A detailed analysis of fertility trends in Peninsular Malaysia from 1947 through 1974, based on annual period rates from vital statistics data and cumulative fertility measures from the 1947, 1957, and 1970 censuses, is presented. Fertility levels from 1947 to 1957 were quite high and possibly increasing, with a crude birth rate in the middle 40s. A rapid decline among all major ethnic groups brought the crude birth rate from 46 in 1956 to 31 in 1974, while over the same period the general fertility rate dropped from 210 to 130 births per 1000 women of reproductive age. Decomposition of changes in the crude birth rate from 1958 to 1970 indicates that most of the decline in the crude birth rate was due to rising average age at marriage, and the rest to small declines in marital fertility. The fall in total fertility rates ranged from 1.2 births per woman among Malays to 3.2 births per woman among Indians between 1958 and 1974. Signs of declining marital fertility among Malay and Indian women in their late 20s and 30s appeared in the late 1960s, but the principal element in their fertility decline was delayed marriage. In 1957 over half of Malay and Indian women aged 15-19 were married, while in 1970 only 1 in 5 were. Changes in age structure reinforced the decline of the Malay crude birth rate but offset part of the reduction of age-specific fertility among Chinese and Indians. Substantial reductions in proportions currently married were important for all ethnic groups. Future fertility declines will depend primarily on changes in marital fertility rates because the age structure will be favorable to higher fertility and marriage postponement is already advanced.

  14. Periodontitis and Cognitive Decline in Alzheimer's Disease.

    PubMed

    Ide, Mark; Harris, Marina; Stevens, Annette; Sussams, Rebecca; Hopkins, Viv; Culliford, David; Fuller, James; Ibbett, Paul; Raybould, Rachel; Thomas, Rhodri; Puenter, Ursula; Teeling, Jessica; Perry, V Hugh; Holmes, Clive

    2016-01-01

    Periodontitis is common in the elderly and may become more common in Alzheimer's disease because of a reduced ability to take care of oral hygiene as the disease progresses. Elevated antibodies to periodontal bacteria are associated with an increased systemic pro-inflammatory state. Elsewhere raised serum pro-inflammatory cytokines have been associated with an increased rate of cognitive decline in Alzheimer's disease. We hypothesized that periodontitis would be associated with increased dementia severity and a more rapid cognitive decline in Alzheimer's disease. We aimed to determine if periodontitis in Alzheimer's disease is associated with both increased dementia severity and cognitive decline, and an increased systemic pro inflammatory state. In a six month observational cohort study 60 community dwelling participants with mild to moderate Alzheimer's Disease were cognitively assessed and a blood sample taken for systemic inflammatory markers. Dental health was assessed by a dental hygienist, blind to cognitive outcomes. All assessments were repeated at six months. The presence of periodontitis at baseline was not related to baseline cognitive state but was associated with a six fold increase in the rate of cognitive decline as assessed by the ADAS-cog over a six month follow up period. Periodontitis at baseline was associated with a relative increase in the pro-inflammatory state over the six month follow up period. Our data showed that periodontitis is associated with an increase in cognitive decline in Alzheimer's Disease, independent to baseline cognitive state, which may be mediated through effects on systemic inflammation. PMID:26963387

  15. Periodontitis and Cognitive Decline in Alzheimer's Disease.

    PubMed

    Ide, Mark; Harris, Marina; Stevens, Annette; Sussams, Rebecca; Hopkins, Viv; Culliford, David; Fuller, James; Ibbett, Paul; Raybould, Rachel; Thomas, Rhodri; Puenter, Ursula; Teeling, Jessica; Perry, V Hugh; Holmes, Clive

    2016-01-01

    Periodontitis is common in the elderly and may become more common in Alzheimer's disease because of a reduced ability to take care of oral hygiene as the disease progresses. Elevated antibodies to periodontal bacteria are associated with an increased systemic pro-inflammatory state. Elsewhere raised serum pro-inflammatory cytokines have been associated with an increased rate of cognitive decline in Alzheimer's disease. We hypothesized that periodontitis would be associated with increased dementia severity and a more rapid cognitive decline in Alzheimer's disease. We aimed to determine if periodontitis in Alzheimer's disease is associated with both increased dementia severity and cognitive decline, and an increased systemic pro inflammatory state. In a six month observational cohort study 60 community dwelling participants with mild to moderate Alzheimer's Disease were cognitively assessed and a blood sample taken for systemic inflammatory markers. Dental health was assessed by a dental hygienist, blind to cognitive outcomes. All assessments were repeated at six months. The presence of periodontitis at baseline was not related to baseline cognitive state but was associated with a six fold increase in the rate of cognitive decline as assessed by the ADAS-cog over a six month follow up period. Periodontitis at baseline was associated with a relative increase in the pro-inflammatory state over the six month follow up period. Our data showed that periodontitis is associated with an increase in cognitive decline in Alzheimer's Disease, independent to baseline cognitive state, which may be mediated through effects on systemic inflammation.

  16. Neural mechanisms of ageing and cognitive decline

    PubMed Central

    Bishop, Nicholas A.; Lu, Tao; Yankner, Bruce A.

    2010-01-01

    During the past century, treatments for the diseases of youth and middle age have helped raise life expectancy significantly. However, cognitive decline has emerged as one of the greatest health threats of old age, with nearly 50% of adults over the age of 85 afflicted with Alzheimer’s disease. Developing therapeutic interventions for such conditions demands a greater understanding of the processes underlying normal and pathological brain ageing. Recent advances in the biology of ageing in model organisms, together with molecular and systems-level studies of the brain, are beginning to shed light on these mechanisms and their potential roles in cognitive decline. PMID:20336135

  17. Recent Declines in Induction of Labor by Gestational Age

    MedlinePlus

    ... rates at 38 weeks of gestation declined for all maternal age groups under 40. Trends in induction ... 38 weeks declined in nearly three-quarters of all states. The largest declines in labor induction for ...

  18. Amphibian and reptile declines over 35 years at La Selva, Costa Rica

    PubMed Central

    Whitfield, Steven M.; Bell, Kristen E.; Philippi, Thomas; Sasa, Mahmood; Bolaños, Federico; Chaves, Gerardo; Savage, Jay M.; Donnelly, Maureen A.

    2007-01-01

    Amphibians stand at the forefront of a global biodiversity crisis. More than one-third of amphibian species are globally threatened, and over 120 species have likely suffered global extinction since 1980. Most alarmingly, many rapid declines and extinctions are occurring in pristine sites lacking obvious adverse effects of human activities. The causes of these “enigmatic” declines remain highly contested. Still, lack of long-term data on amphibian populations severely limits our understanding of the distribution of amphibian declines, and therefore the ultimate causes of these declines. Here, we identify a systematic community-wide decline in populations of terrestrial amphibians at La Selva Biological Station, a protected old-growth lowland rainforest in lower Central America. We use data collected over 35 years to show that population density of all species of terrestrial amphibians has declined by ≈75% since 1970, and we show identical trends for all species of common reptiles. The trends we identify are neither consistent with recent emergence of chytridiomycosis nor the climate-linked epidemic hypothesis, two leading putative causes of enigmatic amphibian declines. Instead, our data suggest that declines are due to climate-driven reductions in the quantity of standing leaf litter, a critical microhabitat for amphibians and reptiles in this assemblage. Our results raise further concerns about the global persistence of amphibian populations by identifying widespread declines in species and habitats that are not currently recognized as susceptible to such risks. PMID:17449638

  19. Amphibian and reptile declines over 35 years at La Selva, Costa Rica.

    PubMed

    Whitfield, Steven M; Bell, Kristen E; Philippi, Thomas; Sasa, Mahmood; Bolaños, Federico; Chaves, Gerardo; Savage, Jay M; Donnelly, Maureen A

    2007-05-15

    Amphibians stand at the forefront of a global biodiversity crisis. More than one-third of amphibian species are globally threatened, and over 120 species have likely suffered global extinction since 1980. Most alarmingly, many rapid declines and extinctions are occurring in pristine sites lacking obvious adverse effects of human activities. The causes of these "enigmatic" declines remain highly contested. Still, lack of long-term data on amphibian populations severely limits our understanding of the distribution of amphibian declines, and therefore the ultimate causes of these declines. Here, we identify a systematic community-wide decline in populations of terrestrial amphibians at La Selva Biological Station, a protected old-growth lowland rainforest in lower Central America. We use data collected over 35 years to show that population density of all species of terrestrial amphibians has declined by approximately 75% since 1970, and we show identical trends for all species of common reptiles. The trends we identify are neither consistent with recent emergence of chytridiomycosis nor the climate-linked epidemic hypothesis, two leading putative causes of enigmatic amphibian declines. Instead, our data suggest that declines are due to climate-driven reductions in the quantity of standing leaf litter, a critical microhabitat for amphibians and reptiles in this assemblage. Our results raise further concerns about the global persistence of amphibian populations by identifying widespread declines in species and habitats that are not currently recognized as susceptible to such risks.

  20. Nutrition, the brain and cognitive decline: insights from epigenetics.

    PubMed

    Dauncey, M J

    2014-11-01

    Nutrition affects the brain throughout life, with profound implications for cognitive decline and dementia. These effects are mediated by changes in expression of multiple genes, and responses to nutrition are in turn affected by individual genetic variability. An important layer of regulation is provided by the epigenome: nutrition is one of the many epigenetic regulators that modify gene expression without changes in DNA sequence. Epigenetic mechanisms are central to brain development, structure and function, and include DNA methylation, histone modifications and non-protein-coding RNAs. They enable cell-specific and age-related gene expression. Although epigenetic events can be highly stable, they can also be reversible, highlighting a critical role for nutrition in prevention and treatment of disease. Moreover, they suggest key mechanisms by which nutrition is involved in the pathogenesis of age-related cognitive decline: many nutrients, foods and diets have both immediate and long-term effects on the epigenome, including energy status, that is, energy intake, physical activity, energy metabolism and related changes in body composition, and micronutrients involved in DNA methylation, for example, folate, vitamins B6 and B12, choline, methionine. Optimal brain function results from highly complex interactions between numerous genetic and environmental factors, including food intake, physical activity, age and stress. Future studies linking nutrition with advances in neuroscience, genomics and epigenomics should provide novel approaches to the prevention of cognitive decline, and treatment of dementia and Alzheimer's disease.

  1. [Cognitive decline in elderly individuals with type 2 diabetes mellitus].

    PubMed

    Sakurai, Takashi

    2013-11-01

    Cognitive decline in diabetes impairs the activity of daily living and shortens the healthy life expectancy. Once diabetes is accompanied by demented disorders, it becomes difficult to achieve good control of diabetes. Treatment for diabetes and demented disease should be provided concomitantly, because cognitive dysfunction worsens diabetic control and hyperglycemia worsens cognitive function vice versa, resulting in increased risks of acute metabolic failure. Compliance to medical treatment of diabetes is seriously impaired in the elderly with cognitive decline. Comprehensive approach with several medical specialists and care stuffs is thus needed. This manuscript briefly summaries the recent evidence for target of glycemic control and appropriate use of anti-diabetic medication in diabetic elderly with cognitive impairment.

  2. Decline of maternal antibodies to plague in Norway rats.

    PubMed

    Williams, J E; Eisenberg, G H; Cavanaugh, D C

    1977-02-01

    The decline of maternal antibodies to the fraciton I antigen of Yersinia pestis was investigated in newly weaned Rattus norvegicus obtained from dams vaccinated with strain EV76(51F) of Y. pestis. IHA titre decreased by 50% each 7-3 days and CF titre declined 50% each 10-0 days in young rats. An analysis of available data indicated that maternal IHA and CF antibodies could persist to 3 months of age. Therefore, positive serologic reactions in young R. norvegicus, detected in the course of serological surveys, could be the result either of active immunization after exposure to the plague bacillus or of transient passive immunization (i.e. maternal antibody). PMID:264498

  3. Capacity decline of ambient temperature secondary lithium battery

    NASA Technical Reports Server (NTRS)

    Shen, D. H.; Subbarao, S.; Nakamura, B. J.; Yen, S. P. S.; Bankston, C. P.

    1988-01-01

    The use of ambient temperature secondary lithium cells is limited primarily because of the poor cycle life performance. Much of the cell capacity is irreversibly lost upon cycling. Studies have been undertaken to understand the problem of capacity decline. Experimental Li-TiS2 cells were fabricated and tested for their cycle life performance. Cells were disassembled at different stages of cycle life, and cell active components were analyzed by various analytical techniques. The results of this study indicate that all the cell's active components/materials are undergoing degradation. Details of the experiments carried out and the results obtained are described.

  4. Exploring the Global Decline of Music Education

    ERIC Educational Resources Information Center

    Aróstegui, José Luis

    2016-01-01

    This article seeks to explain the disjuncture between the decline of music education in schools and the importance music has in popular youth culture and in creativity within the new knowledge economy. The data discussed in this article have been derived from analyses of major documents on curriculum reform as well as e-mail responses from music…

  5. Student Writing: Strategies to Reverse Ongoing Decline

    ERIC Educational Resources Information Center

    Carter, Michael J.; Harper, Heather

    2013-01-01

    This article reports on the decline in writing ability skills in secondary and higher education students. The author discusses changes that have affected student writing skills over the recent decades and offers recommendations for improving these skills, such as: implementing intensive freshman writing courses; adjusting existing course…

  6. Prevalence of Hunger Declines in Rural Households.

    ERIC Educational Resources Information Center

    Nord, Mark; Winicki, F. Joshua

    2000-01-01

    The prevalence of hunger in rural households declined slightly from 1995 to 1998, and food insecurity rates stayed constant. Food insecurity was almost three times as prevalent among rural Blacks as among rural Whites. For rural Hispanics, the rate was about twice that of Whites. Food insecurity was higher in single-parent families than in any…

  7. Declining Enrollments: National Problem--Local Response.

    ERIC Educational Resources Information Center

    Hess, Fritz; And Others

    American schools, after two decades of expansion, are now in the midst of an enrollment decline and inflation. The impact of the shift from growth to retrenchment and streamlining has been severe. An effective approach to this situation requires an understanding of the new conditions and of available alternatives for action. An overview of the…

  8. Migratory diversity predicts population declines in birds.

    PubMed

    Gilroy, James J; Gill, Jennifer A; Butchart, Stuart H M; Jones, Victoria R; Franco, Aldina M A

    2016-03-01

    Declines in migratory species are a pressing concern worldwide, but the mechanisms underpinning these declines are not fully understood. We hypothesised that species with greater within-population variability in migratory movements and destinations, here termed 'migratory diversity', might be more resilient to environmental change. To test this, we related map-based metrics of migratory diversity to recent population trends for 340 European breeding birds. Species that occupy larger non-breeding ranges relative to breeding, a characteristic we term 'migratory dispersion', were less likely to be declining than those with more restricted non-breeding ranges. Species with partial migration strategies (i.e. overlapping breeding and non-breeding ranges) were also less likely to be declining than full migrants or full residents, an effect that was independent of migration distance. Recent rates of advancement in Europe-wide spring arrival date were greater for partial migrants than full migrants, suggesting that migratory diversity may also help facilitate species responses to climate change. PMID:26807694

  9. Complexity versus certainty in understanding species’ declines

    USGS Publications Warehouse

    Sundstrom, Shana M.; Allen, Craig R.

    2014-01-01

    Traditional approaches to predict species declines (e.g. government processes or IUCN Red Lists), may be too simplistic and may therefore misguide management and conservation. Using complex systems approaches that account for scale-specific patterns and processes have the potential to overcome these limitations.

  10. Afterword: The Management and Consequences of Decline.

    ERIC Educational Resources Information Center

    Boyd, William Lowe

    1983-01-01

    Stresses the need for aggressive, farsighted management of decline and for more Federal and State aid to local school administrators to combat the negative effects of school closures and retrenchment, and to ensure that retrenched school systems still serve children effectively. (Author/MJL)

  11. The "Decline" of Private Higher Education

    ERIC Educational Resources Information Center

    Levy, Daniel C.

    2013-01-01

    No topic in private higher education study has attracted as great attention globally as has growth. This is appropriate as private growth has soared to nearly a third of the world's total higher education enrolment. But while private growth continues to be the dominant trend, important declines in private shares have emerged. These must be…

  12. Black Rural Land Decline in the South

    ERIC Educational Resources Information Center

    McGee, Leo; Boone, Robert

    1977-01-01

    Notes that it is widely accepted that millions of blacks who migrated from the South contributed significantly to the decline of black rural land ownership. However, the less than altruistic behavior patterns of land officials has also contributed to the loss of rural land by blacks. (Author/AM)

  13. Why Employee Motivation Has Declined in America.

    ERIC Educational Resources Information Center

    Grant, Philip C.

    1982-01-01

    Examines possible reasons for declining employee motivation: greater instability and diversity of values; more guaranteed rewards; inability of rewards to satisfy emerging needs; disappearing work ethic; reduced costs of failure; rising income and progressive taxation; more group production and problem solving; decreased employee loyalty; less…

  14. Does Vocabulary Decline Qualitatively in Old Age?

    ERIC Educational Resources Information Center

    O'Dowd, Sarah C.

    1984-01-01

    Tested both superior and average-ability subjects (N=112) from contrasting educational settings to examine the apparent decline in vocabulary skills of older adults. Results showed older adults performed better than the young, judged by either standard or qualitative criteria. (BH)

  15. The Decline of Direct Newspaper Competition.

    ERIC Educational Resources Information Center

    Rosse, James N.

    1980-01-01

    Describes the decline of direct newspaper competition in terms of the loss of effective newspaper market segmentation. Examines the following influences on market segmentation: shift in advertising demand, advertiser preferences for differentiated audiences, shift in subscriber demand, growth of alternative media, increasing production costs, and…

  16. Disease management strategy for macadamia quick decline

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trees infected with Macadamia Quick Decline (MQD) exhibit excessive sap bleeding from the trunk, frass from ambrosia beetle feeding, orange fruiting bodies of the fungus Nectria rugulosa and yellowing and browning of the leaves within the tree canopy. MQD threatens commercial and residential product...

  17. Decline and conservation of bumble bees.

    PubMed

    Goulson, D; Lye, G C; Darvill, B

    2008-01-01

    Declines in bumble bee species in the past 60 years are well documented in Europe, where they are driven primarily by habitat loss and declines in floral abundance and diversity resulting from agricultural intensification. Impacts of habitat degradation and fragmentation are likely to be compounded by the social nature of bumble bees and their largely monogamous breeding system, which renders their effective population size low. Hence, populations are susceptible to stochastic extinction events and inbreeding. In North America, catastrophic declines of some bumble bee species since the 1990s are probably attributable to the accidental introduction of a nonnative parasite from Europe, a result of global trade in domesticated bumble bee colonies used for pollination of greenhouse crops. Given the importance of bumble bees as pollinators of crops and wildflowers, steps must be taken to prevent further declines. Suggested measures include tight regulation of commercial bumble bee use and targeted use of environmentally comparable schemes to enhance floristic diversity in agricultural landscapes. PMID:17803456

  18. Why NAD(+) Declines during Aging: It's Destroyed.

    PubMed

    Schultz, Michael B; Sinclair, David A

    2016-06-14

    NAD(+) is required not only for life but for a long life. In this issue, Camacho-Pereira et al. (2016) implicate CD38 in the decline of NAD(+) during aging, with implications for combating age-related diseases. PMID:27304496

  19. Violent Youth Crime May Be Declining.

    ERIC Educational Resources Information Center

    USA Today, 1979

    1979-01-01

    Reports the findings of Frank Zimring, director of the University of Chicago's Center for Criminal Justice, that the rate of four types of serious youth crime (homicide, rape, robbery, and aggravated assault) began to level off around 1970 and may now be declining. (SJL)

  20. Climate change, multiple stressors, and the decline of ectotherms.

    PubMed

    Rohr, Jason R; Palmer, Brent D

    2013-08-01

    Climate change is believed to be causing declines of ectothermic vertebrates, but there is little evidence that climatic conditions associated with declines have exceeded critical (i.e., acutely lethal) maxima or minima, and most relevant studies are correlative, anecdotal, or short-term (hours). We conducted an 11-week factorial experiment to examine the effects of temperature (22 °C or 27 °C), moisture (wet or dry), and atrazine (an herbicide; 0, 4, 40, 400 μg/L exposure as embryos and larvae) on the survival, growth, behavior, and foraging rates of postmetamorphic streamside salamanders (Ambystoma barbouri), a species of conservation concern. The tested climatic conditions were between the critical maxima and minima of streamside salamanders; thus, this experiment quantified the long-term effects of climate change within the noncritical range of this species. Despite a suite of behavioral adaptations to warm and dry conditions (e.g., burrowing, refuge use, huddling with conspecifics, and a reduction in activity), streamside salamanders exhibited significant loss of mass and significant mortality in all but the cool and moist conditions, which were closest to the climatic conditions in which they are most active in nature. A temperature of 27 °C represented a greater mortality risk than dry conditions; death occurred rapidly at this temperature and more gradually under cool and dry conditions. Foraging decreased under dry conditions, which suggests there were opportunity costs to water conservation. Exposure to the herbicide atrazine additively decreased water-conserving behaviors, foraging efficiency, mass, and time to death. Hence, the hypothesis that moderate climate change can cause population declines is even more plausible under scenarios with multiple stressors. These results suggest that climate change within the noncritical range of species and pollution may reduce individual performance by altering metabolic demands, hydration, and foraging effort

  1. Climate change, multiple stressors, and the decline of ectotherms.

    PubMed

    Rohr, Jason R; Palmer, Brent D

    2013-08-01

    Climate change is believed to be causing declines of ectothermic vertebrates, but there is little evidence that climatic conditions associated with declines have exceeded critical (i.e., acutely lethal) maxima or minima, and most relevant studies are correlative, anecdotal, or short-term (hours). We conducted an 11-week factorial experiment to examine the effects of temperature (22 °C or 27 °C), moisture (wet or dry), and atrazine (an herbicide; 0, 4, 40, 400 μg/L exposure as embryos and larvae) on the survival, growth, behavior, and foraging rates of postmetamorphic streamside salamanders (Ambystoma barbouri), a species of conservation concern. The tested climatic conditions were between the critical maxima and minima of streamside salamanders; thus, this experiment quantified the long-term effects of climate change within the noncritical range of this species. Despite a suite of behavioral adaptations to warm and dry conditions (e.g., burrowing, refuge use, huddling with conspecifics, and a reduction in activity), streamside salamanders exhibited significant loss of mass and significant mortality in all but the cool and moist conditions, which were closest to the climatic conditions in which they are most active in nature. A temperature of 27 °C represented a greater mortality risk than dry conditions; death occurred rapidly at this temperature and more gradually under cool and dry conditions. Foraging decreased under dry conditions, which suggests there were opportunity costs to water conservation. Exposure to the herbicide atrazine additively decreased water-conserving behaviors, foraging efficiency, mass, and time to death. Hence, the hypothesis that moderate climate change can cause population declines is even more plausible under scenarios with multiple stressors. These results suggest that climate change within the noncritical range of species and pollution may reduce individual performance by altering metabolic demands, hydration, and foraging effort

  2. Declining world fertility: trends, causes, implications.

    PubMed

    Tsui, A O; Bogue, D J

    1978-10-01

    This Bulletin examines the evidence that the world's fertility has declined in recent years, the factors that appear to have accounted for the decline, and the implications for fertility and population growth rates to the end of the century. On the basis of a compilation of estimates available for all nations of the world, the authors derive estimates which indicate that the world's total fertility rate dropped from 4.6 to 4.1 births per woman between 1968 and 1975, thanks largely to an earlier and more rapid and universal decline in the fertility of less developed countries (LDCs) than had been anticipated. Statistical analysis of available data suggests that the socioeconomic progress made by LDCs in this period was not great enough to account for more than a proportion of the fertility decline and that organized family planning programs were a major contributing factor. The authors' projections, which are compared to similar projections from the World Bank, the United Nations, and the U.S. Bureau of the Census, indicate that, by the year 2000, less than 1/5 of the world's population will be in the "red danger" circle of explosive population growth (2.1% or more annually); most LDCs will be in a phase of fertility decline; and many of them -- along with most now developed countries -- will be at or near replacement level of fertility. The authors warn that "our optimistic prediction is premised upon a big IF -- if (organized) family planning (in LDCs) continues. It remains imperative that all of the developed nations of the world continue their contribution to this program undiminished."

  3. Long-term declines in ADLs, IADLs, and mobility among older Medicare beneficiaries

    PubMed Central

    2011-01-01

    Background Most prior studies have focused on short-term (≤ 2 years) functional declines. But those studies cannot address aging effects inasmuch as all participants have aged the same amount. Therefore, the authors studied the extent of long-term functional decline in older Medicare beneficiaries who were followed for varying time lengths, and the authors also identified the risk factors associated with those declines. Methods The analytic sample included 5,871 self- or proxy-respondents who had complete baseline and follow-up survey data that could be linked to their Medicare claims for 1993-2007. Functional status was assessed using activities of daily living (ADLs), instrumental ADLs (IADLs), and mobility limitations, with declines defined as the development of two of more new difficulties. Multiple logistic regression analysis was used to focus on the associations involving respondent status, health lifestyle, continuity of care, managed care status, health shocks, and terminal drop. Results The average amount of time between the first and final interviews was 8.0 years. Declines were observed for 36.6% on ADL abilities, 32.3% on IADL abilities, and 30.9% on mobility abilities. Functional decline was more likely to occur when proxy-reports were used, and the effects of baseline function on decline were reduced when proxy-reports were used. Engaging in vigorous physical activity consistently and substantially protected against functional decline, whereas obesity, cigarette smoking, and alcohol consumption were only associated with mobility declines. Post-baseline hospitalizations were the most robust predictors of functional decline, exhibiting a dose-response effect such that the greater the average annual number of hospital episodes, the greater the likelihood of functional status decline. Participants whose final interview preceded their death by one year or less had substantially greater odds of functional status decline. Conclusions Both the additive and

  4. Disease-induced decline of an apex predator drives invasive dominated states and threatens biodiversity.

    PubMed

    Hollings, Tracey; Jones, Menna; Mooney, Nick; McCallum, Hamish

    2016-02-01

    Apex predators are important in protecting biodiversity through top-down influence on food webs. Their loss is linked with competitive release of invasive mesopredators and species extinctions. The Tasmanian devil (Sarcophilus harrisii) has experienced severe declines over a 15-yr period as a novel transmissible cancer has spread across its current geographic range. We surveyed the mammalian community, using hair traps, across the spatial extent of the devil's progressive population decline. We found increased activity of alien invasive species (feral cats, black rats), and reduced small and medium-sized native prey species in response to the timing of the decline. In areas of long-term devil decline, invasive species comprised a significantly larger proportion of the community. The results provide evidence that the devil plays a keystone role in Tasmania's ecosystem with their decline linked to a shift toward an invasive state and biodiversity loss in one of Australia's most intact faunal communities.

  5. Social differences in the decline of marital reproduction in rural Navarre (Spain).

    PubMed

    Sanchez, J J

    1998-09-01

    The continued decline of marital fertility in Navarre, Spain, during the first few decades of the 20th century was associated with an increase in life expectancy and greater survival to adulthood. While the decline affected all social strata and geographical regions, it was not homogeneous, with some sectors of Navarrese society beginning the fertility transition earlier than others. Using data drawn from the nominal lists of the 1940 Spanish Census on married women aged 45-49 years, the author investigated the influence of differences in geographical origin, level of urbanization, father's occupation, level of religious devotion, and political factors upon the observed decline in marital fertility. The data support the originators of demographic transition theory, that the more urban populations, and therefore those with a higher percentage of the active population working in nonprimary sectors, led the fertility decline. The degree of a society's secularization also influenced the beginning of the decline of fertility and the levels reached.

  6. Disease-induced decline of an apex predator drives invasive dominated states and threatens biodiversity.

    PubMed

    Hollings, Tracey; Jones, Menna; Mooney, Nick; McCallum, Hamish

    2016-02-01

    Apex predators are important in protecting biodiversity through top-down influence on food webs. Their loss is linked with competitive release of invasive mesopredators and species extinctions. The Tasmanian devil (Sarcophilus harrisii) has experienced severe declines over a 15-yr period as a novel transmissible cancer has spread across its current geographic range. We surveyed the mammalian community, using hair traps, across the spatial extent of the devil's progressive population decline. We found increased activity of alien invasive species (feral cats, black rats), and reduced small and medium-sized native prey species in response to the timing of the decline. In areas of long-term devil decline, invasive species comprised a significantly larger proportion of the community. The results provide evidence that the devil plays a keystone role in Tasmania's ecosystem with their decline linked to a shift toward an invasive state and biodiversity loss in one of Australia's most intact faunal communities. PMID:27145614

  7. What we know and don't know about amphibian declines in the West

    USGS Publications Warehouse

    Corn, Paul Stephen

    1994-01-01

    The problem of declining amphibian species is thought to be particularly acute in western North America, but there are many gaps in our knowledge. Although several declines have been well-documented, other declines are anecdotal or hypothesized. Most documented declines are of ranid frogs or toads (Bufo). Species from montane habitats and those occurring in California have been best studied. Status of many desert species is unknown. Habitat destruction and introduced predators are the most common threats to amphibian populations. Some declines may represent natural variation in population size. Causes have not been determined for several cases where common species have declined over large areas. There are important considerations for ecosystem management, whether changes in amphibian populations are natural or caused by human activities. Causes for declines must be known so that management can be prescribed (or proscribed) to eliminate or minimize these causes. The natural variability of amphibian population numbers and the complexity of metapopulation structure emphasize the necessity of considering multiple temporal and spatial scales in ecosystem management. The decline of amphibian species throughout the world has received considerable recent attention (e.g., Blaustein and Wake 1990, Griffiths and Beebee 1992, Yoffe 1992). Much of this attention derives from a workshop held in February, 1990 on declining amphibians sponsored by the National Research Council Board (NRC) on Biology in Irvine, California (Barinaga 1990, Borchelt 1990). Because of media attention in the aftermath of this conference, it is a popular perception that amphibian declines are a new phenomenon that herpetologists have been slow to recognize (Griffiths and Beebee 1992, Quammen 1993). However, concern about amphibian populations in the United States dates back over 20 years. Beginning in the 1960s, a large, well-documented decline of northern leopard frogs (Rana pipiens) occurred in the

  8. Almagest Declinations: Timocharis, Aristyllus, and Hipparcus

    NASA Astrophysics Data System (ADS)

    Zimmer, Peter C.; Brandt, J. C.; Jones, P. B.

    2013-01-01

    Declinations in the Almagest provide an opportunity to determine the observational precision of the ancient observers and their epochs. The basic data are the original observations (O) and the declinations calculated (C) by precessing modern positions and including refraction. The plots of (O) - (C) can be analyzed using several different approaches. All of the original positions appear to be valid except Timocharis’s value for Arcturus. Consistent results for the precisions and epochs, respectively, are: Timocharis--8.1 arc min, near 296BC; Aristyllus--5.3 arc min, near 258BC; and Hipparcus--6.8 arc min, near 130BC. See the papers by Pannekoek (1955), Maeyama (1984), Rawlins (manuscript, c. 1983), and our earlier (Brandt, Zimmer, and Jones, 2011) report for the development of this subject. The precisions in the range 5-8 arc min are remarkable and the dates are compatible with historical evidence.

  9. Ecology: the proximate cause of frog declines?

    PubMed

    Di Rosa, Ines; Simoncelli, Francesca; Fagotti, Anna; Pascolini, Rita

    2007-05-31

    Pounds et al. argue that global warming contributes to amphibian declines by encouraging outbreaks of the chytrid fungus Batrachochytrium dendrobatidis. Although our findings agree with the climate-linked epidemic hypothesis, this pathogen is probably not the only proximate factor in such cases: in the Trasimeno Lake area of Umbria in central Italy, for example, the water frog Rana lessonae first declined in the late 1990s, yet chytridiomycosis was not observed until 2003 (refs 5, 6). Here we show that the chytrid was common there throughout 1999-2002, in a previously unknown form that did not cause disease. We therefore think that the focus by Pounds et al. on a single pathogen is hard to justify because the host-parasite ecology is at present so poorly understood.

  10. Analysis of production decline in geothermal reservoirs

    SciTech Connect

    Zais, Elliot J.; Bodvarsson, Gunnar

    1980-09-01

    The major objectives of the Decline Curve project were to: (1) test the decline analysis methods used in the petroleum industry on geothermal production data; (2) examine and/or develop new analysis methods; and (3) develop a standard operating procedure for analyzing geothermal production data. Various analysis methods have long been available but they have not been tested on geothermal data because of the lack of publicly available data. The recent release to publication of substantial data sets from Wairakei, New Zealand, Cerro Prieto, Mexico and The Geysers, USA has made this study possible. Geothermal reservoirs are quite different from petroleum reservoirs in many ways so the analysis methods must be tested using geothermal data.

  11. The Decline in Maternal Mortality in Sweden

    PubMed Central

    Högberg, Ulf

    2004-01-01

    The maternal mortality rate in Sweden in the early 20th century was one third that in the United States. This rate was recognized by American visitors as an achievement of Swedish maternity care, in which highly competent midwives attend home deliveries. The 19th century decline in maternal mortality was largely caused by improvements in obstetric care, but was also helped along by the national health strategy of giving midwives and doctors complementary roles in maternity care, as well as equal involvement in setting public health policy. The 20th century decline in maternal mortality, seen in all Western countries, was made possible by the emergence of modern medicine. However, the contribution of the mobilization of human resources should not be underestimated, nor should key developments in public health policy. PMID:15284032

  12. The decline of North American freshwater fishes

    USGS Publications Warehouse

    Walsh, Stephen J.; Jelks, Howard L.; Burkhead, Noel M.

    2009-01-01

    North America has a broad array of freshwater ecosystems because of the continent's complex geography and geological history. Within a multitude of habitats—that include streams, large rivers, natural lakes, springs, and wetlands—rich assemblages of fishes reside, representing diverse taxonomic groups with unique ecological requirements. They face an unprecedented conservation crisis.1 In the last few decades, the proportion of inland fishes of North America, which are considered imperiled or extinct, increased from 20 to 40%.2 Although extinctions have occurred, many species and populations are declining in range size and abundance. The fish biota of the continent as a whole remains diverse; however, we can take action to stem any further declines.

  13. Emerging infectious diseases and amphibian population declines.

    PubMed Central

    Daszak, P.; Berger, L.; Cunningham, A. A.; Hyatt, A. D.; Green, D. E.; Speare, R.

    1999-01-01

    We review recent research on the pathology, ecology, and biogeography of two emerging infectious wildlife diseases, chytridiomycosis and ranaviral disease, in the context of host-parasite population biology. We examine the role of these diseases in the global decline of amphibian populations and propose hypotheses for the origins and impact of these panzootics. Finally, we discuss emerging infectious diseases as a global threat to wildlife populations. PMID:10603206

  14. Reliability of indicators of decline in abundance.

    PubMed

    Porszt, Erin J; Peterman, Randall M; Dulvy, Nicholas K; Cooper, Andrew B; Irvine, James R

    2012-10-01

    Although there are many indicators of endangerment (i.e., whether populations or species meet criteria that justify conservation action), their reliability has rarely been tested. Such indicators may fail to identify that a population or species meets criteria for conservation action (false negative) or may incorrectly show that such criteria have been met (false positive). To quantify the rate of both types of error for 20 commonly used indicators of declining abundance (threat indicators), we used receiver operating characteristic curves derived from historical (1938-2007) data for 18 sockeye salmon (Oncorhynchus nerka) populations in the Fraser River, British Columbia, Canada. We retrospectively determined each population's yearly status (reflected by change in abundance over time) on the basis of each indicator. We then compared that population's status in a given year with the status in subsequent years (determined by the magnitude of decline in abundance across those years). For each sockeye population, we calculated how often each indicator of past status matched subsequent status. No single threat indicator provided error-free estimates of status, but indicators that reflected the extent (i.e., magnitude) of past decline in abundance (through comparison of current abundance with some historical baseline abundance) tended to better reflect status in subsequent years than the rate of decline over the previous 3 generations (a widely used indicator). We recommend that when possible, the reliability of various threat indicators be evaluated with empirical analyses before such indicators are used to determine the need for conservation action. These indicators should include estimates from the entire data set to take into account a historical baseline. PMID:22741815

  15. Family planning programs and fertility decline.

    PubMed

    Cuca, R

    1980-01-01

    A recently completed World Bank statistical study of family planning in 63 developing countries indicated that countries which experienced a large decline in birth rates between 1960-1977 were more likely to have a family planning program, an official population policy aimed at decreasing the birth rate, and a relatively high level of development than countries which experienced smaller or no decline in birth rates. The 65 countries represented 95% of the population of the developing world. Birth rate declines of 10% or more between 1960-1977 were experienced by: 1) 10 of the 26 countries which had a family planning program and a policy aimed at reducing the birth rate; 2) 6 of the 19 countries which had a family planning program but lacked clearly defined population objectives; and 3) 2 of the 18 countries without any population policy or program. Furthermore, the implementation of a family planning program and the adoption of a population policy were directly related to the development level of the country. This finding suggested that countries need to reach a certain level of development before they have the capacity to develop population programs and policies. When a country is sufficiently advanced to collect population data, awareness of population problems increases and they are more likely to adopt a population policy. In addition, government efficiency increases as development proceeds and governments must have a certain level of efficiency before they can implement effective programs.

  16. Reversal of cognitive decline in Alzheimer's disease

    PubMed Central

    Bredesen, Dale E.; Amos, Edwin C.; Canick, Jonathan; Ackerley, Mary; Raji, Cyrus; Fiala, Milan; Ahdidan, Jamila

    2016-01-01

    Alzheimer's disease is one of the most significant healthcare problems nationally and globally. Recently, the first description of the reversal of cognitive decline in patients with early Alzheimer's disease or its precursors, MCI (mild cognitive impairment) and SCI (subjective cognitive impairment), was published [1]. The therapeutic approach used was programmatic and personalized rather than monotherapeutic and invariant, and was dubbed metabolic enhancement for neurodegeneration (MEND). Patients who had had to discontinue work were able to return to work, and those struggling at work were able to improve their performance. The patients, their spouses, and their co-workers all reported clear improvements. Here we report the results from quantitative MRI and neuropsychological testing in ten patients with cognitive decline, nine ApoE4+ (five homozygous and four heterozygous) and one ApoE4−, who were treated with the MEND protocol for 5-24 months. The magnitude of the improvement is unprecedented, providing additional objective evidence that this programmatic approach to cognitive decline is highly effective. These results have far-reaching implications for the treatment of Alzheimer's disease, MCI, and SCI; for personalized programs that may enhance pharmaceutical efficacy; and for personal identification of ApoE genotype. PMID:27294343

  17. 26 CFR 1.167(b)-2 - Declining balance method.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 2 2013-04-01 2013-04-01 false Declining balance method. 1.167(b)-2 Section 1... Declining balance method. (a) Application of method. Under the declining balance method a uniform rate is... declining balance rate may be determined without resort to formula. Such rate determined under section...

  18. 26 CFR 1.167(b)-2 - Declining balance method.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 2 2014-04-01 2014-04-01 false Declining balance method. 1.167(b)-2 Section 1... Declining balance method. (a) Application of method. Under the declining balance method a uniform rate is... declining balance rate may be determined without resort to formula. Such rate determined under section...

  19. 26 CFR 1.167(b)-2 - Declining balance method.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Declining balance method. 1.167(b)-2 Section 1... Declining balance method. (a) Application of method. Under the declining balance method a uniform rate is... declining balance rate may be determined without resort to formula. Such rate determined under section...

  20. 26 CFR 1.167(b)-2 - Declining balance method.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Declining balance method. 1.167(b)-2 Section 1... Declining balance method. (a) Application of method. Under the declining balance method a uniform rate is... declining balance rate may be determined without resort to formula. Such rate determined under section...

  1. 26 CFR 1.167(b)-2 - Declining balance method.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 2 2012-04-01 2012-04-01 false Declining balance method. 1.167(b)-2 Section 1... Declining balance method. (a) Application of method. Under the declining balance method a uniform rate is... declining balance rate may be determined without resort to formula. Such rate determined under section...

  2. Sexually transmitted infections, active component, U.S. Armed Forces, 2000-2012.

    PubMed

    2013-02-01

    This report summarizes incidence rates of the five most commonly diagnosed sexually transmitted infections (STIs) among active component service members of the U.S. Armed Forces during 2000 to 2012. Human papillomavirus (HPV) infections were the most common, followed in decreasing order of frequency by infections associated with chlamydia, herpes simplex virus, gonorrhea, and syphilis. Compared to their counterparts, women, younger service members, soldiers, and enlisted members had higher incidence rates of each STI. Rates tended to be lower among married personnel. Rates of chlamydia, HPV, and gonorrhea diagnoses were notably higher among women during 2006 to 2008 but rates of the latter two infections have since declined sharply. The relatively recent introduction of STI screening among young service women and the HPV vaccine are discussed.

  3. Relationship between Frailty and Cognitive Decline in Older Mexican Americans

    PubMed Central

    Samper-Ternent, Rafael; Snih, Soham Al; Raji, Mukaila A.; Markides, Kyriakos S.; Ottenbacher, Kenneth J.

    2009-01-01

    Objective Examine the association between frailty status and change in cognitive function over time in older Mexican Americans. Design Data used are from the Hispanic Established Population for the Epidemiological Study of the Elderly (H-EPESE) Setting Five Southwestern states: Texas, New Mexico, Colorado, Arizona, and California. Participants 1,370 non-institutionalized Mexican American men and women aged 65 and older with a Mini Mental State Examination (MMSE) ≥ 21 at baseline (1995−1996). Measurements Frailty defined as three or more of the following components: 1) unintentional weight-loss of > 10-lbs, 2) weakness (lowest 20% in grip-strength), 3) self-reported exhaustion, 4) slow walking speed (lowest 20% 16ft walk-time in seconds), and 5) low physical activity level (lowest 20% Physical Activity Scale for the Elderly (PASE) score). Socio-demographic factors, MMSE, medical conditions (stroke, heart-attack, diabetes, arthritis, cancer and hypertension), depressive symptoms and visual-impairment were obtained. Results Of the 1370 subjects, 684 (49.9%) were not-frail, 626 (45.7%) were pre-frail (1 − 2 components) and 60 (4.4%) were frail (≥3 components) in 1995/96. Using general linear mixed models, we found that frail subjects had greater cognitive decline over 10-years compared with non-frail subjects (Estimate = −0.67, SE = 0.13; p< .0001). This association remained statistically significant after controlling for potential confounding factors. Conclusion Frail status in older Mexican Americans with MMSE ≥ 21 at baseline is an independent predictor of MMSE score decline over a 10-year period. Future research is needed to establish pathophysiological components that can clarify the relationship between frailty and cognitive decline. PMID:18811611

  4. Multispectral sensing of citrus young tree decline

    NASA Technical Reports Server (NTRS)

    Edwards, G. J.; Ducharme, E. P.; Schehl, T.

    1975-01-01

    Computer processing of MSS data to identify and map citrus trees affected by young tree decline is analyzed. The data were obtained at 1500-feet altitude in six discrete spectral bands covering regions from 0.53 to 1.3 millimicrons as well as from instrumental ground truths of tree crowns. Measurable spectral reflectance intensity differences are observed in the leaves of healthy and diseased trees, especially at wavelengths of 500 to 600 nm and 700 to 800 nm. The overall accuracy of the method is found to be 89%.

  5. Stabilizing survival selection on presenescent expression of a sexual ornament followed by a terminal decline.

    PubMed

    Simons, M J P; Briga, M; Verhulst, S

    2016-07-01

    Senescence is a decrease in functional capacity, increasing mortality rate with age. Sexual signals indicate functional capacity, because costs of ornamentation ensure signal honesty, and are therefore expected to senesce, tracking physiological deterioration and mortality. For sexual traits, mixed associations with age and positive associations with life expectancy have been reported. However, whether these associations are caused by selective disappearance and/or within-individual senescence of sexual signals, respectively, is not known. We previously reported that zebra finches with redder bills had greater life expectancy, based on a single bill colour measurement per individual. We here extend this analysis using longitudinal data and show that this finding is attributable to terminal declines in bill redness in the year before death, with no detectable change in presenescent redness. Additionally, there was a quadratic relationship between presenescent bill colouration and survival: individuals with intermediate bill redness have maximum survival prospects. This may reflect that redder individuals overinvest in colouration and/or associated physiological changes, while below-average bill redness probably reflects poorer phenotypic quality. Together, this pattern suggests that bill colouration is defended against physiological deterioration, because of mate attraction benefits, or that physiological deterioration is not a gradual process, but accelerates sharply prior to death. We discuss these possibilities in the context of the reliability theory of ageing and sexual selection. PMID:27061923

  6. Complex causes of amphibian population declines.

    PubMed

    Kiesecker, J M; Blaustein, A R; Belden, L K

    2001-04-01

    Amphibian populations have suffered widespread declines and extinctions in recent decades. Although climatic changes, increased exposure to ultraviolet-B (UV-B) radiation and increased prevalence of disease have all been implicated at particular localities, the importance of global environmental change remains unclear. Here we report that pathogen outbreaks in amphibian populations in the western USA are linked to climate-induced changes in UV-B exposure. Using long-term observational data and a field experiment, we examine patterns among interannual variability in precipitation, UV-B exposure and infection by a pathogenic oomycete, Saprolegnia ferax. Our findings indicate that climate-induced reductions in water depth at oviposition sites have caused high mortality of embryos by increasing their exposure to UV-B radiation and, consequently, their vulnerability to infection. Precipitation, and thus water depth/UV-B exposure, is strongly linked to El Niño/Southern Oscillation cycles, underscoring the role of large-scale climatic patterns involving the tropical Pacific. Elevated sea-surface temperatures in this region since the mid-1970s, which have affected the climate over much of the world, could be the precursor for pathogen-mediated amphibian declines in many regions. PMID:11287952

  7. The cultural evolution of fertility decline

    PubMed Central

    Colleran, Heidi

    2016-01-01

    Cultural evolutionists have long been interested in the problem of why fertility declines as populations develop. By outlining plausible mechanistic links between individual decision-making, information flow in populations and competition between groups, models of cultural evolution offer a novel and powerful approach for integrating multiple levels of explanation of fertility transitions. However, only a modest number of models have been published. Their assumptions often differ from those in other evolutionary approaches to social behaviour, but their empirical predictions are often similar. Here I offer the first overview of cultural evolutionary research on demographic transition, critically compare it with approaches taken by other evolutionary researchers, identify gaps and overlaps, and highlight parallel debates in demography. I suggest that researchers divide their labour between three distinct phases of fertility decline—the origin, spread and maintenance of low fertility—each of which may be driven by different causal processes, at different scales, requiring different theoretical and empirical tools. A comparative, multi-level and mechanistic framework is essential for elucidating both the evolved aspects of our psychology that govern reproductive decision-making, and the social, ecological and cultural contingencies that precipitate and sustain fertility decline. PMID:27022079

  8. The impact of freedom on fertility decline.

    PubMed

    Campbell, Martha M; Prata, Ndola; Potts, Malcolm

    2013-01-01

    Although fertility decline often correlates with improvements in socioeconomic conditions, many demographers have found flaws in demographic transition theories that depend on changes in distal factors such as increased wealth or education. Human beings worldwide engage in sexual intercourse much more frequently than is needed to conceive the number of children they want, and for women who do not have access to the information and means they need to separate sex from childbearing, the default position is a large family. In many societies, male patriarchal drives to control female reproduction give rise to unnecessary medical rules constraining family planning (including safe abortion) or justifying child marriage. Widespread misinformation about contraception makes women afraid to adopt modern family planning. The barriers to family planning can be so deeply infused that for many women the idea of managing their fertility is not considered an option. Conversely, there is evidence that once family planning is introduced into a society, then it is normal consumer behaviour for individuals to welcome a new technology they had not wanted until it became realistically available. We contend that in societies free from child marriage, wherever women have access to a range of contraceptive methods, along with correct information and backed up by safe abortion, family size will always fall. Education and wealth can make the adoption of family planning easier, but they are not prerequisites for fertility decline. By contrast, access to family planning itself can accelerate economic development and the spread of education.

  9. The impact of freedom on fertility decline

    PubMed Central

    Campbell, Martha M; Prata, Ndola; Potts, Malcolm

    2013-01-01

    Although fertility decline often correlates with improvements in socioeconomic conditions, many demographers have found flaws in demographic transition theories that depend on changes in distal factors such as increased wealth or education. Human beings worldwide engage in sexual intercourse much more frequently than is needed to conceive the number of children they want, and for women who do not have access to the information and means they need to separate sex from childbearing, the default position is a large family. In many societies, male patriarchal drives to control female reproduction give rise to unnecessary medical rules constraining family planning (including safe abortion) or justifying child marriage. Widespread misinformation about contraception makes women afraid to adopt modern family planning. The barriers to family planning can be so deeply infused that for many women the idea of managing their fertility is not considered an option. Conversely, there is evidence that once family planning is introduced into a society, then it is normal consumer behaviour for individuals to welcome a new technology they had not wanted until it became realistically available. We contend that in societies free from child marriage, wherever women have access to a range of contraceptive methods, along with correct information and backed up by safe abortion, family size will always fall. Education and wealth can make the adoption of family planning easier, but they are not prerequisites for fertility decline. By contrast, access to family planning itself can accelerate economic development and the spread of education. PMID:23296851

  10. Status and trends of amphibian declines and extinctions worldwide.

    PubMed

    Stuart, Simon N; Chanson, Janice S; Cox, Neil A; Young, Bruce E; Rodrigues, Ana S L; Fischman, Debra L; Waller, Robert W

    2004-12-01

    The first global assessment of amphibians provides new context for the well-publicized phenomenon of amphibian declines. Amphibians are more threatened and are declining more rapidly than either birds or mammals. Although many declines are due to habitat loss and overutilization, other, unidentified processes threaten 48% of rapidly declining species and are driving species most quickly to extinction. Declines are nonrandom in terms of species' ecological preferences, geographic ranges, and taxonomic associations and are most prevalent among Neotropical montane, stream-associated species. The lack of conservation remedies for these poorly understood declines means that hundreds of amphibian species now face extinction.

  11. Decline in Health for Older Adults: Five-Year Change in 13 Key Measures of Standardized Health

    PubMed Central

    2013-01-01

    Background. The health of older adults declines over time, but there are many ways of measuring health. It is unclear whether all health measures decline at the same rate or whether some aspects of health are less sensitive to aging than others. Methods. We compared the decline in 13 measures of physical, mental, and functional health from the Cardiovascular Health Study: hospitalization, bed days, cognition, extremity strength, feelings about life as a whole, satisfaction with the purpose of life, self-rated health, depression, digit symbol substitution test, grip strength, activities of daily living, instrumental activities of daily living, and gait speed. Each measure was standardized against self-rated health. We compared the 5-year change to see which of the 13 measures declined the fastest and the slowest. Results. The 5-year change in standardized health varied from a decline of 12 points (out of 100) for hospitalization to a decline of 17 points for gait speed. In most comparisons, standardized health from hospitalization and bed days declined the least, whereas health measured by activities of daily living, instrumental activities of daily living, and gait speed declined the most. These rankings were independent of age, sex, mortality patterns, and the method of standardization. Conclusions. All of the health variables declined, on average, with advancing age, but at significantly different rates. Standardized measures of mental health, cognition, quality of life, and hospital utilization did not decline as fast as gait speed, activities of daily living, and instrumental activities of daily living. Public health interventions to address problems with gait speed, activities of daily living, and instrumental activities of daily living may help older adults to remain healthier in all dimensions. PMID:23666944

  12. Shifting base-lines, declining coral cover, and the erosion of reef resilience: comment on Sweatman et al. (2011)

    NASA Astrophysics Data System (ADS)

    Hughes, T. P.; Bellwood, D. R.; Baird, A. H.; Brodie, J.; Bruno, J. F.; Pandolfi, J. M.

    2011-09-01

    Formal monitoring of the Great Barrier Reef was initiated in 1986 in response to the clear scientific evidence (and growing public concern) over the loss of corals caused by two protracted outbreaks of crown-of thorns starfish, which began in 1962 and 1979. Using monitoring data from manta tows along and across the Great Barrier Reef, Sweatman et al. (Coral Reefs 30:521-531, 2011) show that coral cover after these outbreaks declined further from 28 to 22% between 1986 and 2004. Pointing to the current levels of protection of the Great Barrier Reef, they state that earlier estimates of losses of coral cover since the early 1960s have been exaggerated. However, the loss of close to one-quarter of the coral cover over the past two decades represents an average loss of 0.34% cover per year across the whole GBR after 1986, which is very similar to previously reported rates of annual loss measured over a longer timeframe. The heaviest recent losses have occurred on inshore and mid-shelf reefs, which Sweatman et al. (Coral Reefs 30:521-531, 2011) attribute to a natural cycle of disturbance and recovery. But there has been very limited recovery. While coral cover has increased for short periods on some individual reefs, it has declined sharply on many more to produce the observed system-wide trend of declining cover. Close to 40% of coral cover on inner reefs has been lost since 1986. Of particular significance is the new evidence that coral cover has remained unchanged or declined further from a low 1986 baseline in 28 out of 29 sub-regions of the Great Barrier Reef, indicating a gradual erosion of resilience that is impeding the capacity of this huge reef system to return towards its earlier condition. This result, and other clear evidence of widespread incremental degradation from overfishing, pollution, and climate change, calls for action rather than complacency or denial.

  13. Solar Variability and the Decline of the Bubonic Plague

    NASA Astrophysics Data System (ADS)

    2001-10-01

    The bubonic plague was responsible for the deaths of a very large percentage of the population of Europe in ancient times. Leaders of state made promises to “kill off” the plague, were all unsuccessful. It wasn’t the grand promise of a politician, or some new medicinal invention that was responsible for the final decline of the plague. It appears that a chain of events that began 93,000,000 miles away from Earth exerted an impact that lead to the end of the plague’s activity. Some simple changes in solar activity that began in the early 1300’s started the final to break the stranglehold that the plague had on most of Europe. This chain of events will be presented and discussed in this paper.

  14. Widespread decline of Congo rainforest greenness in the past decade.

    PubMed

    Zhou, Liming; Tian, Yuhong; Myneni, Ranga B; Ciais, Philippe; Saatchi, Sassan; Liu, Yi Y; Piao, Shilong; Chen, Haishan; Vermote, Eric F; Song, Conghe; Hwang, Taehee

    2014-05-01

    Tropical forests are global epicentres of biodiversity and important modulators of climate change, and are mainly constrained by rainfall patterns. The severe short-term droughts that occurred recently in Amazonia have drawn attention to the vulnerability of tropical forests to climatic disturbances. The central African rainforests, the second-largest on Earth, have experienced a long-term drying trend whose impacts on vegetation dynamics remain mostly unknown because in situ observations are very limited. The Congolese forest, with its drier conditions and higher percentage of semi-evergreen trees, may be more tolerant to short-term rainfall reduction than are wetter tropical forests, but for a long-term drought there may be critical thresholds of water availability below which higher-biomass, closed-canopy forests transition to more open, lower-biomass forests. Here we present observational evidence for a widespread decline in forest greenness over the past decade based on analyses of satellite data (optical, thermal, microwave and gravity) from several independent sensors over the Congo basin. This decline in vegetation greenness, particularly in the northern Congolese forest, is generally consistent with decreases in rainfall, terrestrial water storage, water content in aboveground woody and leaf biomass, and the canopy backscatter anomaly caused by changes in structure and moisture in upper forest layers. It is also consistent with increases in photosynthetically active radiation and land surface temperature. These multiple lines of evidence indicate that this large-scale vegetation browning, or loss of photosynthetic capacity, may be partially attributable to the long-term drying trend. Our results suggest that a continued gradual decline of photosynthetic capacity and moisture content driven by the persistent drying trend could alter the composition and structure of the Congolese forest to favour the spread of drought-tolerant species. PMID:24759324

  15. Widespread decline of Congo rainforest greenness in the past decade.

    PubMed

    Zhou, Liming; Tian, Yuhong; Myneni, Ranga B; Ciais, Philippe; Saatchi, Sassan; Liu, Yi Y; Piao, Shilong; Chen, Haishan; Vermote, Eric F; Song, Conghe; Hwang, Taehee

    2014-05-01

    Tropical forests are global epicentres of biodiversity and important modulators of climate change, and are mainly constrained by rainfall patterns. The severe short-term droughts that occurred recently in Amazonia have drawn attention to the vulnerability of tropical forests to climatic disturbances. The central African rainforests, the second-largest on Earth, have experienced a long-term drying trend whose impacts on vegetation dynamics remain mostly unknown because in situ observations are very limited. The Congolese forest, with its drier conditions and higher percentage of semi-evergreen trees, may be more tolerant to short-term rainfall reduction than are wetter tropical forests, but for a long-term drought there may be critical thresholds of water availability below which higher-biomass, closed-canopy forests transition to more open, lower-biomass forests. Here we present observational evidence for a widespread decline in forest greenness over the past decade based on analyses of satellite data (optical, thermal, microwave and gravity) from several independent sensors over the Congo basin. This decline in vegetation greenness, particularly in the northern Congolese forest, is generally consistent with decreases in rainfall, terrestrial water storage, water content in aboveground woody and leaf biomass, and the canopy backscatter anomaly caused by changes in structure and moisture in upper forest layers. It is also consistent with increases in photosynthetically active radiation and land surface temperature. These multiple lines of evidence indicate that this large-scale vegetation browning, or loss of photosynthetic capacity, may be partially attributable to the long-term drying trend. Our results suggest that a continued gradual decline of photosynthetic capacity and moisture content driven by the persistent drying trend could alter the composition and structure of the Congolese forest to favour the spread of drought-tolerant species.

  16. The decline and resurgence of vascular dementia.

    PubMed Central

    Hachinski, V C

    1990-01-01

    Arteriosclerotic narrowing of cerebral arteries was once viewed as the key to mental decline. As Alzheimer's disease gained recognition and the concept of multi-infarct dementia achieved acceptance, vascular dementia came to be regarded as uncommon. The changing nature of cerebral vascular disease, the aging of the population and the widespread use of brain imaging techniques have brought new prominence to vascular dementia, chiefly in the form of an epidemic of "Binswanger's disease". Growing evidence suggests that not only grey matter lesions but also white matter lesions contribute to dementia, that vascular factors commonly coexist and interact with Alzheimer changes and that Alzheimer's disease has a vascular and potentially treatable component. Vascular dementia needs to be redefined, reappraised and reinvestigated. PMID:2403832

  17. Consequences of Age-Related Cognitive Declines

    PubMed Central

    Salthouse, Timothy

    2013-01-01

    Adult age differences in a variety of cognitive abilities are well documented, and many of those abilities have been found to be related to success in the workplace and in everyday life. However, increased age is seldom associated with lower levels of real-world functioning, and the reasons for this lab-life discrepancy are not well understood. This article briefly reviews research concerned with relations of age to cognition, relations of cognition to successful functioning outside the laboratory, and relations of age to measures of work performance and achievement. The final section discusses several possible explanations for why there are often little or no consequences of age-related cognitive declines in everyday functioning. PMID:21740223

  18. Decline of radionuclides in Columbia River biota

    SciTech Connect

    Cushing, C.E.; Watson, D.G.; Scott, A.J.; Gurtisen, J.M.

    1980-03-01

    In January 1971, the last of nine plutonium production reactors using direct discharge of once-through cooling waters into the Columbia River was closed. Sampling was initiated at three stations on the Columbia River to document the decline of the radionuclide body burdens in the biota of the Columbia River ecosystem. The data show that in a river-reservoir complex, the measurable body burden of fission-produced radionuclides decreased to essentially undetectable levels within 18 to 24 mo after cessation of discharge of once-through cooling water into the river. On the basis of data from the free-flowing station, we believe that this decrease would be even more rapid in an unimpounded river.

  19. Global biodiversity: indicators of recent declines

    USGS Publications Warehouse

    Butchart, Stuart H.M.; Walpole, Matt; Collen, Ben; Van Strien, Arco; Scharlemann, Jorn P.W.; Almond, Rosamunde E.A.; Baillie, Jonathan E.M.; Bomhard, Bastian; Brown, Claire; Bruno, John; Carpenter, Kent E.; Carr, Genevieve M.; Chanson, Janice; Chenery, Anna M.; Csirke, Jorge; Davidson, Nick C.; Dentener, Frank; Foster, Matt; Galli, Alessandro; Galloway, James N.; Genovesi, Piero; Gregory, Richard D.; Hockings, Marc; Kapos, Valerie; Lamarque, Jean-Francois; Leverington, Fiona; Loh, Jonathan; McGeoch, Melodie A.; McRae, Louise; Minasyan, Anahit; Morcillo, Monica Hernandez; Oldfield, Thomasina E.E.; Pauly, Daniel; Quader, Suhel; Revenga, Carmen; Sauer, John R.; Skolnik, Benjamin; Spear, Dian; Stanwell-Smith, Damon; Stuart, Simon N.; Symes, Andy; Tierney, Megan; Tyrrell, Tristan D.; Vie, Jean-Christophe; Watson, Reg

    2011-01-01

    In 2002, world leaders committed, through the Convention on Biological Diversity, to achieve a significant reduction in the rate of biodiversity loss by 2010. We compiled 31 indicators to report on progress toward this target. Most indicators of the state of biodiversity (covering species' population trends, extinction risk, habitat extent and condition, and community composition) showed declines, with no significant recent reductions in rate, whereas indicators of pressures on biodiversity (including resource consumption, invasive alien species, nitrogen pollution, overexploitation, and climate change impacts) showed increases. Despite some local successes and increasing responses (including extent and biodiversity coverage of protected areas, sustainable forest management, policy responses to invasive alien species, and biodiversity-related aid), the rate of biodiversity loss does not appear to be slowing.

  20. The decline in child mortality: a reappraisal.

    PubMed Central

    Ahmad, O. B.; Lopez, A. D.; Inoue, M.

    2000-01-01

    The present paper examines, describes and documents country-specific trends in under-five mortality rates (i.e., mortality among children under five years of age) in the 1990s. Our analysis updates previous studies by UNICEF, the World Bank and the United Nations. It identifies countries and WHO regions where sustained improvement has occurred and those where setbacks are evident. A consistent series of estimates of under-five mortality rate is provided and an indication is given of historical trends during the period 1950-2000 for both developed and developing countries. It is estimated that 10.5 million children aged 0-4 years died in 1999, about 2.2 million or 17.5% fewer than a decade earlier. On average about 15% of newborn children in Africa are expected to die before reaching their fifth birthday. The corresponding figures for many other parts of the developing world are in the range 3-8% and that for Europe is under 2%. During the 1990s the decline in child mortality decelerated in all the WHO regions except the Western Pacific but there is no widespread evidence of rising child mortality rates. At the country level there are exceptions in southern Africa where the prevalence of HIV is extremely high and in Asia where a few countries are beset by economic difficulties. The slowdown in the rate of decline is of particular concern in Africa and South-East Asia because it is occurring at relatively high levels of mortality, and in countries experiencing severe economic dislocation. As the HIV/AIDS epidemic continues in Africa, particularly southern Africa, and in parts of Asia, further reductions in child mortality become increasingly unlikely until substantial progress in controlling the spread of HIV is achieved. PMID:11100613

  1. Where the brain grows old: decline in anterior cingulate and medial prefrontal function with normal aging.

    PubMed

    Pardo, José V; Lee, Joel T; Sheikh, Sohail A; Surerus-Johnson, Christa; Shah, Hemant; Munch, Kristin R; Carlis, John V; Lewis, Scott M; Kuskowski, Michael A; Dysken, Maurice W

    2007-04-15

    Even healthy adults worry about declines in mental efficiency with aging. Subjective changes in mental flexibility, self-regulation, processing speed, and memory are often cited. We show here that focal decreases in brain activity occur with normal aging as measured with fluorodeoxyglucose and positron emission tomography. The largest declines localize to a medial network including the anterior cingulate/medial prefrontal cortex, dorsomedial thalamus, and sugenual cingulate/basal forebrain. Declining metabolism in this network correlates with declining cognitive function. The medial prefrontal metabolic changes with aging are similar in magnitude to the hypometabolism found in Mild Cognitive Impairment or Alzheimer's disease. These results converge with data from healthy elderly indicating dysfunction in the anterior attention system. The interaction of attention in the anterior cingulate cortex with memory in the medial temporal lobe may explain the global impairment that defines dementia. Despite the implications for an aging population, the neurophysiologic mechanisms of these metabolic decreases remain unknown. PMID:17321756

  2. The role of contaminants and pollution in species decline

    USGS Publications Warehouse

    Pattee, O.H.; Rattner, B.A.; Eisler, R.; Wegner, V.L.; Bounds, D.L.

    1999-01-01

    Members of over 1,200 taxa have been listed as Threatened or Endangered, and over 4,000 additional organisms have been identified as Candidate Species or Species of Concern. Both naturally-occurring and anthropogenic activities (e.g., environmental contaminants and pollution) have been demonstrated to be a significant factor in depressing populations or catalyzing the final crash of some species. The objective of this project is to develop a synthesis document and database that lists and ranks the presumed causes of decline, with special emphasis on contaminants and pollutant-related situations. This will be accomplished by a synoptic review of all recovery plans (n=517) with listing packages (n= 1180) serving as a secondary source of information, followed by itemization, cross-referencing, enumeration, and ranking of contributing and limiting factors. To date we have analyzed most of the available recovery plans for freshwater mussels (n=39), reptiles (n=26). and amphibians (n=6). We categorized 116 reasons fur the decline in freshwater mussels, subsuming them into 6 classes: habitat alteration/availability (44.4%);.contaminants (24.1%); pollution (18.0%); exploitation/harvest (1.7%); introduction of exotic species (2.7%); miscellaneous others (9.2%). The 171 causes of decline for reptiles can be subsumed into the same categories: habitat alteration/availability (32.7%); contaminants (6.4%); pollution (9.9%); exploitation/harvest (28.7%); introduction of exotic species (11.1%); miscellaneous others (11.1%). The 34 causes for amphibian decline fall into 5 classes: habitat alteration/availability (50.0%); contaminants (5.9%); pollution (5.9%); exploitation/harvest (5.9%); miscellaneous others (32.3%). The contaminant and pollution related causes for the decline in mussels can be attributed to four classes of alterations: water quality (47.2%); effluents/ spills (46.7%); biocides (3.3%); other toxic compounds (2.8%). For reptiles, the contamination and pollution

  3. Agriculture intensifies soil moisture decline in Northern China

    NASA Astrophysics Data System (ADS)

    Liu, Yaling; Pan, Zhihua; Zhuang, Qianlai; Miralles, Diego G.; Teuling, Adriaan J.; Zhang, Tonglin; An, Pingli; Dong, Zhiqiang; Zhang, Jingting; He, Di; Wang, Liwei; Pan, Xuebiao; Bai, Wei; Niyogi, Dev

    2015-07-01

    Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983-2012, we find that topsoil (0-50 cm) volumetric water content during the growing season has declined significantly (p < 0.01), with a trend of -0.011 to -0.015 m3 m-3 per decade. Observed discharge declines for the three large river basins are consistent with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system.

  4. Agriculture intensifies soil moisture decline in Northern China.

    PubMed

    Liu, Yaling; Pan, Zhihua; Zhuang, Qianlai; Miralles, Diego G; Teuling, Adriaan J; Zhang, Tonglin; An, Pingli; Dong, Zhiqiang; Zhang, Jingting; He, Di; Wang, Liwei; Pan, Xuebiao; Bai, Wei; Niyogi, Dev

    2015-01-01

    Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983-2012, we find that topsoil (0-50 cm) volumetric water content during the growing season has declined significantly (p < 0.01), with a trend of -0.011 to -0.015 m(3) m(-3) per decade. Observed discharge declines for the three large river basins are consistent with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system. PMID:26158774

  5. Agriculture intensifies soil moisture decline in Northern China

    DOE PAGES

    Liu, Yaling; Pan, Zhihua; Zhuang, Qianlai; Miralles, Diego; Teuling, Adriann; Zhang, Tonglin; An, Pingli; Dong, Zhiqiang; Zhang, Jingting; He, Di; et al

    2015-07-09

    Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983–2012, we find that topsoil (0–50 cm) volumetric water content during the growing season has declined significantly (p<0.01), with a trend of -0.011 to -0.015 m3 m-3 per decade. Observed discharge declines for the three large river basins are consistentmore » with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system.« less

  6. Agriculture intensifies soil moisture decline in Northern China

    SciTech Connect

    Liu, Yaling; Pan, Zhihua; Zhuang, Qianlai; Miralles, Diego; Teuling, Adriann; Zhang, Tonglin; An, Pingli; Dong, Zhiqiang; Zhang, Jingting; He, Di; Wang, Liwei; Pan, Xuebiao; Bai, Wei; Niyogi, Dev

    2015-07-09

    Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983–2012, we find that topsoil (0–50 cm) volumetric water content during the growing season has declined significantly (p<0.01), with a trend of -0.011 to -0.015 m3 m-3 per decade. Observed discharge declines for the three large river basins are consistent with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system.

  7. Agriculture intensifies soil moisture decline in Northern China.

    PubMed

    Liu, Yaling; Pan, Zhihua; Zhuang, Qianlai; Miralles, Diego G; Teuling, Adriaan J; Zhang, Tonglin; An, Pingli; Dong, Zhiqiang; Zhang, Jingting; He, Di; Wang, Liwei; Pan, Xuebiao; Bai, Wei; Niyogi, Dev

    2015-07-09

    Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983-2012, we find that topsoil (0-50 cm) volumetric water content during the growing season has declined significantly (p < 0.01), with a trend of -0.011 to -0.015 m(3) m(-3) per decade. Observed discharge declines for the three large river basins are consistent with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system.

  8. Red spruce decline---Winter injury and air pollutants

    SciTech Connect

    Roberts, T.M. )

    1989-10-01

    There has been a widespread decline in growth of red spruce (Picea rubens Sarg.) since 1960 in the eastern United States. There is evidence that this decline is at least partly attributable to age- and density-related growth patterns, particularly at lower elevations. Mortality has been severe at high elevation sites where similar episodes have occasionally occurred in the last 100 years. At these sites, periods of low growth preceding 1960 were related to periods with warm late summers and cold early winters. Since 1960, this relationship no longer holds, although there is an association with unusual deviations from mean temperatures. There are field reports that one of the main causes of reduced growth and mortality is apical dieback induced by severe winter conditions. Preliminary observations suggest that high elevation red spruce may not be sufficiently hardened to tolerate low autumn temperatures. However, appearance of injury in the spring, association of injury with wind exposure and correlation of provenance susceptibility with cuticular transpiration rates, including the importance of desiccation injury. Sensitivity to both types of winter injury may be increased by air pollutants (particularly ozone and less probably, acid mist or excess nitrogen deposition). Nutrient deficiency (particularly magnesium and to a lesser extent potassium) may also increase cold sensitivity. The nature and extent of these interactions are being actively researched for red spruce. 48 refs.

  9. Agriculture intensifies soil moisture decline in Northern China

    PubMed Central

    Liu, Yaling; Pan, Zhihua; Zhuang, Qianlai; Miralles, Diego G.; Teuling, Adriaan J.; Zhang, Tonglin; An, Pingli; Dong, Zhiqiang; Zhang, Jingting; He, Di; Wang, Liwei; Pan, Xuebiao; Bai, Wei; Niyogi, Dev

    2015-01-01

    Northern China is one of the most densely populated regions in the world. Agricultural activities have intensified since the 1980s to provide food security to the country. However, this intensification has likely contributed to an increasing scarcity in water resources, which may in turn be endangering food security. Based on in-situ measurements of soil moisture collected in agricultural plots during 1983–2012, we find that topsoil (0–50 cm) volumetric water content during the growing season has declined significantly (p < 0.01), with a trend of −0.011 to −0.015 m3 m−3 per decade. Observed discharge declines for the three large river basins are consistent with the effects of agricultural intensification, although other factors (e.g. dam constructions) likely have contributed to these trends. Practices like fertilizer application have favoured biomass growth and increased transpiration rates, thus reducing available soil water. In addition, the rapid proliferation of water-expensive crops (e.g., maize) and the expansion of the area dedicated to food production have also contributed to soil drying. Adoption of alternative agricultural practices that can meet the immediate food demand without compromising future water resources seem critical for the sustainability of the food production system. PMID:26158774

  10. Concept of functional imaging of memory decline in Alzheimer's disease.

    PubMed

    Drzezga, Alexander

    2008-04-01

    Functional imaging methods such as Positron Emission Tomography (PET) and functional Magnetic Resonance Imaging (fMRI) have contributed inestimably to the understanding of physiological cognitive processes in the brain in the recent decades. These techniques for the first time allowed the in vivo assessment of different features of brain function in the living human subject. It was therefore obvious to apply these methods to evaluate pathomechanisms of cognitive dysfunction in disorders such as Alzheimer's disease (AD) as well. One of the most dominant symptoms of AD is the impairment of memory. In this context, the term "memory" represents a simplification and summarizes a set of complex cognitive functions associated with encoding and retrieval of different types of information. A number of imaging studies assessed the functional changes of neuronal activity in the brain at rest and also during performance of cognitive work, with regard to specific characteristics of memory decline in AD. In the current article, basic principles of common functional imaging procedures will be explained and it will be discussed how they can be reasonably applied for the assessment of memory decline in AD. Furthermore, it will be illustrated how these imaging procedures have been employed to improve early and specific diagnosis of the disease, to understand specific pathomechanisms of memory dysfunction and associated compensatory mechanisms, and to draw reverse conclusions on physiological function of memory.

  11. The birth rate decline in developing countries.

    PubMed

    Robey, B

    1993-01-01

    Family planning programs historically have played an important role in providing information and counseling and supplying modern methods. Most programs are effective due to socioeconomic development and strong political support. Potential demand for services will be growing. This means that donor agencies must commit additional funding, and users must begin paying or paying more for contraceptives. Services and method choices need to be expanded, and quality of care needs to be improved. Three primary factors will impact on fertility decline: 1) the rate of social development, 2) the speed with which small family norms spread and contraception is adopted, and 3) the facility of private and public suppliers to meet contraceptive demand. Other factors influence reproductive decisions (women's roles and status, economic hardships or opportunities, religion, ethnicity, culture, and tradition). Contraceptive prevalence has increased from under 10% in the 1960s to 38% of all married, reproductive age women in the developing world, excluding China, which has contraceptive prevalence of 72%. Regional differences are wide. In Latin America, contraceptive use averages nearly 60% and ranges from over 50% in 10 countries and below 38% in Bolivia, Guatemala, and Haiti. Contraceptive prevalence is above average in Indonesia (50%), Sri Lanka (62%), and Thailand (68%) and just below average in Bangladesh (40%), India (45%), Philippines (34%), and Vietnam (53%). Sub-Saharan Africa has the lowest prevalence, except for Zimbabwe (45%), Botswana (35%), and Kenya (27%). 80% of current users rely on modern methods. In most surveyed countries, 20-30% of married women have unmet demand. Fertility decline, unmet demand, and contraceptive use have all been affected by the diffusion of ideas about the use of family planning and the small family norm. Innovators are usually high status, educated women, who spread their views to other social groups or geographic areas. The spread can be rapid

  12. Neotropical Amphibian Declines Affect Stream Ecosystem Properties

    NASA Astrophysics Data System (ADS)

    Connelly, S.; Pringle, C. M.; Bixby, R. J.; Whiles, M. R.; Lips, K. R.; Brenes, R.; Colon-Gaud, J. C.; Kilham, S.; Hunte-Brown, M.

    2005-05-01

    Global declines of amphibians are well documented, yet effects of these dramatic losses on ecosystem structure and function are poorly understood. As part of a larger collaborative project, we compared two upland Panamanian streams. Both streams are biologically and geologically similar; however, one stream (Fortuna) has recently experienced almost complete extirpation of stream-dwelling frogs, while the other (Cope) still has intact populations. We experimentally excluded tadpoles from localized areas in each stream. We then compared chlorophyll a, algal community composition, ash-free dry mass (AFDM), inorganic matter, and insect assemblages in control and exclusion areas. Additionally, we sampled the natural substrate of both streams monthly for chlorophyll a, algal community composition, AFDM, and inorganic matter. At Cope, chlorophyll a, AFDM, and inorganic matter were greater in areas where tadpoles were excluded than in their presence. Numbers of dominant algal species (e.g., Nupela praecipua and Eunotia siolii) were greater in the exclusion versus control treatments. Monthly sampling of natural substrate indicated higher chlorophyll a and AFDM at Cope compared to Fortuna. Our data suggest that stream-dwelling anuran larvae have significant impacts on algal communities. These results also have implications for predicting the relevance of short-term experimental manipulations to long-term, whole-stream processes.

  13. Declining ecosystem health and the dilution effect

    PubMed Central

    Khalil, Hussein; Ecke, Frauke; Evander, Magnus; Magnusson, Magnus; Hörnfeldt, Birger

    2016-01-01

    The “dilution effect” implies that where species vary in susceptibility to infection by a pathogen, higher diversity often leads to lower infection prevalence in hosts. For directly transmitted pathogens, non-host species may “dilute” infection directly (1) and indirectly (2). Competitors and predators may (1) alter host behavior to reduce pathogen transmission or (2) reduce host density. In a well-studied system, we tested the dilution of the zoonotic Puumala hantavirus (PUUV) in bank voles (Myodes glareolus) by two competitors and a predator. Our study was based on long-term PUUV infection data (2003–2013) in northern Sweden. The field vole (Microtus agrestis) and the common shrew (Sorex araneus) are bank vole competitors and Tengmalm’s owl (Aegolius funereus) is a main predator of bank voles. Infection probability in bank voles decreased when common shrew density increased, suggesting that common shrews reduced PUUV transmission. Field voles suppressed bank vole density in meadows and clear-cuts and indirectly diluted PUUV infection. Further, Tengmalm’s owl decline in 1980–2013 may have contributed to higher PUUV infection rates in bank voles in 2003–2013 compared to 1979–1986. Our study provides further evidence for dilution effect and suggests that owls may have an important role in reducing disease risk. PMID:27499001

  14. Declining ecosystem health and the dilution effect.

    PubMed

    Khalil, Hussein; Ecke, Frauke; Evander, Magnus; Magnusson, Magnus; Hörnfeldt, Birger

    2016-01-01

    The "dilution effect" implies that where species vary in susceptibility to infection by a pathogen, higher diversity often leads to lower infection prevalence in hosts. For directly transmitted pathogens, non-host species may "dilute" infection directly (1) and indirectly (2). Competitors and predators may (1) alter host behavior to reduce pathogen transmission or (2) reduce host density. In a well-studied system, we tested the dilution of the zoonotic Puumala hantavirus (PUUV) in bank voles (Myodes glareolus) by two competitors and a predator. Our study was based on long-term PUUV infection data (2003-2013) in northern Sweden. The field vole (Microtus agrestis) and the common shrew (Sorex araneus) are bank vole competitors and Tengmalm's owl (Aegolius funereus) is a main predator of bank voles. Infection probability in bank voles decreased when common shrew density increased, suggesting that common shrews reduced PUUV transmission. Field voles suppressed bank vole density in meadows and clear-cuts and indirectly diluted PUUV infection. Further, Tengmalm's owl decline in 1980-2013 may have contributed to higher PUUV infection rates in bank voles in 2003-2013 compared to 1979-1986. Our study provides further evidence for dilution effect and suggests that owls may have an important role in reducing disease risk. PMID:27499001

  15. Stormy oceans are associated with declines in sea turtle hatching.

    PubMed

    Van Houtan, Kyle S; Bass, Oron L

    2007-08-01

    Many sea turtle populations are below 10% of their pre-Columbian numbers [1-4]. Though historic and systematic over-exploitation is the principal cause of these declines, sea turtles face similar threats today. Adults and juveniles are actively hunted and commercial fisheries catch them incidentally. Nesting suffers from beach development, egg poaching and the poaching of nesting females. Accompanying these familiar hazards is the largely unknown consequences of recent climate change. Here we report monitoring surveys from the Dry Tortugas National Park (DTNP, 24.64N 82.86W), Florida, and show that hurricanes and other storm events are an additional and increasing threat to loggerhead turtle (Caretta caretta) and green sea turtle (Chelonia mydas) nesting. Both species are listed by the US Endangered Species Act and the IUCN considers them 'endangered'.

  16. Cognitive Declines Precede and Predict Functional Declines in Aging and Alzheimer’s Disease

    PubMed Central

    Zahodne, Laura B.; Manly, Jennifer J.; MacKay-Brandt, Anna; Stern, Yaakov

    2013-01-01

    Objective To investigate the temporal ordering of cognitive and functional declines separately in older adults with or without Alzheimer’s disease (AD). Design and Setting A community-based longitudinal study of aging and dementia in Northern Manhattan (Washington Heights/Hamilton Heights Inwood Columbia Aging Project) and a multicenter, clinic-based longitudinal study of prevalent AD at Columbia University Medical Center, Johns Hopkins School of Medicine, Massachusetts General Hospital, and the Hôpital de la Salpêtrière in Paris, France (the Predictors Study). Participants 3,443 initially non-demented older adults (612 with eventual incident dementia) and 517 patients with AD. Main Outcome Measures Cognitive measures included the modified Mini-Mental State Exam and composite scores of memory and language derived from a standardized neuropsychological battery. Function was measured with the Blessed Dementia Rating Scale, completed by the participant (in the sample of non-demented older adults) or an informant (in the sample of prevalent AD patients). Data were analyzed with autoregressive cross-lagged panel analysis. Results Cognitive scores more consistently predicted subsequent functional abilities than vice versa in non-demented older adults, participants with eventual incident dementia, and patients with prevalent AD. Conclusions Cognitive declines appear to precede and cause functional declines prior to and following dementia diagnosis. Standardized neuropsychological tests are valid predictors of later functional changes in both non-demented and demented older adults. PMID:24023894

  17. How family members manage risk around functional decline: the autonomy management process in households facing dementia.

    PubMed

    Berry, Brandon; Apesoa-Varano, Ester Carolina; Gomez, Yarin

    2015-04-01

    Most dementia research investigates the social context of declining ability through studies of decision-making around medical treatment and end-of-life care. This study seeks to fill an important gap in research about how family members manage the risks of functional decline at home. Drawing on three waves of in-depth interviewing in 2012-2014, it investigates how family members in US households manage decline in an affected individual's natural range of daily activities over time. The findings show that early on in the study period affected individuals were perceived to have awareness of their decline and routinely drew on family members for support. Support transformed when family members detected that the individual's deficit awareness had diminished, creating a corresponding increase in risk of self-harm around everyday activities. With a loss of confidence in the individual's ability to regulate his or her own activities to avoid these risks, family members employed unilateral practices to manage the individual's autonomy around his or her activity involvements. These practices typically involved various deceits and ruses to discourage elders from engaging in activities perceived as potentially dangerous. The study concludes by discussing the implications that the social context of interpretive work around awareness and risk plays an important role in how families perceive an elder's functional ability and manage his or her activity involvements.

  18. How family members manage risk around functional decline: The autonomy management process in households facing dementia

    PubMed Central

    Berry, Brandon; Apesoa-Varano, Ester Carolina; Gomez, Yarin

    2015-01-01

    Most dementia research investigates the social context of declining ability through studies of decision-making around medical treatment and end-of-life care. This study seeks to fill an important gap in research about how family members manage the risks of functional decline at home. Drawing on three waves of retrospective interviewing in 2012–2014, it investigates how family members in US households manage decline in an affected individual’s natural range of daily activities over time. The findings show that early on in the study period affected individuals were perceived to have awareness of their decline and routinely drew on family members for support. Support transformed when family members detected that the individual’s deficit awareness had diminished, creating a corresponding increase in risk of self-harm around everyday activities. With a loss of confidence in the individual’s ability to regulate his or her own activities to avoid these risks, family members employed unilateral practices to manage the individual’s autonomy around his or her activity involvements. These practices typically involved various deceits and ruses to discourage elders from engaging in activities perceived as potentially dangerous. The study concludes by discussing the implications that the social context of interpretive work around awareness and risk plays an important role in how families perceive an elder’s functional ability and manage his or her activity involvements. PMID:25697634

  19. Handgrip Strength Predicts Functional Decline at Discharge in Hospitalized Male Elderly: A Hospital Cohort Study

    PubMed Central

    García-Peña, Carmen; García-Fabela, Luis C.; Gutiérrez-Robledo, Luis M.; García-González, Jose J.; Arango-Lopera, Victoria E.; Pérez-Zepeda, Mario U.

    2013-01-01

    Functional decline after hospitalization is a common adverse outcome in elderly. An easy to use, reproducible and accurate tool to identify those at risk would aid focusing interventions in those at higher risk. Handgrip strength has been shown to predict adverse outcomes in other settings. The aim of this study was to determine if handgrip strength measured upon admission to an acute care facility would predict functional decline (either incident or worsening of preexisting) at discharge among older Mexican, stratified by gender. In addition, cutoff points as a function of specificity would be determined. A cohort study was conducted in two hospitals in Mexico City. The primary endpoint was functional decline on discharge, defined as a 30-point reduction in the Barthel Index score from that of the baseline score. Handgrip strength along with other variables was measured at initial assessment, including: instrumental activities of daily living, cognition, depressive symptoms, delirium, hospitalization length and quality of life. All analyses were stratified by gender. Logistic regression to test independent association between handgrip strength and functional decline was performed, along with estimation of handgrip strength test values (specificity, sensitivity, area under the curve, etc.). A total of 223 patients admitted to an acute care facility between 2007 and 2009 were recruited. A total of 55 patients (24.7%) had functional decline, 23.46% in male and 25.6% in women. Multivariate analysis showed that only males with low handgrip strength had an increased risk of functional decline at discharge (OR 0.88, 95% CI 0.79–0.98, p = 0.01), with a specificity of 91.3% and a cutoff point of 20.65 kg for handgrip strength. Females had not a significant association between handgrip strength and functional decline. Measurement of handgrip strength on admission to acute care facilities may identify male elderly patients at risk of having functional decline, and

  20. Conifer Decline and Mortality in Siberia

    NASA Astrophysics Data System (ADS)

    Kharuk, V.; Im, S.; Ranson, K.

    2015-12-01

    "Dark needle conifer" (DNC: Abies sibirica, Pinus sibirica and Picea obovata) decline and mortality increase were documented in Russia during recent decades. Here we analyzed causes and scale of Siberian pine and fir mortality in Altai-Sayan and Baikal Lake Regions and West Siberian Plane based on in situdata and remote sensing (QuickBird, Landsat, GRACE). Geographically, mortality began on the margins of the DNC range (i.e., within the forest-steppe and conifer-broadleaf ecotones) and on terrain features with maximal water stress risk (narrow-shaped hilltops, convex steep south facing slopes, shallow well-drained soils). Within ridges, mortality occurred mainly along mountain passes, where stands faced drying winds. Regularly mortality was observed to decrease with elevation increase with the exception of Baikal Lake Mountains, where it was minimal near the lake shore and increased with elevation (up to about 1000 m a.s.l.). Siberian pine and fir mortality followed a drying trend with consecutive droughts since the 1980s. Dendrochronology analysis showed that mortality was correlated with vapor pressure deficit increase, drought index, soil moisture decrease and occurrence of late frosts. In Baikal region Siberian pine mortality correlated with Baikal watershed meteorological variables. An impact of previous year climate conditions on the current growth was found (r2 = 0.6). Thus, water-stressed trees became sensitive to bark beetles and fungi impact (including Polygraphus proximus and Heterobasidion annosum). At present, an increase in mortality is observed within the majority of DNC range. Results obtained also showed a primary role of water stress in that phenomenon with a secondary role of bark beetles and fungi attacks. In future climate with increased drought severity and frequency Siberian pine and fir will partly disappear from its current range, and will be substituted by drought-tolerant species (e.g., Pinus silvestris, Larix sibirica).

  1. Do plasma melatonin concentrations decline with age?

    NASA Technical Reports Server (NTRS)

    Zeitzer, J. M.; Daniels, J. E.; Duffy, J. F.; Klerman, E. B.; Shanahan, T. L.; Dijk, D. J.; Czeisler, C. A.

    1999-01-01

    PURPOSE: Numerous reports that secretion of the putative sleep-promoting hormone melatonin declines with age have led to suggestions that melatonin replacement therapy be used to treat sleep problems in older patients. We sought to reassess whether the endogenous circadian rhythm of plasma melatonin concentration changes with age in healthy drug-free adults. METHODS: We analyzed the amplitude of plasma melatonin profiles during a constant routine in 34 healthy drug-free older subjects (20 women and 14 men, aged 65 to 81 years) and compared them with 98 healthy drug-free young men (aged 18 to 30 years). RESULTS: We could detect no significant difference between a healthy and drug-free group of older men and women as compared to one of young men in the endogenous circadian amplitude of the plasma melatonin rhythm, as described by mean 24-hour average melatonin concentration (70 pmol/liter vs 73 pmol/liter, P = 0.97), or the duration (9.3 hours vs 9.1 hours, P = 0.43), mean (162 pmol/liter vs 161 pmol/liter, P = 0.63), or integrated area (85,800 pmol x min/liter vs 86,700 pmol x min/liter, P = 0.66) of the nocturnal peak of plasma melatonin. CONCLUSION: These results do not support the hypothesis that reduction of plasma melatonin concentration is a general characteristic of healthy aging. Should melatonin replacement therapy or melatonin supplementation prove to be clinically useful, we recommend that an assessment of endogenous melatonin be carried out before such treatment is used in older patients.

  2. The lognormal handwriter: learning, performing, and declining.

    PubMed

    Plamondon, Réjean; O'Reilly, Christian; Rémi, Céline; Duval, Thérésa

    2013-01-01

    The generation of handwriting is a complex neuromotor skill requiring the interaction of many cognitive processes. It aims at producing a message to be imprinted as an ink trace left on a writing medium. The generated trajectory of the pen tip is made up of strokes superimposed over time. The Kinematic Theory of rapid human movements and its family of lognormal models provide analytical representations of these strokes, often considered as the basic unit of handwriting. This paradigm has not only been experimentally confirmed in numerous predictive and physiologically significant tests but it has also been shown to be the ideal mathematical description for the impulse response of a neuromuscular system. This latter demonstration suggests that the lognormality of the velocity patterns can be interpreted as reflecting the behavior of subjects who are in perfect control of their movements. To illustrate this interpretation, we present a short overview of the main concepts behind the Kinematic Theory and briefly describe how its models can be exploited, using various software tools, to investigate these ideal lognormal behaviors. We emphasize that the parameters extracted during various tasks can be used to analyze some underlying processes associated with their realization. To investigate the operational convergence hypothesis, we report on two original studies. First, we focus on the early steps of the motor learning process as seen as a converging behavior toward the production of more precise lognormal patterns as young children practicing handwriting start to become more fluent writers. Second, we illustrate how aging affects handwriting by pointing out the increasing departure from the ideal lognormal behavior as the control of the fine motricity begins to decline. Overall, the paper highlights this developmental process of merging toward a lognormal behavior with learning, mastering this behavior to succeed in performing a given task, and then gradually

  3. The lognormal handwriter: learning, performing, and declining

    PubMed Central

    Plamondon, Réjean; O'Reilly, Christian; Rémi, Céline; Duval, Thérésa

    2013-01-01

    The generation of handwriting is a complex neuromotor skill requiring the interaction of many cognitive processes. It aims at producing a message to be imprinted as an ink trace left on a writing medium. The generated trajectory of the pen tip is made up of strokes superimposed over time. The Kinematic Theory of rapid human movements and its family of lognormal models provide analytical representations of these strokes, often considered as the basic unit of handwriting. This paradigm has not only been experimentally confirmed in numerous predictive and physiologically significant tests but it has also been shown to be the ideal mathematical description for the impulse response of a neuromuscular system. This latter demonstration suggests that the lognormality of the velocity patterns can be interpreted as reflecting the behavior of subjects who are in perfect control of their movements. To illustrate this interpretation, we present a short overview of the main concepts behind the Kinematic Theory and briefly describe how its models can be exploited, using various software tools, to investigate these ideal lognormal behaviors. We emphasize that the parameters extracted during various tasks can be used to analyze some underlying processes associated with their realization. To investigate the operational convergence hypothesis, we report on two original studies. First, we focus on the early steps of the motor learning process as seen as a converging behavior toward the production of more precise lognormal patterns as young children practicing handwriting start to become more fluent writers. Second, we illustrate how aging affects handwriting by pointing out the increasing departure from the ideal lognormal behavior as the control of the fine motricity begins to decline. Overall, the paper highlights this developmental process of merging toward a lognormal behavior with learning, mastering this behavior to succeed in performing a given task, and then gradually

  4. Enigmatic declines in bird numbers in lowland forest of eastern Ecuador may be a consequence of climate change.

    PubMed

    Blake, John G; Loiselle, Bette A

    2015-01-01

    Bird populations have declined in many parts of the world but most of those declines can be attributed to effects of human activities (e.g., habitat fragmentation); declines in areas unaffected by human activities are not common. We have been sampling bird populations at an undisturbed site in lowland forest of eastern Ecuador annually since 2001 using a combination of mist nets and direct observations on two 100-ha plots. Bird numbers fluctuated on both plots during the first 8 years but did not show a consistent pattern of change. Since about 2008, numbers of birds on both plots have declined; capture rates in 2014 were ∼40% less than at the start of the study and observation rates were ∼50% less. Both understory and canopy species declined in abundance. Overall, insectivores showed the most pronounced declines but declines varied among trophic groups. The period from 2008 onward also was a period of stronger La Niña events which, at this study site, are associated with increased rainfall. The mechanism for the declines is not known but likely reflects a combination of reduced reproductive success coupled with reduced survival associated with changing climate. PMID:26339554

  5. Enigmatic declines in bird numbers in lowland forest of eastern Ecuador may be a consequence of climate change

    PubMed Central

    Loiselle, Bette A.

    2015-01-01

    Bird populations have declined in many parts of the world but most of those declines can be attributed to effects of human activities (e.g., habitat fragmentation); declines in areas unaffected by human activities are not common. We have been sampling bird populations at an undisturbed site in lowland forest of eastern Ecuador annually since 2001 using a combination of mist nets and direct observations on two 100-ha plots. Bird numbers fluctuated on both plots during the first 8 years but did not show a consistent pattern of change. Since about 2008, numbers of birds on both plots have declined; capture rates in 2014 were ∼40% less than at the start of the study and observation rates were ∼50% less. Both understory and canopy species declined in abundance. Overall, insectivores showed the most pronounced declines but declines varied among trophic groups. The period from 2008 onward also was a period of stronger La Niña events which, at this study site, are associated with increased rainfall. The mechanism for the declines is not known but likely reflects a combination of reduced reproductive success coupled with reduced survival associated with changing climate. PMID:26339554

  6. A review of the role of contaminants in amphibian declines

    USGS Publications Warehouse

    Sparling, D.W.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John=

    2003-01-01

    CONCLUSIONS--Although there are no published studies that demonstrate beyond all doubt that contaminants are involved in long term population declines of amphibians, there is ample evidence and reason to encourage active research and concern about effects. Many contaminants are lethal to amphibians at environmentally realistic concentrations. Acute mortality from these compounds may be difficult to detect because investigators would have to be present shortly after exposures. Chronic mortality may be masked by metapopulation phenomena so that areas that serve as population sinks may be repeatedly recolonized and difficult to identify. Metapopulation dynamics also make it more difficult to define discrete populations. Contaminants also have many sublethal effects on behavior, energetics, malformations, and diverse effects on physiological pathways which, by themselves might not lead to overt death but could alter reproduction or interact with other factors to result in gradual declines in populations. Scientific understanding of these interactions, and of the ecotoxicology of amphibians in general is far behind what is known about birds, fish, and mammals, and research is desperately needed in this area. Some specific suggestions for critically needed research include: (1) Determination of lethal concentrations of common contaminants - pesticides, PAHs, metals--under environmentally realistic conditions of light, temperature, and water chemistry. (2) Better understanding of the effects of long term (weeks, months), low- concentration exposure of persistent pesticides and stable contaminants on amphibians. (3) Development and refinement of bioindicators in amphibians to use in monitoring and screening for potential effects of contaminants in declining amphibian populations. (4) Further studies on the interaction between contaminants and disease agents including immunosuppression in amphibians. (5) Additional research on the interaction between ultraviolet radiation

  7. Japan's declining fertility: "1.53 shock".

    PubMed

    Yanagishita, M

    1992-04-01

    In 1990, the Japanese were upset over the low 1989 total fertility rate (TFR) of 1.57 and continued to be so when they learned that the 1990 rate was even lower (1.53). This meant an annual population growth rate of only 0.33% with population decline beginning after 2010. In the early 1990s, Japan began to feel the demographic effects of such low fertility: a shortage of young workers and rising costs of health care for the elderly. Further, this shortage resulted in increasing business closings between 1988-1990 (1-6%). In 1990, the government began a survey to monitor the beliefs of the population on demographic concerns. The survey revealed that people wanted 2.2 children. Ideal family size was 2.6 which remained the same since 1977. Almost 40% found the falling TFR to be undesirable, especially because the population was aging. Moreover 65% of them though the government should undertake efforts to increase births. The major suggestions included reducing economic costs of raising a child (53%), a more favorable environment to have children such as affordable housing (29%), and developing child care facilities and child care leave (13%). 38% of 25-29 year old women were still unmarried, yet only 2% intended to never marry. Women in their late 20s and early 30s were critical of the 3 generation household with women doing all the housework. Women were more likely to be against premarital and extramarital sex than men. 25-33%, especially women 45 years old, felt the abortion law should be restricted. The 1990 abortion rate was 37.4/100 births. 7% relied on sterilization, yet 25-30% felt it to be an acceptable means of contraception. 75% of those that used a contraceptive used the condom. The government continued to ban oral contraceptives (OCs) claiming they would spread AIDS. Men were more in favor of OCs than women. 48% of those who found the falling population undesirable favored a pronatalist policy over importing foreign laborers. 41% wanted Japan to still help

  8. Anthropogenically-Mediated Density Dependence in a Declining Farmland Bird.

    PubMed

    Dunn, Jenny C; Hamer, Keith C; Benton, Tim G

    2015-01-01

    Land management intrinsically influences the distribution of animals and can consequently alter the potential for density-dependent processes to act within populations. For declining species, high densities of breeding territories are typically considered to represent productive populations. However, as density-dependent effects of food limitation or predator pressure may occur (especially when species are dependent upon separate nesting and foraging habitats), high territory density may limit per-capita productivity. Here, we use a declining but widespread European farmland bird, the yellowhammer Emberiza citrinella L., as a model system to test whether higher territory densities result in lower fledging success, parental provisioning rates or nestling growth rates compared to lower densities. Organic landscapes held higher territory densities, but nests on organic farms fledged fewer nestlings, translating to a 5 times higher rate of population shrinkage on organic farms compared to conventional. In addition, when parental provisioning behaviour was not restricted by predation risk (i.e., at times of low corvid activity), nestling provisioning rates were higher at lower territory densities, resulting in a much greater increase in nestling mass in low density areas, suggesting that food limitation occurred at high densities. These findings in turn suggest an ecological trap, whereby preferred nesting habitat does not provide sufficient food for rearing nestlings at high population density, creating a population sink. Habitat management for farmland birds should focus not simply on creating a high nesting density, but also on ensuring heterogeneous habitats to provide food resources in close proximity to nesting birds, even if this occurs through potentially restricting overall nest density but increasing population-level breeding success. PMID:26431173

  9. Anthropogenically-Mediated Density Dependence in a Declining Farmland Bird.

    PubMed

    Dunn, Jenny C; Hamer, Keith C; Benton, Tim G

    2015-01-01

    Land management intrinsically influences the distribution of animals and can consequently alter the potential for density-dependent processes to act within populations. For declining species, high densities of breeding territories are typically considered to represent productive populations. However, as density-dependent effects of food limitation or predator pressure may occur (especially when species are dependent upon separate nesting and foraging habitats), high territory density may limit per-capita productivity. Here, we use a declining but widespread European farmland bird, the yellowhammer Emberiza citrinella L., as a model system to test whether higher territory densities result in lower fledging success, parental provisioning rates or nestling growth rates compared to lower densities. Organic landscapes held higher territory densities, but nests on organic farms fledged fewer nestlings, translating to a 5 times higher rate of population shrinkage on organic farms compared to conventional. In addition, when parental provisioning behaviour was not restricted by predation risk (i.e., at times of low corvid activity), nestling provisioning rates were higher at lower territory densities, resulting in a much greater increase in nestling mass in low density areas, suggesting that food limitation occurred at high densities. These findings in turn suggest an ecological trap, whereby preferred nesting habitat does not provide sufficient food for rearing nestlings at high population density, creating a population sink. Habitat management for farmland birds should focus not simply on creating a high nesting density, but also on ensuring heterogeneous habitats to provide food resources in close proximity to nesting birds, even if this occurs through potentially restricting overall nest density but increasing population-level breeding success.

  10. Fibrosis with Inflammation at One Year Predicts Transplant Functional Decline

    PubMed Central

    Park, Walter D.; Griffin, Matthew D.; Cornell, Lynn D.; Cosio, Fernando G.

    2010-01-01

    Lack of knowledge regarding specific causes for late loss of kidney transplants hampers improvements in long-term allograft survival. Kidney transplants with both interstitial fibrosis and subclinical inflammation but not fibrosis alone after 1 year have reduced survival. This study tested whether fibrosis with inflammation at 1 year associates with decline of renal function in a low-risk cohort and characterized the nature of the inflammation. We studied 151 living-donor, tacrolimus/mycophenolate-treated recipients without overt risk factors for reduced graft survival. Transplants with normal histology (n = 86) or fibrosis alone (n = 45) on 1-year protocol biopsy had stable renal function between 1 and 5 years, whereas those with both fibrosis and inflammation (n = 20) exhibited a decline in GFR and reduced graft survival. Immunohistochemistry confirmed increased interstitial T cells and macrophages/dendritic cells in the group with both fibrosis and inflammation, and there was increased expression of transcripts related to innate and cognate immunity. Pathway- and pathologic process–specific analyses of microarray profiles revealed that potentially damaging immunologic activities were enriched among the overexpressed transcripts (e.g., Toll-like receptor signaling, antigen presentation/dendritic cell maturation, IFN-γ–inducible response, cytotoxic T lymphocyte–associated and acute rejection–associated genes). Therefore, the combination of fibrosis and inflammation in 1-year protocol biopsies associates with reduced graft function and survival as well as a rejection-like gene expression signature, even among recipients with no clinical risk factors for poor outcomes. Early interventions aimed at altering rejection-like inflammation may improve long-term survival of kidney allografts. PMID:20813870

  11. Anthropogenically-Mediated Density Dependence in a Declining Farmland Bird

    PubMed Central

    Dunn, Jenny C.; Hamer, Keith C.; Benton, Tim G.

    2015-01-01

    Land management intrinsically influences the distribution of animals and can consequently alter the potential for density-dependent processes to act within populations. For declining species, high densities of breeding territories are typically considered to represent productive populations. However, as density-dependent effects of food limitation or predator pressure may occur (especially when species are dependent upon separate nesting and foraging habitats), high territory density may limit per-capita productivity. Here, we use a declining but widespread European farmland bird, the yellowhammer Emberiza citrinella L., as a model system to test whether higher territory densities result in lower fledging success, parental provisioning rates or nestling growth rates compared to lower densities. Organic landscapes held higher territory densities, but nests on organic farms fledged fewer nestlings, translating to a 5 times higher rate of population shrinkage on organic farms compared to conventional. In addition, when parental provisioning behaviour was not restricted by predation risk (i.e., at times of low corvid activity), nestling provisioning rates were higher at lower territory densities, resulting in a much greater increase in nestling mass in low density areas, suggesting that food limitation occurred at high densities. These findings in turn suggest an ecological trap, whereby preferred nesting habitat does not provide sufficient food for rearing nestlings at high population density, creating a population sink. Habitat management for farmland birds should focus not simply on creating a high nesting density, but also on ensuring heterogeneous habitats to provide food resources in close proximity to nesting birds, even if this occurs through potentially restricting overall nest density but increasing population-level breeding success. PMID:26431173

  12. VASCULAR RISK FACTORS AND COGNITIVE DECLINE IN A POPULATION SAMPLE

    PubMed Central

    Ganguli, Mary; Fu, Bo; Snitz, Beth E.; Unverzagt, Frederick W.; Loewenstein, David A.; Hughes, Tiffany F.; Chang, Chung-Chou H.

    2014-01-01

    We examined several vascular factors in relation to rates of decline in five cognitive domains in a population-based cohort. In an age-stratified random sample (N=1982) aged 65+ years, we assessed at baseline the cognitive domains of attention, executive function, memory, language, and visuospatial function, and also vascular, inflammatory, and metabolic indices. Random effects models generated slopes of cognitive decline over the next four years; linear models identified vascular factors associated with these slopes, adjusting for demographics, baseline cognition, and potential interactions. Several vascular risk factors (history of stroke, diabetes, central obesity, C-Reactive Protein), although associated with lower baseline cognitive performance, did not predict rate of subsequent decline. APOE*4 genotype was associated with accelerated decline in language, memory, and executive functions. Homocysteine elevation was associated with faster decline in executive function. Hypertension (history or systolic blood pressure >140 mm) was associated with slower decline in memory. Baseline alcohol consumption was associated with slower decline in attention, language, and memory. Different indices of vascular risk are associated with low performance and with rates of decline in different cognitive domains. Cardiovascular mechanisms explain at least some of the variance in cognitive decline. Selective survival may also play a role. PMID:24126216

  13. Declinations in the Almagest: accuracy, epoch, and observers

    NASA Astrophysics Data System (ADS)

    Brandt, John C.; Zimmer, Peter; Jones, Patricia B.

    2014-11-01

    Almagest declinations attributed to Timocharis, Aristyllos, Hipparchus, and Ptolemy are investigated through comparisons of the reported declinations with the declinations computed from modern positions translated to the earlier epochs. Consistent results indicate an observational accuracy of ≈ 0.1° and epochs of: Timocharis, c. 298 BC; Aristyllos, c. 256 BC, and Hipparchus, c. 128 BC.The ≈ 42-year difference between Aristyllos and Timocharis is confirmed to be statistically significant. The declinations attributed to Ptolemy were likely two distinct groups—observations taken c. AD 57 and observations taken c. AD 128. The later observations could have been taken by Ptolemy himself.

  14. DDT residues and declining reproduction in the Bermuda petrel.

    PubMed

    Wurster, C F; Wingate, D B

    1968-03-01

    Residues of DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane] averaging 6.44 parts per million in eggs and chicks of the carnivorous Bermuda petrel indicate widespread contamination of an oceanic food chain that is remote from applications of DDT. Reproduction by the petrel has declined during the last 10 years at the annual rate of 3.25 percent; if the decline continues, reproduction will fail completely by 1978. Concentrations of residues are similar to those in certain terrestrial carnivorous birds whose productivity is also declining. Various considerations implicate contamination by insecticides as a probable major cause of the decline. PMID:5635996

  15. Hard Times in Mineral Valley: Rural Decline, Cooperation, and Survival in the Stafford School District.

    ERIC Educational Resources Information Center

    Miller, Bruce A.

    1990-01-01

    Reports on a case study of a rural school district in the U.S. northwest that coped with declining school population and loss of revenues because of closure of mining operations during the 1980s. The report analyzes the problem-solving and decision-making activities which encouraged grass-roots leadership and community cooperation. (SM)

  16. What's behind the Good News: The Decline in Teen Pregnancy Rates during the 1990s.

    ERIC Educational Resources Information Center

    Flanigan, Christine

    Noting that rates of teen pregnancies and births have declined over the past decade, this analysis examined how much of the progress is due to fewer teens having sex and how much to lower rates of pregnancy among sexually active teens. The analysis drew on data from the federal government's National Survey of Family Growth (NSFG), a large,…

  17. Explaining the Decline in Teen Labor Force Participation. Chicago Fed Letter. Number 234

    ERIC Educational Resources Information Center

    Aaronson, Daniel; Park, Kyung-Hong; Sullivan, Daniel

    2007-01-01

    Fewer teenagers are participating in the labor force today than at any point since WWII. At just under 44 percent teen labor force participation is 15 percentage points below its peak in the late 1970s. The authors investigate the long-run decline in the work activity of young adults, and the acceleration of this trend during the last five years.…

  18. Declining Use of Wild Resources by Indigenous Peoples of the Ecuadorian Amazon

    PubMed Central

    Gray, Clark L.; Bozigar, Matthew; Bilsborrow, Richard E.

    2015-01-01

    Wild product harvesting by forest-dwelling peoples, including hunting, fishing, forest product collection and timber harvesting, is believed to be a major threat to the biodiversity of tropical forests worldwide. Despite this threat, few studies have attempted to quantify these activities across time or across large spatial scales. We use a unique longitudinal household survey (n = 480) to describe changes in these activities over time in 32 indigenous communities from five ethnicities in the northern Ecuadorian Amazon. To provide insight into the drivers of these changes, we also estimate multilevel statistical models of these activities as a function of household and community characteristics. These analyses reveal that participation in hunting, fishing, and forest product collection is high but declining across time and across ethnicities, with no evidence for a parallel decline in resource quality. However, participation in timber harvesting did not significantly decline and there is evidence of a decline in resource quality. Multilevel statistical models additionally reveal that household and community characteristics such as ethnicity, demographic characteristics, wealth, livelihood diversification, access to forest, participation in conservation programs and exposure to external markets are significant predictors of wild product harvesting. These characteristics have changed over time but cannot account for declining participation in resource harvesting. This finding suggests that participation is declining due to changes in the regional-scale social and economic context, including urbanization and the expansion of government infrastructure and services. The lesson for conservationists is that macro-scale social and economic conditions can drive reductions in wild product harvesting even in the absence of successful conservation interventions. PMID:25620805

  19. Decline or Transformation of the Universities?

    ERIC Educational Resources Information Center

    Touraine, Alain

    1980-01-01

    Concentrates on the crisis of educational institutions, particularly at the university level. Information is presented on the professionalization of teaching, social change, increasing existence of nonuniversity research institutions, political activism, and prognosis for a renaissance of the universities. (Author/DB)

  20. Leading an Entrepreneurial Workforce: Development or Decline?

    ERIC Educational Resources Information Center

    Clargo, Paul; Tunstall, Richard

    2011-01-01

    Purpose: This paper analyses entrepreneurial activity within existing organisations. Research tends to limit entrepreneurial behaviour to owner-managers, corporate senior and middle managers and frequently presents intrapreneurship as a positive phenomenon. This paper seeks to broaden the focus of studies of intrapreneurship and corporate…

  1. Sex, Health Behaviors and Social Support: Functional Decline among Older Diabetics

    PubMed Central

    Nicklett, Emily Joy

    2013-01-01

    Problem statement Men and women experience pronounced differences in functional decline as they age. The mechanisms behind these differences remain unclear, particularly among chronically ill populations. Drawing on the theory of the disablement process, this research examines sex differences in functional decline, focusing on two mechanisms suggested by the literature to partially mediate these disparities: health behaviors and social support. Approach Data from diabetics aged 50 and older from the Health and Retirement Study (n = 2,493) were examined for change in functional status over a 10-year period. Multivariate longitudinal multi-level models were conducted to analyze (1) health behavior (2) social support; and (3) a full model with health behavior and social support together, followed by a separate analysis using sex interaction terms. Results Women and men both experienced functional decline over time. In the models that examined health behaviors and social support separately, women experienced steeper rates of decline. In the full model (which included health behaviors and social support together), men experienced a steeper rate of decline relative to women. The analyses suggest that it is the combination of health and social characteristics (largely through engagement in socially supportive activities that promote health) that are protective against functional decline. Conclusion/Recommendations As diabetic men experienced a steeper rate of functional decline than diabetic women once health behaviors and social support were both held constant, future research must examine (a) how these protective factors operate in tandem to protect against disablement of women with diabetes; and (b) how clinical and social policy can promote multi-pronged interventions to improve health behaviors in supportive contexts. Such research will benefit from multi-disciplinary collaborations. PMID:24358419

  2. Mobile technologies in the early detection of cognitive decline.

    PubMed

    Allard, Michèle; Husky, Mathilde; Catheline, Gwénaëlle; Pelletier, Amandine; Dilharreguy, Bixente; Amieva, Hélène; Pérès, Karine; Foubert-Samier, Alexandra; Dartigues, Jean-François; Swendsen, Joel

    2014-01-01

    The identification of biological and pathophysiological processes implicated in different forms of dementia is itself dependent on reliable descriptions of cognitive performance and capacities. However, traditional instruments are often unable to detect subtle declines in cognitive functions due to natural variation at the time of testing. Mobile technologies permit the repeated assessment of cognitive functions and may thereby provide more reliable descriptions of early cognitive difficulties that are inaccessible to clinic or hospital-based instruments. This assessment strategy is also able to characterize in real-time the dynamic associations between cognitive performance and specific daily life behaviors or activities. In a cohort of elderly rural residents, 60 individuals were administered neuropsychological and neuroimaging exams as well as a one-week period of electronic ambulatory monitoring of behavior, semantic memory performance, and daily life experiences. Whereas imaging markers were unrelated to traditional neuropsychological test scores, they were significantly associated with mobile assessments of semantic memory performance. Moreover, certain daily life activities such as reading or completing crossword puzzles were associated with increases in semantic memory performance over the subsequent hours of the same day. The revolution in mobile technologies provides unprecedented opportunities to overcome the barriers of time and context that characterize traditional hospital and clinical-based assessments. The combination of both novel and traditional methods should provide the best opportunity for identifying the earliest risk factors and biomarkers for Alzheimer's disease and other forms of dementia.

  3. Did the Decline in Social Connections Depress Americans' Happiness?

    ERIC Educational Resources Information Center

    Bartolini, Stefano; Bilancini, Ennio; Pugno, Maurizio

    2013-01-01

    During the last 30 years US citizens experienced, on average, a decline in reported happiness, social connections, and confidence in institutions. We show that a remarkable portion of the decrease in happiness is predicted by the decline in social connections and confidence in institutions. We carry out our investigation in three steps. First, we…

  4. Why have ovarian cancer mortality rates declined? Part I. Incidence.

    PubMed

    Sopik, Victoria; Iqbal, Javaid; Rosen, Barry; Narod, Steven A

    2015-09-01

    The age-adjusted mortality rate from ovarian cancer in the United States has declined over the past several decades. The decline in mortality might be the consequence of a reduced number of cases (incidence) or a reduction in the proportion of patients who die from their cancer (case-fatality). In part I of this three-part series, we examine rates of ovarian cancer incidence and mortality from the Surveillance Epidemiology and End Results (SEER) registry database and we explore to what extent the observed decline in mortality can be explained by a downward shift in the stage distribution of ovarian cancer (i.e. due to early detection) or by fewer cases of ovarian cancer (i.e. due to a change in risk factors). The proportion of localized ovarian cancers did not increase, suggesting that a stage-shift did not contribute to the decline in mortality. The observed decline in mortality paralleled a decline in incidence. The trends in ovarian cancer incidence coincided with temporal changes in the exposure of women from different birth cohorts to various reproductive risk factors, in particular, to changes in the use of the oral contraceptive pill and to declining parity. Based on recent changes in risk factor propensity, we predict that the trend of the declining age-adjusted incidence rate of ovarian cancer in the United States will reverse and rates will increase in coming years. PMID:26080287

  5. FACTORS IMPLICATED IN AMPHIBIAN POPULATION DECLINES IN THE UNITED STATES

    EPA Science Inventory

    This study identified the factors responsible for the decline of native amphibians in the U.S. The type of land use, the introduction of exotic animal species, and chemical contamination were identified as the most likely causes of decline.

  6. Creative Management in a Time of Economic Decline.

    ERIC Educational Resources Information Center

    Millett, John D.

    Economic decline is indicated by productivity per man-hour of work, per capita real personal income, and real gross national product. Unless new technology overcomes the force of a stable population and develops new sources of raw materials and of energy, economic decline seems a likely possibility. Creative management is a process of planning,…

  7. Declining Enrollments: Managing in the Period of Fiscal Retrenchment.

    ERIC Educational Resources Information Center

    Solomon, Margaret

    This guidebook for managing declining enrollment in an era of fiscal retrenchment is presented in three sections. Section 1 describes the extent of enrollment decline; analyzes its causes, including changes in birth rates, women's work roles, and migration and housing patterns; and explores its effects, including reduced school budgets and staffs,…

  8. Does Child Labor Decline with Improving Economic Status?

    ERIC Educational Resources Information Center

    Edmonds, Eric V.

    2005-01-01

    The rapid economic growth of Vietnam provides an interesting insight into the sharp decline in child labor. A study of the rising economic status of the population across Vietnam shows that children returned to school or stopped working as their family incomes grew. The decline in child labor is steep in poor households as they emerged from…

  9. Patterns of widespread decline in North American bumble bees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Declining abundance and range shifts of bumble bee (Bombus) species have been observed in Europe and Asia. However, the status of North America’s bumble bee species has been largely unstudied. Recent reports based on local or regional observations suggest that parallel declines are taking place in N...

  10. Patterns of widespread decline in North America bumble bees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Declining abundance and range shifts of bumble bee (Bombus) species have been observed in Europe and Asia. However, the status of North America’s bumble bee species has been largely unstudied. Recent reports based on local or regional observations suggest that parallel declines are taking place in N...

  11. The Decline of the Adult School Movement between the Wars

    ERIC Educational Resources Information Center

    Freeman, Mark

    2010-01-01

    This article considers the decline of the adult school movement, one of the largest voluntary movements in the history of adult education, and critically examines some of the reasons that have been used to explain it. It explores various features of the decline, using records of selected adult schools, and discussing variations by region and…

  12. AMPHIBIAN DECLINE, ULTRAVIOLET RADIATION AND LOCAL POPULATION ADAPTATION

    EPA Science Inventory

    Amphibian population declines have been noted on both local and global scales. Causes for these declines are unknown although many hypotheses have been offered. In areas adjacent to human development, loss of habitat is a fairly well accepted cause. However in isolated, seemingl...

  13. The SAT Score Decline: A Summary of Related Research.

    ERIC Educational Resources Information Center

    Breland, Hunter M.

    The available evidence pertaining to the decline in scores on the Scholastic Aptitude Test (SAT) and the American College Testing Program (ACT) is reviewed in terms of: the test, the test-taking population, the college bound population, the schools, and societal factors. The SAT score decline is described in both graphic and tabular form, and…

  14. Preventing Age-Related Decline of Gut Compartmentalization Limits Microbiota Dysbiosis and Extends Lifespan.

    PubMed

    Li, Hongjie; Qi, Yanyan; Jasper, Heinrich

    2016-02-10

    Compartmentalization of the gastrointestinal (GI) tract of metazoans is critical for health. GI compartments contain specific microbiota, and microbiota dysbiosis is associated with intestinal dysfunction. Dysbiosis develops in aging intestines, yet how this relates to changes in GI compartmentalization remains unclear. The Drosophila GI tract is an accessible model to address this question. Here we show that the stomach-like copper cell region (CCR) in the middle midgut controls distribution and composition of the microbiota. We find that chronic activation of JAK/Stat signaling in the aging gut induces a metaplasia of the gastric epithelium, CCR decline, and subsequent commensal dysbiosis and epithelial dysplasia along the GI tract. Accordingly, inhibition of JAK/Stat signaling in the CCR specifically prevents age-related metaplasia, commensal dysbiosis and functional decline in old guts, and extends lifespan. Our results establish a mechanism by which age-related chronic inflammation causes the decline of intestinal compartmentalization and microbiota dysbiosis, limiting lifespan. PMID:26867182

  15. Preventing Age-Related Decline of Gut Compartmentalization Limits Microbiota Dysbiosis and Extends Lifespan.

    PubMed

    Li, Hongjie; Qi, Yanyan; Jasper, Heinrich

    2016-02-10

    Compartmentalization of the gastrointestinal (GI) tract of metazoans is critical for health. GI compartments contain specific microbiota, and microbiota dysbiosis is associated with intestinal dysfunction. Dysbiosis develops in aging intestines, yet how this relates to changes in GI compartmentalization remains unclear. The Drosophila GI tract is an accessible model to address this question. Here we show that the stomach-like copper cell region (CCR) in the middle midgut controls distribution and composition of the microbiota. We find that chronic activation of JAK/Stat signaling in the aging gut induces a metaplasia of the gastric epithelium, CCR decline, and subsequent commensal dysbiosis and epithelial dysplasia along the GI tract. Accordingly, inhibition of JAK/Stat signaling in the CCR specifically prevents age-related metaplasia, commensal dysbiosis and functional decline in old guts, and extends lifespan. Our results establish a mechanism by which age-related chronic inflammation causes the decline of intestinal compartmentalization and microbiota dysbiosis, limiting lifespan.

  16. National Survey of Geriatricians to Define Functional Decline in Elderly People with Minor Trauma

    PubMed Central

    Abdulaziz, Kasim; Perry, Jeffrey J.; Taljaard, Monica; Émond, Marcel; Lee, Jacques S.; Wilding, Laura; Sirois, Marie-Josée; Brehaut, Jamie

    2016-01-01

    Background This study was designed to determine a clinically significant point drop in function to define functional decline and the required sensitivity for a clinical decision tool to identify elderly patients at high risk of functional decline following a minor injury. Methods After a rigorous development process, a survey questionnaire was administered to a random sample of 178 geriatricians selected from those registered in a national medical directory. The surveys were distributed using a modified Dillman technique. Results We obtained a satisfactory response rate of 70.5%. Ninety percent of the geriatricians required a sensitivity of 90% or less for a clinical decision tool to identify injured seniors at high risk of functional decline 6 months post injury. Our results indicate that 90% of the respondents considered a drop in function of at least 2 points in activities of daily living (ADL) as clinically significant when considering all 14 ADL items. Considering only the 7 basic ADL items, 90% of physicians considered a 1 point drop as clinically significant. Conclusions A tool with a sensitivity of 90% to detect patients at risk of functional decline at 6 months post minor injury would meet or exceed the sensitivity required by 90% of geriatric specialists. These findings clearly define what is a clinically significant decline following a “minor injury.” PMID:27076859

  17. Geological reasons causing rapid rate decline. A case study of Field T, Russia

    NASA Astrophysics Data System (ADS)

    Kuzmin, S.; Rukavishnikov, V.; Sukovatyi, V.

    2015-02-01

    The paper introduces the complex approach to determining possible geological reasons causing rate decline in the wells of Field T, Russia. Therefore, possible geological reasons are sequentially considered and were divided into three main groups: 1) rate decline due to poorer reservoir quality; 2) rate decline due to facies lateral substitution; 3) rate decline due to active fault tectonics. The most appropriate facies models were constructed on the basis of all available data. Besides, in this study, core, well logging, seismic and well test data were integrated for the fullest reservoir characterization. The core from several recently drilled wells was described in detail to determine clue features. Further, seismic data were interpreted: structural interpretation, including faults and attribute analysis, was implemented. Appropriate electrofacies models were chosen as well. At the final stage, all previously-mentioned data were integrated with appropriate facies model construction. However, as it turned out later, the facies model was not the key factor affecting the rapid decline that appeared in some wells. It is suggested that very proximal faults can be a possible explanation. To confirm this suggestion, well test data were additionally used and both analytical and numerical methods were applied to show the consistency of this theory.

  18. Explaining the Decline in Mexico-U.S. Migration: The Effect of the Great Recession

    PubMed Central

    Villarreal, Andrés

    2014-01-01

    The rate of Mexico-U.S. migration has declined precipitously in recent years. From 25 migrants per thousand in 2005, the annual international migration rate for Mexican men dropped to 7 per thousand by 2012. If sustained, this low migration rate is likely to have a profound effect on the ethnic and national-origin composition of the U.S. population. This study examines the origins of the migration decline using a nationally representative panel survey of Mexican households. The results support an explanation that attributes a large part of the decline to lower labor demand for Mexican immigrants in the United States. Decreases in labor demand in industrial sectors that employ a large percentage of Mexican-born workers, such as construction, are found to be strongly associated with lower rates of migration for Mexican men. Second, changes in migrant selectivity are also consistent with an economic explanation for the decline in international migration. The largest declines in migration occurred precisely among the demographic groups most affected by the Great Recession: namely, economically active young men with low education. Results from the statistical analysis also show that the reduction in labor demand in key sectors of the U.S. economy resulted in a more positive educational selectivity of young migrants. PMID:25407844

  19. Characterizing declines in pediatric antidepressant use after new risk disclosures

    PubMed Central

    Frank, Richard G.; Martin, Andres; Barry, Colleen L.

    2010-01-01

    Steep declines in pediatric antidepressant use were documented following the 2004 release of new safety information associating antidepressants with a risk of suicidality. We examine whether declines in pediatric antidepressant use were steeper among individuals with certain clinical or family characteristics. We find that declines in antidepressant use were associated with new (as compared to ongoing) treatment episodes. Also, although rates of antidepressant use were higher among children of college educated parents prior to risk disclosures, these children were more likely to forgo antidepressant medication than children of less educated parents after risk disclosures. We find that both children with and without psychiatric impairment experienced declines in antidepressant medication use following the risk warnings, although the decline occurred more quickly in the latter group. Our findings highlight the need for additional data to assess the effects of risk disclosures on treatment patterns and health outcomes. PMID:20675349

  20. Declining coral calcification on the Great Barrier Reef.

    PubMed

    De'ath, Glenn; Lough, Janice M; Fabricius, Katharina E

    2009-01-01

    Reef-building corals are under increasing physiological stress from a changing climate and ocean absorption of increasing atmospheric carbon dioxide. We investigated 328 colonies of massive Porites corals from 69 reefs of the Great Barrier Reef (GBR) in Australia. Their skeletal records show that throughout the GBR, calcification has declined by 14.2% since 1990, predominantly because extension (linear growth) has declined by 13.3%. The data suggest that such a severe and sudden decline in calcification is unprecedented in at least the past 400 years. Calcification increases linearly with increasing large-scale sea surface temperature but responds nonlinearly to annual temperature anomalies. The causes of the decline remain unknown; however, this study suggests that increasing temperature stress and a declining saturation state of seawater aragonite may be diminishing the ability of GBR corals to deposit calcium carbonate.

  1. Recent fertility declines in China and India: a comparative view.

    PubMed

    Kulkarni, P M; Rani, S

    1995-12-01

    This paper compares fertility transitions in China and parts of India. It is argued that China experienced a more rapid and more "impressive" decline than that of India. Socioeconomic conditions in China were more conducive to fertility decline. Kerala State in India experienced a similar decline as China but at a slower pace. The birth control campaign in China is credited with an important role in speeding the transition. It is posited that the political and administrative system and economic conditions in India are not compatible with the Chinese style program strategies. Both countries had similar fertility levels in the immediate post-revolutionary period. The most rapid decline occurred during the 1970s in China. The fertility transition was almost completed by 1981. In India, the total fertility rate (TFR) declined by only 1 point between the 1950s and 1981. In China TFR declined over 3 points during 1970-81. 76.7% of the decline in China during 1970-81 is attributed to a marked decline in marital fertility in all age groups, with the exception of ages 15-19 years. The decline in India is attributed to the decline in marital fertility. Female age at marriage rose in India, but less "impressively." In 1981 the mean age at marriage in India was 18.4 years, but it was 22.8 years in China. Marital fertility among women aged older than 30 years was considerably lower in China. Both countries experienced an increase in literacy, but in China the level of literacy was much greater. Both countries faced food shortages, but China improved food availability and calorie consumption per capita. Health services also improved in both countries, but the Chinese system of "barefoot" doctors brought services with easier reach of rural populations. Political structures differed in their dominance and organization. Family planning programs were introduced earlier in India, but prevalence was 64.4% in China in 1981 and about 22% in India.

  2. EEG markers for cognitive decline in elderly subjects with subjective memory complaints.

    PubMed

    Alexander, David M; Arns, Martijn W; Paul, Robert H; Rowe, Donald L; Cooper, Nicholas; Esser, Aristide H; Fallahpour, Kamran; Stephan, Blossom C M; Heesen, Erica; Breteler, Rien; Williams, Leanne M; Gordon, Evian

    2006-03-01

    New treatments for Alzheimer's disease require early detection of cognitive decline. Most studies seeking to identify markers of early cognitive decline have focused on a limited number of measures. We sought to establish the profile of brain function measures which best define early neuropsychological decline. We compared subjects with subjective memory complaints to normative controls on a wide range of EEG derived measures, including a new measure of event-related spatio-temporal waves and biophysical modeling, which derives anatomical and physiological parameters based on subject's EEG measurements. Measures that distinguished the groups were then related to cognitive performance on a variety of learning and executive function tasks. The EEG measures include standard power measures, peak alpha frequency, EEG desynchronization to eyes-opening, and global phase synchrony. The most prominent differences in subjective memory complaint subjects were elevated alpha power and an increased number of spatio-temporal wave events. Higher alpha power and changes in wave activity related most strongly to a decline in verbal memory performance in subjects with subjective memory complaints, and also declines in maze performance and working memory reaction time. Interestingly, higher alpha power and wave activity were correlated with improved performance in reverse digit span in the subjective memory complaint group. The modeling results suggest that differences in the subjective memory complaint subjects were due to a decrease in cortical and thalamic inhibitory gains and slowed dendritic time-constants. The complementary profile that emerges from the variety of measures and analyses points to a nonlinear progression in electrophysiological changes from early neuropsychological decline to late-stage dementia, and electrophysiological changes in subjective memory complaint that vary in their relationships to a range of memory-related tasks. PMID:16544366

  3. Decline in relative abundance of bottlenose dolphins exposed to long-term disturbance.

    PubMed

    Bejder, Lars; Samuels, Amy; Whitehead, Hal; Gales, Nick; Mann, Janet; Connor, Richard; Heithaus, Mike; Watson-Capps, Jana; Flaherty, Cindy; Krützen, Michael

    2006-12-01

    Studies evaluating effects of human activity on wildlife typically emphasize short-term behavioral responses from which it is difficult to infer biological significance or formulate plans to mitigate harmful impacts. Based on decades of detailed behavioral records, we evaluated long-term impacts of vessel activity on bottlenose dolphins (Tursiops sp.) in Shark Bay, Australia. We compared dolphin abundance within adjacent 36-km2 tourism and control sites, over three consecutive 4.5-year periods wherein research activity was relatively constant but tourism levels increased from zero, to one, to two dolphin-watching operators. A nonlinear logistic model demonstrated that there was no difference in dolphin abundance between periods with no tourism and periods in which one operator offered tours. As the number of tour operators increased to two, there was a significant average decline in dolphin abundance (14.9%; 95% CI=-20.8 to -8.23), approximating a decline of one per seven individuals. Concurrently, within the control site, the average increase in dolphin abundance was not significant (8.5%; 95% CI=-4.0 to +16.7). Given the substantially greater presence and proximity of tour vessels to dolphins relative to research vessels, tour-vessel activity contributed more to declining dolphin numbers within the tourism site than research vessels. Although this trend may not jeopardize the large, genetically diverse dolphin population of Shark Bay, the decline is unlikely to be sustainable for local dolphin tourism. A similar decline would be devastating for small, closed, resident, or endangered cetacean populations. The substantial effect of tour vessels on dolphin abundance in a region of low-level tourism calls into question the presumption that dolphin-watching tourism is benign.

  4. Decline and Local Extinction of Caribbean Eusocial Shrimp

    PubMed Central

    Duffy, J. Emmett; Macdonald III, Kenneth S.; Hultgren, Kristin M.; Chak, Tin Chi Solomon; Rubenstein, Dustin R.

    2013-01-01

    The tropical shrimp genus Synalpheus includes the only eusocial marine animals. In much of the Caribbean, eusocial species have dominated the diverse fauna of sponge-dwelling shrimp in coral rubble for at least the past two decades. Here we document a recent, dramatic decline and apparent local extinction of eusocial shrimp species on the Belize Barrier Reef. Our collections from shallow reefs in central Belize in 2012 failed to locate three of the four eusocial species formerly abundant in the area, and showed steep declines in colony size and increases in frequency of queenless colonies prior to their disappearance. Concordant with these declines, several nonsocial, pair-forming Synalpheus species increased in frequency. The decline in eusocial shrimp is explained in part by disappearance of two sponge species on which they specialize. Eusocial shrimp collections from Jamaica in 2012 showed similar patterns of decline in colony size and increased queenlessness compared with prior Jamaican collections. The decline and local extinction of eusocial shrimp happened against a backdrop of changes in coral assemblages during recent decades, and may reflect changes in abundance and quality of dead coral substratum and succession of the diverse cryptic organisms living within it. These changes document potentially worrisome declines in a unique taxon of eusocial marine animals. PMID:23418429

  5. UV-B Radiation Contributes to Amphibian Population Declines

    NASA Astrophysics Data System (ADS)

    Blaustein, Andrew

    2007-05-01

    UV-B (280-315 nm) radiation is the most significant biologically damaging radiation at the terrestrial surface. At the organismal level, UV-B radiation can slow growth rates, cause immune dysfunction and result in sublethal damage. UV-B radiation can lead to mutations and cell death. Over evolutionary time, UV radiation has been an important stressor on living organisms. Natural events, including impacts from comets and asteroids, volcanic activity, supernova explosions and solar flares, can cause large-scale ozone depletion with accompanying increases in UV radiation. However, these natural events are transient. Moreover, the amount of ozone damage due to natural events depends upon a number of variables, including the magnitude of the event. This is different from modern-day human-induced production of chlorofluorocarbons (CFCs) and other chemicals that deplete stratospheric ozone continuously, resulting in long-term increases in UV-B radiation at the surface of the earth. We will briefly review the effects of UV-B exposure in one group of aquatic organisms_amphibians. UV-B has been implicated as a possible factor contributing to global declines and range reductions in amphibian populations.

  6. Chesapeake Bay watershed pesticide use declines but toxicity increases.

    PubMed

    Hartwell, S Ian

    2011-05-01

    Large areas of the Chesapeake Bay, USA, watershed are in agricultural land use, but there is no baywide program to track application rates of current-use pesticides in any of the watershed jurisdictions. Watershed studies demonstrate that several pesticides are present in surface and groundwater throughout the region. Between 1985 and 2004, the Maryland Department of Agriculture conducted surveys to estimate pesticide application within the state. Application rates of the dominant insecticides and herbicides were compiled over the survey period. Toxicity of the pesticides was tabulated, and the toxic units (TU) of applied active ingredients were calculated for several animal and plant species. The total mass of pesticides being applied to the watershed declined during the survey period. Due to increasing potency of the chemicals, however, total TUs applied have remained static or have significantly increased depending on the species of bioassay test organism used to assess toxicity. Applying estimates of pesticide transport into rivers in the Mississippi River basin show that significant quantities of pesticides may be entering Chesapeake Bay.

  7. Methylprednisolone in patients with membranous nephropathy and declining renal function.

    PubMed

    Short, C D; Solomon, L R; Gokal, R; Mallick, N P

    1987-11-01

    Fifteen consecutive patients aged 24 to 70 years, with membranous nephropathy and a progressive decline in renal function, were treated with methylprednisolone, 1 g intravenously daily for five days, followed immediately by a tapering dose of oral prednisolone. Plasma creatinine levels fell by a mean of 46 per cent (range 21-65). In 10 patients the beneficial effect was sustained, but in three it had reversed by six months. In the other two patients the progressive decline of renal function was not influenced. These observations suggest that many patients with membranous nephropathy and declining renal function could benefit from intervention with high dose steroids. PMID:3455548

  8. Decline and demand for petroleum. [USA

    SciTech Connect

    Card, A.M.

    1982-04-01

    Increased supplies and the lowered demand have moved the international oil markets into the current surplus condition. In the United States, the higher prices for petroleum products during 1979 to 80 have spawned a new consumer ethic. US oil consumption has dropped dramatically as motorists, homeowners, and industries are using less energy and finding ways to use it more eficiently. Smaller, more fuel-efficient furnaces and conversion to other fuels have all decreased petroleum demand. Total crude oil consumption has dropped by 13 percent. In the 18-month period ending in September, 1981, industries cut back petroleum use from 38% to 21%. In addition, the consumption of coal, our most abundant energy source, has increased slightly during the past year. Higher prices also have given a direct stimulus to drilling and exploration activities. In 1980, a 24-year-old record was broken when more than 60,000 wells were drilled. The 1981 pace averaged about 27 percent ahead of 1980's record. By conserving, converting, and maintaining its production, the United States has managed to cut its imports of oil from over 8 million barrels a day in 1979 to an average of about 5 million barrels a day in 1981-a reduction of more than 30 percent. That difference would have cost Americans more than $35 billion a year or close to $500 for every household.

  9. Event- and time-dependent decline of outcome information in the primate prefrontal cortex.

    PubMed

    Marcos, Encarni; Tsujimoto, Satoshi; Genovesio, Aldo

    2016-05-10

    The prefrontal cortex (PF) is involved in outcome-based flexible adaptation in a dynamically changing environment. The outcome signal dissipates gradually over time, but the temporal dynamics of this dissipation remains unknown. To examine this issue, we analyzed the outcome-related activity of PF neurons in 2 monkeys in a distance discrimination task. The initial prestimulus period of this task varied in duration, allowing us to dissociate the effects of time and event on the decline in previous outcome-related activity -previous correct versus previous error. We observed 2 types of decline in previous outcome representation: PF neurons that ceased to encode the previous outcome as time passed (time-dependent) and neurons that maintained their signal but it decreased rapidly after the occurrence of a new external event (event-dependent). Although the time-dependent dynamics explained the decline in a greater proportion of neurons, the event-dependent decline was also observed in a significant population of neurons.

  10. Event- and time-dependent decline of outcome information in the primate prefrontal cortex

    PubMed Central

    Marcos, Encarni; Tsujimoto, Satoshi; Genovesio, Aldo

    2016-01-01

    The prefrontal cortex (PF) is involved in outcome-based flexible adaptation in a dynamically changing environment. The outcome signal dissipates gradually over time, but the temporal dynamics of this dissipation remains unknown. To examine this issue, we analyzed the outcome-related activity of PF neurons in 2 monkeys in a distance discrimination task. The initial prestimulus period of this task varied in duration, allowing us to dissociate the effects of time and event on the decline in previous outcome-related activity —previous correct versus previous error. We observed 2 types of decline in previous outcome representation: PF neurons that ceased to encode the previous outcome as time passed (time-dependent) and neurons that maintained their signal but it decreased rapidly after the occurrence of a new external event (event-dependent). Although the time-dependent dynamics explained the decline in a greater proportion of neurons, the event-dependent decline was also observed in a significant population of neurons. PMID:27162060

  11. Terminal Decline in Well-Being: The Role of Social Orientation

    PubMed Central

    Gerstorf, Denis; Hoppmann, Christiane A.; Löckenhoff, Corinna E.; Infurna, Frank J.; Schupp, Jürgen; Wagner, Gert G.; Ram, Nilam

    2016-01-01

    Well-being development at the end of life is often characterized by steep deteriorations, but individual differences in these terminal declines are substantial and not yet well understood. This study moved beyond the typical consideration of health predictors and explored the role of social orientation and engagement. To do so, we made use of social variables at the behavioral level (self-ratings of social participation) and the motivational level (valuing social and family goals), assessed two to four years before death. We applied single- and multi-phase growth models to up to 27-year annual longitudinal data from 2,910 now deceased participants of the nation-wide German Socio-Economic Panel Study (SOEP; age at death: M = 74 years; SD = 14; 48% women). Results revealed that leading a socially active life and prioritizing social goals in late life were independently associated with higher late-life well-being, less pronounced late-life decline, and a later onset of terminal decline. Significant interaction effects suggested that the effects of (reduced) social participation and (lowered) social goals were compounding each other.compound. Findings also indicated that less decline in social participation was associated with shallower rates and a later onset of well-being decline. We found little evidence that valuing family goals is associated with late-life trajectories of well-being. Associations were independent of key correlates of well-being and mortality, including age at death, gender, education, disability, hospital stays, and goals in other life domains. We discuss possible pathways by which maintaining social orientation into late life may help mitigate terminal decline in well-being. PMID:26950226

  12. Trajectory of functional decline before and after ischemic stroke: The Northern Manhattan Study

    PubMed Central

    Dhamoon, Mandip S.; Moon, Yeseon Park; Paik, Myunghee C.; Sacco, Ralph L.; Elkind, Mitchell S. V.

    2012-01-01

    Background Previous research in our cohort showed a delayed decline in functional status after first ischemic stroke. We compared the long-term trajectory of functional status before and after ischemic stroke. Methods The Northern Manhattan Study contains a prospective, population-based study of stroke-free individuals >40 years of age, followed for a median 11 years. The Barthel index (BI), a commonly used measure of activities of daily living, was assessed annually. Generalized estimating equations were used to assess functional decline over time before and beginning 6 months after stroke. Follow-up was censored at the time of recurrent stroke. Results Among 3298 participants, 210 had an ischemic stroke during follow-up and had post-stroke BI assessed. Mean age (+standard deviation) was 77+9 years, 38% were male, 52% were Hispanic, 37% had diabetes, and 31% had coronary artery disease. There was no difference in rate of functional decline over time before and after stroke (p=0.51), with a decline of 0.96 BI points per year before stroke (p<.0001) and 1.24 after stroke (p=0.001). However, when stratified by insurance status, among those with Medicaid or no insurance, in a fully adjusted model, there was a difference in slope before and after stroke (p=0.04), with a decline of 0.58 BI points per year before stroke (p=0.02) and 1.94 after stroke (p=0.001). Conclusions In this large, prospective, population-based study with long-term follow-up, there was a significantly steeper decline in functional status after ischemic stroke compared to before stroke among those with Medicaid or no insurance, after adjusting for confounders. PMID:22649168

  13. Reconciling divergent interpretations of quaking aspen decline on the northern Colorado Front Range.

    PubMed

    Kashian, Daniel M; Romme, William H; Regan, Claudia M

    2007-07-01

    Ecologists have debated over the past 65 years whether quaking aspen (Populus tremuloides Michx.) has or has not declined in abundance, vigor, or regeneration in western North America. Many studies have provided divergent interpretations of the condition of aspen forests, leading to difficulty in translating this ecological information into management recommendations. To reconcile these contrasting conclusions and to test the hypothesis that multiple types of aspen decline and persistence occur simultaneously on heterogeneous landscapes, we assessed 91 aspen stands across the northern Colorado Front Range to determine the range of ecological conditions that underlie aspen decline or persistence. Approximately 15% of aspen forest area in our sample exhibited dieback of mature stems coupled with a lack of young trees indicative of declining stands, most often at lower elevations where elk browsing is heavy and chronic, and where effects of fire exclusion have been most significant. However, 52% of the area sampled had multiple cohorts indicative of self-replacing or persistent stands. Conifer dominance was increasing in over 33% of all aspen forest area sampled, most often at high elevations among lodgepole pine (Pinus contorta var. latifolia Englem. ex Wats.) forests. Reconstructions of relative basal area and density of aspen and lodgepole pine in these stands suggest cyclical dominance of these species, where conifers gradually replace aspen over long fire intervals, and aspen vigorously re-establish following stand-replacing fires. The diversity of ecological contexts across the northern Colorado Front Range creates a variety of aspen dynamics leading to decline or persistence, and no single trend describes the general condition of aspen forests in appropriate detail for managers. Active management may be useful in preserving individual stands at fine scales, but management prescriptions should reflect specific drivers of decline in these stands.

  14. Clinically important FEV1 declines among coal miners: an exploration of previously unrecognised determinants

    PubMed Central

    Wang, M. L.; Petsonk, E. L.; Beeckman, L. A.; Wagner, G. R.

    1999-01-01

    OBJECTIVES: The relation between occupational exposure to dust and loss of ventilatory lung function is now well established. However, many exposures during work and other activities might also have important roles in determining clinically important losses of lung function. In this study, we attempted to explore additional plausible determinants of exposures and other potential risk factors for clinically important decline in forced expiratory volume in 1 second (FEV1) during work in dusty trades. METHODS: The study was performed in 264 underground coal miners whose lung function had been followed up for an average of 11 years. With an extensive follow up questionnaire, miners were asked about their occupational and non-occupational exposures, smoking, personal and family medical history, and living conditions during childhood. RESULTS: Several variables of the mine environment (as well as previously recognised effects of mining work and region) were found to be associated with excess decline in FEV1, including work in roof bolting, exposure to explosive blasting, and to control dust spraying water that had been stored in holding tanks. Use of respiratory protection seemed to reduce the risk of decline in FEV1. Other factors that were found to be associated with declines in pulmonary function included smoking, body mass, weight gain, childhood pneumonia, and childhood exposure in the home to passive tobacco smoke and possibly smoke due to wood and coal fuels. Miners with excessive decline in FEV1 were less likely to be working in mining jobs at follow up. CONCLUSIONS: These findings suggest the existence of additional risk factors for decline in lung function in dusty trades, and may be useful in developing additional approaches to the prevention of chronic respiratory disease.   PMID:10658541

  15. Terminal decline in well-being: The role of social orientation.

    PubMed

    Gerstorf, Denis; Hoppmann, Christiane A; Löckenhoff, Corinna E; Infurna, Frank J; Schupp, Jürgen; Wagner, Gert G; Ram, Nilam

    2016-03-01

    Well-being development at the end of life is often characterized by steep deteriorations, but individual differences in these terminal declines are substantial and not yet well understood. This study moved beyond typical consideration of health predictors and explored the role of social orientation and engagement. To do so, we used social variables at the behavioral level (self-ratings of social participation) and the motivational level (valuing social and family goals), assessed 2 to 4 years before death. We applied single- and multiphase growth models to up to 27-year annual longitudinal data from 2,910 now deceased participants of the nation-wide German Socio-Economic Panel Study (Mage at death = 74 years; SD = 14; 48% women). Results revealed that leading a socially active life and prioritizing social goals in late life were independently associated with higher late-life well-being, less pronounced late-life decline, and a later onset of terminal decline. Significant interaction effects suggested that the combination of (reduced) social participation and (lowered) social goals magnifies the effects of each other. Findings also indicated that less decline in social participation was associated with less severe rates and a later onset of well-being decline. We found little evidence that valuing family goals is associated with late-life trajectories of well-being. Associations were independent of key correlates of well-being and mortality, including age at death, gender, education, disability, hospital stays, and goals in other life domains. We discuss possible pathways by which maintaining social orientation into late life may help mitigate terminal decline in well-being. PMID:26950226

  16. Which Language Declines More? Longitudinal versus Cross-Sectional Decline of Picture Naming in Bilinguals with Alzheimer’s Disease

    PubMed Central

    Ivanova, Iva; Salmon, David P.; Gollan, Tamar H.

    2014-01-01

    In this study, we investigated dual-language decline in non-balanced bilinguals with probable Alzheimer’s Disease (AD) both longitudinally and cross-sectionally. We examined patients’ naming accuracy on the Boston Naming Test (BNT: Kaplan et al., 1983) over three testing sessions (longitudinal analysis) and compared their performance to that of matched controls (cross-sectional analysis). We found different longitudinal and cross-sectional patterns of decline: Longitudinally, the non-dominant language seemed to decline more steeply than the dominant language, but, cross-sectionally, differences between patients and controls were larger for the dominant than for the non-dominant language, especially at the initial testing session. This differential pattern of results for cross-sectional versus longitudinal decline was supported by correlations between decline measures and BNT item characteristics. Further studies will be needed to better characterize the nature of linguistic decline in bilinguals with AD; however, these results suggest that representational robustness of individual lexical representations, rather than language membership, might determine the time course of decline for naming in bilinguals with AD. PMID:24725624

  17. Declined Neural Efficiency in Cognitively Stable Human Immunodeficiency Virus Patients

    PubMed Central

    Ernst, Thomas; Yakupov, Renat; Nakama, Helenna; Crocket, Grace; Cole, Michael; Watters, Michael; Ricardo-Dukelow, Mary Lynn; Chang, Linda

    2009-01-01

    Objective To determine whether brain activation changes in clinically and neurocognitively normal human immunodeficiency virus (HIV)–infected and in HIV-seronegative control (SN) participants over a 1-year period. Methods Functional magnetic resonance imaging (fMRI) was performed in 32 SN and 31 HIV patients (all with stable combination antiretroviral treatment) at baseline and after 1 year. Each participant performed a set of visual attention tasks with increasing attentional load (from tracking two, three, or four balls). All HIV and SN participants had normal neuropsychological function at both examinations. Results Over 1 year, HIV patients showed no change in their neurocognitive status or in task performance during fMRI. However, HIV patients showed significant 1-year increases in fMRI signals in the prefrontal and posterior parietal cortices for the more difficult tasks, whereas SN control participants showed only decreases in brain activation in these regions. This resulted in significant interactions between HIV status and time of study in left insula, left parietal, left temporal, and several frontal regions (left and right middle frontal gyrus, and anterior cingulate). Interpretation Because fMRI task performance remained unchanged in both groups, the HIV patients appeared to maintain performance by increasing usage of the attention network, whereas the control participants reduced usage of the attention network after 1 year. These findings suggest improved efficiency or a practice effect in the SN participants but declined efficiency of the neural substrate in HIV patients, possibly because of ongoing brain injury associated with the HIV infection, despite their apparent stable clinical course. PMID:19334060

  18. A Decline in Numeracy Skills among Bioscience Undergraduates.

    ERIC Educational Resources Information Center

    Tariq, Vicki N.

    2002-01-01

    Provides evidence of a decline in basic numeracy skills among first-year bioscience undergraduate students. Tests conceptualized numeracy skills which form a component of an introductory microbiology module. (Contains 23 references.) (Author/YDS)

  19. ALIEN SPECIES: THEIR ROLE IN AMPHIBIAN POPULATION DECLINES AND RESTORATION

    EPA Science Inventory

    Alien species (also referred to as exotic, invasive, introduced, or normative species) have been implicated as causal agents in population declines of many amphibian species. Herein, we evaluate the relative contributions of alien species and other factors in adversely affecting ...

  20. The Box Turtle: Room with a View on Species Decline.

    ERIC Educational Resources Information Center

    Belzer, Bill; Steisslinger, Mary Beth

    1999-01-01

    Surveys salient aspects of eastern box-turtle natural history. Explores the societal and ecological factors that have contributed to the decline of the box-turtle population. Contains 18 references. (WRM)

  1. When can the cause of a population decline be determined?

    USGS Publications Warehouse

    Hefley, Trevor J.; Hooten, Mevin B.; Drake, John M.; Russell, Robin E.; Walsh, Daniel P.

    2016-01-01

    Inferring the factors responsible for declines in abundance is a prerequisite to preventing the extinction of wild populations. Many of the policies and programmes intended to prevent extinctions operate on the assumption that the factors driving the decline of a population can be determined. Exogenous factors that cause declines in abundance can be statistically confounded with endogenous factors such as density dependence. To demonstrate the potential for confounding, we used an experiment where replicated populations were driven to extinction by gradually manipulating habitat quality. In many of the replicated populations, habitat quality and density dependence were confounded, which obscured causal inference. Our results show that confounding is likely to occur when the exogenous factors that are driving the decline change gradually over time. Our study has direct implications for wild populations, because many factors that could drive a population to extinction change gradually through time.

  2. DECLINE IN LAKE ONTARIO POPULATIONS OF BENTHIC MACROINVERTEBRATES

    EPA Science Inventory

    Surveys of benthic macroinvertebrates conducted in Lake Ontario during 1994 and 1997 revealed declines in populations of three major groups of organisms: oligochaetes, sphariids, and Diporeia spp. (Amphipoda), with the most drastic reductions occurring in the latter. Based on phy...

  3. Decline in bloater fecundity in Southern Lake Michigan after decline of Diporeia

    USGS Publications Warehouse

    Bunnell, D.B.; David, S.R.; Madenjian, C.P.

    2009-01-01

    Population fecundity can vary through time, sometimes owing to changes in adult condition. Consideration of these fecundity changes can improve understanding of recruitment variation. Herein, we estimated fecundity of Lake Michigan bloater Coregonus hoyi during December 2005 and February 2006. Bloater recruitment has been highly variable from 1962 to present, and consistently poor since 1992. We compared our fecundity vs. weight regression to a previously published regression that used fish sampled in October 1969. We wanted to develop a new regression for two reasons. First, it should be more accurate because it uses fish collected closer to spawning, thus minimizing the potential for atresia (egg reabsorption) which could bias fecundity high. Second, we hypothesized that fecundity would be lower in 2006 because adult condition was 41% lower in 2006 compared to 1969, likely owing to the decline of Diporeia spp, a primary prey for bloater. Although the slope of the fecundity versus weight regression was similar between the years, fecundity was 24% lower in 2006 than in 1969 for bloater weighing between 70 and 240??g. Whether this was the result of the difference in sampling time prior to spawning or of differences in condition is unknown. We also found no relationship between maternal size and mature oocyte size. Incorporating our updated fecundity regression into a stock/recruit model failed to improve the model fit, indicating that the low bloater recruitment that has been observed since the early 1990s is not solely the result of reduced fecundity. ?? 2008 Elsevier Inc. All rights reserved.

  4. The historical decline of fertility in Eastern Europe.

    PubMed

    Leasure, J W

    1992-01-01

    Quantitative data from the Princeton European Fertility Project were used to explain the determinants of change in attitudes which lead to use of birth control within marriage and fertility decline in terms of the growth of autonomy over one's political, personal, religious, economic, and reproductive life. The following countries, which are arranged by their chronological order of marital fertility decline, were used in the primarily quantitative analysis: Hungary, Czechoslovakia, Greece, Yugoslavia, Poland, Romania, Bulgaria, and Albania. Prior research had identified an association between a decline in the birth rate and the presence of revolutions nationalist independence movements, or democratic reform movements. The connection is that once control over one's political and economic destiny is made, there is an extension into one's reproductive behavior. Further refinement has occurred. Autonomy is grounded in reason, the natural rights of individuals, and independence of thought. Reflective of this autonomous spirit were affiliations with Congregational, Presbyterian, Quaker, Unitarian, and Universalist religions. The present analysis is historical and describes the events surrounding the decline in marital fertility. These events might have preceded, been concurrent with, or followed the decline, but the thesis remains that the growth in autonomy contributes to political changes and fertility decline. The primary measure of fertility is Ig developed by Coale, and sustained decline maps of Coale and Watkins. Crude birth rate and total fertility rate were also used. the provincial analysis was impeded by lack of long time series for some countries and boundary changes. The hypothesis is generally supported, except in the case of Yugoslavia which varies too much. Support for the thesis was stronger in some countries than in others. Sustained decline occurred by each country in different periods, e.g., in Hungary it began between 1850-60 while in Albania it began

  5. Chesapeake Bay: an unprecedented decline in submerged aquatic vegetation

    SciTech Connect

    Orth, R.J.; Moore, K.A.

    1983-10-07

    Data on the distribution and abundance of submerged aquatic vegetation in Chesapeake Bay indicate a significant reduction in all species in all sections of the bay during the last 15 to 20 years. This decline is unprecedented in the bay's recent history. The reduction in one major species, Zostera marina, may be greater than the decline that occurred during the pandemic demise of the 1930's. 19 references, 2 figures.

  6. The cause of global amphibian declines: a developmental endocrinologist's perspective

    PubMed Central

    Hayes, T. B.; Falso, P.; Gallipeau, S.; Stice, M.

    2010-01-01

    Greater than 70% of the world's amphibian species are in decline. We propose that there is probably not a single cause for global amphibian declines and present a three-tiered hierarchical approach that addresses interactions among and between ultimate and proximate factors that contribute to amphibian declines. There are two immediate (proximate) causes of amphibian declines: death and decreased recruitment (reproductive failure). Although much attention has focused on death, few studies have addressed factors that contribute to declines as a result of failed recruitment. Further, a great deal of attention has focused on the role of pathogens in inducing diseases that cause death, but we suggest that pathogen success is profoundly affected by four other ultimate factors: atmospheric change, environmental pollutants, habitat modification and invasive species. Environmental pollutants arise as likely important factors in amphibian declines because they have realized potential to affect recruitment. Further, many studies have documented immunosuppressive effects of pesticides, suggesting a role for environmental contaminants in increased pathogen virulence and disease rates. Increased attention to recruitment and ultimate factors that interact with pathogens is important in addressing this global crisis. PMID:20190117

  7. The cause of global amphibian declines: a developmental endocrinologist's perspective.

    PubMed

    Hayes, T B; Falso, P; Gallipeau, S; Stice, M

    2010-03-15

    Greater than 70% of the world's amphibian species are in decline. We propose that there is probably not a single cause for global amphibian declines and present a three-tiered hierarchical approach that addresses interactions among and between ultimate and proximate factors that contribute to amphibian declines. There are two immediate (proximate) causes of amphibian declines: death and decreased recruitment (reproductive failure). Although much attention has focused on death, few studies have addressed factors that contribute to declines as a result of failed recruitment. Further, a great deal of attention has focused on the role of pathogens in inducing diseases that cause death, but we suggest that pathogen success is profoundly affected by four other ultimate factors: atmospheric change, environmental pollutants, habitat modification and invasive species. Environmental pollutants arise as likely important factors in amphibian declines because they have realized potential to affect recruitment. Further, many studies have documented immunosuppressive effects of pesticides, suggesting a role for environmental contaminants in increased pathogen virulence and disease rates. Increased attention to recruitment and ultimate factors that interact with pathogens is important in addressing this global crisis.

  8. Focus on Freshman: Basic Instruction Programs Enhancing Physical Activity

    ERIC Educational Resources Information Center

    Curry, Jarred; Jenkins, Jayne M.; Weatherford, Jennifer

    2015-01-01

    Physical activity sharply decreases after different life stages, particularly high school graduation to beginning university education. The purpose of this study was to investigate the effect of a specifically designed university physical activity class, Exercise Planning for Freshman (EPF), on students' physical activity and group cohesion…

  9. [A decline in the French demographic situation in the context of a Europe also in demographic decline].

    PubMed

    Calot, G

    1994-01-01

    The author analyzes the decline in French fertility which has occurred over the past two years using data from official sources. Some comparisons are made with fertility trends in other European countries.

  10. NEDD4 REGULATES PAX7 LEVELS PROMOTING ACTIVATION OF THE DIFFERENTIATION PROGRAM IN SKELETAL MUSCLE PRECURSORS

    PubMed Central

    Bustos, Francisco; de la Vega, Eduardo; Cabezas, Felipe; Thompson, James; Cornelison, DDW; Olwin, Bradley B.; Yates, John R.; Olguín, Hugo C.

    2015-01-01

    The transcription factor Pax7 regulates skeletal muscle stem cell (satellite cells) specification and maintenance through various mechanisms, including repressing the activity of the muscle regulatory factor MyoD. Hence, Pax7-to-MyoD protein ratios can determine maintenance of the committed-undifferentiated state or activation of the differentiation program. Pax7 expression decreases sharply in differentiating myoblasts but is maintained in cells (re)acquiring quiescence, yet the mechanisms regulating Pax7 levels based on differentiation status are not well understood. Here we show that Pax7 levels are directly regulated by the ubiquitin-ligase Nedd4. Our results indicate that Nedd4 is expressed in quiescent and activated satellite cells, that Nedd4 and Pax7 physically interact during early muscle differentiation – correlating with Pax7 ubiquitination and decline – and that Nedd4 loss of function prevented this effect. Furthermore, even transient nuclear accumulation of Nedd4 induced a drop in Pax7 levels and precocious muscle differentiation. Consequently, we propose that Nedd4 functions as a novel Pax7 regulator, which activity is temporally and spatially controlled to modulate the Pax7 protein levels and therefore satellite cell fate. PMID:26304770

  11. Responses of riparian cottonwoods to alluvial water table declines

    USGS Publications Warehouse

    Scott, M.L.; Shafroth, P.B.; Auble, G.T.

    1999-01-01

    Human demands for surface and shallow alluvial groundwater have contributed to the loss, fragmentation, and simplification of riparian ecosystems. Populus species typically dominate riparian ecosystems throughout arid and semiarid regions of North American and efforts to minimize loss of riparian Populus requires an integrated understanding of the role of surface and groundwater dynamics in the establishment of new, and maintenance of existing, stands. In a controlled, whole-stand field experiment, we quantified responses of Populus morphology, growth, and mortality to water stress resulting from sustained water table decline following in-channel sand mining along an ephemeral sandbed stream in eastern Colorado, USA. We measured live crown volume, radial stem growth, annual branch increment, and mortality of 689 live Populus deltoides subsp. monilifera stems over four years in conjunction with localized water table declines. Measurements began one year prior to mining and included trees in both affected and unaffected areas. Populus demonstrated a threshold response to water table declines in medium alluvial sands; sustained declines ???1 m produced leaf desiccation and branch dieback within three weeks and significant declines in live crown volume, stem growth, and 88% mortality over a three-year period. Declines in live Crown volume proved to be a significant leading indicator of mortality in the following year. A logistic regression of tree survival probability against the prior year's live crown volume was significant (-2 log likelihood = 270, ??2 with 1 df = 232, P < 0.0001) and trees with absolute declines in live crown volume of ???30 during one year had survival probabilities <0.5 in the following year. In contrast, more gradual water table declines of ~0.5 m had no measurable effect on mortality, stem growth, or live crown volume and produced significant declines only in annual branch growth increments. Developing quantitative information on the timing and

  12. UV repair and resistance to solar UV-B in amphibian eggs: a link to population declines?

    PubMed

    Blaustein, A R; Hoffman, P D; Hokit, D G; Kiesecker, J M; Walls, S C; Hays, J B

    1994-03-01

    The populations of many amphibian species, in widely scattered habitats, appear to be in severe decline; other amphibians show no such declines. There is no known single cause for the declines, but their widespread distribution suggests involvement of global agents--increased UV-B radiation, for example. We addressed the hypothesis that differential sensitivity among species to UV radiation contributes to these population declines. We focused on species-specific differences in the abilities of eggs to repair UV radiation damage to DNA and differential hatching success of embryos exposed to solar radiation at natural oviposition sites. Quantitative comparisons of activities of a key UV-damage-specific repair enzyme, photolyase, among oocytes and eggs from 10 amphibian species were reproducibly characteristic for a given species but varied > 80-fold among the species. Levels of photolyase generally correlated with expected exposure of eggs to sunlight. Among the frog and toad species studied, the highest activity was shown by the Pacific treefrog (Hyla regilla), whose populations are not known to be in decline. The Western toad (Bufo boreas) and the Cascades frog (Rana cascadae), whose populations have declined markedly, showed significantly lower photolyase levels. In field experiments, the hatching success of embryos exposed to UV radiation was significantly greater in H. regilla than in R. cascadae and B. boreas. Moreover, in R. cascadae and B. boreas, hatching success was greater in regimes shielded from UV radiation compared with regimes that allowed UV radiation. These observations are thus consistent with the UV-sensitivity hypothesis. PMID:8127883

  13. Effects of mammalian herbivore declines on plant communities: observations and experiments in an African savanna

    PubMed Central

    Young, Hillary S; McCauley, Douglas J; Helgen, Kristofer M; Goheen, Jacob R; Otárola-Castillo, Erik; Palmer, Todd M; Pringle, Robert M; Young, Truman P; Dirzo, Rodolfo

    2013-01-01

    1. Herbivores influence the structure and composition of terrestrial plant communities. However, responses of plant communities to herbivory are variable and depend on environmental conditions, herbivore identity and herbivore abundance. As anthropogenic impacts continue to drive large declines in wild herbivores, understanding the context dependence of herbivore impacts on plant communities becomes increasingly important. 2. Exclosure experiments are frequently used to assess how ecosystems reorganize in the face of large wild herbivore defaunation. Yet in many landscapes, declines in large wildlife are often accompanied by other anthropogenic activities, especially land conversion to livestock production. In such cases, exclosure experiments may not reflect typical outcomes of human-driven extirpations of wild herbivores. 3. Here, we examine how plant community responses to changes in the identity and abundance of large herbivores interact with abiotic factors (rainfall and soil properties). We also explore how effects of wild herbivores on plant communities differ between large-scale herbivore exclosures and landscape sites where anthropogenic activity has caused wildlife declines, often accompanied by livestock increases. 4. Abiotic context modulated the responses of plant communities to herbivore declines with stronger effect sizes in lower-productivity environments. Also, shifts in plant community structure, composition and species richness following wildlife declines differed considerably between exclosure experiments and landscape sites in which wild herbivores had declined and were often replaced by livestock. Plant communities in low wildlife landscape sites were distinct in both composition and physical structure from both exclosure and control sites in experiments. The power of environmental (soil and rainfall) gradients in influencing plant response to herbivores was also greatly dampened or absent in the landscape sites. One likely explanation for

  14. Seasonal change in tropical habitat quality and body condition for a declining migratory songbird.

    PubMed

    McKinnon, Emily A; Rotenberg, James A; Stutchbury, Bridget J M

    2015-10-01

    Many migratory songbirds spend their non-breeding season in tropical humid forests, where climate change is predicted to increase the severity and frequency of droughts and decrease rainfall. For conservation of these songbirds, it is critical to understand how resources during the non-breeding season are affected by seasonal patterns of drying, and thereby predict potential long-term effects of climate change. We studied habitat quality for a declining tropical forest-dwelling songbird, the wood thrush (Hylocichla mustelina), and tested the hypothesis that habitat moisture and arthropod abundance are drivers of body condition during the overwintering period. We examined habitat moisture, abundance of arthropods and fruit, and condition of individual birds (n = 418) in three habitat types--mature forest, mature forest with increased presence of human activity, and riparian scrub--from October to April. We found a strong pattern of habitat drying from October (wet season) to March (prior to spring migration) in all habitats, with concurrent declines in arthropod and fruit abundance. Body condition of birds also declined (estimated ~5 % decline over the wintering period), with no significant difference by habitat. Relatively poor condition (low body condition index, low fat and pectoral muscles scores) was equally apparent in all habitat types in March. Climate change is predicted to increase the severity of dry seasons in Central America, and our results suggest that this could negatively affect the condition of individual wood thrushes.

  15. Dietary Approaches and Supplements in the Prevention of Cognitive Decline and Alzheimer's Disease.

    PubMed

    Dominguez, Ligia J; Barbagallo, Mario

    2016-01-01

    Age-associated cognitive decline and dementia are conditions in which there is deterioration in memory, thinking, and behavior, with profound effects on the ability to perform everyday activities and well-being. Even if dementia mainly affects older persons, it is not a normal part of aging. Alzheimer's disease accounts for 60-75% of dementia cases. The number of persons affected will increase in the next decades in parallel with aging of the world population. Hence, unless some approach is found to reduce age-related deterioration of cognitive functions, health care costs will continue to rise exponentially. There is a wealth of epidemiological evidence supporting a relationship between diet and Alzheimer's disease, and suggesting that the risk of cognitive decline may be reduced by dietary interventions. It has been proposed that adopting a healthy diet and lifestyle that improves cardiovascular function may help delaying the onset of Alzheimer's disease due to its potential association with vascular disease. Several nutrients, dietary components, supplements and dietary patterns have been reported in relation to their association with cognition and with the development of cognitive decline and Alzheimer's disease. The possible effect of diet on the prevention of dementia is of tremendous scientific and general interest, because hitherto there is no definitive evidence of any effective pharmacological treatment for dementia. The aim of this review is to evaluate the evidence for the effects of some dietary components, supplements, and dietary patterns as neuroprotective, with potential to delay cognitive decline and the onset of dementia.

  16. Diclofenac residues as the cause of vulture population decline in Pakistan

    USGS Publications Warehouse

    Oaks, J.L.; Gilbert, M.; Virani, M.Z.; Watson, R.T.; Meteyer, C.U.; Rideout, B.A.; Shivaprasad, H.L.; Ahmed, S.; Chaudhry, M.J.I.; Arshad, M.; Mahmood, S.; Ali, A.; Khan, A.A.

    2004-01-01

    The Oriental white-backed vulture (OWBV; Gyps bengalensis) was once one of the most common raptors in the Indian subcontinent. A population decline of >95%, starting in the 1990s, was first noted at Keoladeo National Park, India. Since then, catastrophic declines, also involving Gyps indicus and Gyps tenuirostris, have continued to be reported across the subcontinent. Consequently these vultures are now listed as critically endangered by BirdLife International. In 2000, the Peregrine Fund initiated its Asian Vulture Crisis Project with the Ornithological Society of Pakistan, establishing study sites at 16 OWBV colonies in the Kasur, Khanewal and Muzaffargarha??Layyah Districts of Pakistan to measure mortality at over 2,400 active nest sites5. Between 2000 and 2003, high annual adult and subadult mortality (5a??86%) and resulting population declines (34a??95%) (ref. 5 and M.G., manuscript in preparation) were associated with renal failure and visceral gout. Here, we provide results that directly correlate residues of the anti-inflammatory drug diclofenac with renal failure. Diclofenac residues and renal disease were reproduced experimentally in OWBVs by direct oral exposure and through feeding vultures diclofenac-treated livestock. We propose that residues of veterinary diclofenac are responsible for the OWBV decline.

  17. Decline of Yangtze River water and sediment discharge: Impact from natural and anthropogenic changes

    PubMed Central

    Yang, S. L.; Xu, K. H.; Milliman, J. D.; Yang, H. F.; Wu, C. S.

    2015-01-01

    The increasing impact of both climatic change and human activities on global river systems necessitates an increasing need to identify and quantify the various drivers and their impacts on fluvial water and sediment discharge. Here we show that mean Yangtze River water discharge of the first decade after the closing of the Three Gorges Dam (TGD) (2003–2012) was 67 km3/yr (7%) lower than that of the previous 50 years (1950–2002), and 126 km3/yr less compared to the relatively wet period of pre-TGD decade (1993–2002). Most (60–70%) of the decline can be attributed to decreased precipitation, the remainder resulting from construction of reservoirs, improved water-soil conservation and increased water consumption. Mean sediment flux decreased by 71% between 1950–1968 and the post-TGD decade, about half of which occurred prior to the pre-TGD decade. Approximately 30% of the total decline and 65% of the decline since 2003 can be attributed to the TGD, 5% and 14% of these declines to precipitation change, and the remaining to other dams and soil conservation within the drainage basin. These findings highlight the degree to which changes in riverine water and sediment discharge can be related with multiple environmental and anthropogenic factors. PMID:26206169

  18. Seasonal change in tropical habitat quality and body condition for a declining migratory songbird.

    PubMed

    McKinnon, Emily A; Rotenberg, James A; Stutchbury, Bridget J M

    2015-10-01

    Many migratory songbirds spend their non-breeding season in tropical humid forests, where climate change is predicted to increase the severity and frequency of droughts and decrease rainfall. For conservation of these songbirds, it is critical to understand how resources during the non-breeding season are affected by seasonal patterns of drying, and thereby predict potential long-term effects of climate change. We studied habitat quality for a declining tropical forest-dwelling songbird, the wood thrush (Hylocichla mustelina), and tested the hypothesis that habitat moisture and arthropod abundance are drivers of body condition during the overwintering period. We examined habitat moisture, abundance of arthropods and fruit, and condition of individual birds (n = 418) in three habitat types--mature forest, mature forest with increased presence of human activity, and riparian scrub--from October to April. We found a strong pattern of habitat drying from October (wet season) to March (prior to spring migration) in all habitats, with concurrent declines in arthropod and fruit abundance. Body condition of birds also declined (estimated ~5 % decline over the wintering period), with no significant difference by habitat. Relatively poor condition (low body condition index, low fat and pectoral muscles scores) was equally apparent in all habitat types in March. Climate change is predicted to increase the severity of dry seasons in Central America, and our results suggest that this could negatively affect the condition of individual wood thrushes. PMID:26001604

  19. Decline of Yangtze River water and sediment discharge: Impact from natural and anthropogenic changes.

    PubMed

    Yang, S L; Xu, K H; Milliman, J D; Yang, H F; Wu, C S

    2015-01-01

    The increasing impact of both climatic change and human activities on global river systems necessitates an increasing need to identify and quantify the various drivers and their impacts on fluvial water and sediment discharge. Here we show that mean Yangtze River water discharge of the first decade after the closing of the Three Gorges Dam (TGD) (2003-2012) was 67 km(3)/yr (7%) lower than that of the previous 50 years (1950-2002), and 126 km(3)/yr less compared to the relatively wet period of pre-TGD decade (1993-2002). Most (60-70%) of the decline can be attributed to decreased precipitation, the remainder resulting from construction of reservoirs, improved water-soil conservation and increased water consumption. Mean sediment flux decreased by 71% between 1950-1968 and the post-TGD decade, about half of which occurred prior to the pre-TGD decade. Approximately 30% of the total decline and 65% of the decline since 2003 can be attributed to the TGD, 5% and 14% of these declines to precipitation change, and the remaining to other dams and soil conservation within the drainage basin. These findings highlight the degree to which changes in riverine water and sediment discharge can be related with multiple environmental and anthropogenic factors. PMID:26206169

  20. Toxicity of two insecticides to California, USA, anurans and its relevance to declining amphibian populations.

    PubMed

    Sparling, Donald W; Fellers, Gary M

    2009-08-01

    Contaminants have been associated with population declines of several amphibian species in California (USA). Pesticides from the Central Valley of California are transported by winds into the Sierra Nevada Mountains and precipitate into wet meadows where amphibians breed. The present study examined the chronic toxicity of two of the insecticides most commonly used in the Central Valley and found in the mountains, chlorpyrifos and endosulfan, to larval Pacific treefrogs (Pseudacris regilla) and foothill yellow-legged frogs (Rana boylii) and discusses the implications of this toxicity to declining amphibian populations. Larvae were exposed to the pesticides from Gosner stages 25 to 26 through metamorphosis. The estimated median lethal concentration (LC50) for chlorpyrifos was 365 microg/L in P. regilla and 66.5 microg/L for R. boylii. Time to metamorphosis increased with concentration of chlorpyrifos in both species, and cholinesterase activity declined with exposure concentration in metamorphs of both species at Gosner stages 42 to 46. For endosulfan, the estimated LC50 was 15.6 microg/L for P. regilla and 0.55 microg/L for R. boylii. All R. boylii exposed to concentrations of greater than 0.8 microg/L died before they entered metamorphosis. Pseudacris regilla remains relatively abundant and is broadly distributed throughout California. In contrast, R. boylii is among the species experiencing severe population declines. The present study adds to the increasing evidence that pesticides are very harmful to amphibians living in areas that are miles from sources of pesticide application.

  1. Decline of Yangtze River water and sediment discharge: Impact from natural and anthropogenic changes

    NASA Astrophysics Data System (ADS)

    Yang, S. L.; Xu, K. H.; Milliman, J. D.; Yang, H. F.; Wu, C. S.

    2015-07-01

    The increasing impact of both climatic change and human activities on global river systems necessitates an increasing need to identify and quantify the various drivers and their impacts on fluvial water and sediment discharge. Here we show that mean Yangtze River water discharge of the first decade after the closing of the Three Gorges Dam (TGD) (2003-2012) was 67 km3/yr (7%) lower than that of the previous 50 years (1950-2002), and 126 km3/yr less compared to the relatively wet period of pre-TGD decade (1993-2002). Most (60-70%) of the decline can be attributed to decreased precipitation, the remainder resulting from construction of reservoirs, improved water-soil conservation and increased water consumption. Mean sediment flux decreased by 71% between 1950-1968 and the post-TGD decade, about half of which occurred prior to the pre-TGD decade. Approximately 30% of the total decline and 65% of the decline since 2003 can be attributed to the TGD, 5% and 14% of these declines to precipitation change, and the remaining to other dams and soil conservation within the drainage basin. These findings highlight the degree to which changes in riverine water and sediment discharge can be related with multiple environmental and anthropogenic factors.

  2. Prevention of Age-Related Cognitive Decline: Which Strategies, When, and for Whom?

    PubMed

    Shatenstein, Bryna; Barberger-Gateau, Pascale; Mecocci, Patrizia

    2015-01-01

    Brain aging is characterized by the progressive and gradual accumulation of detrimental changes in structure and function, which increase risk of age-related cognitive decline and dementia. This devastating chronic condition generates a huge social and economic burden and accounts for 11.2% of years of disability. The increase in lifespan has contributed to the increase in dementia prevalence; however, there is currently no curative treatment for most causes of dementias. This paper reviews evidence-based strategies to build, enhance, and preserve cognition over the lifespan by examining approaches that work best, proposing when in the life course they should be implemented, and in which population group(s). Recent work shows a tendency to decreased age-specific prevalence and incidence of cognitive problems and dementia among people born later in the first half of the 20th century, citing higher educational levels, improvements in lifestyle, and better handling of vascular risk factors. This implies that we can target modifiable environmental, lifestyle, and health risk factors to modify the trajectory of cognitive decline before the onset of irreversible dementia. Because building cognitive reserve and prevention of cognitive decline are of critical importance, interventions are needed at every stage of the life course to foster cognitive stimulation, and enable healthy eating habits and physical activity throughout the lifespan. Preventive interventions to decrease and delay cognitive decline and its consequences in old age will also require collaboration and action on the part of policy-makers at the political and social level.

  3. Kidney function decline and physical function in women

    PubMed Central

    Lin, Julie; Curhan, Gary C.

    2008-01-01

    Background. Cross-sectional analyses of kidney function and physical function have identified profound quality of life impairments in people with advanced kidney dysfunction. No data are currently available, however, on how kidney function decline may be associated with physical function. Methods. We undertook a study of kidney function decline and physical function in 2544 women participating in the Nurses’ Health Study. Glomerular filtration rates (GFR) were estimated using the four-variable MDRD equation from plasma creatinine measured in blood collected in 1989 and 2000. Physical function was assessed by the Physical Function Sub-Scale (PFS) score of the Short Form 36 (SF-36) in a questionnaire administered in the year 2000. PFS scores have been shown to correlate well with direct measures of physical function. Results. In the year 2000, the median age was 67 years, median body mass index (BMI) was 25.6 kg/m2, 48.5% had hypertension and 5.8% had diabetes. There were 427 women (16.8%) who experienced an ≥25% decline in eGFR between 1989 and 2000. Median PFS in 2000 for those with an eGFR decline of ≥25% was 80 compared to a PFS score of 85 for those without (P < 0.001). In fully adjusted models, the presence of an eGFR decline of ≥25% was independently associated with a 3.5-point lower PFS score (95% CI −5.4 to −1.5). Also, an eGFR decline of ≥25% was independently associated with an increased odds ratio of being in the lowest quartile of PFS score (OR 1.37; 95% CI 1.04–1.81). Conclusions. We conclude that an eGFR decline of ≥25% over 11 years is independently associated with lower physical function in women. PMID:18398018

  4. Declines of biomes and biotas and the future of evolution

    PubMed Central

    Woodruff, David S.

    2001-01-01

    Although panel discussants disagreed whether the biodiversity crisis constitutes a mass extinction event, all agreed that current extinction rates are 50–500 times background and are increasing and that the consequences for the future evolution of life are serious. In response to the on-going rapid decline of biomes and homogenization of biotas, the panelists predicted changes in species geographic ranges, genetic risks of extinction, genetic assimilation, natural selection, mutation rates, the shortening of food chains, the increase in nutrient-enriched niches permitting the ascendancy of microbes, and the differential survival of ecological generalists. Rates of evolutionary processes will change in different groups, and speciation in the larger vertebrates is essentially over. Action taken over the next few decades will determine how impoverished the biosphere will be in 1,000 years when many species will suffer reduced evolvability and require interventionist genetic and ecological management. Whether the biota will continue to provide the dependable ecological services humans take for granted is less clear. The discussants offered recommendations, including two of paramount importance (concerning human populations and education), seven identifying specific scientific activities to better equip us for stewardship of the processes of evolution, and one suggesting that such stewardship is now our responsibility. The ultimate test of evolutionary biology as a science is not whether it solves the riddles of the past but rather whether it enables us to manage the future of the biosphere. Our inability to make clearer predictions about the future of evolution has serious consequences for both biodiversity and humanity. PMID:11344296

  5. Rapid declines in metabolism explain extended coral larval longevity

    NASA Astrophysics Data System (ADS)

    Graham, E. M.; Baird, A. H.; Connolly, S. R.; Sewell, M. A.; Willis, B. L.

    2013-06-01

    Lecithotrophic, or non-feeding, marine invertebrate larvae generally have shorter pelagic larval durations (PLDs) than planktotrophic larvae. However, non-feeding larvae of scleractinian corals have PLDs far exceeding those of feeding larvae of other organisms and predictions of PLD based on energy reserves and metabolic rates, raising questions about how such longevity is achieved. Here, we measured temporal changes in metabolic rates and total lipid content of non-feeding larvae of four species of reef corals to determine whether changes in energy utilization through time contribute to extended larval durations. The temporal dynamics of both metabolic rates and lipid content were highly consistent among species. Prior to fertilization, metabolic rates were low (2.73-8.63 nmol O2 larva-1 h-1) before rapidly increasing to a peak during embryogenesis and early development 1-2 days after spawning. Metabolic rates remained high until shortly after larvae first became competent to metamorphose and then declined by up to two orders of magnitude to levels at or below rates seen in unfertilized eggs over the following week. Larvae remained in this state of low metabolic activity for up to 2 months. Consistent with temporal patterns in metabolic rates, depletion of lipids was extremely rapid during early development and then slowed dramatically from 1 week onward. Despite the very low metabolic rates in these species, larvae continued to swim and retained competence for at least 2 months. The capacity of non-feeding coral larvae to enter a state of low metabolism soon after becoming competent to metamorphose significantly extends dispersal potential, thereby accruing advantages typically associated with planktotrophy, notably enhanced population connectivity.

  6. Predicting functional decline in behavioural variant frontotemporal dementia.

    PubMed

    Josephs, Keith A; Whitwell, Jennifer L; Weigand, Stephen D; Senjem, Matthew L; Boeve, Bradley F; Knopman, David S; Smith, Glenn E; Ivnik, Robert J; Jack, Clifford R; Petersen, Ronald C

    2011-02-01

    Behavioural variant frontotemporal dementia is characterized by a change in comportment. It is associated with considerable functional decline over the course of the illness albeit with sometimes dramatic variability among patients. It is unknown whether any baseline features, or combination of features, could predict rate of functional decline in behavioural variant frontotemporal dementia. The aim of this study was to investigate the effects of different baseline clinical, neuropsychological, neuropsychiatric, genetic and anatomic predictors on the rate of functional decline as measured by the Clinical Dementia Rating Sum of Boxes scale. We identified 86 subjects with behavioural variant frontotemporal dementia that had multiple serial Clinical Dementia Rating Sum of Boxes assessments (mean 4, range 2-18). Atlas-based parcellation was used to generate volumes for specific regions of interest at baseline. Volumes were utilized to classify subjects into different anatomical subtypes using the advanced statistical technique of cluster analysis and were assessed as predictor variables. Composite scores were generated for the neuropsychological domains of executive, language, memory and visuospatial function. Behaviours from the brief questionnaire form of the Neuropsychiatric Inventory were assessed. Linear mixed-effects regression modelling was used to determine which baseline features predict rate of future functional decline. Rates of functional decline differed across the anatomical subtypes of behavioural variant frontotemporal dementia, with faster rates observed in the frontal dominant and frontotemporal subtypes. In addition, subjects with poorer performance on neuropsychological tests of executive, language and visuospatial function, less disinhibition, agitation/aggression and night-time behaviours at presentation, and smaller medial, lateral and orbital frontal lobe volumes showed faster rates of decline. In many instances, the effect of the predictor

  7. Protozoa as agents responsible for the decline of Xanthomonas campestris in soil.

    PubMed

    Habte, M; Alexander, M

    1975-02-01

    A streptomycin-resistant mutant of Xanthomonas campestris was used to assess the persistence of the plant pathogen in soil and the changes in populations that might be important for its survival. In soil into which large numbers of the organism were introduced, a marked decline in its abundance occurred, but after about 1 week its population density reached a level of about 105 and did not continue to fall during the test period. No such marked decline was evident in sterile soil inoculated with X. campestris. The bacterium did not lose viability if starved for carbon or inorganic nitrogen. Although abundant in soil, the numbers of propagules capable of producing antibiotics or lytic enzymes active against X. campestris did not increase coincident with the pathogen's decline, and no increase in tartrate-extractable toxins was observed. Neither bdellovibrios nor bacteriophages active against the xanthomonad were found in the soil, but a marked increase in the frequency of protozoa paralleled the phase of rapid diminution in the X. campestris population. In actidione-treated soil, in which protozoan activity was severly limited, the high cell density of the pathogen was maintained. On the basis of these data, it is concluded that predation by protozoa is responsible for the abrupt fall in frequency of the bacterium in natural soil. PMID:1115496

  8. Protozoa as Agents Responsible for the Decline of Xanthomonas campestris in Soil

    PubMed Central

    Habte, Mitiku; Alexander, Martin

    1975-01-01

    A streptomycin-resistant mutant of Xanthomonas campestris was used to assess the persistence of the plant pathogen in soil and the changes in populations that might be important for its survival. In soil into which large numbers of the organism were introduced, a marked decline in its abundance occurred, but after about 1 week its population density reached a level of about 105 and did not continue to fall during the test period. No such marked decline was evident in sterile soil inoculated with X. campestris. The bacterium did not lose viability if starved for carbon or inorganic nitrogen. Although abundant in soil, the numbers of propagules capable of producing antibiotics or lytic enzymes active against X. campestris did not increase coincident with the pathogen's decline, and no increase in tartrate-extractable toxins was observed. Neither bdellovibrios nor bacteriophages active against the xanthomonad were found in the soil, but a marked increase in the frequency of protozoa paralleled the phase of rapid diminution in the X. campestris population. In actidione-treated soil, in which protozoan activity was severely limited, the high cell density of the pathogen was maintained. On the basis of these data, it is concluded that predation by protozoa is responsible for the abrupt fall in frequency of the bacterium in natural soil. PMID:1115496

  9. Declining mortality from smoking in the United States.

    PubMed

    Rodu, Brad; Cole, Philip

    2007-07-01

    The proportion of Americans who smoke cigarettes has declined 50% since 1965. The effect on mortality of this considerable reduction has received little attention and is described in this study. U.S. national data were used to enumerate current, former, and never-smokers aged 35 years or older in 1987 and 2002. Mortality rate ratios were used to estimate smoking-attributable deaths among these groups, and corresponding age-adjusted smoking-attributable mortality rates (SAMRs) were calculated. There were 402,000 deaths attributable to smoking in 1987 and 322,000 in 2002. The SAMR for men aged 35 years or more was 556 deaths per 100,000 person-years in 1987, accounting for 24% of all male deaths. By 2002 the SAMR declined 41% to 329 and accounted for only 17% of deaths. The SAMR for women in 1987 was 175, accounting for 12% of deaths. By 2002 the SAMR among women had declined 30% to 122, representing 9% of deaths. The U.S. mortality rate attributable to smoking declined about 35% between 1987 and 2002. The impact of smoking on American society will diminish even further in the foreseeable future as smoking prevalence continues its decline among men and women. PMID:17577808

  10. Arctic Sea Ice Decline: Observations, Projections, Mechanisms, and Implications

    NASA Astrophysics Data System (ADS)

    DeWeaver, Eric T.; Bitz, Cecilia M.; Tremblay, L.-Bruno

    This volume addresses the rapid decline of Arctic sea ice, placing recent sea ice decline in the context of past observations, climate model simulations and projections, and simple models of the climate sensitivity of sea ice. Highlights of the work presented here include • An appraisal of the role played by wind forcing in driving the decline; • A reconstruction of Arctic sea ice conditions prior to human observations, based on proxy data from sediments; • A modeling approach for assessing the impact of sea ice decline on polar bears, used as input to the U.S. Fish and Wildlife Service's decision to list the polar bear as a threatened species under the Endangered Species Act; • Contrasting studies on the existence of a "tipping point," beyond which Arctic sea ice decline will become (or has already become) irreversible, including an examination of the role of the small ice cap instability in global warming simulations; • A significant summertime atmospheric response to sea ice reduction in an atmospheric general circulation model, suggesting a positive feedback and the potential for short-term climate prediction. The book will be of interest to researchers attempting to understand the recent behavior of Arctic sea ice, model projections of future sea ice loss, and the consequences of sea ice loss for the natural and human systems of the Arctic.

  11. Forest declines: Some perspectives on linking processes and patterns

    SciTech Connect

    McLaughlin, S.B.

    1992-01-01

    The regional decline in vigor of some species of forest trees has become an important component in the ecological, aesthetic, and economic criteria by which the costs of anthropogenic pollution are weighed. Because declines are often complex and virtually never without significant natural environmental modifiers, determining the role of specific anthropogenic stresses in initiating or enhancing the rate and direction of change in forest condition represents a significant research challenge. Separation of primary mechanisms that point to principal causes from secondary responses that result from internal feedbacks and the milieu of modifying agents is a critical issue in diagnosing forest decline. Air pollutant stress may have its most significant effects on forest processes by accelerating or amplifying natural stresses. Studies of changes in forest metabolic processes have played an important role in evaluating the role of air pollution in four regional forest declines that are the focus of this paper. The decline of ponderosa pine in the San Bernardino Mountains of California, Norway spruce and silver fir in Europe, loblolly and shortleaf pine in the Southeastern United States, and red spruce in the Eastern Appalachian Mountains provide case studies in which physiological responses to air pollutants under field and laboratory conditions have provided important analytical tools for assessing likely causes. These tools are most effective when both mechanistic explanations and larger scale patterns of response are evaluated in an iterative feedback loop that examines plausible mechanisms and patterns of response at levels ranging from cell membranes to plant populations.

  12. Patterns of widespread decline in North American bumble bees.

    PubMed

    Cameron, Sydney A; Lozier, Jeffrey D; Strange, James P; Koch, Jonathan B; Cordes, Nils; Solter, Leellen F; Griswold, Terry L

    2011-01-11

    Bumble bees (Bombus) are vitally important pollinators of wild plants and agricultural crops worldwide. Fragmentary observations, however, have suggested population declines in several North American species. Despite rising concern over these observations in the United States, highlighted in a recent National Academy of Sciences report, a national assessment of the geographic scope and possible causal factors of bumble bee decline is lacking. Here, we report results of a 3-y interdisciplinary study of changing distributions, population genetic structure, and levels of pathogen infection in bumble bee populations across the United States. We compare current and historical distributions of eight species, compiling a database of >73,000 museum records for comparison with data from intensive nationwide surveys of >16,000 specimens. We show that the relative abundances of four species have declined by up to 96% and that their surveyed geographic ranges have contracted by 23-87%, some within the last 20 y. We also show that declining populations have significantly higher infection levels of the microsporidian pathogen Nosema bombi and lower genetic diversity compared with co-occurring populations of the stable (nondeclining) species. Higher pathogen prevalence and reduced genetic diversity are, thus, realistic predictors of these alarming patterns of decline in North America, although cause and effect remain uncertain.

  13. Global amphibian declines: perspectives from the United States and beyond

    USGS Publications Warehouse

    Densmore, Christine L.; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

    2011-01-01

    Over recent decades, amphibians have experienced population declines, extirpations and species-level extinctions at an alarming rate. Numerous potential etiologies for amphibian declines have been postulated including climate and habitat degradation. Other potential anthropogenic causes including overexploitation and the frequent introductions of invasive predatory species have also been blamed for amphibian declines. Still other underlying factors may include infectious diseases caused by the chytrid fungus Batrachochytrium dendrobatidis, pathogenic viruses (Ranavirus), and other agents. It is nearly certain that more than one etiology is to blame for the majority of the global amphibian declines, and that these causal factors include some combination of climatological or physical habitat destabilization and infectious disease, most notably chytridiomycosis. Scientific research efforts are aimed at elucidating these etiologies on local, regional, and global scales that we might better understand and counteract the driving forces behind amphibian declines. Conservation efforts as outlined in the Amphibian Conservation Action Plan of 2005 are also being made to curtail losses and prevent further extinctions wherever possible.

  14. Decline in long-term growth trends of white oak

    USGS Publications Warehouse

    Phipps, R.L.; Whiton, J.C.

    1988-01-01

    Quercus alba tree-ring collections from 89 locations throughout much of its range, from Connecticut to North Carolina to Iowa, were examined for evidence of growth decline initiated in the 1950s. The expected trend of annual basal area increments, based on pre-1950 growth, appears to be linear, with the slope varying among collections relative to site quality. Growth decline, defined as departure of actual growth below that expected, was identified in 40 to 60 collections judged to have not been affected by local site histories. The percentage of collections showing decline was essentially the same in the Northeast, the Midwest and the Southeast. Onset of decline began during a relatively narrow time window from the mid-1950's to the early 1960's. Since then the growth trend has been linear and appears unrelated to changes in regional sulfur and nitrogen oxide emissions. Events or conditions, unique to the 1950's, initiated a growth rate change in c 2/3 of the stands examined. Initiation of the decline appears to be unrelated to tree age, geographic location, site quality, climatic trends, or regional emissions of sulfur and nitrogen oxides. -from Authors

  15. The decline of teacher autonomy: Tears or cheers?

    NASA Astrophysics Data System (ADS)

    Anderson, Lorin W.

    1987-09-01

    In the United States teacher autonomy has been declining for at least a decade. This decline can be attributed in large part to three factors. First, uniform staff development programmes based on research on effective teaching have become widespread. Second, classroom observations have become an integral part of imposed teacher evaluations. Third, school principals have been called on to assume the role of `instructional leader'. While some may perceive the decline of teacher autonomy negatively, at least two benefits of this decline have been identified. First, a `common language' by which teachers can discuss the problems and potential of instruction and teaching among themselves and with school administrators is developing. Second, the likelihood that teachers will achieve a truly professional status is enhanced. Many educators write as if the natural result of a decline in teacher autonomy is standardization; that is, the cloning of teachers. This article negates such pessimism. Teacher autonomy, like many educational variables, exists along a continuum. As a consequence, a midpoint on the autonomy continuum — a balance between uniqueness and standardization, between license and responsibility — is the desirable state of affairs. Finally, autonomy should be earned by teachers, not simply given to them. In this regard, greater concern should be given to teachers' preparation for, and induction into, their roles as school teachers. Similarly, increases in autonomy should mirror increases in teacher status; status defined in terms of teacher experience, expertise, and excellence.

  16. Intersexuality and the cricket frog decline: historic and geographic trends.

    PubMed

    Reeder, Amy L; Ruiz, Marilyn O; Pessier, Allan; Brown, Lauren E; Levengood, Jeffrey M; Phillips, Christopher A; Wheeler, Matthew B; Warner, Richard E; Beasley, Val R

    2005-03-01

    Exposure to anthropogenic endocrine disruptors has been listed as one of several potential causes of amphibian declines in recent years. We examined gonads of 814 cricket frogs (Acris crepitans) collected in Illinois and deposited in museum collections to elucidate relationships between the decline of this species in Illinois and the spatial and temporal distribution of individuals with intersex gonads. Compared with the preorganochlorine era studied (1852-1929), the percentage of intersex cricket frogs increased during the period of industrial growth and initial uses of polychlorinated biphenyls (PCBs) (1930-1945), was highest during the greatest manufacture and use of p,p-dichlorodiphenyltrichloroethane (DDT) and PCBs (1946-1959), began declining with the increase in public concern and environmental regulations that reduced and then prevented sales of DDT in the United States (1960-1979), and continued to decline through the period of gradual reductions in environmental residues of organochlorine pesticides and PCBs in the midwestern United States (1980-2001). The proportion of intersex individuals among those frogs was highest in the heavily industrialized and urbanized northeastern portion of Illinois, intermediate in the intensively farmed central and northwestern areas, and lowest in the less intensively managed and ecologically more diverse southern part of the state. Records of deposits of cricket frog specimens into museum collections indicate a marked reduction in numbers from northeastern Illinois in recent decades. These findings are consistent with the hypothesis that endocrine disruption contributed to the decline of cricket frogs in Illinois.

  17. Patterns of widespread decline in North American bumble bees.

    PubMed

    Cameron, Sydney A; Lozier, Jeffrey D; Strange, James P; Koch, Jonathan B; Cordes, Nils; Solter, Leellen F; Griswold, Terry L

    2011-01-11

    Bumble bees (Bombus) are vitally important pollinators of wild plants and agricultural crops worldwide. Fragmentary observations, however, have suggested population declines in several North American species. Despite rising concern over these observations in the United States, highlighted in a recent National Academy of Sciences report, a national assessment of the geographic scope and possible causal factors of bumble bee decline is lacking. Here, we report results of a 3-y interdisciplinary study of changing distributions, population genetic structure, and levels of pathogen infection in bumble bee populations across the United States. We compare current and historical distributions of eight species, compiling a database of >73,000 museum records for comparison with data from intensive nationwide surveys of >16,000 specimens. We show that the relative abundances of four species have declined by up to 96% and that their surveyed geographic ranges have contracted by 23-87%, some within the last 20 y. We also show that declining populations have significantly higher infection levels of the microsporidian pathogen Nosema bombi and lower genetic diversity compared with co-occurring populations of the stable (nondeclining) species. Higher pathogen prevalence and reduced genetic diversity are, thus, realistic predictors of these alarming patterns of decline in North America, although cause and effect remain uncertain. PMID:21199943

  18. Detecting insect pollinator declines on regional and global scales

    USGS Publications Warehouse

    Lubuhn, Gretchen; Droege, Sam; Connor, Edward F.; Gemmill-Herren, Barbara; Potts, Simon G.; Minckley, Robert L.; Griswold, Terry; Jean, Robert; Kula, Emanuel; Roubik, David W.; Cane, Jim; Wright, Karen W.; Frankie, Gordon; Parker, Frank

    2013-01-01

    Recently there has been considerable concern about declines in bee communities in agricultural and natural habitats. The value of pollination to agriculture, provided primarily by bees, is >$200 billion/year worldwide, and in natural ecosystems it is thought to be even greater. However, no monitoring program exists to accurately detect declines in abundance of insect pollinators; thus, it is difficult to quantify the status of bee communities or estimate the extent of declines. We used data from 11 multiyear studies of bee communities to devise a program to monitor pollinators at regional, national, or international scales. In these studies, 7 different methods for sampling bees were used and bees were sampled on 3 different continents. We estimated that a monitoring program with 200-250 sampling locations each sampled twice over 5 years would provide sufficient power to detect small (2-5%) annual declines in the number of species and in total abundance and would cost U.S.$2,000,000. To detect declines as small as 1% annually over the same period would require >300 sampling locations. Given the role of pollinators in food security and ecosystem function, we recommend establishment of integrated regional and international monitoring programs to detect changes in pollinator communities.

  19. Sea otter population declines in the Aleutian Archipelago

    USGS Publications Warehouse

    Doroff, Angela; Estes, James A.; Tinker, M. Tim; Burn, Douglas M.; Evans, Thomas J.

    2003-01-01

    Sea otter (Enhydra lutris) populations were exploited to near extinction and began to recover after the cessation of commercial hunting in 1911. Remnant colonies of sea otters in the Aleutian archipelago were among the first to recover; they continued to increase through the 1980s but declined abruptly during the 1990s. We conducted an aerial survey of the Aleutian archipelago in 2000 and compared results with similar surveys conducted in 1965 and 1992. The number of sea otters counted decreased by 75% between 1965 and 2000; 88% for islands at equilibrial density in 1965. The population decline likely began in the mid-1980s and declined at a rate of 17.5%/year in the 1990s. The minimal population estimate was 8,742 sea otters in 2000. The population declined to a uniformly low density in the archipelago, suggesting a common and geographically widespread cause. These data are in general agreement with the hypothesis of increased predation on sea otters. These data chronicle one of the most widespread and precipitous population declines for a mammalian carnivore in recorded history.

  20. Critical Decline of the Eastern Caribbean Sperm Whale Population

    PubMed Central

    Whitehead, Hal

    2016-01-01

    Sperm whale (Physeter macrocephalus) populations were expected to rebuild following the end of commercial whaling. We document the decline of the population in the eastern Caribbean by tracing demographic changes of well-studied social units. We address hypotheses that, over a ten-year period of dedicated effort (2005–2015), unit size, numbers of calves and/or calving rates have each declined. Across 16 units, the number of adults decreased in 12 units, increased in two, and showed no change in two. The number of adults per unit decreased at -0.195 individuals/yr (95% CI: -0.080 to -0.310; P = 0.001). The number of calves also declined, but the decline was not significant. This negative trend of -4.5% per year in unit size started in about 2010, with numbers being fairly stable until then. There are several natural and anthropogenic threats, but no well-substantiated cause for the decline. PMID:27706153

  1. Devil Declines and Catastrophic Cascades: Is Mesopredator Release of Feral Cats Inhibiting Recovery of the Eastern Quoll?

    PubMed Central

    Fancourt, Bronwyn A.; Hawkins, Clare E.; Cameron, Elissa Z.; Jones, Menna E.; Nicol, Stewart C.

    2015-01-01

    The eastern quoll (Dasyurus viverrinus) is a medium-sized Australian marsupial carnivore that has recently undergone a rapid and severe population decline over the 10 years to 2009, with no sign of recovery. This decline has been linked to a period of unfavourable weather, but subsequent improved weather conditions have not been matched by quoll recovery. A recent study suggested another mechanism: that declines in Tasmanian devil (Sarcophilus harrisii) populations, due to the spread of the fatal Devil Facial Tumour Disease, have released feral cats (Felis catus) from competitive suppression, with eastern quoll declines linked to a subsequent increase in cat sightings. Yet current evidence of intraguild suppression among devils, cats and quolls is scant and equivocal. We therefore assessed the influences of top-down effects on abundance and activity patterns among devils, feral cats and eastern quolls. Between 2011 and 2013, we monitored four carnivore populations using longitudinal trapping and camera surveys, and performed camera surveys at 12 additional sites throughout the eastern quoll’s range. We did not find evidence of a negative relationship between devil and cat abundance, nor of higher cat abundance in areas where devil populations had declined the longest. Cats did not appear to avoid devils spatially; however, there was evidence of temporal separation of cat and devil activity, with reduced separation and increasing nocturnal activity observed in areas where devils had declined the longest. Cats and quolls used the same areas, and there was no evidence that cat and quoll abundances were negatively related. Temporal overlap in observed cat and quoll activity was higher in summer than in winter, but this seasonal difference was unrelated to devil declines. We suggest that cats did not cause the recent quoll decline, but that predation of juvenile quolls by cats could be inhibiting low density quoll populations from recovering their former abundance

  2. Compensatory mechanisms in higher-educated subjects with Alzheimer's disease: a study of 20 years of cognitive decline.

    PubMed

    Amieva, Hélène; Mokri, Hind; Le Goff, Mélanie; Meillon, Céline; Jacqmin-Gadda, Hélène; Foubert-Samier, Alexandra; Orgogozo, Jean-Marc; Stern, Yaakov; Dartigues, Jean-François

    2014-04-01

    A better knowledge of long-term trajectories of cognitive decline is a central feature of the study of the process leading to Alzheimer's dementia. Several factors may mitigate such decline, among which is education, a major risk factor for Alzheimer's disease. The aim of our work was to compare the pattern and duration of clinical trajectories before Alzheimer's dementia in individuals with low and high education within the PAQUID cohort involving 20 years of follow-up. The sample comprises 442 participants with incident Alzheimer's disease (27.2% were male)--171 with low education (mean age=86.2 years; standard deviation=5.3 years) and 271 with higher education (mean age=86.5; standard deviation=5.4)--and 442 control subjects matched according to age, sex and education. At each visit and up to the 20-year follow-up visit, several cognitive and clinical measures were collected and incident cases of Alzheimer's disease clinically diagnosed. The evolution of clinical measures in pre-demented subjects and matched controls was analysed with a semi-parametric extension of the mixed effects linear model. The results show that the first signs of cognitive decline occurred 15 to 16 years before achieving dementia threshold in higher-educated subjects whereas signs occurred at 7 years before dementia in low-educated subjects. There seemed to be two successive periods of decline in higher-educated subjects. Decline started ∼15 to 16 years before dementia with subtle impairment restricted to some cognitive tests and with no impact during the first 7 to 8 years on global cognition, cognitive complaints, or activities of daily living scales. Then, ∼7 years before dementia, global cognitive abilities begin to deteriorate, along with difficulties dealing with complex activities of daily living, the increase in self-perceived difficulties and depressive symptoms. By contrast, lower-educated subjects presented a single period of decline lasting ∼7 years, characterized by

  3. Decreased recall of primacy words predicts cognitive decline.

    PubMed

    Bruno, Davide; Reiss, Philip T; Petkova, Eva; Sidtis, John J; Pomara, Nunzio

    2013-03-01

    One of the cognitive changes associated with Alzheimer's disease is a diminution of the primacy effect, i.e., the tendency toward better recall of items studied early on a list compared with the rest. We examined whether learning and recall of primacy words predicted subsequent cognitive decline in 204 elderly subjects who were non-demented and cognitively intact when first examined. Our results show that poorer primacy performance in the Rey Auditory Verbal Learning Test delayed recall trials, but not in immediate recall trials, is an effective predictor of subsequent decline in general cognitive function. This pattern of performance can be interpreted as evidence that failure to consolidate primacy items is a marker of cognitive decline.

  4. Fertility decline in rural China: a comparative analysis.

    PubMed

    Harrell, Stevan; Yuesheng, Wang; Hua, Han; Santos, Gonçalo D; Yingying, Zhou

    2011-01-01

    Many models have been proposed to explain both the rapidity of China's fertility decline after the 1960s and the differential timing of the decline in different places. In particular, scholars argue over whether deliberate policies of fertility control, institutional changes, or general modernization factors contribute most to changes in fertility behavior. Here the authors adopt an ethnographically grounded behavioral-institutional approach to analyze qualitative and quantitative data from three different rural settings: Xiaoshan County in Zhejiang (East China), Ci County in Hebei, (North China), and Yingde County in Guangdong (South China). The authors show that no one set of factors explain differential timing by a combination of differences in social-cultural environments (e.g. spread of education, reproductive ideologies, and gender relations) and politico-economic conditions (e.g. economic development, birth planning campaigns, and collective systems of labor organization) during the early phases of the fertility decline.

  5. The widespread threat of calcium decline in fresh waters.

    PubMed

    Jeziorski, Adam; Yan, Norman D; Paterson, Andrew M; Desellas, Anna M; Turner, Michael A; Jeffries, Dean S; Keller, Bill; Weeber, Russ C; McNicol, Don K; Palmer, Michelle E; McIver, Kyle; Arseneau, Kristina; Ginn, Brian K; Cumming, Brian F; Smol, John P

    2008-11-28

    Calcium concentrations are now commonly declining in softwater boreal lakes. Although the mechanisms leading to these declines are generally well known, the consequences for the aquatic biota have not yet been reported. By examining crustacean zooplankton remains preserved in lake sediment cores, we document near extirpations of calcium-rich Daphnia species, which are keystone herbivores in pelagic food webs, concurrent with declining lake-water calcium. A large proportion (62%, 47 to 81% by region) of the Canadian Shield lakes we examined has a calcium concentration approaching or below the threshold at which laboratory Daphnia populations suffer reduced survival and fecundity. The ecological impacts of environmental calcium loss are likely to be both widespread and pronounced. PMID:19039134

  6. Factors influencing the declining trend of vasectomy in Sichuan, China.

    PubMed

    Nian, Cui; Xiaozhang, Liu; Xiaofang, Pan; Qing, Yang; Minxiang, Li

    2010-07-01

    Vasectomy was once the most common birth control method in both Sichuan Province, China and the world. However, since the 1990s the prevalence of vasectomy in Sichuan, has declined significantly compared to female sterilization in Sichuan and national prevalence of male/female sterilization during the same period. To explore possible reasons for this decline, 27 focus group discussions (FGDs) and 8 in-depth interviews (IDIs) were conducted in four strata of Sichuan. Procedures for qualitative data analysis were used. The findings reveal the decline in vasectomy in Sichuan Province is influenced by multiple factors, including shifts in demographics, changes in family planning working approach and people's perceptions of reproduction, lack of information and misunderstandings about vasectomy, the stereotype of male dominance, bias and preference of program and provider, and the impact of a market economy. Several implications arise from the study for future program development.

  7. The widespread threat of calcium decline in fresh waters.

    PubMed

    Jeziorski, Adam; Yan, Norman D; Paterson, Andrew M; Desellas, Anna M; Turner, Michael A; Jeffries, Dean S; Keller, Bill; Weeber, Russ C; McNicol, Don K; Palmer, Michelle E; McIver, Kyle; Arseneau, Kristina; Ginn, Brian K; Cumming, Brian F; Smol, John P

    2008-11-28

    Calcium concentrations are now commonly declining in softwater boreal lakes. Although the mechanisms leading to these declines are generally well known, the consequences for the aquatic biota have not yet been reported. By examining crustacean zooplankton remains preserved in lake sediment cores, we document near extirpations of calcium-rich Daphnia species, which are keystone herbivores in pelagic food webs, concurrent with declining lake-water calcium. A large proportion (62%, 47 to 81% by region) of the Canadian Shield lakes we examined has a calcium concentration approaching or below the threshold at which laboratory Daphnia populations suffer reduced survival and fecundity. The ecological impacts of environmental calcium loss are likely to be both widespread and pronounced.

  8. On the decline of biodiversity due to area loss

    PubMed Central

    Keil, Petr; Storch, David; Jetz, Walter

    2015-01-01

    Predictions of how different facets of biodiversity decline with habitat loss are broadly needed, yet challenging. Here we provide theory and a global empirical evaluation to address this challenge. We show that extinction estimates based on endemics–area and backward species–area relationships are complementary, and the crucial difference comprises the geometry of area loss. Across three taxa on four continents, the relative loss of species, and of phylogenetic and functional diversity, is highest when habitable area disappears inward from the edge of a region, lower when it disappears from the centre outwards, and lowest when area is lost at random. In inward destruction, species loss is almost proportional to area loss, although the decline in phylogenetic and functional diversity is less severe. These trends are explained by the geometry of species ranges and the shape of phylogenetic and functional trees, which may allow baseline predictions of biodiversity decline for underexplored taxa. PMID:26575347

  9. Test of the invasive pathogen hypothesis of bumble bee decline in North America.

    PubMed

    Cameron, Sydney A; Lim, Haw Chuan; Lozier, Jeffrey D; Duennes, Michelle A; Thorp, Robbin

    2016-04-19

    Emergent fungal diseases are critical factors in global biodiversity declines. The fungal pathogenNosema bombiwas recently found to be widespread in declining species of North American bumble bees (Bombus), with circumstantial evidence suggesting an exotic introduction from Europe. This interpretation has been hampered by a lack of knowledge of global genetic variation, geographic origin, and changing prevalence patterns ofN. bombiin declining North American populations. Thus, the temporal and spatial emergence ofN. bombiand its potential role in bumble bee decline remain speculative. We analyzeNosemaprevalence and genetic variation in the United States and Europe from 1980, before an alleged introduction in the early 1990s, to 2011, extractingNosemaDNA fromBombusnatural history collection specimens from across this time period.Nosema bombiprevalence increased significantly from low detectable frequency in the 1980s to significantly higher frequency in the mid- to late-1990s, corresponding to a period of reported massive infectious outbreak ofN. bombiin commercial bumble bee rearing stocks in North America. Despite the increased frequency, we find no conclusive evidence of an exoticN. bombiorigin based on genetic analysis of globalNosemapopulations; the widespreadNosemastrain found currently in declining United States bumble bees was present in the United States before commercial colony trade. Notably, the USN. bombiis not detectably different from that found predominantly throughout Western Europe, with both regions characterized by low genetic diversity compared with high levels of diversity found in Asia, where commercial bee breeding activities are low or nonexistent. PMID:27044096

  10. Can psychosocial work conditions protect against age-related cognitive decline? Results from a systematic review.

    PubMed

    Nexø, Mette Andersen; Meng, Annette; Borg, Vilhelm

    2016-07-01

    According to the use it or lose it hypothesis, intellectually stimulating activities postpone age-related cognitive decline. A previous systematic review concluded that a high level of mental work demands and job control protected against cognitive decline. However, it did not distinguish between outcomes that were measured as cognitive function at one point in time or as cognitive decline. Our study aimed to systematically review which psychosocial working conditions were prospectively associated with high levels of cognitive function and/or changes in cognitive function over time. Articles were identified by a systematic literature search (MEDLINE, Web of Science (WOS), PsycNET, Occupational Safety and Health (OSH)). We included only studies with longitudinal designs examining the impact of psychosocial work conditions on outcomes defined as cognitive function or changes in cognitive function. Two independent reviewers compared title-abstract screenings, full-text screenings and quality assessment ratings. Eleven studies were included in the final synthesis and showed that high levels of mental work demands, occupational complexity or job control at one point in time were prospectively associated with higher levels of cognitive function in midlife or late life. However, the evidence to clarify whether these psychosocial factors also affected cognitive decline was insufficient, conflicting or weak. It remains speculative whether job control, job demands or occupational complexity can protect against cognitive decline. Future studies using methodological advancements can reveal whether workers gain more cognitive reserve in midlife and late life than the available evidence currently suggests. The public health implications of a previous review should thereby be redefined accordingly. PMID:27178844

  11. Test of the invasive pathogen hypothesis of bumble bee decline in North America.

    PubMed

    Cameron, Sydney A; Lim, Haw Chuan; Lozier, Jeffrey D; Duennes, Michelle A; Thorp, Robbin

    2016-04-19

    Emergent fungal diseases are critical factors in global biodiversity declines. The fungal pathogenNosema bombiwas recently found to be widespread in declining species of North American bumble bees (Bombus), with circumstantial evidence suggesting an exotic introduction from Europe. This interpretation has been hampered by a lack of knowledge of global genetic variation, geographic origin, and changing prevalence patterns ofN. bombiin declining North American populations. Thus, the temporal and spatial emergence ofN. bombiand its potential role in bumble bee decline remain speculative. We analyzeNosemaprevalence and genetic variation in the United States and Europe from 1980, before an alleged introduction in the early 1990s, to 2011, extractingNosemaDNA fromBombusnatural history collection specimens from across this time period.Nosema bombiprevalence increased significantly from low detectable frequency in the 1980s to significantly higher frequency in the mid- to late-1990s, corresponding to a period of reported massive infectious outbreak ofN. bombiin commercial bumble bee rearing stocks in North America. Despite the increased frequency, we find no conclusive evidence of an exoticN. bombiorigin based on genetic analysis of globalNosemapopulations; the widespreadNosemastrain found currently in declining United States bumble bees was present in the United States before commercial colony trade. Notably, the USN. bombiis not detectably different from that found predominantly throughout Western Europe, with both regions characterized by low genetic diversity compared with high levels of diversity found in Asia, where commercial bee breeding activities are low or nonexistent.

  12. Can psychosocial work conditions protect against age-related cognitive decline? Results from a systematic review

    PubMed Central

    Nexø, Mette Andersen; Meng, Annette; Borg, Vilhelm

    2016-01-01

    According to the use it or lose it hypothesis, intellectually stimulating activities postpone age-related cognitive decline. A previous systematic review concluded that a high level of mental work demands and job control protected against cognitive decline. However, it did not distinguish between outcomes that were measured as cognitive function at one point in time or as cognitive decline. Our study aimed to systematically review which psychosocial working conditions were prospectively associated with high levels of cognitive function and/or changes in cognitive function over time. Articles were identified by a systematic literature search (MEDLINE, Web of Science (WOS), PsycNET, Occupational Safety and Health (OSH)). We included only studies with longitudinal designs examining the impact of psychosocial work conditions on outcomes defined as cognitive function or changes in cognitive function. Two independent reviewers compared title-abstract screenings, full-text screenings and quality assessment ratings. Eleven studies were included in the final synthesis and showed that high levels of mental work demands, occupational complexity or job control at one point in time were prospectively associated with higher levels of cognitive function in midlife or late life. However, the evidence to clarify whether these psychosocial factors also affected cognitive decline was insufficient, conflicting or weak. It remains speculative whether job control, job demands or occupational complexity can protect against cognitive decline. Future studies using methodological advancements can reveal whether workers gain more cognitive reserve in midlife and late life than the available evidence currently suggests. The public health implications of a previous review should thereby be redefined accordingly. PMID:27178844

  13. Test of the invasive pathogen hypothesis of bumble bee decline in North America

    PubMed Central

    Cameron, Sydney A.; Lim, Haw Chuan; Lozier, Jeffrey D.; Duennes, Michelle A.; Thorp, Robbin

    2016-01-01

    Emergent fungal diseases are critical factors in global biodiversity declines. The fungal pathogen Nosema bombi was recently found to be widespread in declining species of North American bumble bees (Bombus), with circumstantial evidence suggesting an exotic introduction from Europe. This interpretation has been hampered by a lack of knowledge of global genetic variation, geographic origin, and changing prevalence patterns of N. bombi in declining North American populations. Thus, the temporal and spatial emergence of N. bombi and its potential role in bumble bee decline remain speculative. We analyze Nosema prevalence and genetic variation in the United States and Europe from 1980, before an alleged introduction in the early 1990s, to 2011, extracting Nosema DNA from Bombus natural history collection specimens from across this time period. Nosema bombi prevalence increased significantly from low detectable frequency in the 1980s to significantly higher frequency in the mid- to late-1990s, corresponding to a period of reported massive infectious outbreak of N. bombi in commercial bumble bee rearing stocks in North America. Despite the increased frequency, we find no conclusive evidence of an exotic N. bombi origin based on genetic analysis of global Nosema populations; the widespread Nosema strain found currently in declining United States bumble bees was present in the United States before commercial colony trade. Notably, the US N. bombi is not detectably different from that found predominantly throughout Western Europe, with both regions characterized by low genetic diversity compared with high levels of diversity found in Asia, where commercial bee breeding activities are low or nonexistent. PMID:27044096

  14. Recent water level declines in the Lake Michigan-Huron system.

    PubMed

    Sellinger, Cynthia E; Stow, Craig A; Lamon, E Conrad; Qian, Song S

    2008-01-15

    Great Lakes water levels have fluctuated over thousands of years. High water levels were a problem in the 1980s, but a recent sudden drop in Lakes Michigan and Huron has caused particular concern, in part because lower water levels are consistent with many global climate change scenarios. We examined water level data (1860-2006) representing Lakes Michigan and Huron to evaluate changes in both long-term and seasonal patterns over time, and explore relationships with candidate predictor variables. Our tools for this analysis included both Seasonal Trend decomposition using Loess (STL), and dynamic linear models (DLM). In addition to the recent decline, STL results reveal a sustained decline around 1900, a long-term periodicity of approximately 30 years, and an unexpected correspondence with sunspot activity. DLM results indicate a relationship with precipitation over a three-year lagged period, which has been essentially unchanging from 1900 to present. Additionally, the DLM highlights an underlying lake level decline beginning in approximately 1973 and continuing to the present, which may have been obscured by concurrently increasing precipitation into the 1990s. The current underlying decline might be related to a simultaneous evaporation increase, however, our model could not confirm this relationship, possibly due to the shorter period of record for evaporation data. We cannot be certain that the present observed water level drop is caused by factors related to global climate change, orthat it portends a long-term problem. However, because the underlying decline has been ongoing for approximately 33 years it may be prudent to include lower lake levels in future management planning. PMID:18284132

  15. Gradual decline in mobility with the adoption of food production in Europe

    PubMed Central

    Ruff, Christopher B.; Holt, Brigitte; Niskanen, Markku; Sladek, Vladimir; Berner, Margit; Garofalo, Evan; Garvin, Heather M.; Hora, Martin; Junno, Juho-Antti; Schuplerova, Eliska; Vilkama, Rosa; Whittey, Erin

    2015-01-01

    Increased sedentism during the Holocene has been proposed as a major cause of decreased skeletal robusticity (bone strength relative to body size) in modern humans. When and why declining mobility occurred has profound implications for reconstructing past population history and health, but it has proven difficult to characterize archaeologically. In this study we evaluate temporal trends in relative strength of the upper and lower limb bones in a sample of 1,842 individuals from across Europe extending from the Upper Paleolithic [11,000–33,000 calibrated years (Cal y) B.P.] through the 20th century. A large decline in anteroposterior bending strength of the femur and tibia occurs beginning in the Neolithic (∼4,000–7,000 Cal y B.P.) and continues through the Iron/Roman period (∼2,000 Cal y B.P.), with no subsequent directional change. Declines in mediolateral bending strength of the lower limb bones and strength of the humerus are much smaller and less consistent. Together these results strongly implicate declining mobility as the specific behavioral factor underlying these changes. Mobility levels first declined at the onset of food production, but the transition to a more sedentary lifestyle was gradual, extending through later agricultural intensification. This finding only partially supports models that tie increased sedentism to a relatively abrupt Neolithic Demographic Transition in Europe. The lack of subsequent change in relative bone strength indicates that increasing mechanization and urbanization had only relatively small effects on skeletal robusticity, suggesting that moderate changes in activity level are not sufficient stimuli for bone deposition or resorption. PMID:26060299

  16. Declining populations of the fingernail clam Musculium transversum in the upper Mississippi River

    USGS Publications Warehouse

    Wilson, D.M.; Naimo, T.J.; Weiner, J.G.; Anderson, R.V.; Sandheinrich, M.B.; Sparks, R.E.

    1995-01-01

    We examined recent temporal trends in the abundance of fingernail clams Musculium transversum (formerly Sphaerium transversum) in the upper Mississippi River. Historical data on densities of fingernail clams were obtained from regional scientists and published literature. We also sampled benthos in six navigation pools in summer 1991, finding very few fingernail clams. The combined data set, including historical data and sampling results, extended from 1973 to 1992 and was sufficient to statistically evaluate trends in densities of fingernail clams in eight pools. Populations of fingernail clams declined significantly in five of the eight pools examined (Pools 2, 5, 7, 9, and 19), which spanned a 700-km reach of river from St. Paul, Minnesota, to Keokuk, Iowa. Densities in Pool 19, which had the longest historical record on fingernail clam abundance, averaged 30 000 m super(-2) in 1985 and progressively declined to zero in 1990. Combined data from all eight pools showed a significant decline in abundance of fingernail clams. An evaluation of potential causal factors led us to hypothesize that the population declines in Pools 2 to 9 were linked to point-source pollution rather than to dredging activity or commercial navigation traffic. In Pool 19, the declines of fingernail clams may have resulted from low-flow conditions during drought periods, but the causal mechanisms by which low flow influences fingernail clam abundance are unclear. The decrease in fingernail clam populations may adversely affect certain fish and wildlife, such as migrating lesser scaup Aythya affinis, which feed heavily on the small mollusk. Moreover, the decreases in populations of this pollution-sensitive mollusk may signal a large-scale deterioration in the health of this riverine ecosystem.

  17. Rapid Decline of a Grassland System and Its Ecological and Conservation Implications

    PubMed Central

    Ceballos, Gerardo; Davidson, Ana; List, Rurik; Pacheco, Jesús; Manzano-Fischer, Patricia; Santos-Barrera, Georgina; Cruzado, Juan

    2010-01-01

    One of the most important conservation issues in ecology is the imperiled state of grassland ecosystems worldwide due to land conversion, desertification, and the loss of native populations and species. The Janos region of northwestern Mexico maintains one of the largest remaining black-tailed prairie dog (Cynomys ludovicianus) colony complexes in North America and supports a high diversity of threatened and endangered species. Yet, cattle grazing, agriculture, and drought have greatly impacted the region. We evaluated the impact of human activities on the Janos grasslands, comparing changes in the vertebrate community over the last two decades. Our results reveal profound, rapid changes in the Janos grassland community, demonstrating large declines in vertebrate abundance across all taxonomic groups. We also found that the 55,000 ha prairie dog colony complex has declined by 73% since 1988. The prairie dog complex has become increasingly fragmented, and their densities have shown a precipitous decline over the years, from an average density of 25 per ha in 1988 to 2 per ha in 2004. We demonstrated that prairie dogs strongly suppressed woody plant encroachment as well as created open grassland habitat by clearing woody vegetation, and found rapid invasion of shrubland once the prairie dogs disappeared from the grasslands. Comparison of grasslands and shrublands showed markedly different species compositions, with species richness being greatest when both habitats were considered together. Our data demonstrate the rapid decline of a grassland ecosystem, and documents the dramatic loss in biodiversity over a very short time period concomitant with anthropogenic grassland degradation and the decline of a keystone species. PMID:20066035

  18. Gradual decline in mobility with the adoption of food production in Europe.

    PubMed

    Ruff, Christopher B; Holt, Brigitte; Niskanen, Markku; Sladek, Vladimir; Berner, Margit; Garofalo, Evan; Garvin, Heather M; Hora, Martin; Junno, Juho-Antti; Schuplerova, Eliska; Vilkama, Rosa; Whittey, Erin

    2015-06-01

    Increased sedentism during the Holocene has been proposed as a major cause of decreased skeletal robusticity (bone strength relative to body size) in modern humans. When and why declining mobility occurred has profound implications for reconstructing past population history and health, but it has proven difficult to characterize archaeologically. In this study we evaluate temporal trends in relative strength of the upper and lower limb bones in a sample of 1,842 individuals from across Europe extending from the Upper Paleolithic [11,000-33,000 calibrated years (Cal y) B.P.] through the 20th century. A large decline in anteroposterior bending strength of the femur and tibia occurs beginning in the Neolithic (∼ 4,000-7,000 Cal y B.P.) and continues through the Iron/Roman period (∼ 2,000 Cal y B.P.), with no subsequent directional change. Declines in mediolateral bending strength of the lower limb bones and strength of the humerus are much smaller and less consistent. Together these results strongly implicate declining mobility as the specific behavioral factor underlying these changes. Mobility levels first declined at the onset of food production, but the transition to a more sedentary lifestyle was gradual, extending through later agricultural intensification. This finding only partially supports models that tie increased sedentism to a relatively abrupt Neolithic Demographic Transition in Europe. The lack of subsequent change in relative bone strength indicates that increasing mechanization and urbanization had only relatively small effects on skeletal robusticity, suggesting that moderate changes in activity level are not sufficient stimuli for bone deposition or resorption.

  19. Women With Peripheral Arterial Disease Experience Faster Functional Decline Than Men With Peripheral Arterial Disease

    PubMed Central

    McDermott, Mary M.; Ferrucci, Luigi; Liu, Kiang; Guralnik, Jack M.; Tian, Lu; Kibbe, Melina; Liao, Yihua; Tao, Huimin; Criqui, Michael H.

    2016-01-01

    Objectives We hypothesized that women with lower extremity peripheral arterial disease (PAD) would have greater mobility loss and faster functional decline than men with PAD. Background Whether rates of mobility loss or functional decline differ between men and women with PAD is currently unknown. Methods Three hundred eighty men and women with PAD completed the 6-min walk, were assessed for mobility disability, and underwent measures of 4-m walking velocity at baseline and annually for up to 4 years. Computed tomography-assessed calf muscle characteristics were measured biannually. Outcomes included becoming unable to walk for 6 min continuously among participants who walked continuously for 6 min at baseline. Mobility loss was defined as becoming unable to walk for a quarter mile or to walk up and down 1 flight of stairs without assistance among those without baseline mobility disability. Results were adjusted for age, race, body mass index, physical activity, the ankle brachial index, comorbidities, and other confounders. Results At 4 years of follow-up, women were more likely to become unable to walk for 6 min continuously (hazard ratio: 2.30, 95% confidence interval: 1.30 to 4.06, p = 0.004), more likely to develop mobility disability (hazard ratio: 1.79, 95% confidence interval: 1.30 to 3.03, p = 0.030), and had faster declines in walking velocity (p = 0.022) and the distance achieved in the 6-min walk (p = 0.041) compared with men. Sex differences in functional decline were attenuated after additional adjustment for baseline sex differences in calf muscle area. Conclusions Women with PAD have faster functional decline and greater mobility loss than men with PAD. These sex differences may be attributable to smaller baseline calf muscle area among women with PAD. PMID:21292130

  20. Towards the Understanding of Recent Lake Decline in the Yangtze Basin

    NASA Astrophysics Data System (ADS)

    Wang, J.; Sheng, Y.; Wada, Y.

    2014-12-01

    In the era of Anthropocene, lakes as essential stocks of terrestrial water resources are subject to increasing vulnerability from both climatic variations and human activities. Our recent study reveals a decadal area decline among the largest cluster of freshwater lakes in East Asia, distributed across the Yangtze River Basin downstream of China's Three Gorges Dam (TGD). The observed lake decline, a cumulative rate of 7.4% (~850 km2) from 2000 to 2011, concurred with enduring meteorological drought, continuous population growth, and extensive human water regulation (e.g., the TGD). The decreasing trend was tested significant in all seasons, leading to an evident phase drop of the average annual lake cycle before and after the TGD operation. The most substantial decline in the post-TGD period appears in fall (1.1% yr-1), which intriguingly coincides with the TGD water storage season. Motivated by such findings, this paper provides a comprehensive diagnosis of the potential TGD impacts on the Yangtze-connected downstream lake system, in comparison to the concurrent contributions from local meteorological variations and human water consumption. Results uncover an altered inundation regime of the downstream lake system induced by TGD's water regulation, manifested as evident lake area decrease in fall and increase in spring and winter. As the most substantial influence, reduced lake area in fall explains ~20-80% of the observed post-TGD decline. Concurrent Yangtze channel erosion slightly reinforced the area decrease in fall while counteracting ~30% of the area increase in winter. Human water consumption accumulated through the local river network led to constant discharge reduction, which equals another ~80% of the TGD-induced lake decline in fall and completely counteracts the TGD-induced lake area increase in winter. However, human water consumption only adds minor contribution (< 6%) to the post-TGD lake decline due to slow increasing rates during 2000-2011. The

  1. Trajectory of Mobility Decline by Type of Dementia.

    PubMed

    Tolea, Magdalena I; Morris, John C; Galvin, James E

    2016-01-01

    Cognitive and physical aspects of functionality are closely related. However, whether physical decline differs by dementia type and progression rate is debatable. To address these issues, we conducted a longitudinal study of 766 older adults whose physical performance and cognitive status were assessed annually with standard assessment tools [eg, Physical Performance Test, Clinical Dementia Rate (CDR)] for 8 years. Compared with participants who remained cognitively normal, those progressing to later-stage dementia (CDR=1) declined in their mobility by a factor of 2.82 (P<0.001), followed by those who maintained a later-stage diagnosis (slope=-1.84, P<0.001), those progressing from early-stage to later-stage (CDR=0.5 to CDR=1) dementia (slope=-1.20, P<0.001), and those who progressed to early-stage dementia (slope=-0.39, P=0.038) suggesting a steeper physical decline with dementia progression, particularly in those with the fastest disease progression. Although all types of dementia experienced mobility decline, those progressing to non-Alzheimer disease (AD) dementias, especially vascular dementia declined faster than those who remained normal (slope=-2.70, P<0.001) or progressed to AD (slope=-2.18, P<0.001). These associations were better captured by the gait/balance component of physical functionality. Our findings suggest that rapidly progressing dementia patients particularly those with non-AD subtypes should be targeted for interventions to maintain or improve gait/balance and prevent functional decline and disability although AD patients may also benefit.

  2. Demography and decline of the Mentasta Caribou Herd, Alaska

    USGS Publications Warehouse

    Jenkins, Kurt J.; Barten, Neil L.

    2005-01-01

    We evaluated population trends in the Mentasta caribou (Rangifer tarandus (L., 1758)) herd in Wrangell a?? St. Elias National Park and Preserve, Alaska, from 1990 to 1997 and determined factors contributing to its decline. We postulated that predation-related mortality of adult females and juveniles was the proximate cause of the decline, and that survival of juvenile caribou reflected interactions with winter severity, calving distribution, timing of births, density of caribou, and physical condition of neonates at birth. The population declined at its greatest rate from 1990 to 1993 (r = a??0.32) and at a lower rate from 1994 to 1997 (r = a??0.09). Recruitment (number of calves/100 females during September) averaged 4/100 during the rapid population decline from 1990 to 1993 and 13/100 from 1994 to 1997. Parturition rate of adult females ranged from 65% to 97%. Survival of adult females and juveniles ranged from 0.77 to 0.86 and from 0.00 to 0.22, respectively. Approximately 43%, 59%, and 79% of all juvenile mortality occurred by 1, 2, and 4 weeks of age, respectively. We confirmed predation-related mortality as the primary proximate cause of population decline, with gray wolves (Canis lupus L., 1758), bears (species of the genus Ursus L., 1758), and other predators accounting for 57%, 38%, and 5%, respectively, of all juvenile mortality, and bears causing disproportionate mortality among 0- to 1-week-old neonates. We supported the hypotheses that timing of birth and habitat conditions at the birth site, particularly mottled snow patterns, affected vulnerability and survival of neonates, and birth mass affected survival of juveniles through summer. We speculate that the population will continue to decline before reaching a low-density equilibrium that is sustained by density-dependent changes in the functional responses of predators.

  3. Atrial Fibrillation, Neurocognitive Decline and Gene Expression After Cardiopulmonary Bypass

    PubMed Central

    Dalal, Rahul S.; Sabe, Ashraf A.; Elmadhun, Nassrene Y.; Ramlawi, Basel; Sellke, Frank W.

    2015-01-01

    OBJECTIVE Atrial fibrillation and neurocognitive decline are common complications after cardiopulmonary bypass. By utilizing genomic microarrays we investigate whether gene expression is associated with postoperative atrial fibrillation and neurocognitive decline. METHODS Twenty one cardiac surgery patients were prospectively matched and underwent neurocognitive assessments pre-operatively and four days postoperatively. The whole blood collected in the pre-cardiopulmonary bypass, 6 hours after-cardiopulmonary bypass, and on the 4th postoperative day was hybridized to Affymetrix Gene Chip U133 Plus 2.0 Microarrays. Gene expression in patients who developed postoperative atrial fibrillation and neurocognitive decline (n=6; POAF+NCD) was compared with gene expression in patients with postoperative atrial fibrillation and normal cognitive function (n=5; POAF+NORM) and patients with sinus rhythm and normal cognitive function (n=10; SR+NORM). Regulated genes were identified using JMP Genomics 4.0 with a false discovery rate of 0.05 and fold change of >1.5 or <-1.5. RESULTS Eleven patients developed postoperative atrial fibrillation. Six of these also developed neurocognitive decline. Of the 12 patients with sinus rhythm, only 2 developed neurocognitive decline. POAF+NCD patients had unique regulation of 17 named genes preoperatively, 60 named genes six hours after cardiopulmonary bypass, and 34 named genes four days postoperatively (P<0.05) compared with normal patients. Pathway analysis demonstrated that these genes are involved in cell death, inflammation, cardiac remodeling and nervous system function. CONCLUSION Patients who developed postoperative atrial fibrillation and neurocognitive decline after cardiopulmonary bypass may have differential genomic responses compared to normal patients and patients with only postoperative atrial fibrillation, suggesting common pathophysiology for these conditions. Further exploration of these genes may provide insight into the

  4. Decline in maternal mortality in Matlab, Bangladesh: a cautionary tale.

    PubMed

    Ronsmans, C; Vanneste, A M; Chakraborty, J; van Ginneken, J

    This study examines the impact of the Maternal-Child Health and Family Planning (MCH-FP) program in the Matlab, Bangladesh. Data were obtained from the Matlab surveillance system for treatment and comparison areas. This study reports the trends in maternal mortality since 1976. The MCH-FP area received extensive services in health and family planning since 1977. Services included trained traditional birth attendants and essential obstetric care from government district hospitals and a large number of private clinics. Geographic ease of access to essential obstetric care varied across the study area. Access was most difficult in the northern sector of the MCH-FP area. Contraception was made available through family welfare centers. Tetanus immunization was introduced in 1979. Door-to-door contraceptive services were provided by 80 female community health workers on a twice-monthly basis. In 1987, a community-based maternity care program was added to existing MCH-FP services in the northern treatment area. The demographic surveillance system began collecting data in 1966. During 1976-93 there were 624 maternal deaths among women aged 15-44 years in Matlab (510/100,000 live births). 72.8% of deaths were due to direct obstetric causes: postpartum hemorrhage, induced abortion, eclampsia, dystocia, and postpartum sepsis. Maternal mortality declined in a fluctuating fashion in both treatment and comparison areas. Direct obstetric mortality declined at about 3% per year. After 1987, direct obstetric mortality declined in the north by almost 50%. After the 1990 program expansion in the south, maternal mortality declined, though not significantly, in the south. Maternal mortality declined in the south comparison area during 1987-89 and stabilized. The comparison area of the north showed no decline. PMID:9428252

  5. Trajectory of Mobility Decline by Type of Dementia.

    PubMed

    Tolea, Magdalena I; Morris, John C; Galvin, James E

    2016-01-01

    Cognitive and physical aspects of functionality are closely related. However, whether physical decline differs by dementia type and progression rate is debatable. To address these issues, we conducted a longitudinal study of 766 older adults whose physical performance and cognitive status were assessed annually with standard assessment tools [eg, Physical Performance Test, Clinical Dementia Rate (CDR)] for 8 years. Compared with participants who remained cognitively normal, those progressing to later-stage dementia (CDR=1) declined in their mobility by a factor of 2.82 (P<0.001), followed by those who maintained a later-stage diagnosis (slope=-1.84, P<0.001), those progressing from early-stage to later-stage (CDR=0.5 to CDR=1) dementia (slope=-1.20, P<0.001), and those who progressed to early-stage dementia (slope=-0.39, P=0.038) suggesting a steeper physical decline with dementia progression, particularly in those with the fastest disease progression. Although all types of dementia experienced mobility decline, those progressing to non-Alzheimer disease (AD) dementias, especially vascular dementia declined faster than those who remained normal (slope=-2.70, P<0.001) or progressed to AD (slope=-2.18, P<0.001). These associations were better captured by the gait/balance component of physical functionality. Our findings suggest that rapidly progressing dementia patients particularly those with non-AD subtypes should be targeted for interventions to maintain or improve gait/balance and prevent functional decline and disability although AD patients may also benefit. PMID:25886717

  6. TDP-43 Pathology, Cognitive Decline, and Dementia in Old Age

    PubMed Central

    Wilson, Robert S.; Yu, Lei; Trojanowski, John Q.; Chen, Er-Yun; Boyle, Patricia A.; Bennett, David A.; Schneider, Julie A.

    2013-01-01

    Importance Cognitive decline is a leading cause of disability and death in old age but its neurobiological bases are not well understood. Objective To test the hypothesis that transactive response DNA-binding protein 43 (TDP-43) is related to late life cognitive decline. Design Longitudinal clinical-pathologic cohort study. Setting More than 40 Catholic groups across the United States. Participants A total of 130 older Catholic nuns, priests, and monks underwent annual clinical evaluations, including detailed cognitive testing, for a mean of 10.1 years prior to death. On neuropathologic examination, we collected semiquantitative measures of TDP-43 pathology, density of neuronal neurofibrillary tangles, area occupied by amyloid-beta plaques, and the presence of alpha-synuclein Lewy bodies from multiple brain regions. Gross and microscopic cerebral infarcts and hippocampal sclerosis were also identified. Main Outcome Measure Annual rate of change in a previously established composite measure of global cognition during a mean of 10.1 years of annual observation before death. Results TDP-43 pathology ranging from sparse to severe was identified in 46% of participants and was associated with amyloid plaques, tangles, and hippocampal sclerosis but not neocortical Lewy bodies or cerebral infarcts. After controlling for amyloid plaques, tangles, and hippocampal sclerosis, TDP-43 pathology was associated with more rapid cognitive decline and accounted for nearly as much of the variability in rates of global cognitive decline as did tangles. TDP-43 pathology had a distinct cognitive profile that differed from other neuropathologic processes (related to decline in episodic and working memory but not in other cognitive domains), and it was elevated in those who developed dementia but not in those with mild cognitive impairment. Conclusion The results suggest that TDP-43 is an important brain pathology underlying cognitive decline and dementia in old age. PMID:24080705

  7. Compensatory larger cortical thickness in healthy elderly individuals with electroencephalographic risk for cognitive decline.

    PubMed

    Castro-Chavira, Susana A; Barrios, Fernando A; Pasaye, Erick H; Alatorre-Cruz, Graciela C; Fernández, Thalía

    2016-06-15

    Excess theta electroencephalographic (EEG) activity has been described as an accurate predictor for cognitive decline at least 7 years before symptom presentation. To test whether this predictor for cognitive decline correlates with structural changes in the brains of healthy elderly individuals, we compared the magnetic resonance structural images of healthy individuals with excess of theta activity [group with a risk for cognitive decline, risk group (RG); n=14] with healthy controls with normal EEG activity (control group; n=14). Neuropsychological and epidemiological analyses showed significant differences in only two features: more years of education and better performance in the visuospatial process task in the control group. Voxel-based morphometry results were not conclusive, but showed tendencies toward larger volumes in the prefrontal and parietal lobes, and smaller volumes in the right temporal lobe, right occipital lobe, and left cerebellum for the RG; these tendencies are in agreement with those proposed by the posterior-anterior shift in an aging model. Cortical-thickness analyses yielded a significant correlation between cortical thickness and years of education in the prefrontal and inferior-temporal regions, and larger cortical thickness in the RG, independent of age and years of education, in the right superior temporal region. These results suggest changes in the cortical thickness of structures related to memory and visuospatial functions in healthy, cognitively normal individuals before the appearance of cognitive decline. Thus, the performance of healthy elderly individuals with EEG risk may only be slightly different from normal because of compensation mechanisms allowing them to fulfill daily-life tasks, masking structural changes during preclinical neurocognitive disorders. PMID:27171033

  8. Functional MRI evidence for the decline of word retrieval and generation during normal aging.

    PubMed

    Baciu, M; Boudiaf, N; Cousin, E; Perrone-Bertolotti, M; Pichat, C; Fournet, N; Chainay, H; Lamalle, L; Krainik, A

    2016-02-01

    This fMRI study aimed to explore the effect of normal aging on word retrieval and generation. The question addressed is whether lexical production decline is determined by a direct mechanism, which concerns the language operations or is rather indirectly induced by a decline of executive functions. Indeed, the main hypothesis was that normal aging does not induce loss of lexical knowledge, but there is only a general slowdown in retrieval mechanisms involved in lexical processing, due to possible decline of the executive functions. We used three tasks (verbal fluency, object naming, and semantic categorization). Two groups of participants were tested (Young, Y and Aged, A), without cognitive and psychiatric impairment and showing similar levels of vocabulary. Neuropsychological testing revealed that older participants had lower executive function scores, longer processing speeds, and tended to have lower verbal fluency scores. Additionally, older participants showed higher scores for verbal automatisms and overlearned information. In terms of behavioral data, older participants performed as accurate as younger adults, but they were significantly slower for the semantic categorization and were less fluent for verbal fluency task. Functional MRI analyses suggested that older adults did not simply activate fewer brain regions involved in word production, but they actually showed an atypical pattern of activation. Significant correlations between the BOLD (Blood Oxygen Level Dependent) signal of aging-related (A > Y) regions and cognitive scores suggested that this atypical pattern of the activation may reveal several compensatory mechanisms (a) to overcome the slowdown in retrieval, due to the decline of executive functions and processing speed and (b) to inhibit verbal automatic processes. The BOLD signal measured in some other aging-dependent regions did not correlate with the behavioral and neuropsychological scores, and the overactivation of these uncorrelated

  9. Functional MRI evidence for the decline of word retrieval and generation during normal aging.

    PubMed

    Baciu, M; Boudiaf, N; Cousin, E; Perrone-Bertolotti, M; Pichat, C; Fournet, N; Chainay, H; Lamalle, L; Krainik, A

    2016-02-01

    This fMRI study aimed to explore the effect of normal aging on word retrieval and generation. The question addressed is whether lexical production decline is determined by a direct mechanism, which concerns the language operations or is rather indirectly induced by a decline of executive functions. Indeed, the main hypothesis was that normal aging does not induce loss of lexical knowledge, but there is only a general slowdown in retrieval mechanisms involved in lexical processing, due to possible decline of the executive functions. We used three tasks (verbal fluency, object naming, and semantic categorization). Two groups of participants were tested (Young, Y and Aged, A), without cognitive and psychiatric impairment and showing similar levels of vocabulary. Neuropsychological testing revealed that older participants had lower executive function scores, longer processing speeds, and tended to have lower verbal fluency scores. Additionally, older participants showed higher scores for verbal automatisms and overlearned information. In terms of behavioral data, older participants performed as accurate as younger adults, but they were significantly slower for the semantic categorization and were less fluent for verbal fluency task. Functional MRI analyses suggested that older adults did not simply activate fewer brain regions involved in word production, but they actually showed an atypical pattern of activation. Significant correlations between the BOLD (Blood Oxygen Level Dependent) signal of aging-related (A > Y) regions and cognitive scores suggested that this atypical pattern of the activation may reveal several compensatory mechanisms (a) to overcome the slowdown in retrieval, due to the decline of executive functions and processing speed and (b) to inhibit verbal automatic processes. The BOLD signal measured in some other aging-dependent regions did not correlate with the behavioral and neuropsychological scores, and the overactivation of these uncorrelated

  10. Amphibian decline: An integrated analysis of multiple stressor effects

    USGS Publications Warehouse

    Linder, G.; Krest, S.K.; Sparling, D. W.; Linder, G.; Krest, S.K.; Sparling, D.W.

    2003-01-01

    Capturing the attention and imagination of the public and the scientific community alike, the mysterious decline in amphibian populations drew scientists and resource managers from ecotoxicology and chemistry, ecology and field biology, conservation biology, and natural resource policy to a SETAC–Johnson Foundation workshop. Facilitating environmental stewardship, increasing capacity of the sciences to explain complex stressors, and educating the public on relationships among communities of all types motivated these experts to address amphibian decline and the role of various stressors in these losses.

  11. How personal is the political? Democratic revolution and fertility decline.

    PubMed

    Bailey, Amy Kate

    2009-10-01

    Existing theory has identified the capacity of political revolutions to effect change in a variety of social institutions, although relationships between revolution and many institutions remain unexplored. Using historical data from twenty-two European and four diaspora countries, the author examines the temporal relationship between timing of revolution and onset of fertility decline. The author hypothesizes that specific kinds of revolutionary events affect fertility by engendering ideological changes in popular understandings of the individual's relationship to society and ultimately the legitimacy of couples' authority over their reproductive capacities. Results demonstrate that popular democratic revolutions -- but not institutionalized democratic structures -- predict the timing of the onset of fertility decline.

  12. Rapid cognitive decline: not always Creutzfeldt-Jakob disease.

    PubMed

    Randall, A; Ellis, R; Hywel, B; Davies, R R; Alusi, S H; Larner, A J

    2015-01-01

    A patient with rapidly progressive cognitive decline over an approximately four month period was suspected to have sporadic Creutzfeldt-Jakob disease. Features thought to support this diagnosis included psychiatric symptoms (anxiety and depression), visual hallucinations and a visual field defect. However, the finding of papilloedema broadened the differential diagnosis. Although standard brain imaging and electroencephalography had shown only non-specific abnormalities, subsequent cerebral angiography disclosed an intracranial dural arteriovenous fistula. Following embolisation, the patient made a good functional recovery. Intracranial dural arteriovenous fistula merits consideration in any patient with subacute cognitive decline, and should be included in the differential diagnosis of sporadic Creutzfeldt-Jakob disease. PMID:26517100

  13. The future of species under climate change: resilience or decline?

    PubMed

    Moritz, Craig; Agudo, Rosa

    2013-08-01

    As climates change across already stressed ecosystems, there is no doubt that species will be affected, but to what extent and which will be most vulnerable remain uncertain. The fossil record suggests that most species persisted through past climate change, whereas forecasts of future impacts predict large-scale range reduction and extinction. Many species have altered range limits and phenotypes through 20th-century climate change, but responses are highly variable. The proximate causes of species decline relative to resilience remain largely obscure; however, recent examples of climate-associated species decline can help guide current management in parallel with ongoing research.

  14. Genetic uniformity and the decline of red spruce

    SciTech Connect

    Not Available

    1989-05-01

    This brief note examines current research that suggests genetic uniformity as a cause of red spruce decline. Although acid rain and ozone have been implicated in the decline of the species, dieback has been observed evening areas where pollution is low. In addition, the dieback is not observed in other species. Researchers have analyzed the seeds of approximately 500 red spruce trees representing 13 boreal and Montane populations from southern Appalachia to Canada. Of 42 gene loci examined, on the average only 8% of the genes were heterozygousand only 31% were polymorphic.

  15. [Fertility decline in Colombia: expression of a profound social change].

    PubMed

    De Llinas, H M

    1983-01-01

    Demographers have identified 3 phases in the evolution of human population growth: 1) high mortality and high fertility resulting in very slow growth, 2) declining mortality and high fertility, resulting in rapid growth, and 3) declining mortality and fertility, resulting in slower growth. From the beginning of the century until the 1930s, Colombia was in the 1st phase, while the greatest mortality declines were registered from 1930-60. Fertility did not decline commensurately, and from 1951-64 the rate of population increase was 3.14%. The National Fertility Survey in 1969 and the 1973 census indicated that the country had at last begun its fertility decline. The 1969 survey showed that the total fertility rate (TFR) had dropped from 7.0 in the early 1960s to 6.0 in 1967-68, with fertility declining in both rural and urban areas. The 1973 census showed a rate of growth of 2.8% and an average number of children/woman of 4.7, showing that the fertility decline was structural and reflected profound changes in the values, norms, and attitudes regarding children of the Colombian population. Urbanization, the increased educational level and labor force participation of women, and the influence of the mass media in propagating the values of a consumer society are factors in the reduction of family size. Fertility differentials by region and social group have been declining progressively. The TFR in 1960-64 was 7.0 overall, 6.1 in urban areas, and 7.9 in rural areas, while in 1980 it was 3.6 overall, 3.0 in urban areas, and 5.1 in rural areas. In 1968-69, the TFR was 7.8 in the Atlantic region, 7.9 in the Oriental, 6.8 in the Central, 5.9 in the Pacific, and 4.5 in Bogota, while in 1980 it was 4.1 in the Atlantic, 4.0 in the Oriental, 3.5 in the Central, 3.3 in the Pacific, and 2.8 in Bogota. The number of women using family planning programs increased from 83 in 1965 to 1,790,484 in 1980. The proportion using contraception increased from 53% in 1976 to 55% in 1980. The

  16. How Personal Is the Political? Democratic Revolution and Fertility Decline

    PubMed Central

    Bailey, Amy Kate

    2010-01-01

    Existing theory has identified the capacity of political revolutions to effect change in a variety of social institutions, although relationships between revolution and many institutions remain unexplored. Using historical data from 22 European and four diaspora countries, I examine the temporal relationship between timing of revolution and onset of fertility decline. I hypothesize that specific kinds of revolutionary events affect fertility by engendering ideological changes in popular understandings of the individual’s relationship to society, and ultimately the legitimacy of couples’ authority over their reproductive capacities. Results demonstrate that popular democratic revolution – but not institutionalized democratic structures – predict the timing of the onset of fertility decline. PMID:19999826

  17. Climate Variations and Alaska Tundra Vegetation Productivity Declines in Spring

    NASA Astrophysics Data System (ADS)

    Bhatt, U. S.; Walker, D. A.; Bieniek, P.; Raynolds, M. K.; Epstein, H. E.; Comiso, J. C.; Pinzon, J. E.; Tucker, C. J.

    2015-12-01

    While sea ice has continued to decline, vegetation productivity increases have declined particularly during spring in Alaska as well as many parts of the Arctic tundra. To understand the processes behind these features we investigate spring climate variations that includes temperature, circulation patterns, and snow cover to determine how these may be contributing to spring browning. This study employs remotely sensed weekly 25-km sea ice concentration, weekly surface temperature, and bi-weekly NDVI from 1982 to 2014. Maximum NDVI (MaxNDVI, Maximum Normalized Difference Vegetation Index), Time Integrated NDVI (TI-NDVI), Summer Warmth Index (SWI, sum of degree months above freezing during May-August), atmospheric reanalysis data, dynamically downscaled climate data, meteorological station data, and snow water equivalent (GlobSnow, assimilated snow data set). We analyzed the data for the full period (1982-2014) and for two sub-periods (1982-1998 and 1999-2014), which were chosen based on the declining Alaska SWI since 1998. MaxNDVI has increased from 1982-2014 over most of the Arctic but has declined from 1999 to 2014 southwest Alaska. TI-NDVI has trends that are similar to those for MaxNDVI for the full period but display widespread declines over the 1999-2014 period. Therefore, as the MaxNDVI has continued to increase overall for the Arctic, TI-NDVI has been declining since 1999 and these declines are particularly noteworthy during spring in Alaska. Spring declines in Alaska have been linked to increased spring snow cover that can delay greenup (Bieniek et al. 2015) but recent ground observations suggest that after an initial warming and greening, late season freezing temperature are damaging the plants. The late season freezing temperature hypothesis will be explored with meteorological climate/weather data sets for Alaska tundra regions. References P.A. Bieniek, US Bhatt, DA Walker, MK Raynolds, JC Comiso, HE Epstein, JE Pinzon, CJ Tucker, RL Thoman, H Tran, N M

  18. [Fertility decline in Colombia: expression of a profound social change].

    PubMed

    De Llinas, H M

    1983-01-01

    Demographers have identified 3 phases in the evolution of human population growth: 1) high mortality and high fertility resulting in very slow growth, 2) declining mortality and high fertility, resulting in rapid growth, and 3) declining mortality and fertility, resulting in slower growth. From the beginning of the century until the 1930s, Colombia was in the 1st phase, while the greatest mortality declines were registered from 1930-60. Fertility did not decline commensurately, and from 1951-64 the rate of population increase was 3.14%. The National Fertility Survey in 1969 and the 1973 census indicated that the country had at last begun its fertility decline. The 1969 survey showed that the total fertility rate (TFR) had dropped from 7.0 in the early 1960s to 6.0 in 1967-68, with fertility declining in both rural and urban areas. The 1973 census showed a rate of growth of 2.8% and an average number of children/woman of 4.7, showing that the fertility decline was structural and reflected profound changes in the values, norms, and attitudes regarding children of the Colombian population. Urbanization, the increased educational level and labor force participation of women, and the influence of the mass media in propagating the values of a consumer society are factors in the reduction of family size. Fertility differentials by region and social group have been declining progressively. The TFR in 1960-64 was 7.0 overall, 6.1 in urban areas, and 7.9 in rural areas, while in 1980 it was 3.6 overall, 3.0 in urban areas, and 5.1 in rural areas. In 1968-69, the TFR was 7.8 in the Atlantic region, 7.9 in the Oriental, 6.8 in the Central, 5.9 in the Pacific, and 4.5 in Bogota, while in 1980 it was 4.1 in the Atlantic, 4.0 in the Oriental, 3.5 in the Central, 3.3 in the Pacific, and 2.8 in Bogota. The number of women using family planning programs increased from 83 in 1965 to 1,790,484 in 1980. The proportion using contraception increased from 53% in 1976 to 55% in 1980. The

  19. What could we learn from a sharply falling positron fraction?

    SciTech Connect

    Delahaye, Timur; Kotera, Kumiko; Silk, Joseph

    2014-10-20

    Recent results from the AMS-02 data have confirmed that the cosmic-ray positron fraction increases with energy between 10 and 200 GeV. This quantity should not exceed 50%, and it is hence expected that it will either converge toward 50% or fall. We study the possibility that future data may show the positron fraction dropping down abruptly to the level expected with only secondary production, and forecast the implications of such a feature in term of possible injection mechanisms that include both dark matter and pulsars. Were a sharp steepening to be found, rather surprisingly, we conclude that pulsar models would do at least as well as dark matter scenarios in terms of accounting for any spectral cut-off.

  20. Human Population Decline in North America during the Younger Dryas

    NASA Astrophysics Data System (ADS)

    Anderson, D. G.; Goodyear, A. C.; Stafford, T. W., Jr.; Kennett, J.; West, A.

    2009-12-01

    There is ongoing debate about a possible human population decline or contraction at the onset of the Younger Dryas (YD) at 12.9 ka. We used two methods to test whether the YD affected human population levels: (1) frequency analyses of Paleoindian projectile points, and (2) summed probability analyses of radiocarbon (14C) dates. The results suggest that a significant decline or reorganization of human populations occurred at 12.9 ka, continued through the initial centuries of the YD chronozone, then rebounded by the end of the YD. FREQUENCY ANALYSES: This method employed projectile point data from the Paleoindian Database of the Americas (PIDBA, http://pidba.utk.edu). We tallied diagnostic projectile points and obtained larger totals for Clovis points than for immediately post-Clovis points, which share an instrument-assisted fluting technique, typically using pressure or indirect percussion. Gainey, Vail, Debert, Redstone, and Cumberland point-styles utilized this method and are comparable to the Folsom style. For the SE U.S., the ratio of Clovis points (n=1993) to post-Clovis points (n=947) reveals a point decline of 52%. For the Great Plains, a comparison of Clovis and fluted points (n=4020) to Folsom points (n=2527) shows a point decline of 37%, which may translate into a population contraction of similar magnitude. In addition, eight major Clovis lithic quarry sites in the SE U.S. exhibit little to no evidence for immediate post-Clovis occupations, implying a major population decline. SUMMED PROBABILITIES: This method involved calibrating relevant 14C dates and combining the probabilities, after which major peaks and troughs in the trends are assumed to reflect changes in human demographics. Using 14C dates from Buchanan et al. (2008), we analyzed multiple regions, including the Southeast and Great Plains. Contrary to Buchanan et al., we found an abrupt, statistically significant decline at 12.9 ka, followed 200 to 900 years later by a rebound in the number of

  1. Long-term decline in the calanoid copepod Acartia tonsa in central Chesapeake Bay, USA: An indirect effect of eutrophication?

    NASA Astrophysics Data System (ADS)

    Kimmel, David G.; Boynton, Walter R.; Roman, Michael R.

    2012-04-01

    A long-term abundance record of the calanoid copepod Acartia tonsa in the Maryland portion of Chesapeake Bay was compiled from 1966 to 2002. A significant downward trend in the summertime abundance of Acartia tonsa was found in central Chesapeake Bay. We propose that environmental and food web changes occurred as the Chesapeake Bay became increasingly impacted by human activity which eventually led to the overall decline of A. tonsa. Environmental changes included a long-term rise in water temperature and the volume of hypoxic water during the summer. These changes occurred during the same time period as increases in chlorophyll a concentration, declines in the landings of the eastern oyster Crassostrea virginica, and declines in abundance of the sea nettle Chrysaora quinquecirrha. A CUSUM analysis showed that each time-series experienced a change point during over the past 50 years. These changes occurred sequentially, with chlorophyll a concentration increasing beginning in 1969, water temperature and hypoxic volume increasing beginning in the early 1980s, more recent Maryland C. virginica landings begin declining in the early 1980s and A. tonsa and C. quinquecirrha declining starting in 1989. A stepwise regression analysis revealed that the reduction in A. tonsa abundance appeared to be most associated with a decreasing trend in C. quinquecirrha abundance, though only when trends in the two time-series were present. The drop in C. quinquecirrha abundance is associated with reduced predation on the ctenophore, Mnemiopsis leidyi, a key predator of A. tonsa. The long-term decline of A. tonsa has likely impacted trophic transfer to fish, particularly the zooplanktivorous bay anchovy (Anchoa mitchilli). A time-series of bay anchovy juvenile index showed a negative trend and the CUSUM analysis revealed 1993 as its starting point. Total fisheries landings, excluding menhaden (Brevoortia tyrannus), in Chesapeake Bay have also declined during the same period and this

  2. Preventive effects of Chlorella on cognitive decline in age-dependent dementia model mice.

    PubMed

    Nakashima, Yuya; Ohsawa, Ikuroh; Konishi, Fumiko; Hasegawa, Takashi; Kumamoto, Shoichiro; Suzuki, Yoshihiko; Ohta, Shigeo

    2009-10-30

    Oxidative stress is one of the major causes of age-dependent memory loss and cognitive decline. Cytotoxic aldehydes are derived from lipid peroxides and their accumulation may be responsible for age-dependent neurodegeneration, including Alzheimer's disease. Since aldehyde dehydrogenases detoxify such aldehydes, we constructed transgenic mice with mitochondrial aldehyde dehydrogenase 2 (ALDH2) activity deficiency (DAL101 mice) as an age-dependent dementia model. This model animal is age-dependently progressed by persistent oxidative stress, and thus enables us to investigate foods that prevent dementia. Since Chlorella, a kind of alga, exhibits various anti-oxidative effects, we investigated whether Chlorella has the potential to prevent age-dependent cognitive impairment. We fed Chlorella to DAL101 mice and investigated its effects on oxidative stress and the progression of cognitive decline using the Morris water-maze and object recognition tests. The diet with Chlorella tended to reduce oxidative stress and significantly prevented the decline of cognitive ability, as shown by both methods. Moreover, consumption of Chlorella decreased the number of activated astrocytes in the DAL101 brain. These findings suggest that the prolonged consumption of Chlorella has the potential to prevent the progression of cognitive impairment.

  3. Measurements of Declination at the Helsinki Magnetic-meteorological Observatory 1844-1853

    NASA Technical Reports Server (NTRS)

    Nevanlinna, Heikki; Ketola, Anneli; Kangas, Tuulikki

    1992-01-01

    A project was started with the goal of putting into computer readable form all the old unpublished magnetic data at the Finnish Meteorological Institute (FMI), the successor of the Helsinki magnetic-meteorological observatory. Altogether there are available about 2.5 million visual observations of D, H and Z made during the time interval 1844-1905. The first 10 year period (1844-1853) of declination data now converted to electronic form, includes observations made at every tenth minute. The total number of observations is 489,152. We present some examples of declination observations in forms of tables and graphs showing hourly, daily, monthly, and annual means. Secular variations of the declination in 1844-1853 have been extremely linear, showing a steady eastward increase of 8 prime/year that is more than two times larger than the present annual rate of secular change in Finland. The standard deviation of the daily and monthly residuals, after removing the secular variation trend for the whole time period, is about 1 prime, demonstrating the high stability and reliability of the observations. For this reason the data may be suitable for deriving a 3-hour activity index K and daily Ak numbers, giving new information for extending the existing long series of activity characters backwards in time.

  4. Ability of university-level education to prevent age-related decline in emotional intelligence

    PubMed Central

    Cabello, Rosario; Navarro Bravo, Beatriz; Latorre, José Miguel; Fernández-Berrocal, Pablo

    2014-01-01

    Numerous studies have suggested that educational history, as a proxy measure of active cognitive reserve, protects against age-related cognitive decline and risk of dementia. Whether educational history also protects against age-related decline in emotional intelligence (EI) is unclear. The present study examined ability EI in 310 healthy adults ranging in age from 18 to 76 years using the Mayer–Salovey–Caruso Emotional Intelligence Test (MSCEIT). We found that older people had lower scores than younger people for total EI and for the EI branches of perceiving, facilitating, and understanding emotions, whereas age was not associated with the EI branch of managing emotions. We also found that educational history protects against this age-related EI decline by mediating the relationship between age and EI. In particular, the EI scores of older adults with a university education were higher than those of older adults with primary or secondary education, and similar to those of younger adults of any education level. These findings suggest that the cognitive reserve hypothesis, which states that individual differences in cognitive processes as a function of lifetime intellectual activities explain differential susceptibility to functional impairment in the presence of age-related changes and brain pathology, applies also to EI, and that education can help preserve cognitive-emotional structures during aging. PMID:24653697

  5. Imaging memory and predicting postoperative memory decline in temporal lobe epilepsy: Insights from functional imaging.

    PubMed

    Dupont, S

    2015-03-01

    After medial temporal lobe epilepsy (MTLE) surgery, there is considerable individual variation in the extent, nature and direction of postoperative memory change. Before surgery, epileptic patients who are surgery candidates need precise information about the potential cognitive after effects, and particularly in temporal lobe epilepsy, postoperative memory changes. Clinical and neuropsychological data may bring useful information to predict the postoperative memory outcome, but, these data are not always sufficient to replace the Wada test, considered for a long time, as the gold standard to predict postoperative decline following surgery. In any case, numerous studies demonstrate that the Wada procedure can be nowadays reliably replaced by functional MRI (fMRI) activation studies. A vast majority of fMRI studies suggest that it is the functional adequacy of the resected hippocampus rather than the functional reserve of the contralateral hippocampus that determines the extent of postoperative memory decline. In addition, new functional neuroimaging procedures that explore more widespread network disruptions commonly found in MTLE such as diffusion-tensor imaging (DTI) or connectivity studies could in the future constitute a reliable approach combined with fMRI activation studies to significantly improve the prediction of postsurgical memory decline.

  6. The high energetic particles released during the decline phases of last five solar cycles

    NASA Astrophysics Data System (ADS)

    Hady, A. A., II

    2014-12-01

    During the decline phases of the last five solar cycles, new peak has appeared releasing high energetic particles. During October 2003 (so-called Halloween storms), a sudden increase of the solar activity occurred during the decline phase which has bigger than that occurred during the main peak of that Solar cycle 23. The same situation was repeated again for the solar cycle 24, during its decline phase, giving a new peak during January 2014 and release high energetic particles, which was bigger than that occurred during the mean peak of cycle 24. This means that the solar cycles starting from the cycle 20 have two peaks, the second peak always producing higher energetic flares which affects the Earth's magnetic field. The same situation happened in the cycles 21, and 22, but with lower release of energetic particle, compared with cycles 23 and 24. We will do descriptive studies of these events, according to data analysis, and compare the results. Keywords: Solar cycles; solar activities; solar energetic particles, Halloween storms, January 2014 storms.

  7. An Intrinsic MicroRNA Timer Regulates Progressive Decline in Shoot Regenerative Capacity in Plants

    PubMed Central

    Zhang, Tian-Qi; Lian, Heng; Tang, Hongbo; Dolezal, Karel; Zhou, Chuan-Miao; Yu, Sha; Chen, Juan-Hua; Chen, Qi; Liu, Hongtao; Ljung, Karin

    2015-01-01

    Plant cells are totipotent and competent to regenerate from differentiated organs. It has been shown that two phytohormones, auxin and cytokinin, play critical roles within this process. As in animals, the regenerative capacity declines with age in plants, but the molecular basis for this phenomenon remains elusive. Here, we demonstrate that an age-regulated microRNA, miR156, regulates shoot regenerative capacity. As a plant ages, the gradual increase in miR156-targeted SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors leads to the progressive decline in shoot regenerative capacity. In old plants, SPL reduces shoot regenerative capacity by attenuating the cytokinin response through binding with the B-type ARABIDOPSIS RESPONSE REGULATORs, which encode the transcriptional activators in the cytokinin signaling pathway. Consistently, the increased amount of exogenous cytokinin complements the reduced shoot regenerative capacity in old plants. Therefore, the recruitment of age cues in response to cytokinin contributes to shoot regenerative competence. PMID:25649435

  8. Basal Forebrain Cholinergic Circuits and Signaling in Cognition and Cognitive Decline.

    PubMed

    Ballinger, Elizabeth C; Ananth, Mala; Talmage, David A; Role, Lorna W

    2016-09-21

    Recent work continues to place cholinergic circuits at center stage for normal executive and mnemonic functioning and provides compelling evidence that the loss of cholinergic signaling and cognitive decline are inextricably linked. This Review focuses on the last few years of studies on the mechanisms by which cholinergic signaling contributes to circuit activity related to cognition. We attempt to identify areas of controversy, as well as consensus, on what is and is not yet known about how cholinergic signaling in the CNS contributes to normal cognitive processes. In addition, we delineate the findings from recent work on the extent to which dysfunction of cholinergic circuits contributes to cognitive decline associated with neurodegenerative disorders.

  9. On the Declining Interest in Physics among Students—From the perspective of teachers

    NASA Astrophysics Data System (ADS)

    Oon, Pey-Tee; Subramaniam, R.

    2011-03-01

    This study examines physics teachers' views on factors that contribute to the declining interest in physics among school students. A total of 190 physics teachers from 91 secondary schools and nine junior colleges in Singapore participated in this study, which used a survey instrument to seek their views. Rasch analysis was used to analyze the data. The findings showed that teachers are uncertain about the career prospects of physics graduates and are not very optimistic about the market demand for physics graduates. They feel that physics seems to be difficult and abstract to students. The perception that physics is for boys seems to be rooted in society. The teachers emphasized the importance of co-curricular activities and laboratory work to enhance interest of students in learning physics. We provide several recommendations to arrest the declining interest in physics at the school level.

  10. Basal Forebrain Cholinergic Circuits and Signaling in Cognition and Cognitive Decline.

    PubMed

    Ballinger, Elizabeth C; Ananth, Mala; Talmage, David A; Role, Lorna W

    2016-09-21

    Recent work continues to place cholinergic circuits at center stage for normal executive and mnemonic functioning and provides compelling evidence that the loss of cholinergic signaling and cognitive decline are inextricably linked. This Review focuses on the last few years of studies on the mechanisms by which cholinergic signaling contributes to circuit activity related to cognition. We attempt to identify areas of controversy, as well as consensus, on what is and is not yet known about how cholinergic signaling in the CNS contributes to normal cognitive processes. In addition, we delineate the findings from recent work on the extent to which dysfunction of cholinergic circuits contributes to cognitive decline associated with neurodegenerative disorders. PMID:27657448

  11. Decline of recent seabirds inferred from a composite 1000-year record of population dynamics

    NASA Astrophysics Data System (ADS)

    Xu, Liqiang; Liu, Xiaodong; Wu, Libin; Sun, Liguang; Zhao, Jinjun; Chen, Lin

    2016-10-01

    Based on three ornithogenic sediment profiles and seabird subfossils therein from the Xisha Islands, South China Sea, the relative population size of seabirds over the past 1000 years was reconstructed using reflectance spectrum. Here we present an apparent increase and subsequent decline of seabirds on these islands in the South China Sea. Seabird populations peaked during the Little Ice Age (LIA, 1400–1850 AD), implying that the cool climate during the LIA appears to have been more favorable to seabirds on the Xisha Islands in the South China Sea. Climate change partly explains the recent decrease in seabird populations over the past 150 years, but the significant decline and almost complete disappearance thereof on most of the Xisha Islands is probably attributable to human disturbance. Our study reveals the increasing impact of anthropogenic activities on seabird population in recent times.

  12. Pesticides are involved with population declines of amphibians in the California Sierra Nevadas.

    PubMed

    Sparling, D W; Fellers, G; McConnell, L

    2001-05-01

    Several species of frogs and toads are in serious decline in the Sierra Nevada Mountains of California. These species include the threatened red-legged frog ( Rana aurora ), foothill yellow-legged frog ( R. boylii ), mountain yellow-legged frog ( R. muscosa ), Cascades frog ( Rana cascadae ), western toad ( Bufo boreas ) and Yosemite toad ( B. canorus ). For many of these species current distributions are down to 10% of historical ranges. Several factors including introduced predators, habitat loss, and ultraviolet radiation have been suggested as causes of these declines. Another probable cause is air-borne pesticides from the Central Valley of California. The Central Valley, especially the San Joaquin Valley, is a major agricultural region where millions of pounds of active ingredient pesticides are applied each year (http://www.cdpr.ca.gov/dprdatabase.htm). Prevailing westerly winds from the Pacific Coast transport these pesticides into the into the Sierras.

  13. Decline of recent seabirds inferred from a composite 1000-year record of population dynamics

    PubMed Central

    Xu, Liqiang; Liu, Xiaodong; Wu, Libin; Sun, Liguang; Zhao, Jinjun; Chen, Lin

    2016-01-01

    Based on three ornithogenic sediment profiles and seabird subfossils therein from the Xisha Islands, South China Sea, the relative population size of seabirds over the past 1000 years was reconstructed using reflectance spectrum. Here we present an apparent increase and subsequent decline of seabirds on these islands in the South China Sea. Seabird populations peaked during the Little Ice Age (LIA, 1400–1850 AD), implying that the cool climate during the LIA appears to have been more favorable to seabirds on the Xisha Islands in the South China Sea. Climate change partly explains the recent decrease in seabird populations over the past 150 years, but the significant decline and almost complete disappearance thereof on most of the Xisha Islands is probably attributable to human disturbance. Our study reveals the increasing impact of anthropogenic activities on seabird population in recent times. PMID:27748366

  14. Pesticides are involved with population declines of amphibians in the California Sierra Nevadas

    USGS Publications Warehouse

    Sparling, D.W.; Fellers, G.; McConnell, L.

    2001-01-01

    Several species of frogs and toads are in serious decline in the Sierra Nevada Mountains of California. These species include the threatened red-legged frog ( Rana aurora ), foothill yellow-legged frog ( R. boylii ), mountain yellow-legged frog ( R. muscosa ), Cascades frog ( Rana cascadae ), western toad ( Bufo boreas ) and Yosemite toad ( B. canorus ). For many of these species current distributions are down to 10% of historical ranges. Several factors including introduced predators, habitat loss, and ultraviolet radiation have been suggested as causes of these declines. Another probable cause is air-borne pesticides from the Central Valley of California. The Central Valley, especially the San Joaquin Valley, is a major agricultural region where millions of pounds of active ingredient pesticides are applied each year (http://www.cdpr.ca.gov/dprdatabase.htm). Prevailing westerly winds from the Pacific Coast transport these pesticides into the into the Sierras.

  15. Glucagon-like peptide-1, diabetes, and cognitive decline: possible pathophysiological links and therapeutic opportunities.

    PubMed

    Mossello, Enrico; Ballini, Elena; Boncinelli, Marta; Monami, Matteo; Lonetto, Giuseppe; Mello, Anna Maria; Tarantini, Francesca; Baldasseroni, Samuele; Mannucci, Edoardo; Marchionni, Niccolò

    2011-01-01

    Metabolic and neurodegenerative disorders have a growing prevalence in Western countries. Available epidemiologic and neurobiological evidences support the existence of a pathophysiological link between these conditions. Glucagon-like peptide 1 (GLP-1), whose activity is reduced in insulin resistance, has been implicated in central nervous system function, including cognition, synaptic plasticity, and neurogenesis. We review the experimental researches suggesting that GLP-1 dysfunction might be a mediating factor between Type 2 diabetes mellitus (T2DM) and neurodegeneration. Drug treatments enhancing GLP-1 activity hold out hope for treatment and prevention of Alzheimer's disease (AD) and cognitive decline.

  16. Post-war mortality decline and consumption expenditures in Taiwan.

    PubMed

    Tsay, G

    1977-03-01

    With the objective of testing whether or not mortality decline is independent of economic development, changes are analyzed in mortality levels and consumption patterns in post-World War 2 Taiwan. According to the official statistics, the crude death rate in post-war Taiwan declined continuously from 11.5/1000 in 1950 to 6.8 in 1960, and then to 4.8 in 1974. During the same period, Taiwan also experienced impressive economic growth, with real per capita income rising from less than $150 in the early 1950s to almost $200 in the early 1960s, and then to more than $400 since 1973. Hence, it is hypothesized that mortality decline in post-war Taiwan was not independent of its economic development. The data for the study are annual aggregate statistics from official reports from 1950 to 1974. After eliminating the effect of the age composition from the mortality trend, the data show that the level of mortality improved much more during the 1st 1/2 of the study than during the last 1/2. Attempts were made to clarify the relationship between economic development and mortality decline by analyzing changes of mortality levels and consumption patterns. Although some weaknesses appear in the study, the preliminary results seem to imply that the mortality reduction in post-war Taiwan was not independent of economic progress. If more information becomes available, further investigation concerning this issue should lead to more conclusive results.

  17. Effects of invasive parasites on bumble bee declines.

    PubMed

    Meeus, Ivan; Brown, Mark J F; De Graaf, Dirk C; Smagghe, Guy

    2011-08-01

    Bumble bees are a group of pollinators that are both ecologically and economically important and declining worldwide. Numerous mechanisms could be behind this decline, and the spread of parasites from commercial colonies into wild populations has been implicated recently in North America. Commercial breeding may lead to declines because commercial colonies may have high parasite loads, which can lead to colonization of native bumble bee populations; commercial rearing may allow higher parasite virulence to evolve; and global movement of commercial colonies may disrupt spatial patterns in local adaptation between hosts and parasites. We assessed parasite virulence, transmission mode, and infectivity. Microparasites and so-called honey bee viruses may pose the greatest threat to native bumble bee populations because certain risk factors are present; for example, the probability of horizontal transmission of the trypanosome parasite Crithidia bombi is high. The microsporidian parasite Nosema bombi may play a role in declines of bumble bees in the United States. Preliminary indications that C. bombi and the neogregarine Apicystis bombi may not be native in parts of South America. We suggest that the development of molecular screening protocols, thorough sanitation efforts, and cooperation among nongovernmental organizations, governments, and commercial breeders might immediately mitigate these threats.

  18. Declining Enrollments: A New Dilemma for Educators. Fastback 116.

    ERIC Educational Resources Information Center

    Keough, William F., Jr.

    Twenty years after the baby boom, U.S. population is falling and school enrollment is declining. Contrary to public expectations, smaller enrollment does not mean smaller school budgets, and balancing the educational budget will require cutting programs, closing schools, and reducing teacher force. The experience of the East Meadow (New York)…

  19. Is the Value of College Going Really Declining?

    ERIC Educational Resources Information Center

    Witmer, David R.

    1976-01-01

    The future economic value of college-going is examined in a reply to the pessimistic view offered by Freeman and Hollomon in a 1975 article. It is shown that the issue will remain urgent for years to come, but that the social return on the college investment has not declined. (LBH)

  20. [Birth rates and fertility of foreigners: a trend of decline].

    PubMed

    Tribalat, M

    1986-01-01

    An analysis of the fertility of the foreign population resident in France is presented. The author estimates that fertility among foreigners is still higher than that for the population as a whole, but is declining to the same level. The data are from official sources and concern the period up to 1984.

  1. Long-Range Planning and the Enrollment Decline.

    ERIC Educational Resources Information Center

    Fredrickson, John H.

    The current period of enrollment decline offers school districts an ideal opportunity for program and facility reevaluation and long-range planning. Any long-range plan should evaluate current programs in light of statutory and educational trends, estimate existing facilities' ability to accommodate change, determine the community's potential…

  2. Amphibian Decline: An Integrated Analysis of Multiple Stressor Effects

    USGS Publications Warehouse

    Linder, G.; Krest, S.K.; Sparling, D.W.

    2003-01-01

    Although the effects of contaminants on amphibians have been studied for decades, relatively little is known about these effects compared to the more intensively studied mammals. and birds. Science has advanced its understanding of the complexities linked to declining amphibian populations; however, there are many remaining questions whose answers would directly benefit amphibians and adaptive management plans ministering to them. In an effort to answer those questions and focus on ecological risk assessment of amphibians, scientists, researchers, and resource management professionals from diverse fields participated in a Society of Environmental Toxicology and Chemistry (SETAC)-Johnson Foundation Wingspread conference with three goals: characterize a process that would bring a range of interdisciplinary technical and management tools to the tasks of causal analysis; demonstrate the current state of available technical tools to assess amphibian populations exposed to various environmental stressors; and focus on identifying research that would likely benefit sustainable populations through adaptive management programs. A result of the Wingspread conference, Amphibian Decline examines the ecotoxicology and stressors of amphibians in an attempt to address issues related to declining amphibian populations and the role that various stressors might have in those losses. It identifies gaps in current data, interprets information into an existing framework, and points toward critical areas for future research. Through the combined efforts of research and resource management communities, recommendations can be developed to change current policies and management actions to address the problem of amphibian decline.

  3. Connecting the Dots: The Decline in Meaningful Learning

    ERIC Educational Resources Information Center

    Stewart, Kenneth; Kilmartin, Christopher

    2014-01-01

    The authors describe cross-decades changes in the achievement attitudes and behaviors of average U. S. undergraduates that parallel the declines in meaningful learning reported by Arum and colleagues. Comparisons of pre-1987 and 2004-8 students on seven achievement-predictive measures revealed that (a) average 2004-8 undergraduates scored…

  4. Evidence of disease-related amphibian decline in Colorado

    USGS Publications Warehouse

    Muths, Erin; Corn, Paul Stephen; Pessier, Allan P.; Green, D. Earl

    2003-01-01

    The recent discovery of a pathogenic fungus (Batrachochytrium dendrobatidis) associated with declines of frogs in the American and Australian tropics, suggests that at least the proximate cause, may be known for many previously unexplained amphibian declines. We have monitored boreal toads in Colorado since 1991 at four sites using capturea??recapture of adults and counts of egg masses to examine the dynamics of this metapopulation. Numbers of male toads declined in 1996 and 1999 with annual survival rate averaging 78% from 1991 to 1994, 45% in 1995 and 3% between 1998 and 1999. Numbers of egg masses also declined. An etiological diagnosis of chytridiomycosis consistent with infections by the genus Batrachochytrium was made in six wild adult toads. Characteristic histomorphological features (i.e. intracellular location, shape of thalli, presence of discharge tubes and rhizoids) of chytrid organisms, and host tissue response (acanthosis and hyperkeratosis) were observed in individual toads. These characteristics were indistinguishable from previously reported mortality events associated with chytrid fungus. We also observed epizootiological features consistent with mortality events associated with chytrid fungus: an increase in the ratio of female:male toads captured, an apparent spread of mortalities within the metapopulation and mortalities restricted to post metamorphic animals. Eleven years of population data suggest that this metapopulation of toads is in danger of extinction, pathological and epizootiological evidence indicates that B. dendrobatidis has played a proximate role in this process

  5. When Patients Decline Medical Student Participation: The Preceptors' Perspective

    ERIC Educational Resources Information Center

    Tang, Tricia S.; Skye, Eric P.

    2009-01-01

    Patients' receptivity towards medical student participation has been examined predominantly from the patient and/or the medical student perspective. Few studies have investigated the preceptor's perspective. The study examined preceptors' experience with patients declining medical student participation in clinical care and identified…

  6. Responses of England, Germany and Switzerland to Declining School Enrolments.

    ERIC Educational Resources Information Center

    Michalski, Catherine

    Results of interviews with educators in England, Germany, and Switzerland are combined with statistical data in this study of the effects of declining enrollment and the development of multicultural programs in those countries. In all three countries, the author encountered a prevailing resistance to program change in the face of declining…

  7. Is There a Decline In the Reading Romance?

    ERIC Educational Resources Information Center

    Krashen, Stephen; Von Sprecken, Debra

    2002-01-01

    Reviews research on the development of attitudes toward reading to investigate the idea that as children get older, their interest in reading declines. Highlights include research methodology; attitudes toward recreational reading; reading at home; reading autobiographies; and the need to provide interesting books to children. (LRW)

  8. Long-term declines in nutritional quality of tropical leaves.

    PubMed

    Rothman, Jessica M; Chapman, Colin A; Struhsaker, Thomas T; Raubenheimer, David; Twinomugisha, Dennis; Waterman, Peter G

    2015-03-01

    Global change is affecting plant and animal populations and many of the changes are likely subtle and difficult to detect. Based on greenhouse experiments, changes in temperature and rainfall, along with elevated CO2, are expected to impact the nutritional quality of leaves. Here, we show a decline in the quality of tree leaves 15 and 30 years after two previous studies in an undisturbed area of tropical forest in Kibale National Park, Uganda. After 30 years in a sample of multiple individuals of ten tree species, the mature leaves of all but one species increased in fiber concentrations, with a mean increase of 10%; tagged individuals of one species increased 13% in fiber. After 15 years, in eight tree species the fiber of young leaves increased 15%, and protein decreased 6%. Like many folivores, Kibale colobus monkeys select leaves with a high protein-to-fiber ratio, so for these folivores declining leaf quality could have a major impact. Comparisons among African and Asian forests show a strong correlation between colobine biomass and the protein-to-fiber ratio of the mature leaves from common tree species. Although this model, predicts a 31% decline in monkey abundance for Kibale, we have not yet seen these declines.

  9. Quantitative EEG and Cognitive Decline in Parkinson's Disease.

    PubMed

    Cozac, Vitalii V; Gschwandtner, Ute; Hatz, Florian; Hardmeier, Martin; Rüegg, Stephan; Fuhr, Peter

    2016-01-01

    Cognitive decline is common with the progression of Parkinson's disease (PD). Different candidate biomarkers are currently studied for the risk of dementia in PD. Several studies have shown that quantitative EEG (QEEG) is a promising predictor of PD-related cognitive decline. In this paper we briefly outline the basics of QEEG analysis and analyze the recent publications addressing the predictive value of QEEG in the context of cognitive decline in PD. The MEDLINE database was searched for relevant publications from January 01, 2005, to March 02, 2015. Twenty-four studies reported QEEG findings in various cognitive states in PD. Spectral and connectivity markers of QEEG could help to discriminate between PD patients with different level of cognitive decline. QEEG variables correlate with tools for cognitive assessment over time and are associated with significant hazard ratios to predict PD-related dementia. QEEG analysis shows high test-retest reliability and avoids learning effects associated with some neuropsychological testing; it is noninvasive and relatively easy to repeat.

  10. Decline of red spruce in the Adirondacks, New York

    SciTech Connect

    Scott, J.T.; Siccama, T.G.; Johnson, A.H.; Breisch, A.R.

    1984-01-01

    Thirty-two stands in the spruce-fir forests of Whiteface Mountain in the Adirondacks, originally sampled from 1964-66, were resurveyed in 1982. From 10-25 Bitterlich points were used in each stand in 1982 to obtain an estimate of basal area per hectare. Data were summarized for low elevation (<900m) and high elevation (> or = 900m) forests. Red spruce declined by 40-60% in basal area for the low elevation forests and by 60-70% above 900m. Balsam fir decreased by 35% at high elevations, due to natural disturbance in several of the stands, but was unchanged when only undisturbed stands were considered. The decline of red spruce accounted for about three quarters of the total decrease in basal area for both the high- and low-elevation forests. Spruce seedling frequency for the high-elevation sample decreased by 80%, but was unchanged below 900m. The pattern of spruce decline in the Adirondacks is similar to findings for New England. The cause of the decline is speculative at the time.

  11. Why Is the Divorce Rate Declining in Indonesia?

    ERIC Educational Resources Information Center

    Heaton, Tim B.; Cammack, Mark; Young, Larry

    2001-01-01

    This study examines trends in marital dissolution in Indonesia considering the impact of educational expansion; delayed marriage; urbanization; increasing employment before marriage; legislative change; and increased free choice in marriage on the decline in marital disruption. It suggests that traditional patterns sustaining high levels of…

  12. Evaluating Functional Decline in Patients with Multiple Sclerosis

    ERIC Educational Resources Information Center

    Rosenblum, Sara; Weiss, Patrice L.

    2010-01-01

    Multiple Sclerosis (MS) is a disease with a wide-ranging impact on functional status. The aim of the study was to examine the added value of simultaneously evaluating fatigue, personal ADL and handwriting performance as indicators for functional decline among patients with MS. Participants were 50 outpatients with MS and 26 matched healthy…

  13. Sobering up: A Quantitative Review of Temporal Declines in Expectations

    ERIC Educational Resources Information Center

    Sweeny, Kate; Krizan, Zlatan

    2013-01-01

    Although people's outlook on the future tends to be characterized by hope and optimism, over time this outlook often becomes more dire. We review multiple theoretical accounts of this tendency to "sober up" as feedback about outcomes draws near, and we explicate factors critical to promoting these temporal declines in expectations. We then…

  14. Stagnation in Mortality Decline among Elders in the Netherlands

    ERIC Educational Resources Information Center

    Janssen, Fanny; Nusselder, Wilma J.; Looman, Caspar W. N.; Mackenbach, Johan P.; Kunst, Anton E.

    2003-01-01

    Purpose: This study assesses whether the stagnation of old-age (80+) mortality decline observed in The Netherlands in the 1980s continued in the 1990s and determines which factors contributed to this stagnation. Emphasis is on the role of smoking. Design and Methods: Poisson regression analysis with linear splines was applied to total and…

  15. Declining Health Behavior of Adolescents: A Measure of Alienation.

    ERIC Educational Resources Information Center

    Crase, Darrell

    1981-01-01

    Cites statistics on such adolescent problems as pregnancy, drugs, and obesity as evidence of the serious neglect and alienation of this age group in an era of family instability and declining social roles for youth. Urges educators to give concerted attention to the physical, mental, and health needs of adolescents. (SJL)

  16. Managing Enrollment Decline: Current Knowledge and Future Applications.

    ERIC Educational Resources Information Center

    Berger, Michael A.

    Although educational leaders have been coping with declining enrollment for almost a decade, educational researchers have begun to focus on the topic only recently. The first part of this introduction to a special issue of the Peabody Journal of Education briefly summarizes the contents of the subsequent essays, which are intended to bridge the…

  17. Declining Enrolments in Manitoba's Public Schools: Issues and Information.

    ERIC Educational Resources Information Center

    Husby, P. J.; Riffel, J. A.

    In order to provide a basis for discussion of declining enrollment in the province of Manitoba, the Department of Education commissioned this background paper. Topics covered include student enrollment data, courses and programs, the teaching force and teaching career, student transportation, administrative arrangements, educational finance, and…

  18. Declining Enrollment: The Challenge of the Coming Decade.

    ERIC Educational Resources Information Center

    Abramowitz, Susan, Ed.; Rosenfeld, Stuart, Ed.

    The research reported in this volume covers a range of topics dealing with shifting and declining enrollments and their impact on the financing, organization, and management of schools. The papers have been sorted into three groups. Section 1 discusses the demographic background to changing enrollment patterns. Section 2 presents the view from the…

  19. IQ Decline Following Early Unilateral Brain Injury: A Longitudinal Study

    ERIC Educational Resources Information Center

    Levine, Susan C.; Kraus, Ruth; Alexander, Erin; Suriyakham, Linda Whealton; Huttenlocher, Peter R.

    2005-01-01

    We examine whether children with early unilateral brain injury show an IQ decline over the course of development. Fifteen brain injured children were administered an IQ test once before age 7 and again several years later. Post-7 IQ scores were significantly lower than pre-7 IQ scores. In addition, pre-7 IQ scores were lower for children with…

  20. Infectious Burden and Cognitive Decline in the Northern Manhattan Study

    PubMed Central

    Wright, Clinton B.; Gardener, Hannah; Dong, Chuanhui; Yoshita, Mitsuhiro; DeCarli, Charles; Sacco, Ralph L.; Stern, Yaakov; Elkind, Mitchell S.V.

    2016-01-01

    Objectives To determine whether infectious burden (IB) is associated with worse performance and decline on a battery of neuropsychological tests. Design Prospective cohort study (Northern Manhattan Study (NOMAS)). Setting Community. Participants A subsample of 588 stroke-free NOMAS participants with IB and cognitive data (mean age 71±8, 62% female, 14% white, 16% black, 70% Hispanic) and 419 with repeat cognitive testing. Measurements Samples used for IB data were collected at baseline. Two waves of neurocognitive assessments occurred during follow-up. Participants underwent a neuropsychological battery and had repeated testing (mean time span 6±2 years). Using factor analysis–derived domain-specific Z scores for language, memory, executive function, and processing speed, associations between a quantitative stroke risk-weighted IB index (IBI), based on five common infections (Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, herpes simplex viruses 1 and 2), and cognitive performance and decline in each domain was examined. Results Adjusting for demographic characteristics, socioeconomic status, crystallized cognitive abilities, and vascular risk factors, the IBI was inversely associated with executive function at baseline (beta=−0.10, p=.01) but not with baseline language, memory, or processing speed performance in adjusted analyses. The IBI was associated with cognitive decline in the memory domain, adjusting for demographic and vascular risk factors (p=.02). Conclusion A quantitative measure of IB explained variability in baseline executive function performance and associated with decline in memory. Past exposure to common infections may contribute to vascular cognitive impairment and warrants further study. PMID:26289683

  1. Pesticides and Population Declines of California Alpine Frogs

    EPA Science Inventory

    Airborne pesticides from the Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the mountain yellow-legged frog complex (Rana muscosa and R. sierrae) in the Sierra Nevada. We measured ...

  2. Test Score Decline Among High Achievers: Policy Implications.

    ERIC Educational Resources Information Center

    Goldman, Jerrold; Hsia, Jayjia

    Since 1967, the mean Scholastic Aptitude Test (SAT) score has declined. Likewise, the numbers of candidates receiving high SAT scores have been decreasing steadily. The same downward trend in student achievement can be seen among student groups from grade 4 through post graduate studies. In recent years, policy has been directed towards making…

  3. 34 CFR 303.405 - Parent right to decline service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION EARLY INTERVENTION PROGRAM FOR INFANTS AND... parents of a child eligible under this part may determine whether they, their child, or other family members will accept or decline any early intervention service under this part in accordance with State...

  4. President Hails Continued Decline in Default Rate on Student Loans.

    ERIC Educational Resources Information Center

    Burd, Stephen

    1997-01-01

    President Bill Clinton used the declining default rate on college student loans as a basis for proposing tax breaks for college costs. Reduced defaults have saved taxpayer money and helped reduce the federal deficit. Over 150 colleges and universities, including 25 private institutions, risk losing eligibility for federal grant and loan programs…

  5. Are neonicotinoid insecticides driving declines of widespread butterflies?

    PubMed Central

    Bunnefeld, Nils; Wilson, John McVean; Botham, Marc S.; Brereton, Tom M.; Fox, Richard; Goulson, Dave

    2015-01-01

    There has been widespread concern that neonicotinoid pesticides may be adversely impacting wild and managed bees for some years, but recently attention has shifted to examining broader effects they may be having on biodiversity. For example in the Netherlands, declines in insectivorous birds are positively associated with levels of neonicotinoid pollution in surface water. In England, the total abundance of widespread butterfly species declined by 58% on farmed land between 2000 and 2009 despite both a doubling in conservation spending in the UK, and predictions that climate change should benefit most species. Here we build models of the UK population indices from 1985 to 2012 for 17 widespread butterfly species that commonly occur at farmland sites. Of the factors we tested, three correlated significantly with butterfly populations. Summer temperature and the index for a species the previous year are both positively associated with butterfly indices. By contrast, the number of hectares of farmland where neonicotinoid pesticides are used is negatively associated with butterfly indices. Indices for 15 of the 17 species show negative associations with neonicotinoid usage. The declines in butterflies have largely occurred in England, where neonicotinoid usage is at its highest. In Scotland, where neonicotinoid usage is comparatively low, butterfly numbers are stable. Further research is needed urgently to show whether there is a causal link between neonicotinoid usage and the decline of widespread butterflies or whether it simply represents a proxy for other environmental factors associated with intensive agriculture. PMID:26623186

  6. A Decline in Creativity? It Depends on the Domain

    ERIC Educational Resources Information Center

    Weinstein, Emily C.; Clark, Zachary; DiBartolomeo, Donna J.; Davis, Katie

    2014-01-01

    Earlier studies using psychometric tests have documented declines in creativity over the past several decades. Our study investigated whether and how this apparent trend would replicate through a qualitative investigation using an authentic nontest measure of creativity. Three-hundred and fifty-four visual artworks and 50 creative writing works…

  7. Detecting insect pollinator declines on regional and global scales.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, there has been considerable concern about declines in pollinator populations in both agricultural and natural habitats. The value of pollination services to agriculture, primarily by bees, is conservatively estimated to exceed $200 billion U.S. annually and the value of pollination servic...

  8. Fertility Decline in Rural China: A Comparative Analysis

    PubMed Central

    Harrell, Stevan; Yuesheng, Wang; Hua, Han; Santos, Gonçalo D.; Yingying, Zhou

    2014-01-01

    Many models have been proposed to explain both the rapidity of China’s fertility decline after the 1960s and the differential timing of the decline in different places. In particular, scholars argue over whether deliberate policies of fertility control, institutional changes, or general modernization factors contribute most to changes in fertility behavior. Here the authors adopt an ethnographically grounded behavioral–institutional approach to analyze qualitative and quantitative data from three different rural settings: Xiaoshan County in Zhejiang (East China), Ci County in Hebei (North China), and Yingde County in Guangdong (South China). The authors show that no one set of factors explains the differential timing and rapidity of the fertility decline in the three areas; rather they must explain differential timing by a combination of differences in social–cultural environments (e.g., spread of education, reproductive ideologies, and gender relations) and politico-economic conditions (e.g., economic development, birth planning campaigns, and collective systems of labor organization) during the early phases of the fertility decline. PMID:21319442

  9. Quantitative EEG and Cognitive Decline in Parkinson's Disease

    PubMed Central

    Cozac, Vitalii V.; Gschwandtner, Ute; Hatz, Florian; Hardmeier, Martin; Rüegg, Stephan

    2016-01-01

    Cognitive decline is common with the progression of Parkinson's disease (PD). Different candidate biomarkers are currently studied for the risk of dementia in PD. Several studies have shown that quantitative EEG (QEEG) is a promising predictor of PD-related cognitive decline. In this paper we briefly outline the basics of QEEG analysis and analyze the recent publications addressing the predictive value of QEEG in the context of cognitive decline in PD. The MEDLINE database was searched for relevant publications from January 01, 2005, to March 02, 2015. Twenty-four studies reported QEEG findings in various cognitive states in PD. Spectral and connectivity markers of QEEG could help to discriminate between PD patients with different level of cognitive decline. QEEG variables correlate with tools for cognitive assessment over time and are associated with significant hazard ratios to predict PD-related dementia. QEEG analysis shows high test-retest reliability and avoids learning effects associated with some neuropsychological testing; it is noninvasive and relatively easy to repeat. PMID:27148466

  10. Factors Contributing to Declining Enrollments at the University of Transkei.

    ERIC Educational Resources Information Center

    Imenda, S. N.; Kongolo, M.; Grewal, A. S.

    2002-01-01

    Surveyed students about their decision to enroll at the Unitersity of Transkei in an attempt to determine causes for declining enrollment. Found that career directions and affordability were main criteria. Public image and stability, staff quality, facilities and resources, administrative efficiency, staff friendliness, admissions/registration…

  11. 24 CFR 200.23 - Projects in declining neighborhoods.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Projects in declining neighborhoods. 200.23 Section 200.23 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT GENERAL INTRODUCTION TO FHA PROGRAMS Requirements for...

  12. Decadence, Scorn, and the Decline of Christian Practice on Campus

    ERIC Educational Resources Information Center

    French, David

    2010-01-01

    Religious practice dramatically decreases in college and students' positions on hot-button religious/cultural questions move appreciably to the left. There's no doubt that college students are on a quest for meaning. In this article, the author reports on new data that reveals unequivocally the decline of religious practice among college students.…

  13. Effects of invasive parasites on bumble bee declines.

    PubMed

    Meeus, Ivan; Brown, Mark J F; De Graaf, Dirk C; Smagghe, Guy

    2011-08-01

    Bumble bees are a group of pollinators that are both ecologically and economically important and declining worldwide. Numerous mechanisms could be behind this decline, and the spread of parasites from commercial colonies into wild populations has been implicated recently in North America. Commercial breeding may lead to declines because commercial colonies may have high parasite loads, which can lead to colonization of native bumble bee populations; commercial rearing may allow higher parasite virulence to evolve; and global movement of commercial colonies may disrupt spatial patterns in local adaptation between hosts and parasites. We assessed parasite virulence, transmission mode, and infectivity. Microparasites and so-called honey bee viruses may pose the greatest threat to native bumble bee populations because certain risk factors are present; for example, the probability of horizontal transmission of the trypanosome parasite Crithidia bombi is high. The microsporidian parasite Nosema bombi may play a role in declines of bumble bees in the United States. Preliminary indications that C. bombi and the neogregarine Apicystis bombi may not be native in parts of South America. We suggest that the development of molecular screening protocols, thorough sanitation efforts, and cooperation among nongovernmental organizations, governments, and commercial breeders might immediately mitigate these threats. PMID:21771075

  14. Types and Precipitants of Growth and Decline in Emerging Adulthood

    ERIC Educational Resources Information Center

    Gottlieb, Benjamin H.; Still, Eva; Newby-Clark, Ian R.

    2007-01-01

    To further explore central developmental themes of emerging adulthood, the authors conducted a study that combines qualitative and quantitative data about the types of personal growth and decline reported by a sample of emerging adults, who also described the life events and other experiences that brought about these personal changes. After…

  15. Breast Cancer Deaths Continue to Decline in U.S.

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_161468.html Breast Cancer Deaths Continue to Decline in U.S. And the ... 13, 2016 (HealthDay News) -- The racial gap for breast cancer deaths is closing, particularly among younger women, U.S. ...

  16. Measuring the meltdown: drivers of global amphibian extinction and decline.

    PubMed

    Sodhi, Navjot S; Bickford, David; Diesmos, Arvin C; Lee, Tien Ming; Koh, Lian Pin; Brook, Barry W; Sekercioglu, Cagan H; Bradshaw, Corey J A

    2008-02-20

    Habitat loss, climate change, over-exploitation, disease and other factors have been hypothesised in the global decline of amphibian biodiversity. However, the relative importance of and synergies among different drivers are still poorly understood. We present the largest global analysis of roughly 45% of known amphibians (2,583 species) to quantify the influences of life history, climate, human density and habitat loss on declines and extinction risk. Multi-model Bayesian inference reveals that large amphibian species with small geographic range and pronounced seasonality in temperature and precipitation are most likely to be Red-Listed by IUCN. Elevated habitat loss and human densities are also correlated with high threat risk. Range size, habitat loss and more extreme seasonality in precipitation contributed to decline risk in the 2,454 species that declined between 1980 and 2004, compared to species that were stable (n = 1,545) or had increased (n = 28). These empirical results show that amphibian species with restricted ranges should be urgently targeted for conservation.

  17. Immunological predictors of CD4+ T cell decline in antiretroviral treatment interruptions

    PubMed Central

    Seoane, Elena; Resino, Salvador; Moreno, Santiago; de Quiros, Juan Carlos Lopez Bernaldo; Moreno, Ana; Rubio, Rafael; Gonzalez-García, Juan; Arribas, José Ramón; Pulido, Federico; Muñoz-Fernández, Ma Ángeles

    2008-01-01

    Background The common response to stopping anti-HIV treatment is an increase of HIV-RNA load and decrease in CD4+, but not all the patients have similar responses to this therapeutic strategy. The aim was to identify predictive markers of CD4+ cell count declines to < 350/μL in CD4-guided antiretroviral treatment interruptions. Methods 27 HIV-infected patients participated in a prospective multicenter study in with a 24 month follow-up. Patients on stable highly active antiretroviral therapy (HAART), with CD4+ count > 600/μL, and HIV-RNA < 50 copies/ml for at least 6 months were offered the option to discontinue antiretroviral therapy. The main outcome was a decline in CD4+ cell count to < 350/μL. Results After 24 months of follow-up, 16 of 27 (59%) patients (who discontinued therapy) experienced declines in CD4+ cell count to < 350/μL. Patients with a CD4+ nadir of < 200 cells/μL had a greater risk of restarting therapy during the follow-up (RR (CI95%): 3.37 (1.07; 10.36)). Interestingly, lymphoproliferative responses to Mycobacterium tuberculosis purified protein derivative (PPD) below 10000 c.p.m. at baseline (4.77 (1.07; 21.12)), IL-4 production above 100 pg/mL at baseline (5.95 (1.76; 20.07)) in PBMC cultured with PPD, and increased IL-4 production of PBMC with p24 antigen at baseline (1.25 (1.01; 1.55)) were associated to declines in CD4+ cell count to < 350/μL. Conclusion Both the number (CD4+ nadir) and the functional activity of CD4+ (lymphoproliferative response to PPD) predict the CD4+ decrease associated with discontinuation of ART in patients with controlled viremia. PMID:18302775

  18. Dietary patterns, cognitive decline, and dementia: a systematic review.

    PubMed

    van de Rest, Ondine; Berendsen, Agnes Am; Haveman-Nies, Annemien; de Groot, Lisette Cpgm

    2015-03-01

    Nutrition is an important modifiable risk factor that plays a role in the strategy to prevent or delay the onset of dementia. Research on nutritional effects has until now mainly focused on the role of individual nutrients and bioactive components. However, the evidence for combined effects, such as multinutrient approaches, or a healthy dietary pattern, such as the Mediterranean diet, is growing. These approaches incorporate the complexity of the diet and possible interaction and synergy between nutrients. Over the past few years, dietary patterns have increasingly been investigated to better understand the link between diet, cognitive decline, and dementia. In this systematic review we provide an overview of the literature on human studies up to May 2014 that examined the role of dietary patterns (derived both a priori as well as a posteriori) in relation to cognitive decline or dementia. The results suggest that better adherence to a Mediterranean diet is associated with less cognitive decline, dementia, or Alzheimer disease, as shown by 4 of 6 cross-sectional studies, 6 of 12 longitudinal studies, 1 trial, and 3 meta-analyses. Other healthy dietary patterns, derived both a priori (e.g., Healthy Diet Indicator, Healthy Eating Index, and Program National Nutrition Santé guideline score) and a posteriori (e.g., factor analysis, cluster analysis, and reduced rank regression), were shown to be associated with reduced cognitive decline and/or a reduced risk of dementia as shown by all 6 cross-sectional studies and 6 of 8 longitudinal studies. More conclusive evidence is needed to reach more targeted and detailed guidelines to prevent or postpone cognitive decline.

  19. Almagest Declinations: Ptolemy or “As found by us”

    NASA Astrophysics Data System (ADS)

    Brandt, John C.; Zimmer, P. C.; Jones, P. B.

    2013-01-01

    Consistent results and compatibility with historical evidence were reported by Zimmer, Brandt, and Jones for Almagest declinations determined by Timocharis, Aristyllus, and Hipparcus. Unfortunately, this situation does not apply to the Almagest declinations (Book VII, Chapter 3; Toomer 1998) for Ptolemy or “As found by us.” Our formal solution gives a precision of 11.9 arc min and an epoch near 115AD. The precision is significantly worse than for the earlier observers and the date conflicts with historical data. Inspection of the (O) - (C) plots vs. year reveals that the natural clustering of trajectories seen for the other observers is not seen for the Ptolemy declinations. In addition, the spread in dates of observations estimated from the times of (O) - (C) = 0 shows a much larger value for Ptolemy than for the others. Historically, the Almagest was published around 150AD or perhaps a little later. Ptolemy’s life span was likely from c.100AD to c.175AD. Thus, the 115AD date for his observations is much too early. Maeyama (1984) moved the epoch from 115AD to 137/138AD by dropping stars from the analysis. Rawlins (manuscript, c. 1983) has an extensive discussion, drops several stars, and finds a preferred epoch of 137AD. He regards the observer as unknown. We prefer not to drop stars from the analysis unless the evidence is overwhelming. Our solution is to take Ptolemy literally. In Toomer (1998; tables on pages 331 & 332), these declinations are “As found by us” and in Taliaferro (1952; in the text) are as “we find it.” The idea of multiple observers has been suggested before and our analysis certainly supports the declinations coming from multiple observers through the years.

  20. Evaluating the links between climate, disease spread, and amphibian declines.

    PubMed

    Rohr, Jason R; Raffel, Thomas R; Romansic, John M; McCallum, Hamish; Hudson, Peter J

    2008-11-11

    Human alteration of the environment has arguably propelled the Earth into its sixth mass extinction event and amphibians, the most threatened of all vertebrate taxa, are at the forefront. Many of the worldwide amphibian declines have been caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd), and two contrasting hypotheses have been proposed to explain these declines. Positive correlations between global warming and Bd-related declines sparked the chytrid-thermal-optimum hypothesis, which proposes that global warming increased cloud cover in warm years that drove the convergence of daytime and nighttime temperatures toward the thermal optimum for Bd growth. In contrast, the spatiotemporal-spread hypothesis states that Bd-related declines are caused by the introduction and spread of Bd, independent of climate change. We provide a rigorous test of these hypotheses by evaluating (i) whether cloud cover, temperature convergence, and predicted temperature-dependent Bd growth are significant positive predictors of amphibian extinctions in the genus Atelopus and (ii) whether spatial structure in the timing of these extinctions can be detected without making assumptions about the location, timing, or number of Bd emergences. We show that there is spatial structure to the timing of Atelopus spp. extinctions but that the cause of this structure remains equivocal, emphasizing the need for further molecular characterization of Bd. We also show that the reported positive multi-decade correlation between Atelopus spp. extinctions and mean tropical air temperature in the previous year is indeed robust, but the evidence that it is causal is weak because numerous other variables, including regional banana and beer production, were better predictors of these extinctions. Finally, almost all of our findings were opposite to the predictions of the chytrid-thermal-optimum hypothesis. Although climate change is likely to play an important role in worldwide amphibian declines

  1. Dietary Patterns, Cognitive Decline, and Dementia: A Systematic Review12

    PubMed Central

    van de Rest, Ondine; Berendsen, Agnes AM; Haveman-Nies, Annemien; de Groot, Lisette CPGM

    2015-01-01

    Nutrition is an important modifiable risk factor that plays a role in the strategy to prevent or delay the onset of dementia. Research on nutritional effects has until now mainly focused on the role of individual nutrients and bioactive components. However, the evidence for combined effects, such as multinutrient approaches, or a healthy dietary pattern, such as the Mediterranean diet, is growing. These approaches incorporate the complexity of the diet and possible interaction and synergy between nutrients. Over the past few years, dietary patterns have increasingly been investigated to better understand the link between diet, cognitive decline, and dementia. In this systematic review we provide an overview of the literature on human studies up to May 2014 that examined the role of dietary patterns (derived both a priori as well as a posteriori) in relation to cognitive decline or dementia. The results suggest that better adherence to a Mediterranean diet is associated with less cognitive decline, dementia, or Alzheimer disease, as shown by 4 of 6 cross-sectional studies, 6 of 12 longitudinal studies, 1 trial, and 3 meta-analyses. Other healthy dietary patterns, derived both a priori (e.g., Healthy Diet Indicator, Healthy Eating Index, and Program National Nutrition Santé guideline score) and a posteriori (e.g., factor analysis, cluster analysis, and reduced rank regression), were shown to be associated with reduced cognitive decline and/or a reduced risk of dementia as shown by all 6 cross-sectional studies and 6 of 8 longitudinal studies. More conclusive evidence is needed to reach more targeted and detailed guidelines to prevent or postpone cognitive decline. PMID:25770254

  2. Evaluating the links between climate, disease spread, and amphibian declines.

    PubMed

    Rohr, Jason R; Raffel, Thomas R; Romansic, John M; McCallum, Hamish; Hudson, Peter J

    2008-11-11

    Human alteration of the environment has arguably propelled the Earth into its sixth mass extinction event and amphibians, the most threatened of all vertebrate taxa, are at the forefront. Many of the worldwide amphibian declines have been caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd), and two contrasting hypotheses have been proposed to explain these declines. Positive correlations between global warming and Bd-related declines sparked the chytrid-thermal-optimum hypothesis, which proposes that global warming increased cloud cover in warm years that drove the convergence of daytime and nighttime temperatures toward the thermal optimum for Bd growth. In contrast, the spatiotemporal-spread hypothesis states that Bd-related declines are caused by the introduction and spread of Bd, independent of climate change. We provide a rigorous test of these hypotheses by evaluating (i) whether cloud cover, temperature convergence, and predicted temperature-dependent Bd growth are significant positive predictors of amphibian extinctions in the genus Atelopus and (ii) whether spatial structure in the timing of these extinctions can be detected without making assumptions about the location, timing, or number of Bd emergences. We show that there is spatial structure to the timing of Atelopus spp. extinctions but that the cause of this structure remains equivocal, emphasizing the need for further molecular characterization of Bd. We also show that the reported positive multi-decade correlation between Atelopus spp. extinctions and mean tropical air temperature in the previous year is indeed robust, but the evidence that it is causal is weak because numerous other variables, including regional banana and beer production, were better predictors of these extinctions. Finally, almost all of our findings were opposite to the predictions of the chytrid-thermal-optimum hypothesis. Although climate change is likely to play an important role in worldwide amphibian declines

  3. Has contemporary climate change played a role in population declines of the lizard Ctenophorus decresii from semi-arid Australia?

    PubMed

    Walker, Samantha; Stuart-Fox, Devi; Kearney, Michael R

    2015-12-01

    Whilst contemporary climatic changes are small in magnitude compared to those predicted for the coming decades, they have already been linked to species range shifts and local extinctions. Elucidating the drivers behind species' responses to contemporary climate change will better inform management strategies for vulnerable and pest species alike. A recent proposal to explain worldwide local extinctions in lizards is that increasing maximum temperatures have constrained lizard activity time in the breeding season beyond extinction thresholds. Here we document a significant population decline and potential local extinction at the warm (northern) range margin of the tawny dragon, Ctenophorus decresii, a rock-dwelling lizard from the Flinders Ranges in semi-arid Australia. We developed and tested a biophysical model of tawny dragon thermoregulatory behaviour and drove the model with daily weather data for the period 1990-2009 across the Flinders Ranges. Our results indicate that potential annual activity time has likely increased over this period throughout the historic range, with within-season declines only in the summer months at the northern range limit. However, populations that have declined since 2000 have also likely experienced higher active body temperatures and more stringent retreat-site requirements (deeper crevices) than have regions where the species remains common, during a period of declining rainfall. Our laboratory estimates of thermal preference in this species were insensitive to altered nutritional and hydric state. Thus it is possible that recent population declines are linked to desiccation stress driven by higher body temperatures and declining rainfall. Our study illustrates that simple indices of the impact of climate warming on animals, such as activity restriction, may in fact reflect a variety of potential mechanisms whose ultimate outcome will be contingent on other factors such as water and shelter availability.

  4. Has contemporary climate change played a role in population declines of the lizard Ctenophorus decresii from semi-arid Australia?

    PubMed

    Walker, Samantha; Stuart-Fox, Devi; Kearney, Michael R

    2015-12-01

    Whilst contemporary climatic changes are small in magnitude compared to those predicted for the coming decades, they have already been linked to species range shifts and local extinctions. Elucidating the drivers behind species' responses to contemporary climate change will better inform management strategies for vulnerable and pest species alike. A recent proposal to explain worldwide local extinctions in lizards is that increasing maximum temperatures have constrained lizard activity time in the breeding season beyond extinction thresholds. Here we document a significant population decline and potential local extinction at the warm (northern) range margin of the tawny dragon, Ctenophorus decresii, a rock-dwelling lizard from the Flinders Ranges in semi-arid Australia. We developed and tested a biophysical model of tawny dragon thermoregulatory behaviour and drove the model with daily weather data for the period 1990-2009 across the Flinders Ranges. Our results indicate that potential annual activity time has likely increased over this period throughout the historic range, with within-season declines only in the summer months at the northern range limit. However, populations that have declined since 2000 have also likely experienced higher active body temperatures and more stringent retreat-site requirements (deeper crevices) than have regions where the species remains common, during a period of declining rainfall. Our laboratory estimates of thermal preference in this species were insensitive to altered nutritional and hydric state. Thus it is possible that recent population declines are linked to desiccation stress driven by higher body temperatures and declining rainfall. Our study illustrates that simple indices of the impact of climate warming on animals, such as activity restriction, may in fact reflect a variety of potential mechanisms whose ultimate outcome will be contingent on other factors such as water and shelter availability. PMID:26615728

  5. Rate of CD4 Decline and Factors Associated with Rapid CD4 Decline in Asymptomatic HIV-Infected Patients.

    PubMed

    Chaiyasin, Natdanai; Sungkanuparph, Somnuek

    2016-01-01

    The accurate marker to assess the risk of disease progression in HIV disease is CD4 count. CD4 decline to <200 cells/mm3 prompts the patients to have risk of opportunistic infections. A retrospective cohort study was conducted in asymptomatic HIV-infected patients who had CD4 count>200 cell/mm3, were antiretroviral naive, and had ≥1-year follow-up. Eighty patients, with mean age of 36.4 (standard deviation [SD]=9.1) years and 58.8% females, were analyzed. The mean (SD) baseline CD4 count was 423 (119) cells/mm3. During the median (IQR) time of 29.0 (14.1-49.6) months, 26.3% had CD4 declined to <200 cells/mm3. From Cox proportional hazard model, only baseline CD4 count<350 cells/mm3 was significantly associated with rapid decline in CD4 count (HR 4.208; 95%CI, 1.428-12.397; P=.009). Age, gender, comorbid disease, risk of HIV infection, duration of HIV diagnosis, and body weight were not associated with rapid CD4 decline. This indicates that asymptomatic patients with CD4 count<350 cells/mm3 are at priority for antiretroviral therapy in resource-limited settings.

  6. Multiple stressor effects in relation to declining amphibian populations

    USGS Publications Warehouse

    2003-01-01

    This book represents the work of several authors who participated in the symposium entitled 'Multiple Stressor Effects in Relation to Declining Amphibian Populations' convened 16-17 April, 2002, in Pittsburgh, Pennsylvania. Declines of amphibian populations of varying severity have been observed for many years, and in the last 8 to 10 years considerable progress has been made in documenting the status and distribution of a range of amphibian species. Habitat alteration and destruction are likely linked to many amphibian declines, but a variety of other factors, both anthropogenic and natural, have been observed or proposed to have caused declines or extinctions of amphibian populations. Unfortunately, determining the environmental causes for the decline of many species has proven difficult. The goals of this symposium were three-fold. First, highlight ASTM's historic role in providing a forum for the standardization of amphibian toxicity test methods and the characterization of adverse effects potentially associated with chemical stressors. Second, demonstrate through case studies the current state of technical 'tools' available to biologists, ecologists, environmental scientists and natural resource professionals for assessing amphibian populations exposed to various environmental stressors. And third, characterize a process that brings a range of interdisciplinary technical and management tools to the tasks of causal analysis, especially as those relate to a multiple stressor risk assessment 'mind-set.' As part of the symposium, scientists and resource management professionals from diverse fields including ecotoxicology and chemistry, ecology and field biology, conservation biology, and natural resource management and policy contributed oral presentations and posters that addressed topics related to declining amphibian populations and the role that various stressors have in those losses. The papers contained in this publication reflect the commitment of ASTM

  7. Hearing loss and cognitive decline in older adults.

    PubMed

    Lin, Frank R; Yaffe, Kristine; Xia, Jin; Xue, Qian-Li; Harris, Tamara B; Purchase-Helzner, Elizabeth; Satterfield, Suzanne; Ayonayon, Hilsa N; Ferrucci, Luigi; Simonsick, Eleanor M

    2013-02-25

    BACKGROUND Whether hearing loss is independently associated with accelerated cognitive decline in older adults is unknown. METHODS We studied 1984 older adults (mean age, 77.4 years) enrolled in the Health ABC Study, a prospective observational study begun in 1997-1998. Our baseline cohort consisted of participants without prevalent cognitive impairment (Modified Mini-Mental State Examination [3MS] score, ≥80) who underwent audiometric testing in year 5. Participants were followed up for 6 years. Hearing was defined at baseline using a pure-tone average of thresholds at 0.5 to 4 kHz in the better-hearing ear. Cognitive testing was performed in years 5, 8, 10, and 11 and consisted of the 3MS (measuring global function) and the Digit Symbol Substitution test (measuring executive function). Incident cognitive impairment was defined as a 3MS score of less than 80 or a decline in 3MS score of more than 5 points from baseline. Mixed-effects regression and Cox proportional hazards regression models were adjusted for demographic and cardiovascular risk factors. RESULTS In total, 1162 individuals with baseline hearing loss (pure-tone average >25 dB) had annual rates of decline in 3MS and Digit Symbol Substitution test scores that were 41% and 32% greater, respectively, than those among individuals with normal hearing. On the 3MS, the annual score changes were -0.65 (95% CI, -0.73 to -0.56) vs -0.46 (95% CI, -0.55 to -0.36) points per year (P = .004). On the Digit Symbol Substitution test, the annual score changes were -0.83 (95% CI, -0.94 to -0.73) vs -0.63 (95% CI, -0.75 to -0.51) points per year (P = .02). Compared to those with normal hearing, individuals with hearing loss at baseline had a 24% (hazard ratio, 1.24; 95% CI, 1.05-1.48) increased risk for incident cognitive impairment. Rates of cognitive decline and the risk for incident cognitive impairment were linearly associated with the severity of an individual's baseline hearing loss. CONCLUSIONS Hearing loss is

  8. Monounsaturated, trans & saturated fatty acids and cognitive decline in women

    PubMed Central

    Naqvi, Asghar Z.; Harty, Brian; Mukamal, Kenneth J.; Stoddard, Anne M.; Vitolins, Mara; Dunn, Julie E.

    2011-01-01

    Objectives Prospectively assess effects of select dietary fats on cognitive decline Design Prospective observational; 3-year follow-up Setting Subjects recruited at Northwestern University who participated in Women's Health Initiative Observational Study or control group of Diet Modification arm. Participants 482 women ≥ 60 years Measurements We averaged dietary intake from a validated food frequency questionnaire (FFQ) administered twice (mean=2.7 years apart) before baseline cognitive assessment (mean=2.9 years after 2nd FFQ). Testing of memory, vision, executive function, language, and attention was performed at 2 time points, 3 years apart. We created a global Z-score for both time points by averaging all Z-scores for each participant and defined global cognitive change as the difference between follow-up and baseline Z-scores. Results Median intakes of saturated fats (SFA), trans-fats, (TFA), dietary cholesterol (DC) and monounsaturated fats (MUFA) were 18.53 g/d, 3.45 g/d, 0.201 g/d and 19.39 g/d, respectively. There were no associations between degree of cognitive decline and intakes of SFA (p=0.69), TFA (p=0.54) or DC (p=0.64) after adjusting for baseline cognition, total energy, age, education, reading ability, Apolipoprotein E (ε4) allele, BMI, estrogen and beta-blocker use, and intake of caffeine and other fatty acids. In contrast, compared with participants in the lowest quartile, MUFA intake was associated with lower cognitive decline in fully adjusted linear regression models, with decline of 0.21 + 0.05 SE in the lowest versus 0.05 + 0.05 SE in the highest quartiles (p=0.02). This effect of MUFA intake was primarily in the visual and memory domains (p=0.03 for both). Conclusion Higher intakes of SFA, TFA and DC in these women were not associated with cognitive decline, while MUFA intake was associated with less cognitive decline. PMID:21568955

  9. Use of the Internet as a prevention tool against cognitive decline in normal aging

    PubMed Central

    Klimova, Blanka

    2016-01-01

    Recent demographic trends indicate that older people appear to be one of the fastest growing population groups worldwide. In the year 2000, people older than 65 years represented 12.4% of the population. This number is expected to rise to 19% by 2030, particularly in developed countries. Therefore, there is sustained effort at both national and international levels to prolong the active life of these people as long as possible. Since the present older generation at the age of 55 years is already digitally literate, the use of technologies is one of the solutions. The purpose of this study is to discuss the role of the Internet in the prevention of cognitive decline in normal aging. The author examines clinical studies that exploit the use of the Internet, including online training programs, in the prevention of cognitive decline in healthy older individuals. The findings of the clinical studies indicate that the use of the Internet, especially online cognitive training programs, may have a positive effect on the improvement of cognitive functions in healthy older adults. Nevertheless, larger sample longitudinal randomized controlled clinical trials aimed at the prevention of cognitive decline among healthy older adults are needed. PMID:27672317

  10. Steep declines in atmospheric base cations in regions of Europe and North America

    NASA Astrophysics Data System (ADS)

    Hedin, Lars O.; Granat, Lennart; Likens, Gene E.; Adri Buishand, T.; Galloway, James N.; Butler, Thomas J.; Rodhe, Henning

    1994-01-01

    HUMAN activities have caused marked changes in atmospheric chemistry over large regions of Europe and North America. Although considerable attention has been paid to the effects of changes in the deposition of acid anions (such as sulphate and nitrate) on terrestrial and aquatic ecosystems1-7, little is known about whether the concentrations of basic components of the atmosphere have changed over time8,9 and what the biogeochemical consequences of such potential changes might be. In particular, there has been some controversy8-12 as to whether declines in base-cation deposition have countered effects of recent reductions in SO2emission. Here we report evidence for steep declines in the atmospheric concentrations of base cations (sum of non-sea-salt Ca2+, Mg2+, K+ and Na+) over the past 10 to 26 years from high-quality precipitation chemistry records in Europe and North America. To varying but generally significant degrees, these base-cation trends have offset recent reductions in sulphate deposition in the regions examined. The observed trends seem to be ecologically important on decadal timescales, and support earlier contentions8-10 that declines in the deposition of base cations may have contributed to increased sensitivity of poorly buffered ecosystems.

  11. Use of the Internet as a prevention tool against cognitive decline in normal aging

    PubMed Central

    Klimova, Blanka

    2016-01-01

    Recent demographic trends indicate that older people appear to be one of the fastest growing population groups worldwide. In the year 2000, people older than 65 years represented 12.4% of the population. This number is expected to rise to 19% by 2030, particularly in developed countries. Therefore, there is sustained effort at both national and international levels to prolong the active life of these people as long as possible. Since the present older generation at the age of 55 years is already digitally literate, the use of technologies is one of the solutions. The purpose of this study is to discuss the role of the Internet in the prevention of cognitive decline in normal aging. The author examines clinical studies that exploit the use of the Internet, including online training programs, in the prevention of cognitive decline in healthy older individuals. The findings of the clinical studies indicate that the use of the Internet, especially online cognitive training programs, may have a positive effect on the improvement of cognitive functions in healthy older adults. Nevertheless, larger sample longitudinal randomized controlled clinical trials aimed at the prevention of cognitive decline among healthy older adults are needed.

  12. The mismatch negativity as an index of cognitive decline for the early detection of Alzheimer's disease.

    PubMed

    Ruzzoli, Manuela; Pirulli, Cornelia; Mazza, Veronica; Miniussi, Carlo; Brignani, Debora

    2016-01-01

    Evidence suggests that Alzheimer's disease (AD) is part of a continuum, characterized by long preclinical phases before the onset of clinical symptoms. In several cases, this continuum starts with a syndrome, defined as mild cognitive impairment (MCI), in which daily activities are preserved despite the presence of cognitive decline. The possibility of having a reliable and sensitive neurophysiological marker that can be used for early detection of AD is extremely valuable because of the incidence of this type of dementia. In this study, we aimed to investigate the reliability of auditory mismatch negativity (aMMN) as a marker of cognitive decline from normal ageing progressing from MCI to AD. We compared aMMN elicited in the frontal and temporal locations by duration deviant sounds in short (400 ms) and long (4000 ms) inter-trial intervals (ITI) in three groups. We found that at a short ITI, MCI showed only the temporal component of aMMN and AD the frontal component compared to healthy elderly who presented both. At a longer ITI, aMMN was elicited only in normal ageing subjects at the temporal locations. Our study provides empirical evidence for the possibility to adopt aMMN as an index for assessing cognitive decline in pathological ageing. PMID:27616726

  13. Spilled oil and infaunal activity - Modification of burrowing behavior and redistribution of oil

    USGS Publications Warehouse

    Clifton, H.E.; Kvenvolden, K.A.; Rapp, J.B.

    1984-01-01

    A series of experiments in Willapa Bay, Washington, indicates the degree to which the presence of spilled oil modifies the burrowing behavior of infauna and the extent to which the animals redistribute oil into intertidal sediment. Small amounts of North Slope crude oil introduced at low tide directly into burrow openings (mostly made by the crustacean Callianassa) resulted in a limited and temporary reduction in the number of burrow openings. In contrast, a layer of oil-saturated sand 1 cm thick buried about 5 cm below the sediment surface sharply reduced the number of burrow openings. After a year, the few new burrows penetrated only the margins of the experimental plot, and bioturbation below the buried oil-saturated sand layer declined dramatically. The experiments suggest that small amounts of oil temporarily stranded by tides in themselves have no long-range effect on burrowing behavior. The fauna, however, are capable of introducing measurable amounts of oil into the subsurface, where it is retained long after the rest of the stranded oil had washed away. A buried layer of oil-saturated sand greatly reduces infaunal activity; the oil presents an effective barrier that can persist for years. The oil incorporated into the sediment from burrow openings showed evidence of degradation after 7 months. In contrast the layer of buried oil remained essentially undergraded after a period of two years, even though oil in lower concentrations above the layer was degraded after a period of one year. This variation in degree of degradation of the buried oil, as well as the heterogeneity of oil distribution wherever the oil has been incorporated from the surface, emphasises the importance of careful sampling in any attempt to locate or monitor the presence of spilled oil in the substrate.In a series of experiments in Willapa Bay, Washington, small amounts of North Slope crude oil introduced at low tide directly into burrow openings resulted in a limited and temporary

  14. Declining resilience of ecosystem functions under biodiversity loss

    PubMed Central

    Oliver, Tom H.; Isaac, Nick J. B.; August, Tom A.; Woodcock, Ben A.; Roy, David B.; Bullock, James M.

    2015-01-01

    The composition of species communities is changing rapidly through drivers such as habitat loss and climate change, with potentially serious consequences for the resilience of ecosystem functions on which humans depend. To assess such changes in resilience, we analyse trends in the frequency of species in Great Britain that provide key ecosystem functions—specifically decomposition, carbon sequestration, pollination, pest control and cultural values. For 4,424 species over four decades, there have been significant net declines among animal species that provide pollination, pest control and cultural values. Groups providing decomposition and carbon sequestration remain relatively stable, as fewer species are in decline and these are offset by large numbers of new arrivals into Great Britain. While there is general concern about degradation of a wide range of ecosystem functions, our results suggest actions should focus on particular functions for which there is evidence of substantial erosion of their resilience. PMID:26646209

  15. Does conservation on farmland contribute to halting the biodiversity decline?

    PubMed

    Kleijn, David; Rundlöf, Maj; Scheper, Jeroen; Smith, Henrik G; Tscharntke, Teja

    2011-09-01

    Biodiversity continues to decline, despite the implementation of international conservation conventions and measures. To counteract biodiversity loss, it is pivotal to know how conservation actions affect biodiversity trends. Focussing on European farmland species, we review what is known about the impact of conservation initiatives on biodiversity. We argue that the effects of conservation are a function of conservation-induced ecological contrast, agricultural land-use intensity and landscape context. We find that, to date, only a few studies have linked local conservation effects to national biodiversity trends. It is therefore unknown how the extensive European agri-environmental budget for conservation on farmland contributes to the policy objectives to halt biodiversity decline. Based on this review, we identify new research directions addressing this important knowledge gap.

  16. A rapidly declining perennial sea ice cover in the Arctic

    NASA Astrophysics Data System (ADS)

    Comiso, Josefino C.

    2002-10-01

    The perennial sea ice cover in the Arctic is shown to be declining at -9% per decade using satellite data from 1978 to 2000. A sustained decline at this rate would mean the disappearance of the multiyear ice cover during this century and drastic changes in the Arctic climate system. An apparent increase in the fraction of second year ice in the 1990s is also inferred suggesting an overall thinning of the ice cover. Surface ice temperatures derived from satellite data are negatively correlated with perennial ice area and are shown to be increasing at the rate of 1.2 K per decade. The latter implies longer melt periods and therefore decreasing ice volume in the more recent years.

  17. Social change and early fertility decline in Catalonia.

    PubMed

    Benavente, J

    1989-12-01

    "This article attempts a description of the fertility and nuptiality patterns of a group of selected localities in Catalonia [Spain] from the late eighteenth century to the mid-nineteenth century. The pattern of fertility transition in Catalonia can be described as starting from nuptiality conditions of early and quasi-universal marriage. The pattern of nuptiality is preserved throughout the process in its essentials. The transition, then, was largely limited to a decline in marital fertility. The evidence suggests an onset occurring in the 1830s, closer to the French experience than to that of any other Western European country. Finally, the analysis of the 84 local areas supports the proposition that structural factors had a significant effect on both the mid-nineteenth century level of marital fertility and the rate of decline during the 70-year period under study." (SUMMARY IN FRE)

  18. Nutritional management of older adults with cognitive decline and dementia.

    PubMed

    Ogawa, Sumito

    2014-04-01

    Age-related cognitive decline is a main predictor of disability among elderly people, and with the continued expansion of the aging population and the increase in life expectancy, the prevalence of mild cognitive impairment and dementia represented by Alzheimer's disease (AD), which is a multifactorial neurodegenerative disorder of older adults, have increased. Recent epidemiological and observational studies suggest a relationship exists between lifestyle factors, including nutrition and diet, and cognitive function in aging adults. It is also suggested that malnutrition and nutrient deficiencies are associated with cognitive decline in patients with dementia. There are a variety of nutritional factors, including nutritional status and dietary patterns, that might be associated with cognitive function, and specific micronutrients and dietary components have been suggested to have an association with cognitive function as well. Based on these findings and evidence, evaluation of nutritional state, as well as nutritional intervention, might be able to play a role in the management and prevention of dementia.

  19. Faint UBVRI Standard Star Fields at +50° Declination

    NASA Astrophysics Data System (ADS)

    Clem, James L.; Landolt, Arlo U.

    2016-10-01

    Precise and accurate CCD-based UBVRI photometry is presented for ∼2000 stars distributed around the sky in a declination zone centered approximately at +50°. Their photometry has been calibrated to the standard Johnson UBV and Kron–Cousins RI systems through observations of the UBVRI standard stars presented in the various works of Landolt. The magnitude and color range for these stars are 12 ≲ V ≲ 22 and ‑0.3 ≲ (B ‑ V) ≲ 1.8, respectively. Each star averages 13 measures in each UBVRI filter from data taken on 41 different photometric nights obtained over a 21 month period. Hence, there now exists a network of faint UBVRI photometric standard stars centered on the declination zones δ = ‑50°, 0°, and +50°.

  20. Devastating decline of forest elephants in central Africa.

    PubMed

    Maisels, Fiona; Strindberg, Samantha; Blake, Stephen; Wittemyer, George; Hart, John; Williamson, Elizabeth A; Aba'a, Rostand; Abitsi, Gaspard; Ambahe, Ruffin D; Amsini, Fidèl; Bakabana, Parfait C; Hicks, Thurston Cleveland; Bayogo, Rosine E; Bechem, Martha; Beyers, Rene L; Bezangoye, Anicet N; Boundja, Patrick; Bout, Nicolas; Akou, Marc Ella; Bene, Lambert Bene; Fosso, Bernard; Greengrass, Elizabeth; Grossmann, Falk; Ikamba-Nkulu, Clement; Ilambu, Omari; Inogwabini, Bila-Isia; Iyenguet, Fortune; Kiminou, Franck; Kokangoye, Max; Kujirakwinja, Deo; Latour, Stephanie; Liengola, Innocent; Mackaya, Quevain; Madidi, Jacob; Madzoke, Bola; Makoumbou, Calixte; Malanda, Guy-Aimé; Malonga, Richard; Mbani, Olivier; Mbendzo, Valentin A; Ambassa, Edgar; Ekinde, Albert; Mihindou, Yves; Morgan, Bethan J; Motsaba, Prosper; Moukala, Gabin; Mounguengui, Anselme; Mowawa, Brice S; Ndzai, Christian; Nixon, Stuart; Nkumu, Pele; Nzolani, Fabian; Pintea, Lilian; Plumptre, Andrew; Rainey, Hugo; de Semboli, Bruno Bokoto; Serckx, Adeline; Stokes, Emma; Turkalo, Andrea; Vanleeuwe, Hilde; Vosper, Ashley; Warren, Ymke

    2013-01-01

    African forest elephants- taxonomically and functionally unique-are being poached at accelerating rates, but we lack range-wide information on the repercussions. Analysis of the largest survey dataset ever assembled for forest elephants (80 foot-surveys; covering 13,000 km; 91,600 person-days of fieldwork) revealed that population size declined by ca. 62% between 2002-2011, and the taxon lost 30% of its geographical range. The population is now less than 10% of its potential size, occupying less than 25% of its potential range. High human population density, hunting intensity, absence of law enforcement, poor governance, and proximity to expanding infrastructure are the strongest predictors of decline. To save the remaining African forest elephants, illegal poaching for ivory and encroachment into core elephant habitat must be stopped. In addition, the international demand for ivory, which fuels illegal trade, must be dramatically reduced.