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111.
Mortality, a critical parameter for population dynamics, is difficult to measure in long-lived trees or clonal herbaceous species because of the extremely low frequency of deaths. A model based on shoot recruitment would be helpful to estimate the population fate of species without a sufficient number of observed deaths. Existing matrix models are applicable to the dynamics of physiologically independent shoots, but not to physiologically dependent ones. We developed a shoot-dynamics model for plants with physiologically-dependent shoots, and used the model to estimate the effects of herbivory and conservation measures on the dynamics of a long-lived, shoot-sprouting shrub species, Paliurus ramosissimus (Rhamnaceae). Two populations of the endangered shrub have been severely damaged by herbivory by sika deer. The damage was mainly to new sprouting shoots. No deaths of individual plants were observed during an 8-year survey, and we could not estimate mortality. Thus, prediction of population dynamics based on births and deaths of individuals was impossible. Because P. ramosissimus is a shoot-sprouting species, we instead estimated the decline of individuals using a shoot-dynamics model. Using this model, we estimated the time to an 80 % decrease in shoot number per individual in the two populations at 37.8 and 37.2 years. These lengths suggest an immediate need for conservation measures to prevent herbivory even though no death of any individual was observed in the field survey. The estimated recovery times from the herbivory damage were 28.7 and 29.2 years if herbivory of new shoots is completely prevented by conservation measure.  相似文献   
112.
《Cancer epidemiology》2014,38(6):715-721
BackgroundPrevious studies suggest that elevated resting heart rate (RHR) is related to an increased risk of cancer mortality. The aim of this study was to evaluate the relation between RHR and cancer incidence and mortality in patients with vascular disease.MethodsPatients with manifest vascular disease (n = 6007) were prospectively followed-up for cancer incidence and mortality. At baseline, RHR was obtained from an electrocardiogram. The relation between RHR and cancer incidence, cancer mortality and total mortality was assessed using competing risks models.ResultsDuring a median follow-up of 6.0 years (interquartile range: 3.1–9.3) 491 patients (8%) were diagnosed with cancer and 907 (15%) patients died, 248 (27%) died from cancer. After adjustment for potential confounders, the hazard ratio (HR) for incident cancer per 10 beats/min increase in RHR was 1.00 (95% confidence interval [CI]: 0.93–1.07). There was a trend toward an increased risk of colorectal cancer in patients with higher RHR (HR 1.15, 95% CI 0.97–1.36). The risk of all-cause mortality was increased in patients in the highest quartile of RHR compared to the lowest quartile (HR 1.86, 95% CI 1.53–2.27), but no effect of RHR on cancer mortality was observed (HR 1.01, 95% CI 0.70–1.46).ConclusionsIn patients with manifest vascular disease, elevated RHR was related to a higher risk of premature all-cause mortality, but this was not due to increased cancer mortality. RHR was not related to risk of overall cancer incidence, although a relation between elevated RHR and incident colorectal cancer risk could not be ruled out.  相似文献   
113.
Honey bees are important for ecological health, biodiversity preservation, and crop output. Antimicrobials, like Tetracyclines, are commonly used in agriculture, medicine, and beekeeping, bees might be exposed to Tetracycline residues in the environment either directly or indirectly. This study aimed to determine the effect of antibiotic treatment (Tetracycline) effect on the Bio-efficiency of the larvae honey bee (Apis mellifera jemenatica), when larvae honeybee workers were exposed to different concentrations of it, to see how long they survived after being exposed to it and affected this antibiotic to the histological structure of the midgut. The results demonstrated that the concentration (LC50 = 125.25 μg/ml) of antibiotics Tetracycline leads to kills half of the individuals. Our data indicate that the high concentrations of Tetracycline have a significant effect on the histological composition of the cells of the midgut of honeybee larvae. Antibiotic exposure can negatively impact the health of honey bees, especially Tetracycline because it is the most used antibiotic in apiculture.  相似文献   
114.
Background: This study estimates the burden of cancer in Korea during 2000–2020, ameliorating the Global Burden of Disease Study Group (GBD) method with the Incidence–Prevalence–Mortality (IPM) Model. Methods: Besides using the GBD approach to calculate the Years of Life Lost in Korea during 2000–2020, this research calculates the Years Lived with Disability (YLDs) of major cancers based on the combination of the GBD method and the IPM Model. Results: Colon, breast and thyroid cancers became more significant in terms of Disability Adjusted Life Years during 2000–2010 and this will continue during 2010–2020, colon cancer leading the pack instead of stomach cancer in 2020. The rise of colon cancer is more evident for the older age group and the opposite is true for breast and thyroid cancers. Indeed, stomach and liver cancers were resilient in terms of DALYs during 2000–2010 and this will continue during 2010–2020. Overall, the burden of cancer in Korea is characterized by an increasing centrality of YLDs (chronic components) as in other advanced nations. Conclusions: Korea's convergence with other advanced nations in cancer burden might reflect their convergence in living standards, the age structure, health behavior and medical technology during the past four decades. These transitions have been reflected in the Second 10-Year Plan for Cancer Control in Korea during 2006–2015, government policy consisting of four main programs, i.e., primary prevention, early detection, diagnosis/treatment and palliative care.  相似文献   
115.
In this study we focused on sow responsiveness towards piglet screams which are proposed to have an important link to posture changes and early piglet crushing. A sow's responsiveness to screams of her piglets was investigated along the first 24 h after birth, the period of highest mortality, in 15 lactating sows housed in farrowing crates. We compared the sow's response to playbacks of screams of trapped piglets to her response to a control sound during birth, 8–12 h postpartum and 20–24 h postpartum. We did the same with playbacks of screams of fighting piglets during nursings 8–12 h postpartum and 20–24 h postpartum. The sow’ responsiveness to screams of own trapped piglets was analyzed within the whole 24 h and to screams of fighting piglets 30 min between 8 and 12 h postpartum and 30 min between 20 and 24 h postpartum. A sow was scored as responsive if she changed her posture in response to the stimuli. Sows had a four times higher response towards playbacks with screams than towards the control stimulus. The proportion of the sows’ responsiveness to screams (44%) of trapped piglets did not change significantly between birth, 8–12 h postpartum and 20–24 h postpartum. Sows responded to 28% of playbacks of fighting piglets by terminating a nursing independently from the time after birth. Playbacks and real screams of own piglets were similarly effective in evoking a response for both types of screams. There was no significant association between the sows’ responsiveness to screams of trapped piglets and piglet mortality nor between screams of fighting piglets and weight gain. In conclusion our results indicate that sows maintained their responsiveness towards piglet screams during trapping and during fighting for teats within the first 24 h. Playbacks and real screams were similarly effective in evoking a response. We discuss the importance of the sound characteristics of piglet screams related to the sows’ response.  相似文献   
116.
This study analyses the relationship between consanguinity, fertility and child mortality in a rural population of two moroccan High-Atlas valleys. Among this very endogamous population, we have reconstituted, by inquiries, for each family, the totality of its reproductive life as well as the genealogic relationships that exist between the spouses on several generations. The analysis carried out on the group of families with women who are over 40 years old (438 families) has shown that the population was very strong related (28% of marriages are consanguineaous). A positive association between levels of fertility, infant mortality and consanguinity was observed.  相似文献   
117.
Bat hibernacula with high numbers of bats can become high-risk areas, as they attract flying and non-flying predators. In order to protect hibernating bats effectively, more knowledge about mortality factors is needed. During the winters of 2003–2015, we found 214 dead bats in 12 hibernacula in The Netherlands province of Zuid-Holland. Most bat remains were found in December and January, with a second peak in April. Their remains showed a typical pattern of lesions consistent with those caused by predation by the wood mouse (Apodemus sylvaticus). Trail camera surveys showed that wood mice actively searched for bats. Predation pressure seemed to vary between winters, with a peak in the winters of 2004, 2011 and 2015. The annual mortality (relative to the maximum winter population size) caused by wood mouse predation varied between 0.1 and 8.8 %, with a maximum local effect of 83.6 %. The years with high wood mouse predation pressure were characterized by a long frost period and a low mast production of common oak in the preceding autumn. The size of a hibernaculum and the population density of its bats had an effect on predation-dependent mortality. The highest predation risk occurred near the entrance of bunkers. From these results we tentatively conclude that predation is not incidental and that wood mice actively search for and kill hibernating bats or scavenge for weakened individuals.  相似文献   
118.
Six monoterpenes, ((?)-citronellal, p-cymene, (?)-menthone, α-pinene, α-terpinene and (?)-terpinen-4-ol) and two phenylpropenes, (trans-cinnamaldehyde and eugenol) were tested for their insecticidal activity against the rice weevil, Sitophilus oryzae under laboratory conditions. The bioassays were carried out on wheat at the concentrations of 0.5, 1.0 and 5.0?g/kg. Adult mortality was assessed after 14?days of exposure. After this interval, the treated wheat was retained for an additional period of 90?days, in order to evaluate progeny production and wheat loss. At the concentrations of 0.5 and 1.0?g/kg, trans-cinnamaldehyde and eugenol achieved highest adult mortality. At 5.0?g/kg, all compounds except for p-cymene and α-pinene caused complete (100%) adult mortality. Generally, trans-cinnamaldehyde was the most potent compound causing complete inhibition of progeny at the three concentrations. Similarly, no progeny were observed in the wheat treated with (?)-citronellal, eugenol, p-cymene, (?)-menthone, and (?)-terpinen-4-ol at 5.0?g/kg after 45 and 90?days. Similar trends were noted for wheat weight loss and damage as the treatment with monoterpenes and phenylpropenes at the highest rate preserved the wheat intact and free from damage by S. oryzae for 90?days. Our findings suggest the tested compounds except p-cymene and α-pinene could be recommended for use as part of an integrated pest management program for S. oryzae control in stored wheat.  相似文献   
119.
The probiotic effects of seven newly isolated gut bacteria, from the indegenous honey bees of Saudi Arabia were investigated. In vivo bioassays were used to investigate the effects of each gut bacterium namely, Fructobacillus fructosus (T1), Proteus mirabilis (T2), Bacillus licheniformis (T3), Lactobacillus kunkeei (T4), Bacillus subtilis (T5), Enterobacter kobei (T6), and Morganella morganii (T7) on mortality percentage of honey bee larvae infected with P. larvae spores along with negative control (normal diet) and positive control (normal diet spiked with P. larvae spores). Addition of gut bacteria to the normal diet significantly reduced the mortality percentage of the treated groups. Mortality percentage in all treated groups ranged from 56.67% up to 86.67%. T6 treated group exhibited the highest mortality (86.67%), whereas T4 group showed the lowest mortality (56.67%). Among the seven gut bacterial treatments, T4 and T3 decreased the mortality 56.67% and 66.67%, respectively, whereas, for T2, T6, and T7 the mortality percentage was equal to that of the positive control (86.67%). Mortality percentages in infected larval groups treated with T1, and T5 were 78.33% and 73.33% respectively. Most of the mortality occurred in the treated larvae during days 2 and 3. Treatments T3 and T4 treatments showed positive effects and reduced mortality.  相似文献   
120.
对许多多年生克隆植物来说,大量的研究表明:当光是限制因子时,随着立地密度的不断增加,克隆分株的出生率逐渐减小、死亡率逐渐增加。本文观测了乔木状高大竹类植物毛竹竹笋的出生与存活过程,结果表明:竹笋的出生率,即每样方的出笋数,明显地随着成竹立竹度的增加而增加。更确切地说,竹笋的数量,不管是出笋数还是活笋数,都明显地随着带新叶(1龄叶)的成竹立竹度的增加而增加,而与带老叶(2龄叶)的成竹立竹度相关性不显著。并且竹笋的死亡率是非密度制约的。这可能是由于对毛竹来说,其立地总是比较开敞,而且,其竹笋的生长在很大程度上是不直接需光的。  相似文献   
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