Animal mortality during fire Jolly, Chris J.; Dickman, Chris R.; Doherty, Tim S. ...
Global change biology,
March 2022, Letnik:
28, Številka:
6
Journal Article
Recenzirano
Earth's rapidly warming climate is propelling us towards an increasingly fire‐prone future. Currently, knowledge of the extent and characteristics of animal mortality rates during fire remains ...rudimentary, hindering our ability to predict how animal populations may be impacted in the future. To address this knowledge gap, we conducted a global systematic review of the direct effects of fire on animal mortality rates, based on studies that unequivocally determined the fate of animals during fire. From 31 studies spanning 1984–2020, we extracted data on the direct impacts of fire on the mortality of 31 species from 23 families. From these studies, there were 43 instances where direct effects were measured by reporting animal survival from pre‐ to post‐fire. Most studies were conducted in North America (52%) and Oceania (42%), focused largely on mammals (53%) and reptiles (30%), and reported mostly on animal survival in planned (82%) and/or low severity (70%) fires. We found no studies from Asia, Europe or South America. Although there were insufficient data to conduct a formal meta‐analysis, we tested the effect of fire type, fire severity, fire regime, animal body mass, ecological attributes and class on survival. Only fire severity affected animal mortality, with a higher proportion of animals being killed by high than low severity fires. Recent catastrophic fires across the globe have drawn attention to the plight of animals exposed to wildfire. Yet, our systematic review suggests that a relatively low proportion of animals (mean predicted mortality 95% CI = 3% 1%–9%) are killed during fire. However, our review also underscores how little we currently know about the direct effects of fire on animal mortality, and highlights the critical need to understand the effects of high severity fire on animal populations.
Our understanding of animal mortality rates during fire is rudimentary. Here, we conducted a global systematic review of the direct effects of fire on animal mortality rates. From 31 studies spanning 1984–2020, we extracted data on the direct impacts of fire on the mortality of 31 species from 23 families. Our systematic review suggests that a relatively low proportion of animals (3% 1%–9%) are killed during fire. However, our review also underscores how little we currently know about the direct effects of fire on animal mortality, and highlights the critical need to understand the effects of high severity fire on animal populations.
We report the discovery of the first hot Jupiter in the Hyades open cluster. HD 285507b orbits a V = 10.47 K4.5V dwarf (M sub(*) = 0.734 M sub(middot in circle); R sub(*) = 0.656 R sub(middot in ...circle)) in a slightly eccentric (e = 0.086 super(+0.018) sub(-0.019) ) orbit with a period of 6.0881 super(+0.0019) sub(-0.0018) days. The induced stellar radial velocity corresponds to a minimum companion mass of M sub(p) sin i = 0.917 + or - 0.033 M sub(Jup). Line bisector spans and stellar activity measures show no correlation with orbital phase, and the radial velocity amplitude is independent of wavelength, supporting the conclusion that the variations are caused by a planetary companion. Follow-up photometry indicates with high confidence that the planet does not transit. HD 285507b joins a small but growing list of planets in open clusters, and its existence lends support to a planet formation scenario in which a high stellar space density does not inhibit giant planet formation and migration. We calculate the circularization timescale for HD 285507b to be larger than the age of the Hyades, which may indicate that this planet's non-zero eccentricity is the result of migration via interactions with a third body. We also demonstrate a significant difference between the eccentricity distributions of hot Jupiters that have had time to tidally circularize and those that have not, which we interpret as evidence against Type II migration in the final stages of hot Jupiter formation. Finally, the dependence of the circularization timescale on the planetary tidal quality factor, Q sub(p), allows us to constrain the average value for hot Jupiters to be log Q sub(p) = 6.14 super(+0.41) sub(-0.25).
Kepler-16: A Transiting Circumbinary Planet Doyle, Laurance R.; Carter, Joshua A.; Fabrycky, Daniel C. ...
Science (American Association for the Advancement of Science),
09/2011, Letnik:
333, Številka:
6049
Journal Article
Recenzirano
Odprti dostop
We report the detection of a planet whose orbit surrounds a pair of low-mass stars. Data from the Kepler spacecraft reveal transits of the planet across both stars, in addition to the mutual eclipses ...of the stars, giving precise constraints on the absolute dimensions of all three bodies. The planet is comparable to Saturn in mass and size and is on a nearly circular 229-day orbit around its two parent stars. The eclipsing stars are 20 and 69% as massive as the Sun and have an eccentric 41-day orbit. The motions of all three bodies are confined to within 0.5° of a single plane, suggesting that the planet formed within a circumbinary disk.
Kepler-47: A Transiting Circumbinary Multiplanet System Orosz, Jerome A.; Welsh, William F.; Carter, Joshua A. ...
Science (American Association for the Advancement of Science),
09/2012, Letnik:
337, Številka:
6101
Journal Article
Recenzirano
Odprti dostop
We report the detection of Kepler-47, a system consisting of two planets orbiting around an eclipsing pair of stars. The inner and outer planets have radii 3.0 and 4.6 times that of Earth, ...respectively. The binary star consists of a Sun-like star and a companion roughly one-third its size, orbiting each other every 7.45 days. With an orbital period of 49.5 days, 18 transits of the inner planet have been observed, allowing a detailed characterization of its orbit and those of the stars. The outer planet's orbital period is 303.2 days, and although the planet is not Earth-like, it resides within the classical "habitable zone," where liquid water could exist on an Earth-like planet. With its two known planets, Kepler-47 establishes that close binary stars can host complete planetary systems.
The Sun's equator and the planets' orbital planes are nearly aligned, which is presumably a consequence of their formation from a single spinning gaseous disk. For exoplanetary systems this ...well-aligned configuration is not guaranteed: dynamical interactions may tilt planetary orbits, or stars may be misaligned with the protoplanetary disk through chaotic accretion , magnetic interactions or torques from neighbouring stars. Indeed, isolated 'hot Jupiters' are often misaligned and even orbiting retrograde. Here we report an analysis of transits of planets over starspots on the Sun-like star Kepler-30 (ref. 8), and show that the orbits of its three planets are aligned with the stellar equator. Furthermore, the orbits are aligned with one another to within a few degrees. This configuration is similar to that of our Solar System, and contrasts with the isolated hot Jupiters. The orderly alignment seen in the Kepler-30 system suggests that high obliquities are confined to systems that experienced disruptive dynamical interactions. Should this be corroborated by observations of other coplanar multi-planet systems, then star-disk misalignments would be ruled out as the explanation for the high obliquities of hot Jupiters, and dynamical interactions would be implicated as the origin of hot Jupiters.
In rodents and humans there is a sexually dimorphic pattern of GH secretion that influences the serum concentration of IGF-I. Pattern differences can be identified in children, but it is not known ...how early this difference is established. We studied the plasma concentrations of IGF-I, IGF-II, IGF-binding protein-3 (BP-3), and GH in cord blood taken from the offspring of 1650 singleton Caucasian pregnancies born at term and related these values to birth weight, length, and head circumference. Pregnancies complicated by preterm delivery, antepartum hemorrhage, pregnancy-induced hypertension, preeclampsia, or gestational diabetes and where cigarette smoking continued were excluded, resulting in a cohort of 987. Cord plasma concentrations of IGF-I, IGF-II, and IGFBP-3 were influenced by factors influencing birth size: gestational age at delivery, mode of delivery, maternal height, and parity of the mother. Plasma GH concentrations were inversely related to the plasma concentrations of IGF-I and IGFBP-3; 10.2% of the variability in cord plasma IGF-I concentration and 2.7% for IGFBP-3 was explained by sex of the offspring and parity. None of the factors, apart from maternal height, influenced cord serum IGF-II concentrations (adjusted r2 = 1%). Sex of the baby, mode of delivery, and parity influenced cord serum GH concentrations (adjusted r2 = 2.6%). Birth weight, length, and head circumference measurements were greater in males than females (P < 0.001). Mean cord plasma concentrations of IGF-I (males, 66.4 ± 1.2 μg/liter; females, 74.5 ± 1.3 μg/liter; P < 0.001) and IGFBP-3 (males, 910 ± 13 μg/liter; females 978 ± 13 μg/liter; P < 0.001) were significantly lower in males than females. Cord plasma GH concentrations were higher in males than females (males, 30.0 ± 1.2 mU/liter; females, 26.9 ± 1.1 mU/liter; P = 0.05), but no difference was noted between the sexes for IGF-II (males, 508 ± 6 μg/liter; females, 519 ± 6 μg/liter; P = NS). After adjustment for gestational age, parity, and maternal height, cord plasma concentrations of IGF-I and IGFBP-3 along with sex explained 38.0% of the variability in birth weight, 25.0% in birth length, and 22.7% in head circumference. These data demonstrate that in a group of singleton Caucasian babies born at term, cord plasma IGF-I, IGFBP-3, and GH concentrations relate to birth size, with evidence for sexual dimorphism in the GH-IGF axis.
Background: Maternal smoking during pregnancy is associated with a reduction in birth size. Very few studies have collated changes in fetal biometry, neonatal anthropometry, biochemical factors ...involved in fetal growth, and measures of uterine and umbilical blood flow.
Methods: We related smoking status in 1650 low-risk, singleton Caucasian pregnancies delivering at term to measures of fetal growth, uterine and umbilical artery blood flow, placental appearance, birth size, and cord concentrations of IGF-I and -II and IGF binding protein (IGFBP)-3.
Results: Mothers who smoked in pregnancy were younger (P < 0.001) and shorter (P = 0.03) and from lower socioeconomic groups (P < 0.001). Mean umbilical artery blood flow at 20 wk gestation was not associated with smoking status but was significantly higher in smokers at 30 wk (P = 0.006). Uterine artery blood flow was unaffected. Smoking was associated with an increase in the percentage of abnormal placentas in a dose-dependent manner and with a 3.1-fold increased risk (odds ratio 3.1, 95% confidence interval 1.3–7.6) of abnormal umbilical artery blood flow (P = 0.009). Smoking was associated with a reduction in fetal femur length (P = 0.005) and abdominal circumference as well as birth weight, length, and head circumference but not skinfold thickness. Cord plasma concentrations of IGF-I and IGFBP-3 were lower in the babies of mothers who had smoked (P = 0.02 and P = 0.01, respectively).
Conclusion: We concluded that maternal smoking is associated with an altered placental appearance on ultrasonography, increased umbilical artery blood flow resistance, and a reduction in longitudinal and intraabdominal organ growth. Circulating concentrations of IGF-I and IGFBP-3 along with measures of birth size but not markers of body fat are reduced, suggesting smoking results in a reduction in organ size and function.
We report the discovery of two giant planets orbiting stars in Praesepe (also known as the Beehive Cluster). These are the first known hot Jupiters in an open cluster and the only planets known to ...orbit Sun-like, main-sequence stars in a cluster. The planets are detected from Doppler-shifted radial velocities; line bisector spans and activity indices show no correlation with orbital phase, confirming the variations are caused by planetary companions. Pr0201b orbits a V = 10.52 late F dwarf with a period of 4.4264 + or - 0.0070 days and has a minimum mass of 0.540 + or - 0.039 M sub(Jup), and Pr0211b orbits a V = 12.06 late G dwarf with a period of 2.1451 + or - 0.0012 days and has a minimum mass of 1.844 + or - 0.064 M sub(Jup). The detection of two planets among 53 single members surveyed establishes a lower limit of (ProQuest: Formulae and/or non-USASCI delta text omitted) the hot Jupiter frequency in this metal-rich open cluster. Given the precisely known age of the cluster, this discovery also demonstrates that, in at least two cases, giant planet migration occurred within 600 Myr after formation. As we endeavor to learn more about the frequency and formation history of planets, environments with well-determined properties-such as open clusters like Praesepe-may provide essential clues to this end.
Human growth is a continuous process. Studies defining factors influencing growth focus on discrete time points (e.g., birth), overlooking the conditional nature of the process. One thousand six ...hundred fifty Caucasian mothers who gave birth at term after an uncomplicated singleton pregnancy were studied using conditional analysis. Infant height, weight, and head circumference were obtained at birth and 6 mo of age. Data analysis, conditional upon birth size, was conducted as a stepped consideration of factors influencing phases of fetal and infant growth beginning with determinants of placental size. Placental weight was related to birth size. Seven percent of the variance in placental weight was explained by a combination of gestation at delivery, maternal size at first prenatal visit, paternal height (all positive), and increasing parity (negative). When centered on birth weight, 41% of the variance in placental weight was explained by birth weight, length of gestation, smoking during pregnancy (all positive), and a female baby (negative). Maternal and paternal stature equally influenced newborn and infant size. Conditional analysis reveals a series of modifiable (parity, length of gestation, and smoking) and nonmodifiable factors at different stages of the growth process.
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