Lower Escape Rates Research Articles

The impact of bushfires on animal abundance and diversity across land tenures in Miombo woodlands, Tanzania

Abstract. Matimbwi L, Madoffe SS. 2022. The impact of bushfires on animal abundance and diversity across land tenures in Miombo woodlands, Tanzania. Asian J For 6: 43-51. Southern Africa is dominated by Miombo forests (woodlands), the world's largest savanna. The purpose of this research was to examine how bushfires affect mammalian populations in Miombo woodlands under various forest tenure systems. The data was gathered through household questionnaires, a probing question checklist for key informants, participant observation, Participatory Rural Appraisal (PRA) methods, and a field inventory. We enlisted the aid of the local communities in our analysis of the PRA data we collected. Quantitative and qualitative data and information were subjected to content and structural-functional analysis. Quantitative data was examined using Statistical Package for the Social Sciences (SPSS) software. Microsoft Excel was used to examine inventory data on animal stocks. The average number of mammals collected from each forest tenure system was compared using Analysis of Variance (ANOVA) to see if there were statistically significant variations. The variety of mammal species in various forest tenure systems was measured using the Shannon-Wiener Index (H). Based on the findings, agricultural activities (44.5%), charcoal production (21.1%), and wildlife hunting (18.9%) accounted for the vast majority of bushfires in Miombo woods. It was thought that illegal logging and honey collection were the only contributing factors. Mammal populations tend to be most significant in Central Governmental Forest Reserves, then in those of the Local Government, and finally in those of the Village Government. Mildly burned sections in the Central Governmental Forest Reserve had a diversity index of 3.2. In contrast, those in the Local Government Forest Reserve and the Village Forest Reserve had indices of 2.0. There was little difference in the diversity index values of the Central Governmental Forest Reserve (2.0) and the Village Forest Reserve (2.0) for moderately burned blocks and the Local Government Forest Reserve (1.6) for unburned blocks. The Central Governmental Forest Reserve had a diversity value of 1.5 for the severely burned blocks, the Village Governmental Forest Reserve had a value of 1.4, and the Local Government Forest Reserve had a value of 1.2. Like other mammals with a low fire escape rate, bushfires hit the rock hyrax particularly hard. As a result, it is suggested that the current management regimes of Local Government Authorities be strengthened to ensure enhanced local community participation with more effective law enforcement measures to save the woods from deterioration. Similarly, communities should be given access to financing and encouragement to pursue income-generating activities to lessen their reliance on Miombo woodlands.

The antitumor activity of Bax BH3 peptide delivered by gold nanoparticles

Cancer has long remained one of the primary causes of disease and death globally, and it continues to pose a significant threat to human health. Surgery, radiotherapy, and chemotherapy are traditional treatments for cancer which are still widely used. However, while both surgery and radiotherapy remain acceptably effective in addressing a variety of primary tumors, neither possesses therapeutic potential for unknown metastatic lesions which may exist elsewhere in the patient’s body. Conversely, while systemic chemotherapy does have the potential for therapeutic efficacy on both primary and metastatic lesions alike, drug targeting is often poor, side effects are typically high, and treatment efficacy is still often lacking. Nanomedicine presents a promising solution to the above issues. For example, nanocarriers can be used to increase drug selectivity and targeting, increasing efficacy and decreasing side effects. Based on the role of the lethal domain of Bcl-2 family proteins, which play roles in apoptosis, the BH3-only protein, a section of BH3 peptide with a sequence of Asp-Ala-Ser-Thr-Lys-Lys-Leu-Ser-Glu-Cys-Leu-Arg-Arg-Ile-Gly-Asp-Glu-Leu-Asp-Ser. However, treatments based on soluble BH3 peptides, as with those based on other biologically active macromolecules, exhibit low cell membrane permeability, poor stability against proteolysis, and low endosomal escape rates. In this paper, attempt to address these issues by developing a variety of BH3@gold nanoparticle drug systems with different coating ratios. We demonstrate, high loading efficiency and, excellent anti-tumor effects in vitro, including inhibition of proliferation and migration in the human lung adenocarcinoma cell line, A549. Our results present a new possibility for anticancer peptide drugs in the future.

Stationary states in two-lane traffic: Insights from kinetic theory.

Kinetics of dilute heterogeneous traffic on a two-lane road is formulated in the framework of Ben-Naim-Krapivsky model and stationary state properties are analytically derived in the asymptotic limit. The heterogeneity is introduced into the model as a quenched disorder in desired speeds of vehicles. The two-lane model assumes that each vehicle or platoon in a lane moves ballistically until it approaches a slow-moving vehicle or platoon and then joins it. Vehicles in a platoon are assumed to escape the platoon at a constant rate by changing lanes after which they continue to move at their desired speeds. Each lane is assumed to have a different escape rate. As the stationary state is approached, the platoon densities in the two lanes become equal, whereas the vehicle densities and fluxes are higher in the lane with lower escape rate. A majority of the vehicles enjoy a free flow if the harmonic mean of the escape rates of the lanes is comparable to average initial flux on the road. The average platoon size is close to unity in the free-flow regime. If the harmonic mean is lower than the average initial flux, then vehicles with desired speeds lower than a characteristic speed v^{*} still enjoy free flow while those vehicles with desired speeds that are greater than v^{*} experience congestion and form platoons behind the slower vehicles. The characteristic speed depends on the mean of escape times [R=(R_{1}+R_{-1})/2] of the two lanes (represented by 1 and -1) as v^{*}∼R^{-1/μ+2}, where μ is the exponent of the quenched disorder distribution for desired speed in the small speed limit. The average platoon size in a lane, when v^{*}≪1, is proportional to R^{μ+1/μ+2} plus a lane-dependent correction. Equationsfor the kinetics of platoon size distribution for two-lane traffic are also studied. It is shown that a stationary state with platoons as large as road length can occur only if the mean escape rate is independent of platoon size.

Determination of Ghost Fishing Starting Time by Four Different Baited Fish Traps in the Çanakkale Strait (North Aegean Sea)

In this study, the starting time of ghost fishing in baited fish traps were determined. Two separate trials using 4 different types of fish traps (foldable, conical, “O” shaped Round and cylindrical) were carried out in the Çanakkale Strait at a depth of 5m between July - December 2013. A total of 12 fish traps (3 for each trap type) were used in the study. Each trial lasted a period of 45 days. Major features of the traps were as follows: the foldable fish trap had “V” shaped inclined funnel; the conical fish trap had a conical entrance from the top; The “O” shaped fish trap had a “V” shaped entrance on the base; the cylindrical trap had a conical entrance on the side. In all trials fresh sardine, black mussel and bread placed in a net bag were used as bait and fixed in the traps. Underwater observations showed that fish entrapped in all trap types escaped from the traps within 8-10 days. Fish mortality was due to accidental entanglement of fish on the mesh material covering the traps or due to predation. Molluscs such as octopuses and squids escaped within 4-7 days whereas crabs suffered from cannibalism or starvation due to their lower escape rates. In conclusion, in the present study while trap ghost fishing for fish and cephalopods were not observed, ghost fishing for crabs were observed and was a factor of entrance design and location on traps.

Operation Condition Evaluation and Risk Prediction of Air Preheater in Coal-fired Power Plant

Air preheater is an important flue gas heat exchanger in tail flue for coal-fired power plant. In this paper, the operation of air preheater was evaluated from three aspects: the influence of denitrification system on the operation of air preheater, the calculation of air leakage rate of air preheater and the evaluation of low temperature corrosion for air preheater. The results shown that: the corrosion of downstream air preheater caused by ammonium bisulfate was limited due to the low ammonia escape rate; The air leakage rate is higher than the normal value of the air leakage rate; the temperature in the cold end of B-side for air preheater is lower than acid dew point of flue gas due to air leakage, which results in sulphuric acid fog condensation and sulphuric acid corrosion on the air preheater.

Reversal time of jump-noise magnetization dynamics in nanomagnets via Monte Carlo simulations

The jump-noise is a nonhomogeneous Poisson process which models thermal effects in magnetization dynamics, with special applications in low temperature escape rate phenomena. In this work, we develop improved numerical methods for Monte Carlo simulation of the jump-noise dynamics and validate the method by comparing the stationary distribution obtained empirically against the Boltzmann distribution. In accordance with the Néel-Brown theory, the jump-noise dynamics display an exponential relaxation toward equilibrium with a characteristic reversal time, which we extract for nanomagnets with uniaxial and cubic anisotropy. We relate the jump-noise dynamics to the equivalent Landau-Lifshitz dynamics up to second order correction for a general energy landscape and obtain the analogous Néel-Brown theory's solution of the reversal time. We find that the reversal time of jump-noise dynamics is characterized by Néel-Brown theory's solution at the energy saddle point for small noise. For large noise, the magnetization reversal due to jump-noise dynamics phenomenologically represents macroscopic tunneling of magnetization.

Species specific behaviour and catchability of gadoid fish to floated and bottom set pots

To increase our understanding of the interaction between fish and baited fishing gear we quantitatively described the behaviour of cod (Gadus morhua), saithe (Pollachius virens), and haddock (Melanogrammus aeglefinus) to baited pots in a fjord in northern Norway. Detailed video analyses were made to describe species specific responses and examine the effect of lifting the pot off the bottom. The majority of both cod and saithe approached the pots in an upstream direction, and fish approached floated pots higher in the water column than bottom set pots. Cod tended to approach a pot along the seabed and were more likely to encounter the bottom set pot than the floated pot, whereas saithe more often approached in the water column. The capture efficiency was low for all species, but cod were more likely to be caught than saithe and haddock. Cod showed a high encounter rate, low entrance rate and high escape rate. For saithe, a low encounter rate was the chief factor limiting capture efficiency. The observed differences between cod and saithe were explained by species-specific food-search strategies. No difference in entrance rate, escape rate or catch efficiency between the two pot types were found.

Floated cod pots with one entrance reduce probability of escape and increase catch rates compared with pots with two entrances

The development of low impact and fuel efficient (LIFE) fishing is being paid growing attention. Pot fishing has lower environmental impact and fuel consumption than most other fishing methods. However, pots typically have low capture efficiency for most ground-fish species, and efforts to develop effective commercial pots are needed. Bycatch of red king crab (Paralithodes camtschaticus) is a severe problem in the coastal fishery for cod (Gadus morhua) in the Barents Sea. In a previous publication, we demonstrated that cod pots floated off the bottom eliminated this problem. Our original bottom-set cod pot has two entrances in order to increase the rate of entry of fish, but when this pot is floated, fish that search for food by following chemical cues up-current will only encounter the entrance that is oriented down-current. We therefore compared the catch rates of floated pots with one and two entrances, and predicted that the new design with only one entrance would achieve higher catch rates due to a lower rate of escape. Pots with one entrance caught significantly more cod and haddock (Melanogrammus aeglefinus) than pots with two entrances. The catch rate of cod above minimum landing size (≥44cm) of pots with one entrance was 82% higher than that of pots with two entrances. Pots that were snagged and did not float properly caught large numbers of king crab. The larger catches of pots with one entrance could be explained by lower escape rate from this design. The observed difference in catch rates between the two pot types indicates that more than 50% of the large cod and haddock that entered the pot with two entrances escaped. There is therefore great potential for increased catching efficiency of pots through improved pot design.

Experimental study of mixed additive of Ni(II) and piperazine on ammonia escape in CO2 capture using ammonia solution

In order to obtain high CO2 absorption efficiency and low ammonia escape rate, mixed additives of piperazine and Ni(II) were used as absorbent in bubbling reactor. The effects of mixed additive on CO2 absorption efficiency and ammonia escape rate were investigated; the performances of mixed additive in removal process were compared with that of pure ammonia solution. The proposed mechanism was analyzed by XRD and UV–visible spectrophotometer. The mixed additive has well effect on CO2 absorption efficiency and ammonia escape reduction. The CO2 absorption efficiency was 72% when 2wt% ammonia solution mixed with 0.025mol/L piperazine and 0.05mol/L Ni(II), higher than that achieved by 3wt% ammonia solution without additive, and the amount of ammonia loss was nearly 1/3 compared with 3wt% pure ammonia solution. This paper provided one feasible method which is beneficial to the balance between CO2 absorption and ammonia escape in CO2 capture process.

Lower Escape Rate of Symmetric Jump-diffusion Processes

AbstractWe establish an integral test on the lower escape rate of symmetric jump-diffusion processes generated by regular Dirichlet forms. Using this test, we can find the speed of particles escaping to infinity. We apply this test to symmetric jump processes of variable order. We also derive the upper and lower escape rates of time-changed processes by using those of underlying processes.

Comparison of capture and escape rates between different types of portable cowbird traps

ABSTRACTControl of brown‐headed cowbirds (Molothrus ater) is often advocated to reduce parasitism and improve nesting success of sensitive populations of passerine birds, but little information is available in the literature concerning the relative effectiveness of different types of cowbird traps or the effects of these traps on non‐target species. We used portable traps to capture cowbirds in 2003–2007 at 3 study areas in southern Nevada and western Arizona. We compared the effectiveness of traps with flat tops versus funnel‐shaped tops in 2005 and compared entrance slots of 2 different widths in 2006–2007. Traps with funnel‐shaped tops had higher cowbird capture rates and lower escape rates than did flat‐topped traps. Funnel‐topped traps also had a higher capture rate of non‐target species. Funnel‐topped traps with a 3.8‐cm‐wide entrance slot had a higher capture rate for male cowbirds than did identical traps with a 3.2‐cm‐wide entrance slot. Capture rates for female cowbirds did not differ between slot sizes, nor did escape rates for either males or females. Capture rates for non‐target species did not differ between slot widths, but wider slots captured larger bodied species (e.g., white‐winged dove [Zenaida asiatica] and great‐tailed grackle [Quiscalus mexicanus]) that were not seen in the traps with narrower slots in the years when both slot widths were tested. Cowbird traps with a funnel‐topped design should be used to maximize the number of cowbirds captured and removed from a site. A slot width of 3.2 cm may minimize non‐target captures, particularly of larger bodied species, while still allowing effective removal of female cowbirds. © 2014 The Wildlife Society.

Effective hydrodynamic hydrogen escape from an early Earth atmosphere inferred from high-accuracy numerical simulation

Hydrodynamic escape of hydrogen driven by solar extreme ultraviolet (EUV) radiation heating is numerically simulated by using the constrained interpolation profile scheme, a high-accuracy scheme for solving the one-dimensional advection equation. For a wide range of hydrogen number densities at the lower boundary and solar EUV fluxes, more than half of EUV heating energy is converted to mechanical energy of the escaping hydrogen. Less energy is lost by downward thermal conduction even giving low temperature for the atmospheric base. This result differs from a previous numerical simulation study that yielded much lower escape rates by employing another scheme in which relatively strong numerical diffusion is implemented. Because the solar EUV heating effectively induces hydrogen escape, the hydrogen mixing ratio was likely to have remained lower than 1vol% in the anoxic Earth atmosphere during the Archean era.

Behaviour of the escape rate function in hyperbolic dynamical systems

For a fixed initial reference measure, we study the dependence of the escape rate on the hole for a smooth or piecewise smooth hyperbolic map. First, we prove the existence and Hölder continuity of the escape rate for systems with small holes admitting Young towers. Then we consider general holes for Anosov diffeomorphisms, without size or Markovian restrictions. We prove bounds on the upper and lower escape rates using the notion of pressure on the survivor set and show that a variational principle holds under generic conditions. However, we also show that the escape rate function forms a devil's staircase with jumps along sequences of regular holes and present examples to elucidate some of the difficulties involved in formulating a general theory.

Technical Evaluation of the Selection of Flue Gas Purifying Device of Power Plant

The paper introduced several ash separator, desulfurization devices and denitrification devices which were widespread used in thermal power plant in recent years and respectively compared the technicality efficiency of them. It comes to the conclusion that: in the choice of ash separators, bag filter which has more merits than ESP, it has the advantages of reliable operation, simple maintenance, adapting to change in different coal and higher efficiency. In the choice of desulfurization technology, wet limestone-gypsum desulfurization technology is the most mature, which has stable operation and wide adaptability. Therefore, the thermal power plant prefer to it. In the choice of denitrification devices, SCR with low NH3 escape rate and easy to maintain, so it has become the mature and mainstream technology at home and abroad.

Invasive Extravillous Trophoblasts Restrict Intracellular Growth and Spread of Listeria monocytogenes

Listeria monocytogenes is a facultative intracellular bacterial pathogen that can infect the placenta, a chimeric organ made of maternal and fetal cells. Extravillous trophoblasts (EVT) are specialized fetal cells that invade the uterine implantation site, where they come into direct contact with maternal cells. We have shown previously that EVT are the preferred site of initial placental infection. In this report, we infected primary human EVT with L. monocytogenes. EVT eliminated ∼80% of intracellular bacteria over 24-hours. Bacteria were unable to escape into the cytoplasm and remained confined to vacuolar compartments that became acidified and co-localized with LAMP1, consistent with bacterial degradation in lysosomes. In human placental organ cultures bacterial vacuolar escape rates differed between specific trophoblast subpopulations. The most invasive EVT—those that would be in direct contact with maternal cells in vivo—had lower escape rates than trophoblasts that were surrounded by fetal cells and tissues. Our results suggest that EVT present a bottleneck in the spread of L. monocytogenes from mother to fetus by inhibiting vacuolar escape, and thus intracellular bacterial growth. However, if L. monocytogenes is able to spread beyond EVT it can find a more hospitable environment. Our results elucidate a novel aspect of the maternal-fetal barrier.

Habitat-specific constraints on induced hatching in a treefrog with reproductive mode plasticity

Many organisms show adaptive phenotypic plasticity in response to environmental variation. Some environmental factors may, however, impose constraints on the ability of organisms to respond to other factors. The neotropical treefrog Dendropsophus ebraccatus lays eggs both above water on leaves and directly in water, thereby exposing embryos to different abiotic conditions and predator communities. Rising pond levels can also flood arboreal clutches after rainstorms. We tested for predator-induced hatching in submerged and arboreal D. ebraccatus egg masses and assessed effects of prior hydration or desiccation on escape success in attacks by a terrestrial predator, Azteca ants, and an aquatic predator, large conspecific tadpoles. Embryos responded to both aquatic and terrestrial predator attacks by hatching prematurely, as much as 67% earlier than the peak of hatching in undisturbed clutches. Desiccation reduced the hatching response of terrestrial embryos, resulting in substantially lower escape rates. This desiccation effect disappeared rapidly with flooding; all embryos showed high escape hatching success underwater. The occurrence of predator-induced escape hatching in response to 2 different predators, in 2 different physical environments, suggests that this is a general response of D. ebraccatus to egg predator attack. Both ant attack and sublethal desiccation are common in nature, thus the inhibition of escape hatching in this context likely impacts tadpole recruitment. More generally, we demonstrate that an adaptive plastic response to risk is contingent on additional environmental variables and suggest that many instances of plasticity may similarly be modified by environmental constraints. Key words: abiotic‐biotic environmental variation, adaptive phenotypic plasticity, anura, complex life cycle, Hyla ebraccata, interaction modification, predator-facilitated hatching. [Behav Ecol]

Apparent pacemaker malfunction following atrioventricular node ablation

61-year-old woman received backup ventricular pacing and atrioventricular (AV) node ablation for chronic atrial fibrillation with poor ventricular rate control. Following uneventful single-chamber pacemaker implantation (Sensia; Medtronic Inc, USA), AV node ablation was performed, which resulted in complete AV block with ventricular escape rates of 35 beats/min to 40 beats/min. A lower pacemaker rate was then programmed in VVI mode (95 beats/min lower heart rate) to prevent bradycardia, a potential trigger for torsades de pointes (1). During postprocedure monitoring, telemetry recordings showed multiple episodes of long pauses with no pacing output (Figure 1). The pacemaker pacing and sensing parameters, and lead and impedance, even with pacemaker pocket manipulation, were normal. Analysis of the tracing showed that the pauses between the intrinsic R wave and the paced beat were exactly 1200 ms. Also, the pauses between any two intrinsic R waves remained less than 1200 ms. There were no pauses following paced beats. These findings suggested that the hysteresis feature had been left on at a rate of 50 beats/min, which was confirmed. The patient had regained some degree of AV nodal conduction and her intrinsic R waves appeared intermittently at shorter cycle lengths than the lower rate interval, which triggered the hysteresis feature and caused the pauses. This feature was switched off and no pauses were documented subsequently. Hysteresis programmed on would not be a problem in a pacemakerdependent patient with complete AV block and low ventricular escape rates. However, if AV nodal conduction recovers, as in the present patient, hysteresis could be the cause of cardiac pauses, a potential trigger for life-threatening torsades de pointes. imAges in cArdiology

ANALYSIS OF KINETIC PROCESS OF ENERGETIC ELECTRON DURING A FLARE ON 2004 DECEMBER 1

We analyze the M1.1 flare event peaked at 07:20:00 UT on 2004 December 1 mainly from radio and hard X-ray (HXR) observations. By eliminating the thermal component from the observed total radio emission flux, the non-thermal part of the radio and HXR burst process is investigated in a self-consistent way. The spectral index of energetic electrons deduced from the radio burst evolves as a Soft-Hard-Hard pattern and that from HXR as a Soft-Hard-Soft pattern corresponding to an initial-main-decay phase. The trap-plus-precipitation model is applied in the kinetic process of energetic electrons for this flare event. The radio fluxes at six frequencies selected from the 2.6-7.6 GHz range are fitted with a gyrosynchrotron radiation mechanism. It is found that a linearly increasing electron escape rate can best fit to the observed radio fluxes from 07:00:00 UT to 07:40:00 UT and the slope of the electron escape rate for the six selected frequencies decreases with increasing frequency. During the decay phase from 07:15:00 UT to 07:20:00 UT, the hardened spectrum of the radio burst may be due to the increasing amount of trapped electrons with higher energy by a lower escape rate. Meanwhile, the increasing amount of precipitating electrons with a lower energy band may soften the HXR spectrum. In the decay phase after 07:20:00 UT, thermal emission is the dominating component for the radio burst.

Hybrid code simulations of the solar wind interaction with Pluto

Pluto's low gravity implies that the atmosphere is only weakly bound and that significant hydrodynamic outflow can exist. Though surface spectroscopy of Pluto has revealed methane frost, the dominant escaping neutral gas is thought to be N2. These escaping neutrals are photoionized, and the heavy ions (N2+) move away from Pluto in the direction perpendicular to the solar wind flow (i.e., nearly unmagnetized relative to the length scales of the plasma interaction region). The turning distance of the solar wind protons at the magnetic pileup boundary is large compared to the interaction region. As a result, large ion gyroradius effects determine Pluto's highly asymmetric interaction with the solar wind. We use a three‐dimensional hybrid code (fluid electrons, kinetic ions) to investigate the geometry of the interaction region for a variety of possible atmospheric escape rates in anticipation of the New Horizons encounter with Pluto. We find considerable structuring in the wake region due to bi‐ion waves and Kelvin‐Helmholtz waves. The shock structures vary from a simple Mach cone for low escape rates (∼2 × 1026 s−1) to a full detached bow shock for large escape rates (∼2 × 1028 s−1).

HDO and H2O vertical distributions and isotopic ratio in the Venus mesosphere by Solar Occultation at Infrared spectrometer on board Venus Express

Vertical distributions of the molecular density and mixing ratios of H2O and HDO in the Venus mesosphere have been obtained using Solar Occultation at Infrared (SOIR), a high‐resolution (with λ/δλ ∼ 20,000) echelle spectrometer on Venus Express. The atmosphere is sounded in solar occultation in the range of altitudes from 65 to 130 km. Simultaneous measurements of water vapor lines in the spectral range around 2.61 μm (3830 cm−1) at altitudes between 70 and 110 km and HDO lines around 3.58 μm (2715cm−1) at altitudes 70–95 km have been performed. During 1 1/2 years, from April 2006 to August 2007, 54 such measurements have been carried out at different locations of Venus from the north pole to middle south latitudes. Most of the observations at morning and evening terminator correspond to high northern latitudes. We report values of mixing ratio and isotopic ratio obtained for 22 of those measurements occurring in the northern polar area. The average value of the volume mixing ratio of H2O is 1.16 ± 0.24 ppm and that of HDO is 0.086 ± 0.020 ppm. A depletion in the mixing ratio for both H2O and HDO is observed at 85 km, which can be related to a depletion of CO2 density above (∼95 km) and a possible temperature inversion at these altitudes. The vertical variation of HDO and H2O mixing ratio is within a factor of 2–3 for the analyzed set of observations. The temporal variations have been investigated, and no noticeable variability of H2O is reported at high northern altitudes. The average ratio of HDO/H2O obtained in this work, 240 ± 25 times the terrestrial ratio, is higher (≈1.5 times) than the value of 157 ± 30 times terrestrial reported for the lower atmosphere. This could be explained by a lower photodissociation of HDO and/or a lower escape rate of D atoms versus H atoms.